JP2022127004A - CO2 SEPARATOR AND METHOD OF OPERATION THEREOF - Google Patents

Abstract

The present disclosure provides a carbon dioxide separator capable of supplying carbon dioxide-enriched gas with stable purity even when the carbon dioxide concentration in the carbon dioxide-containing gas supplied to the carbon dioxide separator changes. A carbon dioxide separation device according to the present disclosure has a first space in which a carbon dioxide-containing gas flows in and a non-permeating gas that has not permeated through the separation membrane flows out to a non-permeating gas flow path. and a second space in which the permeated gas that has permeated the separation membrane flows out to the permeated gas flow channel, and a carbon dioxide separator filled with a carbon dioxide adsorbent and connected to the downstream side of the non-permeated gas flow channel. An adsorption apparatus having a plurality of adsorbers, a permeable gas amount adjusting means for adjusting the flow rate of the permeable gas, and a controller for controlling the permeable gas amount adjusting means so that the carbon dioxide concentration of the non-permeable gas is within a predetermined range. , provided. [Selection drawing] Fig. 1

Description

TECHNICAL FIELD The present disclosure relates to carbon dioxide separators and methods of operating same.

Patent Document 1 discloses a carbon dioxide separation system capable of efficiently separating a mixed gas having a wide range of carbon dioxide concentrations and pressures into a high-concentration carbon dioxide gas and a carbon dioxide-removed gas.

In this carbon dioxide separation system, a mixed gas with a carbon dioxide concentration of 3 to 75% is introduced into a primary carbon dioxide separator equipped with a zeolite membrane for carbon dioxide separation, and a carbon dioxide concentration of 80% or more is introduced on the permeation side of the zeolite membrane. While generating a primary permeate gas, the carbon dioxide concentration of the primary non-permeate side gas of the zeolite membrane is reduced to 3-15%.

Next, this primary non-permeate side gas is introduced into a secondary carbon dioxide separator by the amine absorption method or the PSA method to generate a secondary separated gas with a carbon dioxide concentration of 80% or more separated by the separator, It produces a carbon dioxide removal gas with a carbon concentration of 2% or less.

That is, a raw material gas containing carbon dioxide is supplied to a separator that separates a first separated gas and a second separated gas having a higher carbon dioxide concentration than the first separated gas, and the first separated gas generated in the separator is adsorbed. The second separated gas and the desorbed gas containing high-concentration carbon dioxide generated from the adsorber are both used as the carbon dioxide-enriched gas.

WO2012/153808

The present disclosure provides a carbon dioxide separation device that can supply carbon dioxide-enriched gas with stable purity even when the carbon dioxide concentration in the carbon dioxide-containing gas supplied to the carbon dioxide separation device changes, and an operation method thereof. do.

The carbon dioxide separation device in the present disclosure includes a carbon dioxide separator, a decompression pump, a carbon dioxide concentration detector, permeable gas amount adjusting means, an adsorption device, an exhaust gas flow path, a desorbed gas discharge flow path, A suction pump and a controller are provided.

The carbon dioxide separator has an internal space partitioned into a first space and a second space by a separation membrane that selectively permeates carbon dioxide.

The first space is a space into which the carbon dioxide-containing gas flows from the carbon dioxide-containing gas channel, and a space into which the non-permeating gas that has not permeated the separation membrane flows out to the non-permeating gas channel. The second space is a space in which the permeated gas that has permeated the separation membrane flows out to the permeated gas channel.

The decompression pump is a pump that is provided in the middle of the permeated gas flow path and configured to decompress the second space. Carbon dioxide contained in the carbon dioxide-containing gas permeates the separation membrane due to the decompression operation of the decompression pump, and the permeated gas flows out to the permeated gas flow path.

The carbon dioxide concentration detector is adapted to detect the concentration of carbon dioxide contained in either the carbon dioxide-containing gas flowing through the carbon dioxide-containing gas flow path or the non-permeating gas flowing through the non-permeating gas flow path. is configured to The permeation gas amount adjusting means is means for adjusting the flow rate of the permeation gas.

The adsorption device has a plurality of adsorbers filled with an adsorbent that adsorbs carbon dioxide and connected to the downstream side of the non-permeating gas flow path. In the adsorption device, at least one remaining adsorber desorbs carbon dioxide from the adsorbent while at least one adsorber is in the adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbent. Configured to be in a regeneration process.

The exhaust gas flow path is a flow path connected downstream of a plurality of adsorbers so that the non-permeating gas that has not been adsorbed by the adsorbers in the adsorption step is exhausted from the adsorbers in the adsorption step to the outside.

The desorbed gas discharge channel is a channel connected to a plurality of adsorbers so that the desorbed gas desorbed from the adsorbers in the regeneration process is recovered from the adsorbers in the regeneration process.

The suction pump is provided in the middle of the desorbed gas discharge channel. Further, the suction pump is configured to decompress the inside of the adsorber in the regeneration step, desorb carbon dioxide from the adsorbent, and cause the desorbed gas to flow out to the desorbed gas discharge channel.

The controller adjusts the amount of permeating gas based on the concentration detected by the carbon dioxide concentration detector so that the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber in the adsorption step falls within a predetermined range. configured to control means.

A method of operating a carbon dioxide separation apparatus according to the present disclosure includes a carbon dioxide separator configured as described above, a decompression pump configured as described above, a carbon dioxide concentration detector configured as described above, a permeation gas amount adjusting means configured as described above, and a permeation gas amount adjusting means configured as described above. 2. A method of operating a carbon dioxide separator comprising the adsorption device of 1, the exhaust gas flow path having the above configuration, the desorbed gas discharge flow path having the above configuration, and the suction pump having the above configuration.

Then, based on the concentration detected by the carbon dioxide concentration detector, the permeation gas amount adjusting means adjusts the concentration of carbon dioxide contained in the non-permeation gas flowing into the adsorber in the adsorption step to fall within a predetermined range. It is characterized by adjusting the gas flow rate.

The carbon dioxide separation device and the operating method thereof in the present disclosure can change the amount of carbon dioxide permeating the separation membrane when the carbon dioxide concentration in the carbon dioxide-containing gas flowing into the adsorber changes. It is possible to control the concentration of carbon dioxide in the carbon dioxide-containing gas flowing into the system within a predetermined range.

Therefore, by stabilizing the amount of carbon dioxide adsorbed by the adsorbent, it becomes possible to stabilize the concentration of carbon dioxide in the desorbed gas. can provide.

FIG. 2 is a block diagram showing the configuration of the carbon dioxide separation apparatus according to Embodiment 1 in which an adsorption step is performed in an adsorber 2a and a regeneration step is performed in an adsorber 2b; Flowchart showing basic operation of the carbon dioxide separator according to Embodiment 1 Flowchart showing start-up operation of carbon dioxide separator in Embodiment 1 Flowchart showing the CO ₂ concentration adjustment operation of the carbon dioxide separator according to Embodiment 1 Flowchart showing PSA operation of the carbon dioxide separator in Embodiment 1 FIG. 10 is a block diagram showing the configuration of a carbon dioxide separation apparatus according to Embodiment 2, in which an adsorption step is performed in an adsorber 2a and a regeneration step is performed in an adsorber 2b. Flowchart showing the basic operation of the carbon dioxide separator according to Embodiment 2 Flowchart showing CO ₂ concentration adjustment operation of the carbon dioxide separator according to Embodiment 2 FIG. 4 is a block diagram showing the configuration of the carbon dioxide separation apparatus according to Embodiment 2, in which an adsorption step is performed in an adsorber 2a and a purge step is performed in an adsorber 2b. Flowchart showing PSA operation of carbon dioxide separator in Embodiment 2 FIG. 10 is a block diagram showing the configuration of the carbon dioxide separation apparatus according to Embodiment 3, in which the adsorption step is performed in the adsorber 2a and the regeneration step is performed in the adsorber 2d. Flowchart showing the basic operation of the carbon dioxide separator according to Embodiment 3 Flowchart showing startup operation of carbon dioxide separator in Embodiment 3 Flowchart showing the CO ₂ concentration determination operation of the carbon dioxide separator according to Embodiment 3 In the carbon dioxide separation apparatus according to Embodiment 3, the adsorber 2b is connected in series to the downstream side of the adsorber 2a, the adsorption step is performed in the adsorbers 2a and 2b, and the regeneration step is performed in the adsorbers 2c and 2d. Block diagram showing the configuration of the Flowchart showing PSA operation (serial mode) of the carbon dioxide separator in Embodiment 3 In the carbon dioxide separation apparatus according to Embodiment 3, the non-permeating gas is supplied in parallel to the adsorbers 2a and 2b, the adsorption step is performed in the adsorbers 2a and 2b, and the regeneration step is performed in the adsorbers 2c and 2d. Block diagram showing the configuration of the Flowchart showing PSA operation (parallel mode) of carbon dioxide separator in Embodiment 3

(Knowledge, etc. on which this disclosure is based)
In recent years, CCS (Carbon dioxide Capture and Storage), which captures carbon dioxide, which is a greenhouse gas, and stores it underground, has attracted attention as a countermeasure against global warming.

In CCS, carbon dioxide is stored underground in a supercritical state, so it needs to be compressed. A concentration of 95% or more is required. In addition, in order to efficiently treat the carbon dioxide in the exhaust gas generated in large quantities, there is a demand for a means for separating carbon dioxide that reduces energy consumption.

At the time when the inventors came up with the present disclosure, in the field of separating carbon dioxide from carbon dioxide-containing gases such as boiler exhaust gas, non-permeable gas and permeable gas with a higher carbon dioxide concentration than non-permeable gas There is a carbon dioxide separation system that uses both a separator using a separation membrane that separates into two and an adsorption separation device that uses a pressure swing adsorption method (PSA method) for concentrating carbon dioxide in non-permeable gas.

In this system, the non-permeating gas from the separator is adsorbed and desorbed by the adsorber to further concentrate carbon dioxide, and the permeated gas from the separator and the desorbed gas from the adsorber are combined. By mixing, a carbon dioxide enriched gas is obtained.

However, in this device, when the concentration of carbon dioxide in the carbon dioxide-containing gas changes due to the start/stop of the boiler, which is the emission source of the carbon dioxide-containing gas, or due to changes in the combustion conditions of the boiler, adsorption from the separator Since the carbon dioxide concentration in the non-permeating gas supplied to the separation device also changes, the amount of carbon dioxide adsorbed by the adsorbent in the adsorption separation device changes, and the carbon dioxide concentration in the desorbed gas changes.

For this reason, this apparatus has a problem that it is not possible to obtain a carbon dioxide-enriched gas of stable purity under conditions where the carbon dioxide concentration in the carbon dioxide-containing gas changes.

Therefore, the present disclosure provides a carbon dioxide separator that can supply carbon dioxide-enriched gas with stable purity even when the carbon dioxide concentration in the carbon dioxide-containing gas supplied to the carbon dioxide separator changes.

Hereinafter, embodiments will be described in detail with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially the same configurations may be omitted.

It should be noted that the accompanying drawings and the following description are provided to allow those skilled in the art to fully understand the present disclosure and are not intended to limit the claimed subject matter thereby.

(Embodiment 1)
Embodiment 1 will be described below with reference to FIGS. 1 to 5. FIG.

[1-1. Constitution]
FIG. 1 is a block diagram showing the configuration of a carbon dioxide separator 1000 according to Embodiment 1. Particularly, in an adsorption device 200, an adsorption step is performed in an adsorber 2a and a regeneration step is performed in an adsorber 2b. state.

As shown in FIG. 1 , the carbon dioxide separator 1000 uses a carbon dioxide separator 1 and an adsorption device 200 to convert carbon dioxide-containing gas supplied from a carbon dioxide-containing gas supply source 100 into stable-purity carbon dioxide. It is configured to generate a carbon-enriched gas and supply the carbon dioxide-enriched gas to the carbon dioxide utilization device 16 .

The internal space of the carbon dioxide separator 1 is partitioned into a first space and a second space by a separation membrane 3 that selectively permeates carbon dioxide.

One end of the first space communicates with an outlet of a carbon dioxide-containing gas supply source 100 via a carbon dioxide-containing gas supply channel 9 . The carbon dioxide-containing gas supply channel 9 includes a supply pump 6 configured to supply the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 to the first space at a set supply rate. The other end of the first space communicates with the inlet of the adsorption device 200 by a non-permeating gas flow path 120 equipped with a carbon dioxide concentration sensor 5 .

One end of the second space communicates with the carbon dioxide utilization device 16 by a permeate gas flow path 121 comprising a vacuum pump 7 configured to reduce the pressure of the second space.

In the carbon dioxide separation device 1000, the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 flows into the first space from the carbon dioxide-containing gas supply channel 9 when both the supply pump 6 and the decompression pump 7 operate. Then, part of the carbon dioxide-containing gas that has flowed into the first space permeates the separation membrane 3 and flows into the second space, and the carbon dioxide-containing gas (permeated gas ) flows out from the second space into the permeating gas flow path 121, and among the carbon dioxide-containing gas that has flowed into the first space, the carbon dioxide-containing gas that has not permeated the separation membrane 3 (non-permeating gas) is the first It is configured to be supplied to the adsorption device 200 after flowing out from the space into the non-permeating gas flow path 120 .

The supply pump 6 and the A carbon dioxide-containing gas supply channel 9 between the carbon dioxide separator 1 (first space) and a non-permeating gas channel between the carbon dioxide separator 1 (first space) and the carbon dioxide concentration detector 5 120 is connected by a separator bypass passage provided with a bypass flow control valve 17 .

The adsorption device 200 has two adsorbers 2 a and 2 b filled with adsorbents 4 a and 4 b for adsorbing carbon dioxide and connected to the downstream side of the non-permeating gas flow path 120 .

In the two adsorbers 2a and 2b, in addition to the non-permeable gas channel 120, an exhaust gas channel for discharging the non-permeable gas not adsorbed by the adsorbers 2a and 2b to the outside of the carbon dioxide separator 1000. 11, a suction pump 15 is provided in the middle of the channel, and the desorbed gas desorbed from the adsorbers 2a and 2b is recovered from the adsorbers 2a and 2b, and carbon dioxide is used together with the permeated gas in the permeated gas channel 121. A desorption gas discharge channel 14 for supplying to the device 16 is connected.

The non-permeating gas channel 120 is connected to one end in the longitudinal direction of the adsorbers 2a and 2b, the exhaust gas channel 11 is connected to the other end in the longitudinal direction of the adsorbers 2a and 2b, and the desorbed gas discharge channel 14 is connected to the adsorption It is connected to one longitudinal end of the container 2a, 2b.

A control valve V1a is provided in the branched flow path of the non-permeating gas flow path 120 that branches from the shared non-permeating gas flow path 120 and is connected to the adsorber 2a. A control valve V1b is provided in a branch channel of the non-permeating gas channel 120 connected to the adsorber 2b.

A control valve V2a is provided in a branched flow path of the exhaust gas flow path 11 that is branched from the shared exhaust gas flow path 11 and connected to the adsorber 2a, and is branched from the shared exhaust gas flow path 11 and connected to the adsorber 2b. A control valve V2b is provided in a branched flow path of the exhaust gas flow path 11.

A control valve V3a is provided in a branched flow path of the desorbed gas discharge flow path 14 branched from the shared desorbed gas discharge flow path 14 and connected to the adsorber 2a. A control valve V3b is provided in the branched flow path of the desorbed gas discharge flow path 14 branched from and connected to the adsorber 2b.

When the carbon dioxide-containing gas is being supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separator 1000, and the adsorber 2b is performing a regeneration step of desorbing carbon dioxide from the adsorbent 4b, the adsorber 2a performs an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbent 4a, and the control valve V1a, the control valve V2a, and the control valve V3b are each in an open state, and the control valve V3a and the control valve V1b are in an open state. Each of the control valves V2b is closed.

When the carbon dioxide-containing gas is being supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separator 1000, and the adsorber 2a is performing a regeneration step for desorbing carbon dioxide from the adsorbent 4a, the adsorber 2b performs an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbent 4b, and the control valve V1b, the control valve V2b, and the control valve V3a are each in an open state, and the control valve V3b and the control valve V1a are in an open state. Each of the control valves V2a is closed.

When the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separation device 1000 (the non-permeating gas is supplied to the adsorption device 200 from the non-permeating gas flow path 120) in the adsorption device 200 , one of the adsorbers 2a and 2b performs an adsorption step in which the carbon dioxide contained in the non-permeable gas is adsorbed by the adsorbents 4a and 4b, and one of the adsorbers 2a and 2b absorbs the non-permeable gas. While performing the adsorption step of adsorbing the carbon dioxide contained in the adsorbents 4a and 4b, the other of the adsorbers 2a and 2b performs the regeneration step of desorbing carbon dioxide from the adsorbents 4a and 4b. , the controller C1 controls the open/close states of the control valves V1a, V1b, V2a, V2b, V3a, and V3b.

The exhaust gas flow path 11 is downstream of the two adsorbers 2a and 2b so that the non-permeating gas that has not been adsorbed by the adsorbers 2a and 2b in the adsorption step is exhausted to the outside from the adsorbers 2a and 2b in the adsorption step. It is a flow path connected to the side.

One end (upstream side end) of the desorbed gas discharge channel 14 has two lines so that the desorbed gas desorbed from the adsorbers 2a and 2b in the regeneration process is recovered from the adsorbers 2a and 2b in the regeneration process. Flow path connected to adsorbers 2a and 2b and connected to permeation gas flow path 121 so that the other end (downstream end) communicates with permeation gas flow path 121 between decompression pump 7 and carbon dioxide utilization device 16 is.

The suction pump 15 is arranged in the middle of the shared channel in the desorbed gas discharge channel 14 . In addition, the suction pump 15 reduces the pressure inside the adsorbers 2a and 2b in the regeneration process, desorbs carbon dioxide from the adsorbents 4a and 4b, and causes the desorbed gas to flow out to the desorbed gas discharge passage 14. is configured to

Here, the suffixes of the reference numerals of these constituent elements will be described by taking the adsorbers 2a and 2b as an example. When the adsorber 2a among the plurality of adsorbers 2a and 2b is described separately from others, it will be described as the adsorber 2a. When the adsorber 2b of the plurality of adsorbers 2a and 2b is to be distinguished from others, it will be described as the adsorber 2b.

When describing a plurality of adsorbers 2a and 2b at the same time and equivalently, they are referred to as adsorbers 2a and 2b or adsorbers 2a to 2b. Like the container 2, the description will be given with reference numerals omitting lower-case alphabetic characters.

The carbon dioxide separator 1 includes a separation membrane 3 which is a membrane that selectively permeates carbon dioxide and divides the internal space of the carbon dioxide separator 1 into two spaces.

The carbon dioxide-containing gas supply channel 9 and the non-permeating gas channel 120 are connected in the internal space of the carbon dioxide separator 1 by the separation membrane 3, and the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply channel 9. It is divided into a first space into which the non-permeating gas flows into the non-permeating gas passage 120 and a second space in which the permeating gas passage 121 is connected and the pressure is reduced by the decompression pump 7 provided in the permeating gas passage 121. It is

Carbon dioxide supplied from the carbon dioxide-containing gas supply channel 9 to the first space of the carbon dioxide separator 1 selectively permeates through the separation membrane 3 due to the partial pressure difference between the carbon dioxide in the first space and the second space. .

Of the carbon dioxide-containing gas supplied to the first space, the non-permeable gas that has not permeated the separation membrane 3 flows out from the first space into the non-permeable gas channel 120 . Of the carbon dioxide-containing gas supplied to the first space, the permeating gas that permeates the separation membrane 3 and flows out from the second space to the permeating gas flow path 121 does not permeate the separation membrane 3 and leaves the first space. This gas has a higher carbon dioxide concentration than the non-permeating gas that flows out to the permeating gas flow path 120 .

Adsorbers 2a and 2b constituting the adsorption device 200 are provided with adsorbents 4a and 4b for adsorbing carbon dioxide therein. The material of the adsorbents 4a and 4b is zeolite that adsorbs carbon dioxide.

The separation membrane 3 that selectively permeates carbon dioxide contains monoethanolamine, which is a type of alkanolamine.

The carbon dioxide concentration detector 5 is provided in the non-permeating gas flow path 120 and detects the carbon dioxide concentration in the non-permeating gas supplied to the adsorbers 2a and 2b.

The supply pump 6 is a pump that supplies the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separator and the adsorber 2 (adsorption device 200). It is arranged on the upstream side from the branch point with the vessel bypass flow path 18 .

The decompression pump 7 decompresses the second space of the carbon dioxide separator 1 to promote permeation of carbon dioxide contained in the carbon dioxide-containing gas from the first space of the carbon dioxide separator 1 to the second space, The permeated gas that permeates the separation membrane 3 from the first space of the carbon dioxide separator 1 to the second space flows out from the second space to the permeated gas flow path 121 and is supplied to the carbon dioxide utilization device 16, and the exhaust speed can be adjusted. and is arranged in the permeate gas flow path 121 .

The carbon dioxide-containing gas supply channel 9 has a supply pump 6 in the middle of the channel so that the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 is supplied to the first space of the carbon dioxide separator 1. ing.

The carbon dioxide-containing gas supply channel 9 connects the carbon dioxide-containing gas supply source 100 and the carbon dioxide separator 1 (first space), and is separated from the channel between the supply pump 6 and the carbon dioxide separator 1. The vessel bypass channel 18 is a channel through which the carbon dioxide-containing gas flows.

The exhaust gas channel 11 is a non-permeating gas supplied to the adsorber 2 (adsorption device 200) through the non-permeating gas channel 120 (carbon dioxide bypassing the first space of the carbon dioxide separator 1 through the separator bypass channel 18). The adsorber 2 (adsorber 200) is used so that the gas that is not adsorbed by the adsorbent 4 of the adsorber 2 (including the contained gas) can be discharged from the adsorber 2 (adsorber 200) to the outside of the carbon dioxide separation device 1000. 200).

The non-permeable gas channel 120 is a non-permeable gas (dioxide Carbon-containing gas) is supplied to the adsorber 2 (adsorption device 200), the carbon dioxide separator 1 (first space) and the adsorption device 2 (adsorption device 200) are connected, and the carbon dioxide separator 1 ( The separator bypass flow path 18 joins the flow path between the first space) and the carbon dioxide concentration detector 5, and the non-permeating gas flows through the flow path.

The permeated gas channel 121 has a decompression pump 7 in the middle of the channel so that the permeated gas that has permeated the separation membrane 3 from the first space of the carbon dioxide separator 1 to the second space is supplied to the carbon dioxide utilization device 16 . , the carbon dioxide separator 1 (second space) and the carbon dioxide utilization device 16 are connected, and the desorption gas discharge flow passage 14 joins the flow path between the decompression pump 7 and the carbon dioxide utilization device 16 , is a channel through which a permeating gas flows.

The desorbed gas discharge channel 14 is located in the middle of the channel so that the desorbed gas desorbed from the adsorbent 4 of the adsorber 2 is supplied to the carbon dioxide utilization device 16 via the permeated gas channel 121. is provided with a suction pump 15, connects the flow path between the decompression pump 7 and the carbon dioxide utilization device 16 and the adsorber 2 (adsorption device 200), and desorbed gas flows through the flow path. be.

The suction pump 15 decompresses the inside of the adsorber 2 to desorb the carbon dioxide adsorbed by the adsorbent 4 of the adsorber 2 from the adsorbent 4 and causes it to flow out to the desorbed gas discharge channel 14 . The desorbed gas discharge channel 14 is equipped with a pump that supplies permeate gas to the permeating gas channel 121 between the decompression pump 7 and the carbon dioxide utilization device 16 .

The bypass flow rate control valve 17 is a flow rate control valve that adjusts the amount of the carbon dioxide-containing gas flowing through the separator bypass flow path 18 and is provided in the separator bypass flow path 18 .

In the separator bypass channel 18, part of the carbon dioxide-containing gas discharged from the supply pump 6 and flowing through the carbon dioxide-containing gas supply channel 9 bypasses the carbon dioxide separator 1 (first space). , the carbon dioxide-containing gas supply channel 9 between the supply pump 6 and the carbon dioxide separator 1 (first space), and the dioxide A non-permeating gas flow path 120 between the carbon separator 1 (first space) and the carbon dioxide concentration detector 5 is connected.

The separator bypass flow path 18 is a flow path having a bypass flow control valve 17 in the middle of the flow path and through which part of the carbon dioxide-containing gas flows.

The control valves V1a and V1b are provided in branch flow paths corresponding to the adsorbers 2a and 2b in the non-permeating gas flow path 120, respectively. The control valves V2a and V2b are provided in branch flow paths corresponding to the adsorbers 2a and 2b in the exhaust gas flow path 11, respectively. The control valves V3a and V3b are provided in branch flow paths corresponding to the adsorbers 2a and 2b in the desorbed gas discharge flow path 14, respectively.

The adsorption device 200 has adsorbers 2a and 2b. The adsorber 2a has control valves V1a, V2a and V3a, and the adsorber 2b has control valves V1b, V2b and V3b.

Controller C1 controls the operation of carbon dioxide separator 1000 . The controller C1 includes a signal input/output unit (not shown), an arithmetic processing unit (not shown), and a storage unit (not shown) for storing control programs.

The controller C1 is configured to operate the supply pump 6, the decompression pump 7, the suction pump 15, the bypass flow control valve 17, and the control valves V1a to V3b according to commands from the controller C1.

Based on the concentration detected by the carbon dioxide concentration detector 5, the controller C1 controls the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step to fall within a predetermined range. It is configured to control the amount adjusting means (supply pump 6, decompression pump 7, bypass flow control valve 17).

[1-2. motion]
The operation of the carbon dioxide separator 1000 configured as described above will be described in detail with reference to FIGS. 2 to 5. FIG.

[1-2-1. basic action]
FIG. 2 is a flow chart showing the basic operation of the carbon dioxide separator 1000. As shown in FIG.

The following operations are performed by controlling the carbon dioxide separator 1000 by the controller C1.

When an operation start request is received, the carbon dioxide separator 1000 performs a start-up operation (S000) and starts operation under the control of the controller C1.

Next, under the control of the controller C1, the carbon dioxide separation device 1000 performs a CO ₂ concentration adjustment operation (S100) for adjusting the carbon dioxide concentration in the non-permeating gas flowing into the adsorption device 200 (adsorber 2), and The PSA operation (S200) of the adsorption device 200 is performed in parallel.

In this way, the carbon dioxide separator 1000 performs the PSA operation of the adsorption device 200 while adjusting the concentration of carbon dioxide in the non-permeating gas flowing into the adsorption device 200 (adsorber 2) within a predetermined range. , desorbed gas of stable concentration is generated from the adsorption device 200, and combined with the permeated gas of the carbon dioxide separator 1, carbon dioxide-enriched gas of stable concentration is generated.

Next, the controller C1 determines whether or not there is a command to stop the operation of the carbon dioxide separator 1000 (S300). As a result of the determination in S300, if there is no operation stop command, the CO ₂ concentration adjustment operation (S100) and PSA operation (S200) are continued until the operation stop command is received.

As a result of the determination in S300, if there is an operation stop command, the controller C1 controls the supply pump 6 for supplying the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 to the first space of the carbon dioxide separator 1, the dioxide A decompression pump 7 for depressurizing the second space of the carbon separator 1 and causing the permeated gas that has passed through the separation membrane 3 from the first space of the carbon dioxide separator 1 to the second space to flow out from the second space to the permeated gas flow path 121. , the suction pump 15 for depressurizing the adsorber 2 in the regeneration step and discharging the desorbed gas desorbed from the adsorbent 4 to the desorbed gas discharge passage 14 is stopped (S400), the operation flag of the adsorber 2, After storing the operation step information and the opening/closing information of all the control valves in the memory of the controller C1, all the control valves are closed (S500) to stop the operation of the carbon dioxide separator 1000. FIG.

[1-2-2. Startup action]
Next, the startup operation (S100) of the carbon dioxide separator 1000 will be described in detail.

FIG. 3 is a flow chart showing the startup operation (S100) of the carbon dioxide separator 1000. As shown in FIG.

The following operations are performed by controlling the carbon dioxide separator 1000 by the controller C1.

First, the controller C1 activates the decompression pump 7 that decompresses the second space of the carbon dioxide separator 1 so that the pressure in the second space of the carbon dioxide separator 1 reaches the predetermined pressure (20 kPa). By adjusting the exhaust speed of the decompression pump 7, the pressure in the second space of the carbon dioxide separator 1 is decompressed to a predetermined pressure of 20 kPa (S001).

Next, the controller C1 reads the flag information of the adsorption devices 2a and 2b of the adsorption device 200 during the previous operation, the operation step information, and the opening/closing information of the control valves V1a to V3b stored in the memory of the controller C1. and reflected in the adsorption device 200 (S002).

Next, the controller C1 operates the supply pump 6 for supplying the carbon dioxide-containing gas to the first space of the carbon dioxide separator 1 at the first supply rate (30 L/min), thereby causing the carbon dioxide-containing gas supply source The carbon dioxide-containing gas from 100 is supplied to (the inlet of) the first space of the carbon dioxide separator 1 (S003).

[1-2-3. CO ₂ concentration adjustment operation]
Next, the CO ₂ concentration adjustment operation (S100) of the carbon dioxide separation device 1000 will be explained using FIG.

First, the controller C1 controls the carbon dioxide concentration detector 5 provided in the non-permeating gas flow path 120 connecting the outlet of the first space of the carbon dioxide separator 1 and the inlet of the adsorption device 200 (adsorber 2). It is determined whether or not the carbon dioxide concentration in the detected non-permeable gas is within a predetermined concentration range (S101).

As a result of the determination in S101, if the concentration is within the predetermined range, S101 is branched to the Yes side, the CO ₂ concentration adjustment operation is completed, and the process transitions to the next step.

As a result of the determination in S101, if it is outside the predetermined concentration range, S101 is branched to the No side, and the controller C1 detects that the concentration of carbon dioxide in the non-permeating gas detected by the carbon dioxide concentration detector 5 is the predetermined concentration. It is determined whether or not the upper limit of the range is exceeded (S102).

As a result of the determination in S102, if the upper limit value of the predetermined concentration range is exceeded, S102 is branched to the Yes side, and the controller C1 causes the carbon dioxide-containing gas supply channel 9 to pass through the separator bypass channel 18. Bypassing the carbon dioxide separator 1 (first space), the bypass flow control valve 17 for adjusting the amount of carbon dioxide-containing gas flowing into the non-permeating gas flow path 120 is 0%, that is, fully closed. It is determined whether or not (S103).

As a result of the determination in S102, if the upper limit value of the predetermined concentration range is not exceeded, S102 is branched to the No side, and the controller C1 decompresses the second space of the carbon dioxide separator 1 to reduce the pressure from the first space. Determination is made as to whether or not the pumping speed of the decompression pump 7 configured to cause the permeated gas that has permeated the separation membrane 3 into the second space to flow out from the second space to the permeating gas flow path 121 is the minimum pumping speed. (S108).

As a result of the determination in S103, if the valve opening degree of the bypass flow control valve 17 is not 0%, S103 is branched to the No side, and the controller C1 detects the concentration detected by the carbon dioxide concentration detector 5 and the predetermined concentration range. , the opening degree of the bypass flow control valve 17 is lowered (S107), the CO ₂ concentration control operation is terminated, and the next step is performed.

As a result, the amount of the carbon dioxide-containing gas that flows through the separator bypass flow path 18 and is added to the non-permeating gas decreases, and the amount of the carbon dioxide-containing gas that is supplied to the carbon dioxide separator 1 increases. Since the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 200 decreases, it is possible to control the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 200 so as not to exceed the upper limit of a predetermined concentration range. can.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied to the carbon dioxide utilization device 16 .

If the valve opening degree of the bypass flow control valve 17 is 0% as a result of the determination in S103, S103 is branched to the Yes side, and the controller C1 determines whether the exhaust speed of the pressure reducing pump 7 is lower than the maximum exhaust speed. It is determined whether or not (S104).

As a result of the determination in S104, if the exhaust speed of the decompression pump 7 is lower than the maximum exhaust speed, S104 is branched to the Yes side, and the controller C1 determines the difference between the concentration detected by the carbon dioxide concentration detector 5 and the predetermined concentration range. The pumping speed of the decompression pump 7 is increased according to the difference (S105), the CO ₂ concentration adjusting operation is terminated, and the process proceeds to the next step.

Thereby, the average value of the carbon dioxide partial pressure in the permeate gas flowing through the second space is subtracted from the average value of the carbon dioxide partial pressure in the carbon dioxide-containing gas flowing through the first space of the carbon dioxide separator 1. As the partial pressure difference increases, the amount of carbon dioxide that permeates the separation membrane 3 from the first space to the second space increases. Since the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 200 decreases, the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 200 can be controlled so as not to exceed the upper limit of the predetermined concentration range.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied to the carbon dioxide utilization device 16 .

As a result of the determination in S104, if the exhaust speed of the decompression pump 7 is the maximum exhaust speed, S104 is branched to the No side, and the controller C1 determines the difference between the concentration detected by the carbon dioxide concentration detector 5 and the predetermined concentration range. By reducing the carbon dioxide-containing gas supply amount of the supply pump 6 from the current first supply amount according to the difference, the amount of the non-permeating gas flowing out from the first space of the carbon dioxide separator 1 to the non-permeating gas flow path 120 is reduced. The amount of outflow is reduced (S106), the CO ₂ concentration adjustment operation is completed, and the next step is performed.

As a result, by reducing the supply amount of the carbon dioxide-containing gas exceeding a predetermined concentration to the adsorption device 200, the adsorption amount per unit time of carbon dioxide adsorbed by the adsorbent 4 inside the adsorption device 2 in the adsorption step is reduced. To supply carbon dioxide-enriched gas of stable purity by limiting the amount of adsorption to a predetermined amount so that the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 does not exceed the upper limit of a predetermined concentration range. can be done.

As a result of the determination in S108, if the exhaust speed of the decompression pump 7 is the minimum exhaust speed, S108 is branched to the Yes side, and the controller C1 determines that the opening degree of the bypass flow control valve 17 is 100%, that is, fully open. (S109).

As a result of the determination in S108, if the exhaust speed of the decompression pump 7 is not the minimum exhaust speed, S108 is branched to the No side, and the controller C1 determines the difference between the concentration detected by the carbon dioxide concentration detector 5 and the predetermined concentration range. The pumping speed of the decompression pump 7 is reduced according to the difference (S111), the CO ₂ concentration adjustment operation is terminated, and the process proceeds to the next step.

Thereby, the average value of the carbon dioxide partial pressure in the permeate gas flowing through the second space is subtracted from the average value of the carbon dioxide partial pressure in the carbon dioxide-containing gas flowing through the first space of the carbon dioxide separator 1. As the partial pressure difference decreases, the amount of carbon dioxide that permeates the separation membrane 3 from the first space to the second space decreases, and the carbon dioxide flows out from the first space to the non-permeating gas flow path 120 to the adsorption device 200. Since the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 200 increases, the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 200 can be controlled so as not to fall below the lower limit of the predetermined concentration range.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied to the carbon dioxide utilization device 16 .

As a result of the determination in S109, if the opening degree of the bypass flow control valve 17 is 100%, the controller C1 issues a command to stop the carbon dioxide separator 1000 (S110), ends the CO ₂ concentration adjustment operation, Transition to the next step.

As a result, when the carbon dioxide-containing gas containing low-concentration carbon dioxide that cannot be controlled within a predetermined concentration range by the carbon dioxide separation device 1000 is supplied to the carbon dioxide separation device 1000, the low-concentration carbon dioxide-enriched gas is converted to carbon dioxide. It is possible to prevent the data from being supplied to the utilization device 16 .

If the opening degree of the bypass flow control valve 17 is 100% as a result of the determination in S109, the controller C1 adjusts the bypass flow control valve according to the difference between the concentration detected by the carbon dioxide concentration detector 5 and the predetermined concentration range. 17 is increased (S112), the CO ₂ concentration adjustment operation is completed, and the next step is performed.

As a result, the amount of the carbon dioxide-containing gas that flows through the separator bypass channel 18 and is added to the non-permeating gas increases, and the amount of the carbon dioxide-containing gas that is supplied to the carbon dioxide separator 1 decreases. Since the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 200 increases, it is necessary to control the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 200 so as not to fall below the lower limit of a predetermined concentration range. can.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied to the carbon dioxide utilization device 16 .

[1-2-4. PSA operation]
Next, the PSA operation (S200) of carbon dioxide separator 1000 will be described using FIG.

In this step, the controller C1 performs determination and operation in parallel for each of the adsorbers 2 provided in the carbon dioxide separator 1000 . Therefore, although FIG. 5 shows the operation of the adsorber 2a, the other adsorbers 2b operate similarly and in parallel.

First, the controller C1 determines whether or not there is an adsorber 2 whose adsorption process flag is ON (S201). repeat the judgment.

As a result of the determination in S201, if there is no adsorber 2 whose adsorption process flag is ON, S201 is branched to the No side, and the adsorption process flag of the adsorber 2a is turned ON (S202).

Next, the controller C1 opens the control valves V1a and V2a while closing the control valve V3a, thereby supplying the non-permeating gas in the non-permeating gas flow path 120 to the adsorber 2a (S203). .

As a result, the carbon dioxide contained in the non-permeable gas is adsorbed by the adsorbent 4a in the adsorber 2a, and of the non-permeable gas supplied to the adsorber 2a, the impurity gas that is not adsorbed by the adsorbent 4a is It is exhausted via the exhaust gas flow path 11 .

Next, the controller C1 checks whether or not a predetermined time (30 min) has elapsed since the adsorption process flag of the adsorber 2a was turned ON (S204). If so, the confirmation of S204 is repeated until the time elapses.

As a result of confirmation in S204, if a predetermined time has passed since the adsorption process flag of the adsorber 2a was turned ON, S204 is branched to the Yes side, and the controller C1 sets the adsorption process flag of the adsorber 2a. It is turned off to close the control valves V1a and V2a (S205).

Here, in the present embodiment, the predetermined time for the adsorption step is set to 30 minutes, but this is merely an example.

Here, the predetermined time for the adsorption step is a value obtained in advance by experiments. During the predetermined time of the adsorption step, the carbon dioxide in the non-permeating gas is adsorbed by the adsorbents 4a and 4b in the adsorbers 2a and 2b, and the carbon dioxide adsorbed by the adsorbents 4a and 4b is desorbed. The carbon dioxide concentration in the degassed gas may be changed according to the measured value of the carbon dioxide concentration detector 5 as long as the concentration reaches the concentration required by the carbon dioxide utilization device 16 . Therefore, the predetermined time for the adsorption step is not quantitatively deterministic.

That is, here, when the elapsed time from the time when the adsorption process flag is turned ON reaches 30 minutes, it is determined that the concentration of carbon dioxide in the desorbed gas reaches the concentration required by the carbon dioxide utilization device 16, and the elapsed time It is determined that the carbon dioxide concentration in the desorbed gas does not reach the concentration required by the carbon dioxide utilization device 16 before is 30 min, but this criterion is only an example.

Next, the controller C1 determines whether or not there is an adsorber 2 whose regeneration process flag is ON (S206). The determination of S206 is repeated.

As a result of the determination in S206, if there is no adsorber 2 whose regeneration process flag is ON, S206 branches to No, and the regeneration process flag of the adsorber 2a is turned ON (S207).

Next, the controller C1 opens the control valve V3a to operate the suction pump 15 (S208) to start the regeneration process.

As a result, the carbon dioxide and the impurity gas adsorbed in the adsorber 2a in the adsorption step are desorbed from the adsorber 2a (adsorbent 4a), and the desorbed gas flows out to the desorbed gas discharge passage 14.

Next, the controller C1 checks whether or not a predetermined time (30 min) has elapsed since the regeneration process flag of the adsorber 2a was turned ON (S209). If so, the confirmation of S209 is repeated until the time elapses.

As a result of confirmation in S209, if a predetermined time has passed since the regeneration process flag of the adsorber 2a was turned ON, S209 branches to the Yes side, and the controller C1 closes the control valve V3a to perform suction. The pump 15 is stopped (S210), the regeneration step flag of the adsorber 2a is turned off (S211), and the process proceeds to the next step.

Here, in the present embodiment, the predetermined time for the regeneration process is set to 30 minutes, but this is merely an example.

Here, the predetermined time for the regeneration process is a value obtained in advance by experiments. The predetermined time for the regeneration step may be any value that allows determination of whether or not the desorption of carbon dioxide adsorbed by the adsorbents 4a and 4b in the adsorbers 2a and 2b is complete. Therefore, the predetermined time for the regeneration step is not quantitatively deterministic.

That is, here, when the elapsed time from the time when the regeneration process flag is turned ON reaches 30 minutes, it is determined that the desorption of the carbon dioxide adsorbed by the adsorbents 4a and 4b is completed, and before the elapsed time reaches 30 minutes. Although it is determined that the carbon dioxide adsorbed by the adsorbents 4a and 4b is not completely desorbed, this determination criterion is only an example.

When the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separation device 1000 (the non-permeating gas is supplied to the adsorption device 200), in the adsorption device 200, the adsorbers 2a and 2b performs an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbents 4a and 4b.

While one of the adsorbers 2a and 2b is performing the adsorption step of adsorbing the carbon dioxide contained in the non-permeating gas onto the adsorbents 4a and 4b, the other of the adsorbers 2a and 2b is A regeneration step is performed to desorb carbon dioxide from 4a and 4b.

For example, when the adsorber 2b is performing a regeneration step of desorbing carbon dioxide from the adsorbent 4b, the adsorber 2a is performing an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas onto the adsorbent 4a. , the control valve V1a, the control valve V2a, and the control valve V3b are in an open state, and the control valve V3a, the control valve V1b, and the control valve V2b are in a closed state.

Similarly, when the adsorber 2a is performing a regeneration step of desorbing carbon dioxide from the adsorbent 4a, the adsorber 2b is performing an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas onto the adsorbent 4b. The control valve V1b, the control valve V2b, and the control valve V3a are each open, and the control valve V3b, the control valve V1a, and the control valve V2a are each closed.

[1-3. effects, etc.]
As described above, the carbon dioxide separator 1000 in the present embodiment includes the carbon dioxide separator 1, the decompression pump 7, the carbon dioxide concentration detector 5, the supply pump 6 functioning as permeation gas amount adjusting means, and the bypass flow rate. It includes a control valve 17, an adsorption device 200, an exhaust gas flow path 11, a desorbed gas discharge flow path 14, a suction pump 15, and a controller C1. The decompression pump 7 also functions as permeable gas amount adjusting means.

The carbon dioxide separator 1 has an internal space partitioned into a first space and a second space by a separation membrane 3 that selectively permeates carbon dioxide. The first space is a space into which the carbon dioxide-containing gas flows from the carbon dioxide-containing gas supply channel 9, and a space into which the non-permeating gas that has not permeated the separation membrane 3 flows out to the non-permeating gas channel 120. be. The second space is a space through which the permeated gas that has permeated the separation membrane 3 flows out to the permeated gas channel 121 .

The decompression pump 7 is a pump that is provided in the middle of the permeated gas flow path 121 and configured to decompress the second space at an exhaust speed set for the decompression pump 7 . Due to the decompression operation of the decompression pump 7 , carbon dioxide contained in the carbon dioxide-containing gas permeates the separation membrane 3 and the permeated gas flows out to the permeated gas flow path 121 .

The carbon dioxide concentration detector 5 is arranged in the middle of the non-permeating gas channel 120 and configured to detect the concentration of carbon dioxide contained in the non-permeating gas flowing through the non-permeating gas channel 120. .

The adsorption device 200 has two adsorbers 2 a and 2 b filled with adsorbents 4 a and 4 b for adsorbing carbon dioxide and connected to the downstream side of the non-permeating gas flow path 120 .

In the adsorption device 200, the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separation device 1000 (the non-permeating gas is supplied to the adsorption device 200 from the non-permeating gas flow path 120). ), one of the adsorbers 2a and 2b performs the adsorption step of adsorbing the carbon dioxide contained in the non-permeating gas onto the adsorbents 4a and 4b, and one of the adsorbers 2a and 2b performs the adsorption step. In the meantime, the other of the adsorbers 2a, 2b is configured to perform a regeneration process for desorbing carbon dioxide from the adsorbents 4a, 4b.

The exhaust gas flow path 11 is downstream of the two adsorbers 2a and 2b so that the non-permeating gas that has not been adsorbed by the adsorbers 2a and 2b in the adsorption step is exhausted to the outside from the adsorbers 2a and 2b in the adsorption step. is a flow path connected to

The desorbed gas discharge channel 14 is connected to the two adsorbers 2a and 2b so that the desorbed gas desorbed from the adsorbers 2a and 2b in the regeneration process is recovered from the adsorbers 2a and 2b in the regeneration process. It is a flow path that has been designed.

The suction pump 15 is provided in the middle of the desorbed gas discharge channel 14 . In addition, the suction pump 15 reduces the pressure inside the adsorbers 2a and 2b in the regeneration process, desorbs carbon dioxide from the adsorbents 4a and 4b, and causes the desorbed gas to flow out to the desorbed gas discharge passage 14. is configured to

The supply pump 6 is provided in the middle of the carbon dioxide-containing gas supply channel 9 . In addition, the supply pump 6 supplies the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 to the first space of the carbon dioxide separator 1 at a supply amount set for the supply pump 6. It is configured.

The bypass flow rate control valve 17 is provided in the middle of the separator bypass flow path 18, and by adjusting the opening degree of the valve, the flow rate of the carbon dioxide-containing gas flowing through the separator bypass flow path 18 can be adjusted. is configured to

The separator bypass flow path 18 bypasses the carbon dioxide-containing gas supply flow path 9 and the non-permeating gas flow path 120 so that the carbon dioxide separator 1 is bypassed and the carbon dioxide concentration detector 5 is not bypassed. It is connected via valve 17 .

Based on the concentration detected by the carbon dioxide concentration detector 5, the controller C1 controls the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber in the adsorption step to fall within a predetermined range. It is configured to control any one of the supply pump 6, the bypass flow control valve 17, and the decompression pump 7, which function as volume control means.

In the carbon dioxide separation apparatus 1000 having the above configuration, the controller C1 detects the concentration of carbon dioxide contained in the non-permeating gas detected by the carbon dioxide concentration detector 5 provided in the non-permeating gas flow path 120, The flow rate of the permeating gas is adjusted (permeating gas amount adjusting means is controlled) so that the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the process falls within a predetermined range. When the carbon dioxide concentration in the non-permeable gas flowing into the adsorber 2) changes, the amount of carbon dioxide permeating the separation membrane 3 can be changed, and the non-permeable gas flowing into the adsorber 2 in the adsorption step can be changed. It is possible to control the concentration of carbon dioxide in a predetermined range.

Therefore, the concentration of carbon dioxide flowing into the adsorption device 200 (adsorber 2) is stabilized, and the adsorbent 4
By stabilizing the amount of carbon dioxide adsorbed to the carbon dioxide, the concentration of carbon dioxide in the desorbed gas can be stabilized, and carbon dioxide enriched gas with stable purity can be supplied to the carbon dioxide utilization device 16. becomes.

As in the present embodiment, the carbon dioxide separator 1000 calculates the carbon dioxide content in the permeate gas flowing through the second space from the average value of the carbon dioxide partial pressure in the carbon dioxide-containing gas flowing through the first space. By controlling the partial pressure difference obtained by subtracting the average value of the pressure, the flow rate of the permeating gas is adjusted so that the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step falls within a predetermined range. I don't mind.

In this case, based on the carbon dioxide concentration in the non-permeating gas detected by the carbon dioxide concentration detector 5, the controller C1 controls the amount of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step. If it is determined that the concentration exceeds the upper limit of the predetermined range, the partial pressure difference is adjusted to increase the partial pressure difference within the range of 0 or more, and if it is determined that the concentration is below the lower limit of the predetermined range, the partial pressure difference The partial pressure difference may be adjusted so that is small within the range of 0 or more.

The partial pressure difference can be adjusted by adjusting the pumping speed of the decompression pump 7 or adjusting the supply amount of the supply pump 6 . Increasing the exhaust speed of the decompression pump 7 increases the partial pressure difference, and decreasing the exhaust speed of the decompression pump 7 decreases the partial pressure difference. When the supply amount of the supply pump 6 is increased, the partial pressure difference increases, and when the supply amount of the supply pump 6 is decreased, the partial pressure difference decreases.

As a result, the influence of the carbon dioxide concentration in the permeated gas staying in the second space of the carbon dioxide separator 1 can be suppressed, and the carbon dioxide permeation amount of the separation membrane 3 can be adjusted.

Therefore, even if the carbon dioxide concentration in the carbon dioxide-containing gas changes significantly, the effect of the carbon dioxide concentration immediately before the change can be suppressed, and the amount of permeating gas can be quickly adjusted, resulting in a high recovery rate. can be maintained and the carbon dioxide concentration in the desorbed gas can be further stabilized.

In addition, as in the present embodiment, the carbon dioxide separator 1000 may have the decompression pump 7 configured to have a variable capacity.

In this case, based on the carbon dioxide concentration in the non-permeating gas detected by the carbon dioxide concentration detector 5, the controller C1 controls the amount of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step. When it is determined that the concentration exceeds the upper limit of the predetermined range, the exhaust capacity of the decompression pump 7 is increased, and when it is determined that the concentration is below the lower limit of the predetermined range, the exhaust capacity of the decompression pump 7 is decreased. You can control it.

Thereby, the partial pressure difference can be increased without increasing the pressure of the carbon dioxide-containing gas flowing through the carbon dioxide-containing gas supply passage 9 .

Therefore, even when water vapor is contained in the carbon dioxide-containing gas, dew condensation on the surface of the separation membrane 3 can be suppressed, thereby suppressing a decrease in the usable membrane area due to adhesion of water droplets to the surface of the separation membrane 3. Since the control of the amount of permeating gas is simplified, the concentration of carbon dioxide in the desorbed gas can be further stabilized.

In addition, as in the present embodiment, the carbon dioxide separator 1000 has a carbon dioxide-containing gas supply channel 9 and a non-permeable gas so as not to bypass the carbon dioxide separator 1 and bypass the carbon dioxide concentration detector 5. The separator bypass flow path 18 connects the flow path 120 to The flow rate of the permeate gas may be adjusted by adjusting the flow rate of the carbon dioxide-containing gas flowing into the non-permeate gas channel 120 .

In this case, the controller C1 detects the carbon dioxide concentration in the non-permeating gas detected by the carbon dioxide concentration detector 5 when part of the carbon dioxide-containing gas is flowing through the separator bypass channel 18. Based on this, when it is determined that the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step exceeds the upper limit value of the predetermined range, the bypass flow control valve 17 allows the separator bypass passage 18 to pass through. When the flow rate of the flowing carbon dioxide-containing gas is reduced and the bypass flow control valve 17 is not fully open, if it is determined that the concentration is below the lower limit value of the predetermined range, the bypass flow control valve 17 reduces the separator bypass flow path 18 may be controlled to increase the flow rate of the carbon dioxide-containing gas that flows through.

As a result, the amount of carbon dioxide-containing gas flowing into the carbon dioxide separator 1 can be adjusted, and the permeation gas amount can be controlled without changing the permeation flux of the separation membrane 3 .

Therefore, the permeation gas amount can be controlled in a short time compared to the case where the permeation flux of the separation membrane 3 is changed, so that the change in carbon dioxide concentration in the desorbed gas can be further suppressed.

(Embodiment 2)
Embodiment 2 will be described below with reference to FIGS. 6 to 10. FIG. In addition, in FIG. 6, the same reference numerals are assigned to the same configurations as those of the first embodiment shown in FIG. 1, and detailed description thereof may be omitted.

[2-1. Constitution]
FIG. 6 is a block diagram showing the configuration of the carbon dioxide separation device 1001 according to Embodiment 2. In particular, in the adsorption device 201, the adsorption step is performed in the adsorption device 2a and the regeneration step is performed in the adsorption device 2b. state.

FIG. 9 is a block diagram showing the configuration of the carbon dioxide separation device 1001 according to Embodiment 2. In particular, in the adsorption device 201, the adsorption step is performed in the adsorption device 2a and the purge step is performed in the adsorption device 2b. state.

As shown in FIGS. 6 and 9, the carbon dioxide separation device 1001 uses the carbon dioxide separator 1 and the adsorption device 201 to stabilize the carbon dioxide-containing gas supplied from the carbon dioxide-containing gas supply source 100. It is configured to produce carbon dioxide-enriched gas of purity and supply the carbon dioxide-enriched gas to the carbon dioxide utilization device 16 .

The internal space of the carbon dioxide separator 1 is partitioned into a first space and a second space by a separation membrane 31 that selectively permeates carbon dioxide. The separation membrane 31 has a characteristic that the carbon dioxide permeation performance increases as the moisture content of the membrane increases, and a characteristic that the carbon dioxide permeation performance increases as the temperature of the membrane increases.

A temperature controller 8 is provided outside the carbon dioxide separator 1 . The temperature controller 8 includes a heater that heats the carbon dioxide separator 1 and temperature detection means (not shown) that detects the temperature of the carbon dioxide separator 1. When the set temperature is set, It is configured so that the carbon dioxide separator 1 can be heated to a set temperature.

One end of the first space communicates with an outlet of a carbon dioxide-containing gas supply source 100 via a carbon dioxide-containing gas supply channel 9 . The carbon dioxide-containing gas supply channel 9 includes a humidifier 171 configured to humidify the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100.
It has

The other end of the first space is connected to the inlet of the adsorption device 201 (two adsorbers in the 2a and 2b).

The supply pump 61 is configured so that the supply amount of the supply pump 61 can be set to the supply amount set for the supply pump 61 .

In addition, the supply pump 61 supplies the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 to the first space by the action of the supply pump 61, and the non-permeating gas discharged from the first space is transferred to the adsorption device 201. It is arranged in the non-permeating gas flow path 120 connecting the first space and the adsorber 2 so that it can be supplied to the adsorber 2 of the second space.

One end of the second space is provided with a decompression pump 7 configured to decompress the second space, and the permeate gas flow path 122 branched downstream of the decompression pump 7 allows the two gases in the adsorption device 201 to be separated from each other. One end of each of the adsorbers 2a and 2b and the carbon dioxide utilization device 16 are communicated with each other.

The other end of the second space communicates with a water vapor outlet of a humidifier 172 that delivers water vapor to the second space.

In the carbon dioxide separation device 1001, when both the supply pump 61 and the decompression pump 7 operate, the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 flows from the carbon dioxide-containing gas supply channel 9 into the first space. Part of the carbon dioxide-containing gas that has flowed into the first space passes through the separation membrane 31 and flows into the second space, and the carbon dioxide-containing gas that has flowed into the second space through the separation membrane 31 ( permeation gas) is supplied to the adsorption device 201 after flowing out from the second space to the permeation gas flow path 122, and out of the carbon dioxide-containing gas that has flowed into the first space, the carbon dioxide-containing gas that has not permeated the separation membrane 31 The gas (non-permeable gas) is configured to be supplied to the adsorption device 201 after flowing out from the first space to the non-permeable gas channel 120 .

The adsorption device 201 is filled with adsorbents 4a and 4b that adsorb carbon dioxide, and is connected to the downstream side of each of the non-permeating gas channel 120 and the permeating gas channel 122. It has vessels 2a and 2b.

In the two adsorbers 2a and 2b, in addition to the non-permeating gas flow path 120 and the permeating gas flow path 122, the non-permeating gas not adsorbed by the adsorbers 2a and 2b is exhausted to the outside of the carbon dioxide separator 1001. and a suction pump 15 in the middle of the flow path to recover the desorbed gas desorbed from the adsorbers 2a and 2b from the adsorbers 2a and 2b and recover the permeated gas in the permeated gas flow path 122. and a desorption gas discharge channel 14 for supplying to the carbon dioxide utilization equipment 16 are connected together.

The non-permeating gas channel 120 is connected to one longitudinal end of the adsorbers 2a and 2b, the permeating gas channel 122 is connected to one longitudinal end of the adsorbers 2a and 2b, and the exhaust gas channel 11 is connected to adsorption. The desorbed gas discharge channel 14 is connected to one longitudinal end of each of the adsorbers 2a and 2b.

A control valve V1a is provided in the branched flow path of the non-permeating gas flow path 120 that branches from the shared non-permeating gas flow path 120 and is connected to the adsorber 2a. A control valve V1b is provided in a branch channel of the non-permeating gas channel 120 connected to the adsorber 2b.

A control valve V2a is provided in a branched flow path of the exhaust gas flow path 11 that is branched from the shared exhaust gas flow path 11 and connected to the adsorber 2a, and is branched from the shared exhaust gas flow path 11 and connected to the adsorber 2b. A control valve V2b is provided in a branched flow path of the exhaust gas flow path 11.

A control valve V3a is provided in a branched flow path of the desorbed gas discharge flow path 14 branched from the shared desorbed gas discharge flow path 14 and connected to the adsorber 2a. A control valve V3b is provided in the branched flow path of the desorbed gas discharge flow path 14 branched from and connected to the adsorber 2b.

A control valve V4a is provided in a branched flow path of the permeated gas flow path 122 which is further branched from the branched flow path of the permeated gas flow path 122 shared by the adsorbers 2a and 2b and connected to the adsorber 2a. A control valve V4b is provided in the branched flow path of the permeated gas flow path 122 which is further branched from the branched flow path of the permeated gas flow path 122 shared by 2a and 2b and connected to the adsorber 2b.

At the upstream side of the confluence with the desorbed gas discharge channel 14 in the branched channel of the permeated gas channel 122 branched from the shared permeated gas channel 122 and connected to the carbon dioxide utilization device 16, there is a purge flow rate A control valve 10 is provided.

The purge flow rate control valve 10 is a valve capable of adjusting the flow rate configured so that the opening degree of the valve can be set to the opening degree set for the purge flow rate control valve 10 .

The purge flow control valve 10 is fully open when either one of the adsorbers 2a and 2b is not performing the purge process, but when one of the adsorbers 2a and 2b is performing the purge process, A second setting in which the opening degree of the purge flow control valve 10 is smaller than the fully open (first set value) so that the flow rate of the permeating gas passing through the purge flow control valve 10 is lower than when it is fully open (first set value). value is changed.

When the carbon dioxide-containing gas is being supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separator 1001, and the adsorber 2b is performing a regeneration step for desorbing carbon dioxide from the adsorbent 4b, the adsorber 2a performs an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbent 4a, and the control valve V1a, the control valve V2a, and the control valve V3b are each in an open state, and the control valve V3a and the control valve V1b are in an open state. Each of the control valve V2b, the control valve V4a, and the control valve V4b is closed.

When the carbon dioxide-containing gas is being supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separator 1001 and the adsorber 2a is performing a regeneration step for desorbing carbon dioxide from the adsorbent 4a, the adsorber 2b performs an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbent 4b, and the control valve V1b, the control valve V2b, and the control valve V3a are each in an open state, and the control valve V3b and the control valve V1a are in an open state. Each of the control valve V2a, the control valve V4a, and the control valve V4b is closed.

When the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separation device 1001, the adsorber 2b introduces the permeation gas into the adsorber 2b, thereby discharging the impurity gas from the adsorber 2b. to increase the carbon dioxide concentration in the adsorber 2b, the adsorber 2a is performing the adsorption step of adsorbing the carbon dioxide contained in the non-permeating gas onto the adsorbent 4a, and the control valve V1a, control valve V2a, control valve V2b, and control valve V4b are each open, and control valve V3a, control valve V3b, control valve V1b, and control valve V4a are each closed.

When the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separator 1001, the adsorber 2a introduces the permeation gas into the adsorber 2a, thereby discharging the impurity gas from the adsorber 2a. to increase the carbon dioxide concentration in the adsorber 2a, the adsorber 2b is performing the adsorption step of adsorbing the carbon dioxide contained in the non-permeating gas to the adsorbent 4b, and the control valve Each of the control valve V1b, the control valve V2a, the control valve V2b, and the control valve V4a is open, and each of the control valve V3a, the control valve V3b, the control valve V1a, and the control valve V4b is closed.

When the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separation device 1001 (the non-permeating gas is supplied to the adsorption device 201 from the non-permeating gas flow path 120) of the adsorption device 201 , one of the adsorbers 2a and 2b performs the adsorption step of adsorbing the carbon dioxide contained in the non-permeating gas onto the adsorbents 4a and 4b, and one of the adsorbers 2a and 2b performs the adsorption step. In the meantime, a purge step in which either one of the adsorbers 2a and 2b discharges the impurity gas in the adsorbers 2a and 2b by the permeating gas to increase the carbon dioxide concentration in the adsorbers 2a and 2b, and the adsorbents 4a and 4b The controller C2 controls the opening/closing states of the control valves V1a, V1b, V2a, V2b, V3a, V3b, V4a, and V4b so as to sequentially perform a regeneration step of desorbing carbon dioxide from 4b.

In the exhaust gas flow path 11, the non-permeating gas that has not been adsorbed by the adsorbers 2a and 2b in the adsorption process is discharged to the outside from the adsorbers 2a and 2b in the adsorption process, and the impurity gas is discharged from the adsorbers 2a and 2b in the purge process. is connected to the downstream side of the two adsorbers 2a and 2b so that the is discharged to the outside.

The desorbed gas discharge flow path 14 has one end (upstream side end) is connected to two adsorbers 2a and 2b, and the other end (downstream end) is downstream of the purge flow control valve 10 (between the purge flow control valve 10 and the carbon dioxide utilization equipment 16). It is a channel connected to the gas channel 122 .

The suction pump 15 is provided in the middle of the shared channel in the desorbed gas discharge channel 14 . In addition, the suction pump 15 reduces the pressure inside the adsorbers 2a and 2b in the regeneration step, desorbs carbon dioxide from the adsorbents 4a and 4b, and causes the desorbed gas to flow through the permeating gas flow path 122. It is configured to be mixed with the permeate gas and delivered to the carbon dioxide utilization device 16 .

The separation membrane 31 that divides the internal space of the carbon dioxide separator 1 into a first space and a second space is a membrane that selectively permeates carbon dioxide, and contains monoethanolamine, which is a type of alkanolamine. The separation membrane 31 has a characteristic that the carbon dioxide permeation performance of the separation membrane 31 improves as the moisture content of the membrane increases and as the temperature rises.

The humidifier 171 provided in the carbon dioxide-containing gas supply channel 9 humidifies the carbon dioxide-containing gas supplied to the first space of the carbon dioxide separator 1, thereby increasing the water content of the separation membrane 31 more than when not humidified. By changing the amount of humidification, the moisture content (permeability of carbon dioxide) of the separation membrane 31 is changed.

The humidifier 172 connected to the second space of the carbon dioxide separator 1 is a humidifier that sends water vapor to the second space, and sends water vapor to the second space by sending water vapor to the second space. The water content of the separation membrane 31 is made higher than that in the case of not using it, and the water content (permeability of carbon dioxide) of the separation membrane 31 is changed by changing the amount of water vapor delivered.

Humidifiers 171 and 172 each include relative humidity detection means (not shown) for detecting relative humidity. It is configured so that it can be humidified to the set value.

The control valves V1a and V1b are provided in branch flow paths corresponding to the adsorbers 2a and 2b in the non-permeating gas flow path 120, respectively. The control valves V2a and V2b are provided in branch flow paths corresponding to the adsorbers 2a and 2b in the exhaust gas flow path 11, respectively.

The control valves V3a and V3b are provided in branch flow paths corresponding to the adsorbers 2a and 2b in the desorbed gas discharge flow path 14, respectively. The control valves V4a and V4b are provided in branch flow paths corresponding to the adsorbers 2a and 2b in the permeating gas flow path 122, respectively.

The adsorption device 201 has adsorbers 2 a and 2 b, a purge flow control valve 10 and a suction pump 15 . The adsorber 2a has control valves V1a, V2a, V3a and V4a, and the adsorber 2b has control valves V1b, V2b, V3b and V4b.

Controller C2 controls the operation of carbon dioxide separator 1001 . The controller C2 includes a signal input/output unit (not shown), an arithmetic processing unit (not shown), and a storage unit (not shown) for storing control programs.

The controller C2 operates the supply pump 61, the decompression pump 7, the suction pump 15, the purge flow control valve 10, the temperature controller 8, the humidifiers 171 and 172, and the control valves V1a to V4b according to commands from the controller C2. is configured as

Based on the concentration detected by the carbon dioxide concentration detector 5, the controller C2 controls the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step to fall within a predetermined range. It is configured to control the amount adjusting means (supply pump 61, temperature controller 8, humidifiers 171, 172).

[2-2. motion]
The operation of the carbon dioxide separator 1001 configured as described above will be described in detail with reference to FIGS.

[2-2-1. basic action]
FIG. 7 is a flow chart showing the basic operation of the carbon dioxide separator 1001. As shown in FIG.

The basic operation in the present embodiment is the CO ₂ concentration adjustment operation (S100) in the flowchart of the basic operation in the _first embodiment shown in FIG. Since these correspond to the respective replacements of the operation (S220), redundant description will be omitted.

[2-2-2. CO ₂ concentration adjustment operation]
Next, the CO ₂ concentration adjustment operation (S120) of the carbon dioxide separation device 1001 will be described using FIG.

First, the controller C2 controls the carbon dioxide concentration detector 5 provided in the non-permeating gas flow path 120 connecting the outlet of the first space of the carbon dioxide separator 1 and the inlet of the adsorption device 201 (adsorber 2). (S121).

As a result of the determination in S121, if the concentration is within the predetermined range, S121 is branched to the Yes side, the CO ₂ concentration adjustment operation is terminated, and the process proceeds to the next step.

As a result of the determination in S121, if it is outside the predetermined concentration range, S121 is branched to the No side, and the controller C2 detects that the concentration of carbon dioxide in the non-permeating gas detected by the carbon dioxide concentration detector 5 has reached the predetermined concentration. It is determined whether or not the upper limit of the range is exceeded (S122).

As a result of the determination in S122, if the upper limit value of the predetermined concentration range is exceeded, S122 is branched to the Yes side, and the controller C2 sets the relative humidity set values of both the humidifiers 171 and 172 to 100%. (S123).

As a result of the determination in S122, if the upper limit of the predetermined concentration range is not exceeded, S122 is branched to the No side, and the controller C2 determines whether or not the set temperature of the temperature controller 8 is higher than the outside air temperature. (S124).

As a result of the determination in S123, if the relative humidity set value of at least one of the humidifier 171 and the humidifier 172 is lower than 100%, S123 branches to the No side, and the controller C2 controls the humidifier 171 and the humidifier. Of the humidifiers 172, control is performed to increase the relative humidity setting values of the humidifiers 171 and 172 whose relative humidity setting values are not 100% (S125), the CO ₂ concentration adjusting operation is completed, and the next step is performed.

As a result, the water vapor in the first space or the second space of the carbon dioxide separator 1 increases and the water content of the separation membrane 31 increases, thereby improving the carbon dioxide permeation performance of the separation membrane 31 and permeating the separation membrane 31. Since the amount of carbon dioxide to be absorbed increases, the concentration of carbon dioxide in the non-permeating gas flowing out from the first space to the non-permeating gas channel 120 can be reduced, and the carbon dioxide in the non-permeating gas supplied to the adsorption device 201 can be reduced. Since the concentration decreases, the carbon dioxide concentration in the non-permeating gas supplied to the adsorption device 201 can be controlled so as not to exceed the upper limit of the predetermined concentration range.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied to the carbon dioxide utilization device 16 .

Here, if the relative humidity setting values of both the humidifier 171 and the humidifier 172 are not 100%, and the relative humidity setting value of either the humidifier 171 or the humidifier 172 is preferentially increased , the increase in the concentration of water vapor in the non-permeating gas flowing out from the first space to the non-permeating gas flow path 120 and being supplied to the adsorber 2 can be relatively suppressed. Since a decrease in the carbon dioxide concentration can be suppressed and the effect of purging the second space by the increased amount of water vapor can be expected, it is better to preferentially increase the relative humidity set value of the humidifier 172 .

If the relative humidity set values of both the humidifier 171 and the humidifier 172 are 100% as a result of the determination in S123, S123 branches to the Yes side, and the controller C2 determines that the set temperature of the temperature controller 8 is dioxidic. It is determined whether or not the temperature is lower than the upper limit temperature of the carbon separator 1 (S126).

As a result of the determination in S126, if the set temperature of the temperature adjuster 8 is lower than the upper limit temperature of the carbon dioxide separator 1, S126 is branched to the Yes side, and the controller C2 raises the set temperature of the temperature adjuster 8. Control is performed (S129), the CO ₂ concentration adjustment operation is completed, and the next step is performed.

As a result, the temperature of the carbon dioxide separator 1 rises and the temperature of the separation membrane 31 rises, thereby improving the carbon dioxide permeation performance of the separation membrane 31 and increasing the amount of carbon dioxide that permeates the separation membrane 31. Therefore, the concentration of carbon dioxide in the non-permeating gas flowing out from the first space to the non-permeating gas channel 120 can be reduced, and the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 201 is reduced. The carbon dioxide concentration in the non-permeate gas supplied to the device 201 can be controlled so as not to exceed the upper limit of a predetermined concentration range.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied to the carbon dioxide utilization device 16 .

Here, the upper limit temperature of the carbon dioxide separator 1 is a value obtained by experiments based on the structure of the carbon dioxide separator 1 or the durability of the separation membrane 31, and is not a quantitatively determined value. do not have.

As a result of the determination in S126, if the set temperature of the temperature controller 8 has reached the upper limit temperature of the carbon dioxide separator 1, S126 is branched to the No side, and the controller C2 adjusts the supply amount of the supply pump 61. The value is changed to a value smaller than the first supply amount (S130), the CO ₂ concentration adjustment operation is terminated, and the next step is performed.

As a result, by reducing the supply amount of the non-permeating gas having a carbon dioxide concentration exceeding a predetermined concentration to the adsorption device 201, the amount of carbon dioxide adsorbed by the adsorbent 4 inside the adsorber 2 in the adsorption step The adsorption amount is limited to a predetermined adsorption amount so that the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 does not exceed the upper limit of the predetermined concentration range, thereby producing carbon dioxide-enriched gas with stable purity. can supply.

As a result of the determination in S124, if the set temperature of the temperature adjuster 8 is higher than the outside air temperature, S124 is branched to the Yes side, and the controller C2 performs control to lower the set temperature of the temperature adjuster 8 (S127 ), end the CO ₂ concentration adjustment operation, and proceed to the next step.

As a result, the temperature of the carbon dioxide separator 1 is lowered and the temperature of the separation membrane 31 is lowered, whereby the carbon dioxide permeation performance of the separation membrane 31 is lowered, and the amount of carbon dioxide permeating the separation membrane 31 is reduced. Therefore, the concentration of carbon dioxide in the non-permeating gas flowing out from the first space to the non-permeating gas channel 120 can be increased, and the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 201 increases. The carbon dioxide concentration in the non-permeate gas supplied to the device 201 can be controlled so as not to exceed the lower limit of a predetermined concentration range.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied to the carbon dioxide utilization device 16 .

As a result of the determination in S124, if the set temperature of the temperature controller 8 is equal to or lower than the outside air temperature, S124 is branched to the No side, and the controller C2 determines that the relative humidity set values of both the humidifiers 171 and 172 are It is determined whether or not it is 0% (S128).

As a result of the determination in S128, if the relative humidity set value of at least one of the humidifier 171 and the humidifier 172 is not 0%, the controller C2 determines that the relative humidity set value of the humidifier 171 and the humidifier 172 is Control is performed to lower the relative humidity set values of the humidifiers 171 and 172 that are not 0% (S131), the CO ₂ concentration adjustment operation is completed, and the next step is performed.

As a result, the amount of water vapor in the first space or the second space of the carbon dioxide separator 1 decreases and the water content of the separation membrane 31 decreases. Since the amount of carbon dioxide to be discharged is reduced, the carbon dioxide concentration of the non-permeable gas flowing out from the first space to the non-permeable gas flow path 120 can be increased, and the carbon dioxide in the non-permeable gas supplied to the adsorption device 201 can be increased. Since the concentration increases, the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 201 can be controlled so as not to exceed the lower limit of the predetermined concentration range.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied to the carbon dioxide utilization device 16 .

If the relative humidity set values of both the humidifier 171 and the humidifier 172 are 0% as a result of the determination in S128, the controller C2 issues a command to stop the carbon dioxide separation device 1001 (S132), and adjusts the CO ₂ concentration. End the operation and proceed to the next step.

As a result, when the carbon dioxide-containing gas containing low-concentration carbon dioxide that cannot be controlled within a predetermined concentration range by the carbon dioxide separation device 1001 is supplied to the carbon dioxide separation device 1001, the low-concentration carbon dioxide-enriched gas becomes carbon dioxide. It is possible to prevent the data from being supplied to the utilization device 16 .

[2-2-3. PSA operation]
Next, the PSA operation (S220) of the carbon dioxide separator 1001 will be explained using FIG.

In this step, the controller C2 performs determination and operation in parallel for each of the adsorbers 2 provided in the carbon dioxide separator 1001 . Therefore, although FIG. 10 shows the operation of the adsorber 2a, the other adsorbers 2b operate similarly and in parallel.

First, the controller C2 determines whether or not there is an adsorber 2 whose adsorption process flag is ON (S221). repeat the judgment.

As a result of the determination in S221, if there is no adsorber 2 whose adsorption process flag is ON, S221 is branched to the No side, and the adsorption process flag of the adsorber 2a is turned ON (S222).

Next, the controller C2 opens the control valves V1a and V2a while the control valves V3a and V4a are closed, thereby supplying the non-permeating gas in the non-permeating gas flow path 120 to the adsorber 2a ( S223).

As a result, the carbon dioxide contained in the non-permeable gas is adsorbed by the adsorbent 4a in the adsorber 2a, and of the non-permeable gas supplied to the adsorber 2a, the impurity gas that is not adsorbed by the adsorbent 4a is It is exhausted via the exhaust gas flow path 11 .

Next, the controller C2 checks whether or not a predetermined time (30 min) has elapsed since the adsorption process flag of the adsorber 2a was turned ON (S224). If so, the confirmation of S224 is repeated until the time elapses.

As a result of confirmation in S224, if a predetermined time has elapsed since the adsorption process flag of the adsorber 2a was turned ON, S224 is branched to the Yes side, and the controller C2 sets the adsorption process flag of the adsorber 2a. It is turned off to close the control valves V1a and V2a (S225).

Here, in the present embodiment, the predetermined time for the adsorption step is set to 30 minutes, but this is merely an example.

Here, the predetermined time for the adsorption step is a value obtained in advance by experiments. The predetermined time of the adsorption step may be a time during which the carbon dioxide in the non-permeating gas is adsorbed by the adsorbents 4a and 4b in the adsorbers 2a and 2b and the adsorption amount becomes the designed adsorption amount. It may be changed according to the measured value of the concentration detector 5 . Therefore, the predetermined time for the adsorption step is not quantitatively deterministic.

That is, here, when the elapsed time from the time when the adsorption process flag is turned ON reaches 30 minutes, it is determined that the amount of carbon dioxide adsorbed by the adsorbent 4a reaches the designed adsorption amount, and the elapsed time becomes 30 minutes. In the previous description, it is determined that the amount of carbon dioxide adsorbed by the adsorbent 4a does not reach the designed adsorption amount, but this criterion is only an example.

Next, the controller C2 determines whether or not there is an adsorber 2 whose purge process flag is ON (S226). The determination of S226 is repeated.

As a result of the determination in S226, if there is no adsorber 2 whose purge process flag is ON, S226 is branched to the No side to turn ON the purge process flag of the adsorber 2a (S227).

Next, the controller C2 opens the control valves V2a and V4a while keeping the control valves V1a and V3a closed, and sets the opening degree of the purge flow control valve 10 to a value lower than the full open (first set value). By changing to the second set value, part of the permeating gas flowing through the permeating gas flow path 122 is supplied to the adsorber 2a via the control valve V4a (S228) to start the purge process.

As a result, the permeating gas having a higher carbon dioxide concentration than the non-permeating gas is supplied to the adsorber 2a, and the impurity gas (impurity gas adsorbed by the adsorbent 4a) in the adsorber 2a is replaced with carbon dioxide to adsorb. Since the impurity gas in the device 2a (impurity gas desorbed from the adsorbent 4a) is discharged to the exhaust gas flow path 11, the amount of carbon dioxide adsorbed by the adsorbent 4a in the adsorber 2a increases.

Next, the controller C2 confirms whether or not a predetermined time (10 minutes) has elapsed since the purge process flag of the adsorber 2a was turned ON (S229). If so, the confirmation of S229 is repeated until the time elapses.

As a result of confirmation in S229, if a predetermined time has passed since the purge process flag of the adsorber 2a was turned ON, S229 branches to the Yes side, and the controller C2 sets the purge process flag of the adsorber 2a. It is turned off, the control valves V2a and V4a are closed, and the opening degree of the purge flow control valve 10 is returned to 100%, that is, fully open (first set value) (S230).

Here, in the present embodiment, the predetermined time for the purge step is set to 10 minutes, but this is merely an example.

Here, the predetermined time for the purge step is a value obtained in advance by experiments. Carbon dioxide in the permeating gas is adsorbed by the adsorbents 4a and 4b in the adsorbers 2a and 2b for a predetermined time in the purge process, and the amount of this adsorption provides the desorbed gas with the concentration required by the carbon dioxide utilization device 16. It can be changed according to the set temperature of the temperature controller 8 and the carbon dioxide concentration in the permeated gas calculated from the relative humidity set values of the humidifiers 171 and 172. may Therefore, the predetermined time for the purge step is not quantitatively deterministic.

That is, here, when the elapsed time reaches 10 minutes from the time when the purge process flag is turned ON, it is determined that the amount of carbon dioxide adsorbed by the adsorbent 4a reaches the required adsorption amount, and the elapsed time becomes 10 minutes. In the previous description, it is determined that the amount of carbon dioxide adsorbed by the adsorbent 4a does not reach the required adsorption amount, but this determination criterion is only an example.

Next, the controller C2 determines whether or not there is an adsorber 2 whose regeneration process flag is ON (S231). The determination of S231 is repeated.

As a result of the determination in S231, if there is no adsorber 2 whose regeneration process flag is ON, S231 is branched to the No side, and the regeneration process flag of the adsorber 2a is turned ON (S232).

Next, the controller C2 opens the control valve V3a to operate the suction pump 15 (S233) to start the regeneration process.

As a result, the carbon dioxide and the impurity gas adsorbed in the adsorber 2a in the adsorption step are desorbed from the adsorber 2a (adsorbent 4a), and the desorbed gas flows out to the desorbed gas discharge passage 14.

Next, the controller C2 confirms whether or not a predetermined time (15 minutes) has elapsed since the regeneration process flag of the adsorber 2a was turned ON (S234). If so, the confirmation of S234 is repeated until the time elapses.

As a result of confirmation in S234, if a predetermined time has passed since the regeneration process flag of the adsorber 2a was turned ON, S234 is branched to the Yes side, and the controller C2 closes the control valve V3a to perform suction. The pump 15 is stopped (S235), the regeneration process flag of the adsorber 2a is turned OFF (S211), and the process proceeds to the next process.

Here, in the present embodiment, the predetermined time for the regeneration process is set to 30 minutes, but this is merely an example.

Here, the predetermined time for the regeneration process is a value obtained in advance by experiments. The predetermined time for the regeneration step may be any value that allows determination of whether or not the desorption of carbon dioxide adsorbed by the adsorbents 4a and 4b in the adsorbers 2a and 2b is complete. Therefore, the predetermined time for the regeneration step is not quantitatively deterministic.

That is, here, when the elapsed time from the time when the regeneration process flag is turned ON reaches 15 minutes, it is determined that the desorption of the carbon dioxide adsorbed by the adsorbents 4a and 4b is completed, and before the elapsed time reaches 15 minutes. Although it is determined that the carbon dioxide adsorbed by the adsorbents 4a and 4b is not completely desorbed, this determination criterion is only an example.

When the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separation device 1001 (the non-permeating gas is supplied to the adsorption device 201), the adsorption devices 2a and 2b in the adsorption device 201 performs an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbents 4a and 4b.

Then, while one of the adsorbers 2a and 2b is performing the adsorption step of adsorbing the carbon dioxide contained in the non-permeable gas to the adsorbents 4a and 4b, the other of the adsorbers 2a and 2b absorbs the permeable gas. A purge process for discharging impurity gases in the adsorbers 2a and 2b to increase the carbon dioxide concentration in the adsorbers 2a and 2b, and a regeneration process for desorbing carbon dioxide from the adsorbents 4a and 4b in this order. Is going.

For example, when the adsorber 2b is performing a purging step in which the impurity gas is discharged from the adsorber 2b by introducing the permeating gas into the adsorber 2b to increase the carbon dioxide concentration in the adsorber 2b, adsorption The device 2a is performing an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbent 4a. , the control valve V3b, the control valve V1b, and the control valve V4a are each closed.

Similarly, when the adsorber 2a is performing a purging step in which the impurity gas is discharged from the adsorber 2a by introducing the permeating gas into the adsorber 2a to increase the carbon dioxide concentration in the adsorber 2a, The adsorber 2b is performing an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbent 4b, and the control valve V1b, the control valve V2a, the control valve V2b, and the control valve V4a are each in an open state, and the control valve Each of V3a, control valve V3b, control valve V1a, and control valve V4b is closed.

For example, when the adsorber 2b is performing a regeneration step of desorbing carbon dioxide from the adsorbent 4b, the adsorber 2a is performing an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas onto the adsorbent 4a. , the control valve V1a, the control valve V2a, and the control valve V3b are open, and the control valve V3a, the control valve V1b, the control valve V2b, the control valve V4a, and the control valve V4b are closed.

Similarly, when the adsorber 2a is performing a regeneration step of desorbing carbon dioxide from the adsorbent 4a, the adsorber 2b is performing an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas onto the adsorbent 4b. The control valve V1b, the control valve V2b, and the control valve V3a are each open, and the control valve V3b, the control valve V1a, the control valve V2a, the control valve V4a, and the control valve V4b are each closed.

[2-3. effects, etc.]
As described above, the carbon dioxide separator 1001 in the present embodiment includes the carbon dioxide separator 1, the decompression pump 7, the carbon dioxide concentration detector 5, the supply pump 61 functioning as permeable gas amount adjusting means, and the temperature controller. 8, humidifiers 171 and 172, an adsorption device 201, an exhaust gas flow path 11, a desorbed gas discharge flow path 14, a suction pump 15, and a controller C2.

The carbon dioxide separator 1 has an internal space partitioned into a first space and a second space by a separation membrane 31 that selectively permeates carbon dioxide. The first space is a space into which the carbon dioxide-containing gas flows from the carbon dioxide-containing gas supply channel 9, and a space into which the non-permeating gas that has not permeated the separation membrane 31 flows out to the non-permeating gas channel 120. be. The second space is a space through which the permeated gas that permeates the separation membrane 31 flows out to the permeated gas channel 122 .

The decompression pump 7 is a pump that is provided in the middle of the permeated gas flow path 122 and configured to decompress the second space. Due to the decompression operation of the decompression pump 7 , carbon dioxide contained in the carbon dioxide-containing gas permeates the separation membrane 31 and the permeated gas flows out to the permeated gas flow path 122 .

The carbon dioxide concentration detector 5 is arranged in the middle of the non-permeating gas channel 120 and configured to detect the concentration of carbon dioxide contained in the non-permeating gas flowing through the non-permeating gas channel 120. .

The adsorption device 201 is filled with adsorbents 4a and 4b for adsorbing carbon dioxide, and has two adsorbers 2a and 2 connected downstream of the non-permeating gas channel 120 and the permeating gas channel 122, respectively. 2b.

In addition, when the carbon dioxide-containing gas is supplied to the carbon dioxide separation device 1001 (the non-permeating gas is supplied to the adsorption device 201 from the non-permeating gas flow path 120), the adsorption device 201 is operated by the adsorbers 2a, 2b performs an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas on the adsorbents 4a and 4b, and while one of the adsorbers 2a and 2b is performing the adsorption step, the adsorbers 2a and 2b The other is a purging step in which the impurity gas in the adsorbers 2a and 2b is discharged by the permeating gas to increase the carbon dioxide concentration in the adsorbers 2a and 2b, and a regeneration step in which carbon dioxide is desorbed from the adsorbents 4a and 4b. and are configured to be performed in order.

The exhaust gas flow path 11 is downstream of the two adsorbers 2a and 2b so that the non-permeating gas that has not been adsorbed by the adsorbers 2a and 2b in the adsorption step is exhausted to the outside from the adsorbers 2a and 2b in the adsorption step. is a flow path connected to

The desorbed gas discharge channel 14 is connected to the two adsorbers 2a and 2b so that the desorbed gas desorbed from the adsorbers 2a and 2b in the regeneration process is recovered from the adsorbers 2a and 2b in the regeneration process. It is a flow path that has been designed.

The suction pump 15 is provided in the middle of the desorbed gas discharge channel 14 . In addition, the suction pump 15 reduces the pressure inside the adsorbers 2a and 2b in the regeneration process, desorbs carbon dioxide from the adsorbents 4a and 4b, and causes the desorbed gas to flow out to the desorbed gas discharge passage 14. is configured to

The supply pump 61 is arranged in the non-permeating gas flow path 120 . In addition, the supply pump supplies the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 to the first space by the action of the supply pump 61, and supplies the non-permeable gas discharged from the first space to the supply pump 6 It is configured to be able to supply to the adsorbers 2a and 2b at a supply amount set for .

The temperature controller 8 adjusts the temperature of the carbon dioxide separator 1 and is configured to heat the carbon dioxide separator 1 to a set temperature.

The humidifier 171 is provided in the carbon dioxide-containing gas supply channel 9, and the relative humidity of the carbon dioxide-containing gas supplied to the first space of the carbon dioxide separator 1 is set to the relative humidity of the humidifier 171. It is configured so as to humidify the carbon dioxide-containing gas.

The humidifier 172 is connected to the second space of the carbon dioxide separator 1, and can humidify the second space so that the relative humidity of the second space reaches the relative humidity set for the humidifier 172. It is configured.

The humidifiers 171 and 172 function as moisture amount adjusting means for adjusting the moisture content of the separation membrane 31 .

Based on the concentration detected by the carbon dioxide concentration detector 5, the controller C2 controls the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber in the adsorption step to fall within a predetermined range. It is configured to control any one of the supply pump 61, the temperature controller 8, and the humidifiers 171 and 172 that function as volume control means.

In the carbon dioxide separation device 1001 having the above configuration, the controller C2 detects the concentration of carbon dioxide contained in the non-permeating gas detected by the carbon dioxide concentration detector 5 provided in the non-permeating gas flow path 120, and adsorbs The flow rate of the permeating gas is adjusted (permeating gas amount adjusting means is controlled) so that the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the process falls within a predetermined range. When the concentration of carbon dioxide in the non-permeable gas flowing into the adsorber 2) changes, the amount of carbon dioxide permeating the separation membrane 31 can be changed, and the amount of carbon dioxide in the non-permeable gas flowing into the adsorber 2 in the adsorption step can be changed. It is possible to control the concentration of carbon dioxide in a predetermined range.

Therefore, the concentration of carbon dioxide flowing into the adsorption device 201 (adsorber 2) is stabilized, and the amount of carbon dioxide adsorbed by the adsorbent 4 is stabilized, so that the concentration of carbon dioxide in the desorbed gas can be stabilized. Therefore, it becomes possible to supply the carbon dioxide-enriched gas of stable purity to the carbon dioxide utilization equipment 16 .

Further, as in the present embodiment, if the separation membrane 31 of the carbon dioxide separator 1001 has a characteristic that the carbon dioxide permeation performance increases as the water content of the separation membrane 31 increases, carbon dioxide A humidifier 171 capable of humidifying the carbon dioxide-containing gas supplied to the first space of the separator 1 to a set humidity, and a humidifier 172 capable of humidifying the second space of the carbon dioxide separator 1 to a set humidity. and , the amount of carbon dioxide permeation through the separation membrane 31 may be adjusted by adjusting the water content of the separation membrane 31 using the humidifiers 171 and 172 .

In this case, the controller C2 controls the amount of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step based on the carbon dioxide concentration in the non-permeating gas detected by the carbon dioxide concentration detector 5. When it is determined that the concentration exceeds the upper limit of the predetermined range, humidifiers 171 and 172 increase the humidity in the carbon dioxide separator 1 to increase the moisture content of the separation membrane 31, and the concentration reaches the lower limit of the predetermined range. If it is determined that the moisture content of the separation membrane 31 is lower, the amount of humidification by the humidifiers 171 and 172 may be reduced to lower the humidity in the carbon dioxide separator 1 and lower the moisture content of the separation membrane 31 .

This makes it possible to adjust the carbon dioxide permeation amount of the separation membrane 31 while suppressing the influence of the change in the water content in the carbon dioxide-containing gas supplied to the separation membrane 31 .

Therefore, even when the amount of water vapor in the carbon dioxide-containing gas fluctuates, the amount of carbon dioxide permeated through the separation membrane 31 can be easily adjusted, and the carbon dioxide concentration in the desorbed gas can be further stabilized.

Further, as in the present embodiment, the carbon dioxide separator 1001 can separate carbon dioxide if the separation membrane 31 has a characteristic that the permeation performance of carbon dioxide increases as the temperature of the separation membrane 31 increases. Equipped with a temperature controller 8 that adjusts the temperature of the carbon dioxide separator 1 so that the temperature of the vessel 1 reaches the set temperature, and by adjusting the temperature of the carbon dioxide separator 1 to the set temperature with the temperature controller 8, The carbon dioxide permeation amount of the separation membrane 31 may be adjusted.

In this case, the controller C2 controls the amount of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step based on the carbon dioxide concentration in the non-permeating gas detected by the carbon dioxide concentration detector 5. When it is determined that the concentration exceeds the upper limit of the predetermined range, the temperature controller 8 raises the temperature of the carbon dioxide separator 1 (separation membrane 31), and when it is determined that the concentration is below the lower limit of the predetermined range, The temperature controller 8 may be controlled to lower the temperature of the carbon dioxide separator 1 (separation membrane 31).

As a result, the carbon dioxide permeation amount of the separation membrane 31 can be adjusted while suppressing the influence of the change in the membrane temperature that accompanies the change in the amount of the supplied carbon dioxide-containing gas.

Therefore, even when the temperature of the carbon dioxide-containing gas changes, the carbon dioxide permeation amount of the separation membrane 31 can be easily adjusted, and the carbon dioxide concentration in the desorbed gas can be further stabilized.

In addition, as in the present embodiment, the carbon dioxide separation device 1001 is arranged such that the permeation gas flow is The passage 122 branches downstream of the decompression pump 7, and the passage between the branch point and the carbon dioxide utilization device 16 is provided with a purge flow control valve 10 that can be adjusted to a set opening, While one of the adsorbers 2a and 2b is performing the adsorption process, the other of the adsorbers 2a and 2b discharges the impurity gas in the adsorbers 2a and 2b by the permeating gas, and the adsorbers 2a and 2b A purge process for increasing the concentration of carbon dioxide in the adsorbents 4a and 4b and a regeneration process for desorbing carbon dioxide from the adsorbents 4a and 4b may be performed in order.

Thereby, the permeating gas having a high carbon dioxide concentration can be adsorbed by the adsorbent 4 . When a high concentration of carbon dioxide is adsorbed, the adsorption amount of the adsorbent 4 approaches the maximum adsorption amount. It becomes possible to further stabilize the carbon dioxide concentration in the gas.

(Embodiment 3)
Embodiment 3 will be described below with reference to FIGS. 11 to 18. FIG. 11, 15, and 17, the same components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof may be omitted.

[3-1. Constitution]
FIG. 11 is a block diagram showing the configuration of the carbon dioxide separation device 1002 according to Embodiment 3. In particular, in the adsorption device 202, the adsorption step is performed in the adsorption device 2a and the regeneration step is performed in the adsorption device 2d. state.

FIG. 15 is a block diagram showing the configuration of the carbon dioxide separator 1002 according to the third embodiment. 2a and 2b are used for the adsorption process, and adsorbers 2c and 2d are used for the regeneration process.

FIG. 17 is a block diagram showing the configuration of the carbon dioxide separator 1002 according to Embodiment 3. In particular, in the adsorption device 202, the non-permeable gas is supplied in parallel to the adsorbers 2a and 2b to adsorb The adsorbers 2a and 2b perform the adsorption process, and the adsorbers 2c and 2d perform the regeneration process.

As shown in FIGS. 11, 15, and 17, the carbon dioxide separator 1002 uses the carbon dioxide separator 1 and the adsorption device 202 to separate the carbon dioxide-containing gas supplied from the carbon dioxide-containing gas supply source 100. , to generate carbon dioxide-enriched gas of stable purity and supply the carbon dioxide-enriched gas to the carbon dioxide utilization device 16 .

The internal space of the carbon dioxide separator 1 is partitioned into a first space and a second space by a separation membrane 3 that selectively permeates carbon dioxide.

One end of the first space communicates with an outlet of a carbon dioxide-containing gas supply source 100 via a carbon dioxide-containing gas supply channel 9 . The carbon dioxide-containing gas supply channel 9 includes a supply pump 6 configured to supply the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 to the first space at a set supply rate. The other end of the first space communicates with the inlet of the adsorption device 202 by a non-permeating gas flow path 120 equipped with a carbon dioxide concentration sensor 5 .

One end of the second space communicates with the carbon dioxide utilization device 16 by a permeate gas flow path 121 comprising a vacuum pump 7 configured to reduce the pressure of the second space.

In the carbon dioxide separator 1002, the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 flows into the first space from the carbon dioxide-containing gas supply channel 9 when both the supply pump 6 and the decompression pump 7 are operated. Then, part of the carbon dioxide-containing gas that has flowed into the first space selectively permeates the separation membrane 3 due to the partial pressure difference between the carbon dioxide in the first space and the second space, flows into the second space, and is separated The carbon dioxide-containing gas (permeated gas) that has permeated the membrane 3 and flowed into the second space flows out from the second space into the permeated gas flow path 121, and out of the carbon dioxide-containing gas that has flowed into the first space, the separation membrane The carbon dioxide-containing gas (non-permeable gas) that has not permeated through 3 flows out from the first space into the non-permeable gas flow path 120, and is then supplied to the adsorption device 202.

The adsorption device 202 includes an adsorption device 2a that is filled with an adsorption material 4a that adsorbs carbon dioxide and is connected to the downstream side of the non-permeating gas flow path 120, and an adsorption device 4b that is filled with an adsorption material 4b that adsorbs carbon dioxide. The adsorber 2b connected to the downstream side of the permeating gas flow path 120, the adsorber 2c filled with an adsorbent 4c that adsorbs carbon dioxide and connected to the downstream side of the non-permeating gas flow path 120, and It has an adsorber 2 d filled with an adsorbent 4 d that adsorbs carbon dioxide and connected to the downstream side of the non-permeating gas channel 120 , and an adsorber connecting channel 19 .

In addition to the non-permeable gas flow path 120, the four adsorbers 2a to 2d have an exhaust gas flow path for discharging the non-permeable gas not adsorbed by the adsorbers 2a to 2d to the outside of the carbon dioxide separator 1002. 11, a suction pump 15 is provided in the middle of the flow path, and the desorbed gas desorbed from the adsorbers 2a to 2d is recovered from the adsorbers 2a to 2d and used together with the permeated gas in the permeated gas flow path 121 for carbon dioxide. A desorbed gas discharge channel 14 for supplying to the device 16 and an adsorber connection channel 19 for connecting any two of the adsorbers 2a to 2d in series are connected.

The non-permeating gas channel 120 is connected to one end in the longitudinal direction of the adsorbers 2a to 2d, the exhaust gas channel 11 is connected to the other end in the longitudinal direction of the adsorbers 2a to 2d, and the desorbed gas discharge channel 14 is for adsorption. It is connected to one end in the longitudinal direction of the devices 2a to 2d. The upstream end of the adsorber connection channel 19 is connected to the other end in the longitudinal direction of the adsorbers 2a to 2d, and the downstream end of the adsorber connection channel 19 is connected to one end in the longitudinal direction of the adsorbers 2a to 2d. ing.

Here, in the adsorber-connecting channel 19 , the upstream side of the adsorber-connecting channel 19 refers to the upstream side of the gas flowing through the adsorber-connecting channel 19 . The downstream side refers to the downstream side for the gas flowing through the adsorber connecting channel 19 .

A control valve V1a is provided in the branched flow path of the non-permeating gas flow path 120 that branches from the shared non-permeating gas flow path 120 and is connected to the adsorber 2a. A control valve V1b is provided in the branched flow path of the non-permeating gas flow path 120 connected to the adsorber 2b, and the non-permeating gas branched from the shared non-permeating gas flow path 120 and connected to the adsorber 2c. A control valve V1c is provided in the branch flow path of the flow path 120, and a control A valve V1d is provided.

A control valve V2a is provided in a branched flow path of the exhaust gas flow path 11 that is branched from the shared exhaust gas flow path 11 and connected to the adsorber 2a, and is branched from the shared exhaust gas flow path 11 and connected to the adsorber 2b. A control valve V2b is provided in the branched flow path of the exhaust gas flow path 11, and the branched flow path of the exhaust gas flow path 11 branched from the shared exhaust gas flow path 11 and connected to the adsorber 2c is equipped with a control valve V2b. V2c is provided, and a control valve V2d is provided in a branch flow path of the exhaust gas flow path 11 branched from the shared exhaust gas flow path 11 and connected to the adsorber 2d.

A control valve V3a is provided in a branched flow path of the desorbed gas discharge flow path 14 branched from the shared desorbed gas discharge flow path 14 and connected to the adsorber 2a. A control valve V3b is provided in the branched flow path of the desorbed gas discharge flow path 14 branched from and connected to the adsorber 2b, and is branched from the shared desorbed gas discharge flow path 14 and connected to the adsorber 2c. A control valve V3c is provided in a branched flow path of the desorbed gas discharge flow path 14, and the desorbed gas discharge flow path 14 branched from the shared desorbed gas discharge flow path 14 and connected to the adsorber 2d. is provided with a control valve V3d.

A control valve V6a is provided in the branch channel of the adsorber connection channel 19 that branches from the downstream end of the shared adsorber connection channel 19 and is connected to the adsorber 2a. A control valve V6b is provided in the branched flow path of the adsorber connection flow path 19 branched from the downstream end of the adsorber connection flow path 19 and connected to the adsorber 2b. A control valve V6c is provided in the branch channel of the adsorber connection channel 19 that is connected to the adsorber 2c, and the downstream end of the shared adsorber connection channel 19 branches and connects to the adsorber 2d. A control valve V6d is provided in a branch flow path of the adsorber connection flow path 19 that is connected.

A control valve V7a is provided in the branch channel of the adsorber connection channel 19 that branches from the upstream end of the shared adsorber connection channel 19 and is connected to the adsorber 2a. A control valve V7b is provided in the branched flow path of the adsorber connection flow path 19 branched from the upstream end of the adsorber connection flow path 19 and connected to the adsorber 2b. A control valve V7c is provided in the branched channel of the adsorber connection channel 19 that is connected to the adsorber 2c, and branches from the upstream end of the shared adsorber connection channel 19 to connect to the adsorber 2d. A control valve V7d is provided in a branch flow path of the adsorber connection flow path 19 that is connected.

When the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separation device 1002 (the non-permeating gas is supplied to the adsorption device 202 from the non-permeating gas flow path 120) of the adsorption device 202 performs an adsorption step in which one or two of the adsorbers 2a to 2d adsorb carbon dioxide contained in the non-permeating gas to the adsorbents 4a to 4d, and any one of the adsorbers 2a to 2d Alternatively, the controller so that one or two of the other adsorbers 2a to 2d perform a regeneration step of desorbing carbon dioxide from the adsorbents 4a to 4d while two are performing the adsorption step. C3 controls the open/close states of the control valves V1a-V1d, V2a-V2d, V3a-V3d, V6a-V6d, and V7a-V7d.

If any two of the adsorbers 2a to 2d are performing an adsorption step of adsorbing the carbon dioxide contained in the non-permeable gas to the adsorbents 4a to 4d, any two of the adsorbers 2a to 2d are in the adsorption step. is performed, the controller C3 controls the control valves V1a to V1d, V2a so that any two of the other adsorbers 2a to 2d perform a regeneration process in which carbon dioxide is desorbed from the adsorbents 4a to 4d. to V2d, V3a to V3d, V6a to V6d, and V7a to V7d are controlled.

When any two of the adsorbers 2a to 2d are performing an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbents 4a to 4d, the two adsorbers 2a to 2d performing the adsorption step are When connecting in series, for the adsorbers 2a to 2d on the upstream side of the two adsorbers 2a to 2d connected in series, control valves V1a to V1d corresponding to the adsorbers 2a to 2d, control With the valves V7a-V7d open, the other control valves V2a-V2d, V3a-V3d, and V6a-V6d are controlled to be closed, and the downstream side of the two adsorbers 2a-2d connected in series. Regarding the adsorbers 2a to 2d, the control valves V2a to V2d and the control valves V6a to V6d corresponding to the adsorbers 2a to 2d are open, and the other control valves V1a to V1d, V3a to V3d, and V7a to V7d are closed. State controlled.

For the adsorbers 2a to 2d that are not connected in series and are performing the adsorption process, the control valves V1a to V1d and the control valves V2a to V2d corresponding to the adsorbers 2a to 2d are open, and the other control valve V3a is closed. .about.V3d, V6a to V6d, and V7a to V7d are controlled to be closed.

For the adsorbers 2a to 2d that are performing the regeneration process, the control valves V3a to V3d corresponding to the adsorbers 2a to 2d are open, and the other control valves V1a to V1d, V2a to V2d, V6a to V6d, and V7a are open. ˜V7d are controlled to the closed state.

The exhaust gas flow path 11 is downstream of the four adsorbers 2a to 2d so that the non-permeating gas that has not been adsorbed by the adsorbers 2a to 2d in the adsorption step is exhausted to the outside from the adsorbers 2a to 2d in the adsorption step. It is a flow path connected to the side.

One end (upstream side end) of the desorbed gas discharge channel 14 is four so that the desorbed gas desorbed from the adsorbers 2a to 2d in the regeneration process is recovered from the adsorbers 2a to 2d in the regeneration process. Flow path connected to adsorbers 2a to 2d and connected to permeated gas flow path 121 so that the other end (downstream end) communicates with permeated gas flow path 121 between decompression pump 7 and carbon dioxide utilization device 16 is.

The suction pump 15 is arranged in the middle of the shared channel in the desorbed gas discharge channel 14 . In addition, the suction pump 15 reduces the pressure inside the adsorbers 2a to 2d in the regeneration process, desorbs carbon dioxide from the adsorbents 4a to 4d, and causes the desorbed gas to flow out to the desorbed gas discharge passage 14. is configured to

Adsorbers 2a to 2d constituting the adsorption device 202 are provided with adsorbents 4a to 4d for adsorbing carbon dioxide. The material of the adsorbents 4a-4d is zeolite that adsorbs carbon dioxide.

The separation membrane 3 that selectively permeates carbon dioxide contains monoethanolamine, which is a type of alkanolamine.

The control valves V1a to V1d are provided in branch flow paths corresponding to the adsorbers 2a to 2d in the non-permeating gas flow path 120, respectively. The control valves V2a to V2d are provided in branch flow paths corresponding to the adsorbers 2a to 2d in the exhaust gas flow path 11, respectively. The control valves V3a to V3d are provided in branch flow paths corresponding to the adsorbers 2a to 2d in the desorbed gas discharge flow path 14, respectively.

The control valves V6a to V6d are provided in branch flow paths corresponding to the adsorbers 2a to 2d branched from the downstream end of the adsorber connecting flow path 19, respectively. The control valves V7a to V7d are provided in branch flow paths corresponding to the adsorbers 2a to 2d branched from the upstream end of the adsorber connection flow path 19, respectively.

Controller C3 controls the operation of carbon dioxide separator 1002 . The controller C3 includes a signal input/output unit (not shown), an arithmetic processing unit (not shown), and a storage unit (not shown) for storing control programs.

The controller C3 is configured to operate the supply pump 6, the decompression pump 7, the suction pump 15, and the control valves V1a to V7d according to commands from the controller C3.

Based on the concentration detected by the carbon dioxide concentration detector 5, the controller C3 controls the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step to fall within a predetermined range. It is configured to control the volume control means (supply pump 6, vacuum pump 7).

[3-2. motion]
The operation of the carbon dioxide separator 1002 configured as described above will be described in detail with reference to FIGS. 12 to 17. FIG.

[3-2-1. basic action]
FIG. 12 is a flow chart showing the basic operation of the carbon dioxide separator 1002. As shown in FIG.

The following operations are performed by controlling the carbon dioxide separator 1002 by the controller C3.

When an operation start request is received, the carbon dioxide separator 1002 performs a start-up operation (S050) and starts operation under the control of the controller C3.

Next, under the control of the controller C3, the carbon dioxide separation device 1002 performs a CO ₂ concentration adjustment operation (S600) to adjust the carbon dioxide concentration in the non-permeated gas flowing into the adsorption device 202, It stabilizes the carbon dioxide concentration in the supplied non-permeate gas and at the same time stores the operating mode of PSA operation in the memory of controller C3. In parallel with this, the controller C3 switches the operation mode of the PSA operation of the adsorption device ₂₀₂ based on the information stored in the memory. It is checked whether the operation mode of the PSA operation of the adsorption device 202 stored in is the normal mode, the serial mode, or the parallel mode (S650).

As a result of checking in S650, if the mode is the normal mode, the controller C3 performs the PSA operation (normal mode) in which the adsorption step is performed with one adsorber 2 (S200).

As a result of confirmation in S650, if the series mode is selected, the controller C3 performs a PSA operation (serial mode) in which a plurality of (two) series-connected adsorbers 2 perform an adsorption process (S700).

As a result of checking in S650, if the parallel mode is selected, the controller C3 performs PSA operation (parallel mode) in which a plurality of (two) adsorbers 2 connected in parallel perform an adsorption process (S900).

Thus, the carbon dioxide separator 1002 adjusts the concentration of carbon dioxide in the non-permeating gas flowing into the adsorption device 202 (adsorber 2) within a predetermined range, and performs the PSA operation of the adsorption device 202. , the desorbed gas of stable concentration is generated from the adsorption device 202 , and combined with the permeated gas of the carbon dioxide separator 1 to generate a carbon dioxide-enriched gas of stable concentration.

Next, the controller C3 determines whether or not there is a command to stop the operation of the carbon dioxide separator 1002 (S300). As a result of the determination in S300, if there is no operation stop command, the CO ₂ concentration adjustment operation (S600) and PSA operation (S200, S700, S900) are continued until the operation stop command is received.

As a result of the determination in S300, if there is an operation stop command, the controller C3 controls the supply pump 6 for supplying the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 to the first space of the carbon dioxide separator 1, the dioxide A decompression pump 7 for depressurizing the second space of the carbon separator 1 and causing the permeated gas that has passed through the separation membrane 3 from the first space of the carbon dioxide separator 1 to the second space to flow out from the second space to the permeated gas flow path 121. , the suction pump 15 for depressurizing the adsorber 2 in the regeneration step and discharging the desorbed gas desorbed from the adsorbent 4 to the desorbed gas discharge passage 14 is stopped (S400), the operation flag of the adsorber 2, After storing the operation step information and the opening/closing information of all the control valves in the memory of the controller C3, all the control valves are closed (S500) to stop the operation of the carbon dioxide separator 1002. FIG.

[3-2-2. Startup action]
Next, the activation operation (S050) of the carbon dioxide separation device 1002 will be described with reference to FIG. FIG. 13 is a flow chart showing the startup operation (S050) of the carbon dioxide separator 1002. As shown in FIG.

The following operations are performed by controlling the carbon dioxide separator 1002 by the controller C3.

First, the controller C3 activates the decompression pump 7 that decompresses the second space of the carbon dioxide separator 1 so that the pressure of the second space of the carbon dioxide separator 1 reaches the predetermined pressure (20 kPa). By adjusting the exhaust speed of the decompression pump 7, the pressure in the second space of the carbon dioxide separator 1 is decompressed to a predetermined pressure of 20 kPa (S001).

Next, the controller C3 controls the operation mode in the PSA operation of the adsorption device 202 during the previous operation stored in the memory of the controller C3, the flag information of the adsorption devices 2a to 2d, the operation step information, the control valves V1a The open/close information of V7d is read out and reflected in the adsorption device 202 . If the memory does not store the information of the previous operation, the operation mode in the PSA operation is reflected in the adsorption device 202 as the normal mode.

Next, the controller C3 operates the supply pump 6 that supplies the carbon dioxide-containing gas to the first space of the carbon dioxide separator 1 at the first supply rate (30 L/min), thereby causing the carbon dioxide-containing gas supply source The carbon dioxide-containing gas from 100 is supplied to (the inlet of) the first space of the carbon dioxide separator 1 (S003).

[3-2-3. CO ₂ concentration adjustment operation]
Next, the CO ₂ concentration adjustment operation (S600) of the carbon dioxide separator 1002 will be described using FIG.

First, the controller C3 controls the carbon dioxide concentration detector 5 provided in the non-permeating gas flow path 120 connecting the outlet of the first space of the carbon dioxide separator 1 and the inlet of the adsorption device 202 (adsorber 2). It is determined whether or not the carbon dioxide concentration in the detected non-permeable gas is within a predetermined concentration range (S601).

As a result of the determination in S601, if the concentration is within the predetermined range, S601 is branched to the Yes side, the PSA operation mode (stored in the memory) is changed to the normal mode (S613), and the CO ₂ concentration is adjusted. End the operation and proceed to the next step.

As a result of the determination in S601, if it is outside the predetermined concentration range, S601 is branched to the No side, and the controller C3 detects that the concentration of carbon dioxide in the non-permeating gas detected by the carbon dioxide concentration detector 5 has reached the predetermined concentration. It is determined whether or not the upper limit of the range is exceeded (S602).

As a result of the determination in S602, if the upper limit of the predetermined concentration range is exceeded, S602 is branched to the Yes side, and the controller C3 determines that the current PSA operation mode (the PSA operation mode stored in the memory) is It is determined whether or not it is the serial mode (S603).

As a result of the determination in S602, if the upper limit value of the predetermined concentration range is not exceeded, S602 is branched to the No side, and the controller C3 determines that the current PSA operation mode (the PSA operation mode stored in the memory) is It is determined whether or not it is in parallel mode (S608).

If the current PSA operation mode (the PSA operation mode stored in the memory) is the serial mode as a result of the determination in S603, S603 branches to the Yes side, and the controller C3 determines that the pumping speed of the decompression pump 7 is It is determined whether or not it is lower than the maximum exhaust speed (S604).

As a result of the determination in S603, if the current PSA operation mode (the PSA operation mode stored in the memory) is not the serial mode, S603 is branched to the No side, and the controller C3 (stored in the memory ) The PSA operation mode is changed to the series mode (S606), the CO ₂ concentration adjustment operation is terminated, and the next step is performed.

As a result, a plurality of adsorbers 2 are connected in series, so the pressure loss of the adsorption device 202 increases, and as a result, the pressure in the first space of the carbon dioxide separator 1 increases. As the amount of carbon dioxide that permeates the separation membrane 3 from the space to the second space increases, the concentration of carbon dioxide in the non-permeable gas that flows out from the first space to the non-permeable gas channel 120 and is supplied to the adsorption device 202 is lowered, the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 202 can be controlled so as not to exceed the upper limit of the predetermined concentration range.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied.

As a result of the determination in S604, if the exhaust speed of the decompression pump 7 is lower than the maximum exhaust speed, S604 is branched to the Yes side, and the controller C3 determines the difference between the concentration detected by the carbon dioxide concentration detector 5 and the predetermined concentration range. The pumping speed of the decompression pump 7 is increased according to the difference (S605), the CO ₂ concentration adjusting operation is terminated, and the process proceeds to the next step.

Thereby, the average value of the carbon dioxide partial pressure in the permeate gas flowing through the second space is subtracted from the average value of the carbon dioxide partial pressure in the carbon dioxide-containing gas flowing through the first space of the carbon dioxide separator 1. As the partial pressure difference increases, the amount of carbon dioxide that permeates the separation membrane 3 from the first space to the second space increases. Since the concentration of carbon dioxide in the non-permeating gas supplied to the adsorber 202 is lowered, the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 202 can be controlled so as not to exceed the upper limit of the predetermined concentration range.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied to the carbon dioxide utilization device 16 .

As a result of the determination in S604, if the exhaust speed of the decompression pump 7 is the maximum exhaust speed, S604 is branched to the No side, and the controller C3 determines the difference between the concentration detected by the carbon dioxide concentration detector 5 and the predetermined concentration range. By reducing the carbon dioxide-containing gas supply amount of the supply pump 6 from the current first supply amount according to the difference, the amount of the non-permeating gas flowing out from the first space of the carbon dioxide separator 1 to the non-permeating gas flow path 120 is reduced. The amount of outflow is reduced (S607), the CO ₂ concentration adjustment operation is terminated, and the next step is performed.

As a result, by reducing the supply amount of the carbon dioxide-containing gas exceeding a predetermined concentration to the adsorption device 202, the adsorption amount per unit time of carbon dioxide adsorbed by the adsorption material 4 inside the adsorption device 2 in the adsorption step is reduced. To supply carbon dioxide-enriched gas of stable purity by limiting the amount of adsorption to a predetermined amount so that the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 does not exceed the upper limit of a predetermined concentration range. can be done.

If the result of determination in S608 is that the current PSA operation mode (the PSA operation mode stored in the memory) is the parallel mode, it is determined whether or not the pumping speed of the decompression pump 7 is higher than the minimum pumping speed ( S609).

As a result of the determination in S608, if the current PSA operation mode (the PSA operation mode stored in the memory) is not the parallel mode, S608 is branched to the No side, and the controller C3 (stored in the memory ) The PSA operation mode is changed to the parallel mode (S611), the _CO2 concentration adjustment operation is completed, and the next process is performed.

As a result, since a plurality of adsorbers 2 are connected in parallel, the pressure loss of the adsorption device 202 is reduced, and the pressure in the first space of the carbon dioxide separator 1 is lowered, so that the first space is connected to the first space. Since the amount of carbon dioxide that permeates the separation membrane 3 to the second space decreases, the carbon dioxide concentration of the non-permeable gas that flows out from the first space to the non-permeable gas flow path 120 and is supplied to the adsorption device 202 increases. Therefore, the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 202 can be controlled so as not to fall below the lower limit of the predetermined concentration range.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied.

As a result of the determination in S609, if the pumping speed of the decompression pump 7 is higher than the minimum pumping speed, S609 is branched to the Yes side, and the controller C3 detects the concentration detected by the carbon dioxide concentration detector 5 and the predetermined concentration range. The pumping speed of the decompression pump 7 is reduced according to the difference (S610), the CO ₂ concentration adjustment operation is terminated, and the process proceeds to the next step.

Thereby, the average value of the carbon dioxide partial pressure in the permeate gas flowing through the second space is subtracted from the average value of the carbon dioxide partial pressure in the carbon dioxide-containing gas flowing through the first space of the carbon dioxide separator 1. As the partial pressure difference becomes smaller, the amount of carbon dioxide that permeates the separation membrane 3 from the first space to the second space decreases, so that Since the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 202 increases, the concentration of carbon dioxide in the non-permeating gas supplied to the adsorption device 202 can be controlled so as not to fall below the lower limit of the predetermined concentration range.

Therefore, the concentration of carbon dioxide in the desorbed gas flowing out of the adsorber 2 can be stabilized, and carbon dioxide-enriched gas with stable purity can be supplied to the carbon dioxide utilization device 16 .

As a result of the determination in S609, if the pumping speed of the decompression pump 7 is the minimum pumping speed, S609 is branched to the No side, and the controller C3 issues a command to stop the carbon dioxide separator 1002 (S612), After completing the _two -density adjustment operation, the process proceeds to the next step.

As a result, the low-concentration carbon dioxide-enriched gas due to the supply of the carbon dioxide-containing gas containing low-concentration carbon dioxide that cannot be controlled within a predetermined concentration range by the carbon-dioxide separator 1002 to the carbon-dioxide separator 1002 is converted into carbon dioxide. It is possible to prevent the data from being supplied to the utilization device 16 .

[3-2-4. PSA operation in series mode]
Next, the PSA operation (S700 in FIG. 12) in series mode of the carbon dioxide separator 1002 will be described with reference to FIGS. 15 and 16. FIG.

In this step, the controller C3 divides the four adsorbers 2 provided in the carbon dioxide separation device 1002 into a group of adsorbers 2a and 2b and a group of adsorbers 2c and 2d, and divides each group into two groups. Work as a group. Therefore, although FIGS. 15 and 16 show the operation of adsorbers 2a and 2b, other groups of adsorbers 2 (adsorbers 2c and 2d) operate similarly and in parallel.

First, the controller C3 determines whether or not there is an adsorber 2 whose adsorption process flag is ON (S701). repeat the judgment. As a result of the determination in S701, if there is no adsorber 2 whose adsorption process flag is ON, S701 is branched to the No side, and the adsorption process flags of adsorbers 2a and 2b are turned ON (S702).

Next, the controller C3 closes the control valves V2a, V3a, V6a, V1b, V3b, and V7b and opens the control valves V1a, V7a, V2b, and V6b so that the non-permeating gas flow path 120 is supplied to the adsorber 2a, and the non-permeable gas discharged from the adsorber 2a is supplied to the adsorber 2b (S703).

As a result, the carbon dioxide contained in the non-permeating gas is adsorbed by the adsorbents 4a and 4b in the adsorbers 2a and 2b, and the impurity gas that is not adsorbed by the adsorbents 4a and 4b passes through the exhaust gas flow path 11. exhausted.

Next, the controller C3 checks whether or not a predetermined time (60 min) has elapsed since the adsorption process flags of the adsorbers 2a and 2b were turned ON (S704). If not, the confirmation of S704 is repeated until the time elapses.

As a result of confirmation in S704, if a predetermined time has elapsed since the adsorption process flags of the adsorbers 2a and 2b were turned ON, S704 is branched to the Yes side, and the controller C3 causes the adsorbers 2a and 2b to The adsorption process flag is turned off, and the control valves V1a, V7a, V2b, and V6b are closed (S705).

Here, in the present embodiment, the predetermined time for the adsorption step is set to 60 minutes, but this is merely an example.

Here, the predetermined time for the adsorption step is a value obtained in advance by experiments. During the predetermined time of the adsorption step, the carbon dioxide in the non-permeating gas is adsorbed by the adsorbents 4a and 4b in the adsorbers 2a and 2b, and the carbon dioxide adsorbed by the adsorbents 4a and 4b is desorbed. The carbon dioxide concentration in the degassed gas may be changed according to the measured value of the carbon dioxide concentration detector 5 as long as the concentration reaches the concentration required by the carbon dioxide utilization device 16 . Therefore, the predetermined time for the adsorption step is not quantitatively deterministic.

That is, here, when the elapsed time from the time when the adsorption process flag is turned ON reaches 60 minutes, it is determined that the concentration of carbon dioxide in the desorbed gas reaches the concentration required by the carbon dioxide utilization device 16, and the elapsed time It is determined that the carbon dioxide concentration in the desorbed gas does not reach the concentration required by the carbon dioxide utilization device 16 before is 60 min, but this criterion is only an example.

Next, the controller C3 determines whether or not there is an adsorber 2 whose regeneration process flag is ON (S706). The determination of S706 is repeated. As a result of the determination in S706, if there is no adsorber 2 whose regeneration process flag is ON, S706 is branched to the No side, and the regeneration process flags of adsorbers 2a and 2b are turned ON (S707).

Next, the controller C3 opens the control valves V3a and V3b to operate the suction pump 15 (S708) to start the regeneration process.

As a result, the carbon dioxide and the impurity gas adsorbed by the adsorbers 2a and 2b in the adsorption step are desorbed from the adsorbers 2a and 2b (adsorbents 4a and 4b), and the desorbed gas becomes the desorbed gas discharge stream. It flows out to path 14 .

Next, the controller C3 checks whether or not a predetermined time (30 min) has elapsed since the regeneration process flags of the adsorbers 2a and 2b were turned ON (S709). If not, the confirmation of S709 is repeated until the time elapses.

As a result of confirmation in S709, if a predetermined time has elapsed since the regeneration process flags of the adsorbers 2a and 2b were turned ON, S709 is branched to the Yes side, and the controller C3 causes the adsorbers 2a and 2b to The regeneration process flag is turned off, the control valves V3a and V3b are closed, the suction pump 15 is stopped (S710), and the process proceeds to the next process.

Here, in the present embodiment, the predetermined time for the regeneration process is set to 30 minutes, but this is merely an example.

Here, the predetermined time for the regeneration process is a value obtained in advance by experiments. The predetermined time for the regeneration step may be any value that allows determination of whether or not the desorption of carbon dioxide adsorbed by the adsorbents 4a and 4b in the adsorbers 2a and 2b is complete. Therefore, the predetermined time for the regeneration step is not quantitatively deterministic.

That is, here, when the elapsed time from the time when the regeneration process flag is turned ON reaches 30 minutes, it is determined that the desorption of the carbon dioxide adsorbed by the adsorbents 4a and 4b is completed, and before the elapsed time reaches 30 minutes. Although it is determined that the carbon dioxide adsorbed by the adsorbents 4a and 4b is not completely desorbed, this determination criterion is only an example.

When the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separation device 1002 (the non-permeating gas is supplied to the adsorption device 202), the adsorption devices 2a and 2b in the adsorption device 202 , or the group of adsorbers 2c and 2d performs an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas onto the adsorbents 4a to 4d.

Then, while one of the group of adsorbers 2a and 2b and the group of adsorbers 2c and 2d is performing the adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbents 4a to 4d, the adsorbers Either the group of 2a, 2b or the group of adsorbers 2c, 2d is performing a regeneration process for desorbing carbon dioxide from the adsorbents 4a to 4d.

For example, as shown in FIG. 15, when the group of adsorbers 2c and 2d is performing a regeneration process for desorbing carbon dioxide from the adsorbents 4c and 4d, the group of adsorbers 2a and 2b becomes non-permeable gas. An adsorption process is performed in which the contained carbon dioxide is adsorbed by the adsorbents 4a and 4b, and each of the control valves V1a, V7a, V2b, V6b, V3c and V3d is in an open state, and the remaining control valves V2a, V3a, V6a, Each of V1b, V3b, V7b, V1c, V2c, V6c, V7c, V1d, V2d, V6d, and V7d is closed.

[3-2-5. PSA operation in normal mode]
The PSA operation in the normal mode of the carbon dioxide separator 1002 (S200 in FIG. 12) is the same as the PSA operation in Embodiment 1 shown in FIG. 5, so the description is omitted.

[3-2-6. PSA operation in parallel mode]
Next, the PSA operation (S900 in FIG. 12) in the parallel mode of carbon dioxide separator 1002 will be described with reference to FIGS. 17 and 18. FIG.

In this step, the controller C3 divides the four adsorbers 2 provided in the carbon dioxide separation device 1002 into a group of adsorbers 2a and 2b and a group of adsorbers 2c and 2d, and divides each group into two groups. Work as a group. Therefore, although FIGS. 17 and 18 show the operation of adsorbers 2a and 2b, other groups of adsorbers 2 (adsorbers 2c and 2d) operate similarly and in parallel.

First, the controller C3 determines whether or not there is an adsorber 2 whose adsorption process flag is ON (S901). repeat the judgment. As a result of the determination in S901, if there is no adsorber 2 whose adsorption process flag is ON, S901 is branched to the No side, and the adsorption process flags of adsorbers 2a and 2b are turned ON (S902).

Next, the controller C3 closes the control valves V3a, V6a, V7a, V3b, V6b, and V7b and opens the control valves V1a, V2a, V1b, and V2b to of non-permeable gas is distributed and supplied to the adsorber 2a and the adsorber 2b (S903).

As a result, the carbon dioxide contained in the non-permeating gas is adsorbed by the adsorbents 4a and 4b in the adsorbers 2a and 2b, and the impurity gas that is not adsorbed by the adsorbents 4a and 4b passes through the exhaust gas flow path 11. exhausted.

Next, the controller C3 checks whether or not a predetermined time (60 minutes) has elapsed since the adsorption process flags of the adsorbers 2a and 2b were turned ON (S904). If not, the confirmation of S904 is repeated until the time elapses.

As a result of confirmation in S904, if a predetermined time has elapsed since the adsorption process flags of the adsorbers 2a and 2b were turned ON, S904 branches to the Yes side, and the controller C3 causes the adsorbers 2a and 2b to The adsorption process flag is turned off, and the control valves V1a, V2a, V1b, and V2b are closed (S905).

Here, in the present embodiment, the predetermined time for the adsorption step is set to 60 minutes, but this is merely an example.

Here, the predetermined time for the adsorption step is a value obtained in advance by experiments. During the predetermined time of the adsorption step, the carbon dioxide in the non-permeating gas is adsorbed by the adsorbents 4a and 4b in the adsorbers 2a and 2b, and the carbon dioxide adsorbed by the adsorbents 4a and 4b is desorbed. The carbon dioxide concentration in the degassed gas may be changed according to the measured value of the carbon dioxide concentration detector 5 as long as the concentration reaches the concentration required by the carbon dioxide utilization device 16 . Therefore, the predetermined time for the adsorption step is not quantitatively deterministic.

That is, here, when the elapsed time from the time when the adsorption process flag is turned ON reaches 60 minutes, it is determined that the concentration of carbon dioxide in the desorbed gas reaches the concentration required by the carbon dioxide utilization device 16, and the elapsed time It is determined that the carbon dioxide concentration in the desorbed gas does not reach the concentration required by the carbon dioxide utilization device 16 before is 60 min, but this criterion is only an example.

Next, the controller C3 determines whether or not there is an adsorber 2 whose regeneration process flag is ON (S
906), as a result of the determination, if there is an adsorber 2 whose regeneration process flag is ON, the determination of S906 is repeated. As a result of the determination in S906, if there is no adsorber 2 whose regeneration process flag is ON, S906 is branched to No, and the regeneration process flags of adsorbers 2a and 2b are turned ON (S907).

Next, the controller C3 opens the control valves V3a and V3b to operate the suction pump 15 (S908) to start the regeneration process.

As a result, the carbon dioxide and the impurity gas adsorbed by the adsorbers 2a and 2b in the adsorption step are desorbed from the adsorbers 2a and 2b (adsorbents 4a and 4b), and the desorbed gas becomes the desorbed gas discharge stream. It flows out to path 14 .

Next, the controller C3 checks whether or not a predetermined time (30 min) has elapsed since the regeneration process flags of the adsorbers 2a and 2b were turned ON (S909). If not, the confirmation of S909 is repeated until the time elapses.

As a result of confirmation in S909, if a predetermined time has elapsed since the regeneration process flags of the adsorbers 2a and 2b were turned ON, S909 is branched to the Yes side, and the controller C3 causes the adsorbers 2a and 2b to The regeneration process flag is turned off, the control valves V3a and V3b are closed, the suction pump 15 is stopped (S910), and the process proceeds to the next process.

Here, in the present embodiment, the predetermined time for the regeneration process is set to 30 minutes, but this is merely an example.

Here, the predetermined time for the regeneration process is a value obtained in advance by experiments. The predetermined time for the regeneration step may be any value that allows determination of whether or not the desorption of carbon dioxide adsorbed by the adsorbents 4a and 4b in the adsorbers 2a and 2b is complete. Therefore, the predetermined time for the regeneration step is not quantitatively deterministic.

That is, here, when the elapsed time from the time when the regeneration process flag is turned ON reaches 30 minutes, it is determined that the desorption of the carbon dioxide adsorbed by the adsorbents 4a and 4b is completed, and before the elapsed time reaches 30 minutes. Although it is determined that the carbon dioxide adsorbed by the adsorbents 4a and 4b is not completely desorbed, this determination criterion is only an example.

When the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separation device 1002 (the non-permeating gas is supplied to the adsorption device 202), the adsorption devices 2a and 2b in the adsorption device 202 , or the group of adsorbers 2c and 2d performs an adsorption step of adsorbing carbon dioxide contained in the non-permeating gas onto the adsorbents 4a to 4d.

Then, while one of the group of adsorbers 2a and 2b and the group of adsorbers 2c and 2d is performing the adsorption step of adsorbing carbon dioxide contained in the non-permeating gas to the adsorbents 4a to 4d, the adsorbers Either the group of 2a, 2b or the group of adsorbers 2c, 2d is performing a regeneration process for desorbing carbon dioxide from the adsorbents 4a to 4d.

For example, as shown in FIG. 17, when the group of adsorbers 2c and 2d is performing a regeneration process for desorbing carbon dioxide from the adsorbents 4c and 4d, the group of adsorbers 2a and 2b becomes non-permeable gas. An adsorption process is performed in which the contained carbon dioxide is adsorbed by the adsorbents 4a and 4b, and each of the control valves V1a, V2a, V1b, V2b, V3c and V3d is in an open state, and the remaining control valves V3a, V6a, V7a, V3b, V6b, V7b, V1c, V2c, V6c, V7c,
Each of V1d, V2d, V6d, and V7d is closed.

[3-3. effects, etc.]
As described above, the carbon dioxide separator 1002 in the present embodiment includes the carbon dioxide separator 1, the decompression pump 7, the carbon dioxide concentration detector 5, the supply pump 6 functioning as permeation gas amount adjusting means, and the control valve It has V6a to V7d, an adsorption device 202, an exhaust gas flow path 11, a desorbed gas discharge flow path 14, a suction pump 15, and a controller C3. The decompression pump 7 also functions as permeable gas amount adjusting means.

The carbon dioxide separator 1 has an internal space partitioned into a first space and a second space by a separation membrane 3 that selectively permeates carbon dioxide. The first space is a space into which the carbon dioxide-containing gas flows from the carbon dioxide-containing gas supply channel 9, and a space into which the non-permeating gas that has not permeated the separation membrane 3 flows out to the non-permeating gas channel 120. be. The second space is a space through which the permeated gas that has permeated the separation membrane 3 flows out to the permeated gas channel 121 .

The decompression pump 7 is a pump that is provided in the middle of the permeated gas flow path 121 and configured to decompress the second space at an exhaust speed set for the decompression pump 7 . Due to the decompression operation of the decompression pump 7 , carbon dioxide contained in the carbon dioxide-containing gas permeates the separation membrane 3 and the permeated gas flows out to the permeated gas flow path 121 .

The carbon dioxide concentration detector 5 is arranged in the middle of the non-permeating gas channel 120 and configured to detect the concentration of carbon dioxide contained in the non-permeating gas flowing through the non-permeating gas channel 120. .

The adsorption device 202 includes four adsorbers 2a to 2d, which are filled with adsorbents 4a to 4d for adsorbing carbon dioxide and connected to the downstream side of the non-permeating gas flow path 120, and the adsorbers 2a to 2d. and an adsorber connection channel 19 for connecting any two of them in series.

In the adsorption device 202, the carbon dioxide-containing gas is supplied from the carbon dioxide-containing gas supply source 100 to the carbon dioxide separation device 1002 (the non-permeating gas is supplied to the adsorption device 202 from the non-permeating gas flow path 120). ), any one or two of the adsorbers 2a to 2d perform an adsorption step in which the carbon dioxide contained in the non-permeating gas is adsorbed by the adsorbents 4a to 4d, and any one of the adsorbers 2a to 2d Alternatively, one or two of the remaining adsorbers 2a to 2d are configured to perform a regeneration step of desorbing carbon dioxide from the adsorbents 4a to 4d while two are performing the adsorption step. there is

In the adsorption device 202 that performs PSA operation in the normal mode, one of the adsorbers 2a to 2d performs an adsorption step in which carbon dioxide contained in the non-permeating gas is adsorbed by the adsorbents 4a to 4d. Any one of the remaining adsorbers 2a to 2d is configured to perform a regeneration step of desorbing carbon dioxide from the adsorbents 4a to 4d while any one of the adsorbers 2a to 2d is performing the adsorption step. .

The adsorption device 202 that performs the PSA operation in series mode performs an adsorption step in which carbon dioxide contained in the non-permeating gas is adsorbed by the adsorbents 4a to 4d while any two of the adsorbers 2a to 2d are connected in series. While any two of the adsorbers 2a to 2d are performing the adsorption step, any two of the remaining adsorbers 2a to 2d perform a regeneration step in which carbon dioxide is desorbed from the adsorbents 4a to 4d. configured to do so.

In the adsorption device 202 that performs PSA operation in parallel mode, the non-permeable gas is distributed and supplied to any two of the adsorbers 2a to 2d, and the carbon dioxide contained in the non-permeable gas is adsorbed by the adsorbents 4a to 4d. Regeneration in which any two of the remaining adsorbers 2a to 2d desorb carbon dioxide from the adsorbents 4a to 4d while performing the process and any two of the adsorbers 2a to 2d are performing the adsorption process. configured to perform a process.

The exhaust gas flow path 11 is downstream of the four adsorbers 2a to 2d so that the non-permeating gas that has not been adsorbed by the adsorbers 2a to 2d in the adsorption step is exhausted to the outside from the adsorbers 2a to 2d in the adsorption step. is a flow path connected to

The desorbed gas discharge channel 14 is connected to the two adsorbers 2a to 2d so that the desorbed gas desorbed from the adsorbers 2a to 2d in the regeneration process is recovered from the adsorbers 2a to 2d in the regeneration process. It is a flow path that has been designed.

The suction pump 15 is provided in the middle of the desorbed gas discharge channel 14 . In addition, the suction pump 15 reduces the pressure inside the adsorbers 2a to 2d in the regeneration process, desorbs carbon dioxide from the adsorbents 4a to 4d, and causes the desorbed gas to flow out to the desorbed gas discharge passage 14. is configured to

The supply pump 6 is provided in the middle of the carbon dioxide-containing gas supply channel 9 . In addition, the supply pump 6 supplies the carbon dioxide-containing gas from the carbon dioxide-containing gas supply source 100 to the first space of the carbon dioxide separator 1 at a supply amount set for the supply pump 6. It is configured.

The control valves V6a to V6d are provided in branch flow paths corresponding to the adsorbers 2a to 2d branched from the downstream end of the adsorber connecting flow path 19, respectively. The control valves V7a to V7d are provided in branch flow paths corresponding to the adsorbers 2a to 2d branched from the upstream end of the adsorber connection flow path 19, respectively.

Based on the concentration detected by the carbon dioxide concentration detector 5, the controller C3 controls the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber in the adsorption step to fall within a predetermined range. It is configured to control any one of the supply pump 6, the decompression pump 7, and the control valves V6a to V7d, which function as volume control means.

In the carbon dioxide separation device 1002 having the above configuration, the controller C3 detects the concentration of carbon dioxide contained in the non-permeating gas detected by the carbon dioxide concentration detector 5 provided in the non-permeating gas flow path 120, and adsorbs Since the flow rate of the permeating gas is adjusted (by controlling the permeating gas amount adjusting means) so that the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the process falls within a predetermined range, the adsorption device 202 ( When the carbon dioxide concentration in the non-permeable gas flowing into the adsorber 2) changes, the amount of carbon dioxide permeating the separation membrane 3 can be changed, and the non-permeable gas flowing into the adsorber 2 in the adsorption step can be changed. It is possible to control the concentration of carbon dioxide in a predetermined range.

Therefore, the concentration of carbon dioxide flowing into the adsorption device 202 (adsorber 2) is stabilized, and the amount of carbon dioxide adsorbed by the adsorbent 4 is stabilized, so that the concentration of carbon dioxide in the desorbed gas can be stabilized. Therefore, it becomes possible to supply the carbon dioxide-enriched gas of stable purity to the carbon dioxide utilization equipment 16 .

As in this embodiment, the carbon dioxide separator 1002 calculates the carbon dioxide content in the permeate gas flowing through the second space from the average value of the carbon dioxide partial pressure in the carbon dioxide-containing gas flowing through the first space. By controlling the partial pressure difference obtained by subtracting the average value of the pressure, the flow rate of the permeating gas is adjusted so that the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step falls within a predetermined range. I don't mind.

In this case, the controller C3 controls the amount of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step based on the carbon dioxide concentration in the non-permeating gas detected by the carbon dioxide concentration detector 5. If it is determined that the concentration exceeds the upper limit of the predetermined range, the partial pressure difference is adjusted to increase the partial pressure difference within the range of 0 or more, and if it is determined that the concentration is below the lower limit of the predetermined range, the partial pressure difference The partial pressure difference may be adjusted so that is small within the range of 0 or more.

The partial pressure difference can be adjusted by adjusting the pumping speed of the decompression pump 7 or adjusting the supply amount of the supply pump 6 . Increasing the exhaust speed of the decompression pump 7 increases the partial pressure difference, and decreasing the exhaust speed of the decompression pump 7 decreases the partial pressure difference. When the supply amount of the supply pump 6 is increased, the partial pressure difference increases, and when the supply amount of the supply pump 6 is decreased, the partial pressure difference decreases.

In addition, the adjustment of the partial pressure difference is performed by changing the operation mode of the PSA operation to the normal mode in which any one of the adsorbers 2a to 2d performs the adsorption process, and the state in which any two of the adsorbers 2a to 2d are connected in series. and a parallel mode in which the adsorption step is performed while the non-permeating gas is distributed and supplied to any two of the adsorbers 2a to 2d to change the pressure loss of the adsorption device 202. It can be done by

When the operation mode of the PSA operation is changed from the normal mode to the series mode by changing the open/closed states of the control valves V6a to V7d, the pressure loss of the adsorption device 202 becomes larger than before the change, the partial pressure difference becomes larger, and the PSA When the operating mode of operation is changed from the normal mode to the parallel mode, the pressure loss of the adsorption device 202 becomes smaller and the partial pressure difference becomes smaller than before the change.

As a result, the influence of the carbon dioxide concentration in the permeated gas staying in the second space of the carbon dioxide separator 1 can be suppressed, and the carbon dioxide permeation amount of the separation membrane 3 can be adjusted.

Therefore, even if the carbon dioxide concentration in the carbon dioxide-containing gas changes significantly, the effect of the carbon dioxide concentration immediately before the change can be suppressed, and the amount of permeating gas can be quickly adjusted, resulting in a high recovery rate. can be maintained and the carbon dioxide concentration in the desorbed gas can be further stabilized.

Further, as in the present embodiment, the carbon dioxide separator 1002 may have the decompression pump 7 configured to have a variable capacity.

In this case, the controller C3 controls the amount of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step based on the carbon dioxide concentration in the non-permeating gas detected by the carbon dioxide concentration detector 5. When it is determined that the concentration exceeds the upper limit of the predetermined range, the exhaust capacity of the decompression pump 7 is increased, and when it is determined that the concentration is below the lower limit of the predetermined range, the exhaust capacity of the decompression pump 7 is decreased. You can control it.

Thereby, the partial pressure difference can be increased without increasing the pressure of the carbon dioxide-containing gas flowing through the carbon dioxide-containing gas supply passage 9 .

Therefore, even when water vapor is contained in the carbon dioxide-containing gas, dew condensation on the surface of the separation membrane 3 can be suppressed, thereby suppressing a decrease in the usable membrane area due to adhesion of water droplets to the surface of the separation membrane 3. Since the control of the amount of permeating gas is simplified, the concentration of carbon dioxide in the desorbed gas can be further stabilized.

Further, as in the present embodiment, the carbon dioxide separator 1002 includes at least three adsorbers 2 (in the present embodiment, four adsorbers 2) in the adsorption device 202, and each adsorber 2 is , the adsorbers 2 can be connected in series, and may be connected by an adsorber connection channel 19 having control valves V6a to V7d on the way.

In this case, based on the concentration detected by the carbon dioxide concentration detector 5, the controller C3 determines the upper limit value of the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step within a predetermined range. If it is determined that it exceeds, the control valves V6a to V7d are controlled so that the adsorbers 2 in the adsorption process are connected in series, thereby making the adsorption device 202 function as permeable gas amount adjusting means. I do not care.

By controlling the control valves V6a to V7d, the operation mode of the PSA operation is changed from the normal mode to the serial mode in which any two of the adsorbers 2a to 2d are connected in series and the adsorption process is performed. The pressure loss of the adsorption device 202 becomes larger than before, and the partial pressure difference becomes larger.

As a result, the carbon dioxide partial pressure in the carbon dioxide-containing gas flowing through the first space of the carbon dioxide separator 1 can be increased by utilizing the pressure loss of the adsorber 2 without using an auxiliary device such as a pump. becomes possible, and the amount of carbon dioxide that permeates the separation membrane 3 can be increased.

Therefore, the carbon dioxide concentration in the desorbed gas can be further stabilized while suppressing energy consumption.

Further, as in the present embodiment, the carbon dioxide separator 1002 includes at least four adsorbers 2 (in the present embodiment, four adsorbers 2) in the adsorption device 202, and the non-permeating gas flow path 120 and the exhaust gas flow path 11 are branched corresponding to the respective adsorbers 2a to 2d, the branched flow paths are connected to the adsorbers 2a to 2d, and the adsorbers 2a to 2d in the non-permeating gas flow path 120 Corresponding branch flow paths may be provided with control valves V1a to V1d, respectively, and branch flow paths corresponding to adsorbers 2a to 2d in exhaust gas flow path 11 may be provided with control valves V2a to V2d, respectively.

In this case, based on the concentration detected by the carbon dioxide concentration detector 5, the controller C3 determines the lower limit value of the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber 2 in the adsorption step within a predetermined range. If it is determined that the adsorption device 202 is lower, the control valves V1a to V2d may be controlled so that the adsorbers 2 in the adsorption process are connected in parallel, thereby allowing the adsorption device 202 to function as permeable gas amount adjusting means.

By controlling the control valves V1a to V2d, the operation mode of the PSA operation is changed from the normal mode to the parallel mode in which the adsorption step is performed while the non-permeating gas is distributed and supplied to any two of the adsorbers 2a to 2d. , the pressure loss of the adsorption device 202 becomes smaller than before the change, and the partial pressure difference becomes smaller.

As a result, the carbon dioxide partial pressure in the carbon dioxide-containing gas flowing through the first space of the carbon dioxide separator 1 is reduced by using the pressure loss of the adsorber 2 without using auxiliary equipment such as a pump. , and the amount of carbon dioxide that permeates the separation membrane 3 can be reduced.

Therefore, the carbon dioxide concentration in the desorbed gas can be further stabilized while suppressing energy consumption.

(Other embodiments)
As described above, Embodiments 1 to 3 have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to embodiments with modifications, replacements, additions, omissions, and the like. Also, it is possible to combine the constituent elements described in the first to third embodiments to form a new embodiment.

Therefore, other embodiments will be exemplified below.

In Embodiments 1 to 3, as an example of the separation membrane 3, a facilitated transport membrane containing monoethanolamine, which is a type of alkanolamine, has been described. The separation membrane 3 may selectively permeate carbon dioxide or selectively permeate impurity gases coexisting with carbon dioxide in the source gas.

Therefore, the separation membrane 3 is not limited to the amine compound monoethanolamine. For example, if the separation membrane 3 is a separation membrane made of other amine compounds, a separation membrane containing an ionic liquid, or a separation membrane containing an alkali carbonate, a high carbon dioxide permeation rate can be obtained.

In Embodiments 1 to 3, the duration of the adsorption process, the purge process, and the regeneration process is determined based on the elapsed time from the time when each operation flag is turned ON. A temperature sensor may be included to determine the temperature change.

That is, when carbon dioxide is supplied to the adsorbent 4, adsorption of carbon dioxide proceeds from the upstream portion of the adsorber 2, and at the same time the temperature of the adsorbent 4 rises due to the heat of adsorption. Therefore, by detecting the temperature of the adsorbent 4 with a temperature detector, it is possible to detect the position in the adsorber 2 where the adsorption zone in which carbon dioxide is being adsorbed has reached.

This makes it possible to detect the passage of carbon dioxide supplied to the adsorbent 4 before it passes through.

Therefore, especially when the carbon dioxide concentration changes significantly during PSA operation, it is possible to prevent carbon dioxide from being mixed into the exhaust gas and discharged, thereby improving the recovery rate of carbon dioxide.

In addition to the temperature change described above, it is possible to detect the breakthrough by using the change in physical quantity due to the adsorption of carbon dioxide. Changes in the physical quantity include changes in the weight of the adsorbent 4 due to adsorption of carbon dioxide, changes in the exhaust gas flow rate and exhaust gas composition due to adsorption of carbon dioxide, and the like. In order to detect the state of adsorption using those values, necessary equipment such as a weighing scale, a flow meter, and a concentration detector may be added.

In Embodiments 1 to 3, carbon dioxide is desorbed from the adsorbent 4 by depressurization by the suction pump 15, but a heater configured to heat the adsorbent 4 is further provided, and adsorbs by heating. Carbon dioxide may be desorbed from the material 4 .

Alternatively, for example, the supply pump 6 may be a compressible pump, the exhaust gas flow path 11 may be provided with pressure loss such as an orifice, the suction pump 15 may be eliminated from the configuration, and the suction pump 15 may be removed by the operation of the control valve V3. can also

This simplifies the configuration of the device, thereby reducing the cost of the device.

Further, in Embodiments 1 to 3, the carbon dioxide concentration detector 5 is provided in the non-permeating gas flow path 120 on the downstream side of the carbon dioxide separator 1, but is provided in the carbon dioxide-containing gas supply flow path 9. good too. In that case, the amount of carbon dioxide permeating the separation membrane 3 is obtained from the temperature and water content of the carbon dioxide separator 1, the operation amount of the supply pump 6 and the decompression pump 7, etc., and the carbon dioxide concentration in the non-permeating gas is calculated. be able to.

As a result, it is possible to stabilize the carbon dioxide concentration in the non-permeating gas before the carbon dioxide-containing gas is supplied to the adsorption devices 200 to 202, so that a more stable carbon dioxide-enriched gas can be supplied. .

Note that the above-described embodiment is for illustrating the technology in the present disclosure, and various changes, replacements, additions, omissions, etc. can be made within the scope of the claims or equivalents thereof.

The present disclosure uses a carbon dioxide separator using a separation membrane that selectively permeates carbon dioxide, and an adsorption apparatus equipped with a plurality of adsorbers filled with an adsorbent that adsorbs carbon dioxide. It can be applied to a carbon dioxide separator that separates and recovers carbon dioxide from contained gas. Specifically, the present disclosure is applicable to a hydrogen production apparatus using hydrocarbon as fuel, a carbon dioxide separation and recovery apparatus that concentrates carbon dioxide in exhaust gas of a boiler, etc., and uses it as an industrial raw material.

1 carbon dioxide separator 2, 2a, 2b, 2c, 2d adsorber 3, 31 separation membrane 4, 4a, 4b, 4c, 4d adsorbent 5 carbon dioxide concentration detector 6, 61 supply pump 7 decompression pump 8 temperature controller 9 Carbon dioxide-containing gas supply channel 10 Purge flow control valve 11 Exhaust gas channel 14 Desorbed gas discharge channel 15 Suction pump 16 Carbon dioxide utilization device 17 Bypass flow control valve 18 Separator bypass channel 19 Adsorber connection channel 120 Non-permeating gas channel 121 Permeating gas channel 122 Permeating gas channel 200, 201, 202 Adsorption device 1000, 1001, 1002 Carbon dioxide separator C1, C2, C3 Controller V1a, V1b, V1c, V1d Control valve V2a, V2b , V2c, V2d control valves V3, V3a, V3b, V3c, V3d control valves V4a, V4b control valves V6a, V6b, V6c, V6d control valves V7a, V7b, V7c, V7d control valves

Claims (10)

By the separation membrane that selectively permeates carbon dioxide, the carbon dioxide-containing gas flows into the internal space from the carbon dioxide-containing gas channel, and the non-permeating gas that has not permeated the separation membrane flows out to the non-permeating gas channel. a carbon dioxide separator partitioned into a first space and a second space in which the permeated gas that has permeated the separation membrane flows out to the permeated gas flow path;
A pressure reducing device provided in the middle of the permeating gas flow path for depressurizing the second space so that carbon dioxide contained in the carbon dioxide-containing gas permeates the separation membrane and the permeating gas flows out to the permeating gas flow path. a pump;
Carbon dioxide concentration detection for detecting the concentration of carbon dioxide contained in either the carbon dioxide-containing gas flowing through the carbon dioxide-containing gas flow path or the non-permeating gas flowing through the non-permeating gas flow path vessel and
a permeable gas amount adjusting means for adjusting the flow rate of the permeable gas;
It has a plurality of adsorbers filled with an adsorbent that adsorbs carbon dioxide and connected to the downstream side of the non-permeable gas flow path, and at least one of the adsorbers absorbs carbon dioxide contained in the non-permeable gas. an adsorption device configured such that, while in an adsorption step of adsorbing onto said adsorbent, at least one remaining said adsorber is in a regeneration step of desorbing carbon dioxide from said adsorbent;
an exhaust gas channel connected downstream of the plurality of adsorbers so that the non-permeating gas not adsorbed by the adsorber in the adsorption step is exhausted from the adsorber in the adsorption step to the outside;
a desorbed gas discharge channel connected to a plurality of said adsorbers such that the desorbed gas desorbed from said adsorber in said regeneration step is recovered from said adsorber in said regeneration step;
decompressing the interior of the adsorber provided in the desorbed gas discharge channel in the regeneration step to desorb carbon dioxide from the adsorbent and cause the desorbed gas to flow out to the desorbed gas discharge channel; a suction pump;
Based on the concentration detected by the carbon dioxide concentration detector, the permeable gas amount adjusting means so that the concentration of carbon dioxide contained in the non-permeable gas flowing into the adsorber in the adsorption step is within a predetermined range. and a controller for controlling the carbon dioxide separation device. The permeation gas amount adjusting means adjusts the average value of the carbon dioxide partial pressure in the permeation gas flowing through the second space from the average value of the carbon dioxide partial pressure in the carbon dioxide-containing gas flowing through the first space. It functions as a partial pressure difference adjusting means for controlling the subtracted partial pressure difference,
When the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber in the adsorption step exceeds the upper limit of a predetermined range, the controller detects the concentration detected by the carbon dioxide concentration detector. If it is determined, the partial pressure difference adjusting means is controlled to increase the partial pressure difference within a range of 0 or more, and if it is determined that the concentration is below the lower limit of the predetermined range, the partial pressure difference is increased to 0 or more. 2. The carbon dioxide separator according to claim 1, wherein said partial pressure difference adjusting means is controlled so as to reduce within a range. The decompression pump is configured to have a variable capacity so as to also serve as the partial pressure difference adjusting means,
When the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber in the adsorption step exceeds the upper limit of a predetermined range, the controller detects the concentration detected by the carbon dioxide concentration detector. 3. The carbon dioxide separation according to claim 2, wherein the exhaust capacity of the decompression pump is increased when it is determined, and the exhaust capacity of the decompression pump is decreased when it is determined that the concentration is below the lower limit value of the predetermined range. Device. The adsorption device comprises at least three adsorbers,
Each of the adsorbers can be connected in series with each other, and is connected by a pipe equipped with a control valve in the middle,
When the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber in the adsorption step exceeds the upper limit of a predetermined range, the controller detects the concentration detected by the carbon dioxide concentration detector. 4. The carbon dioxide according to claim 2 or 3, which functions as said permeable gas amount adjusting means by controlling said control valve so that when it is determined, the adsorbers in said adsorption step are connected in series. separation device. The adsorption device comprises at least four adsorbers,
The respective adsorbers can be connected in parallel with each other, and are connected by a pipe equipped with a control valve on the way,
Based on the concentration detected by the carbon dioxide concentration detector, the controller detects when the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber in the adsorption step falls below the lower limit of a predetermined range. 5. Any one of claims 2 to 4, wherein, when determined, the control valve functions as the permeable gas amount adjusting means by controlling the control valve so that the adsorbers in the adsorption step are connected in parallel with each other. A carbon dioxide separation device according to any one of the preceding paragraphs. The separation membrane has a characteristic that the carbon dioxide permeation performance increases as the water content of the separation membrane increases,
The permeable gas amount adjusting means functions as a water amount adjusting means for adjusting the water content of the separation membrane,
When the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber in the adsorption step exceeds the upper limit of a predetermined range, the controller detects the concentration detected by the carbon dioxide concentration detector. If determined, the moisture content is increased by the moisture content adjusting means, and if it is determined that the concentration is below the lower limit of a predetermined range, the moisture content is decreased by the moisture content adjusting means. The carbon dioxide separator according to any one of 1. The separation membrane has a characteristic that the carbon dioxide permeation performance increases as the temperature of the separation membrane increases,
The permeable gas amount adjusting means functions as a temperature controller that adjusts the temperature of the carbon dioxide separator,
When the concentration of carbon dioxide contained in the non-permeating gas flowing into the adsorber in the adsorption step exceeds the upper limit of a predetermined range, the controller detects the concentration detected by the carbon dioxide concentration detector. If determined, the temperature controller raises the temperature of the carbon dioxide separator, and if it is determined that the concentration is below the lower limit of the predetermined range, the temperature controller lowers the temperature of the carbon dioxide separator. A carbon dioxide separator according to any one of claims 1 to 6. A separator bypass that connects the carbon dioxide-containing gas flow path and the non-permeating gas flow path via a bypass flow control valve so as to bypass the carbon dioxide separator and not the carbon dioxide concentration detector. further comprising a flow path,
The bypass flow rate adjustment valve adjusts the permeation gas amount by adjusting the flow rate of the carbon dioxide-containing gas flowing from the carbon dioxide-containing gas flow path through the separator bypass flow path to the non-permeating gas flow path. act as a means of
The controller controls the adsorber in the adsorption step based on the concentration detected by the carbon dioxide concentration detector when part of the carbon dioxide-containing gas is flowing through the separator bypass channel. When it is determined that the concentration of carbon dioxide contained in the non-permeating gas flowing into the separator exceeds the upper limit of the predetermined range, the bypass flow control valve controls the concentration of the carbon dioxide-containing gas flowing through the separator bypass flow path. If the flow rate is reduced and the bypass flow control valve is not fully open and it is determined that the concentration is below the lower limit of the predetermined range, the bypass flow control valve causes the dioxide to flow through the separator bypass flow path. 8. The carbon dioxide separator of any one of claims 1-7, wherein the flow rate of the carbon-containing gas is increased. Each of the adsorbers has a control valve in the middle which is controlled to be open when the permeating gas is allowed to flow into the adsorber and to be closed when the permeating gas is not allowed to flow into the adsorber. 9. The carbon dioxide separator according to any one of claims 1 to 8, wherein a pipe branched from said permeating gas flow path downstream of said decompression pump is connected. By the separation membrane that selectively permeates carbon dioxide, the carbon dioxide-containing gas flows into the internal space from the carbon dioxide-containing gas channel, and the non-permeating gas that has not permeated the separation membrane flows out to the non-permeating gas channel. a carbon dioxide separator partitioned into a first space and a second space in which the permeated gas that has permeated the separation membrane flows out to the permeated gas flow path;
A pressure reducing device provided in the middle of the permeating gas flow path for depressurizing the second space so that carbon dioxide contained in the carbon dioxide-containing gas permeates the separation membrane and the permeating gas flows out to the permeating gas flow path. a pump;
Carbon dioxide concentration detection for detecting the concentration of carbon dioxide contained in either the carbon dioxide-containing gas flowing through the carbon dioxide-containing gas flow path or the non-permeating gas flowing through the non-permeating gas flow path vessel and
a permeable gas amount adjusting means for adjusting the flow rate of the permeable gas;
It has a plurality of adsorbers filled with an adsorbent that adsorbs carbon dioxide and connected to the downstream side of the non-permeable gas flow path, and at least one of the adsorbers absorbs carbon dioxide contained in the non-permeable gas. an adsorption device configured such that, while in an adsorption step of adsorbing onto said adsorbent, at least one remaining said adsorber is in a regeneration step of desorbing carbon dioxide from said adsorbent;
an exhaust gas channel connected downstream of the plurality of adsorbers so that the non-permeating gas not adsorbed by the adsorber in the adsorption step is exhausted from the adsorber in the adsorption step to the outside;
a desorbed gas discharge channel connected to a plurality of said adsorbers such that the desorbed gas desorbed from said adsorber in said regeneration step is recovered from said adsorber in said regeneration step;
decompressing the interior of the adsorber provided in the desorbed gas discharge channel in the regeneration step to desorb carbon dioxide from the adsorbent and cause the desorbed gas to flow out to the desorbed gas discharge channel; A method of operating a carbon dioxide separator comprising a suction pump,
Based on the concentration detected by the carbon dioxide concentration detector, the permeable gas amount adjusting means so that the concentration of carbon dioxide contained in the non-permeable gas flowing into the adsorber in the adsorption step is within a predetermined range. A method of operating a carbon dioxide separator, wherein the flow rate of the permeate gas is adjusted by

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