JP7519149B1 - Gas Concentrator - Google Patents

Abstract

[Problem] To recover carbon dioxide at a higher concentration than when recovering carbon dioxide from a gas through a one-stage gas concentration process. [Solution] A gas concentration device 1 comprises a gas intake section 10 for taking in gas, a first concentration section 2 for generating a first concentrated gas with an increased carbon dioxide concentration from the taken in gas, a second concentration section 5 for generating a second concentrated gas with an even higher carbon dioxide concentration from the first concentrated gas, and a gas exhaust section 70 for exhausting the second concentrated gas to the outside. [Selected Figure] Figure 1

Description

The present invention relates to a device for concentrating gas from the atmosphere.

Devices for concentrating gas components in a gas have been known for some time.

For example, Patent Document 1 describes a gas concentration device that recovers high-concentration carbon dioxide from a raw gas (gas) containing carbon dioxide through a one-stage gas concentration process.

JP 2022-127000 A

However, the technology described in Patent Document 1 has a limit to the gas concentration that can be concentrated depending on the gas concentration, and it is not possible to directly recover higher concentrations of carbon dioxide from very low concentrations in the atmosphere.

In view of the above problems, the present invention aims to provide a gas concentration device that can recover carbon dioxide at a higher concentration than when carbon dioxide is recovered from a gas through a one-stage gas concentration process.

In order to solve the above problem, according to a first aspect of the present invention, the following gas concentration device is provided. This gas concentration device includes a gas intake section that takes in gas, a first concentration section that generates a first concentrated gas from the taken-in gas with an increased concentration of carbon dioxide, a second concentration section that generates a second concentrated gas from the first concentrated gas with an even increased concentration of carbon dioxide, and a gas exhaust section that exhausts the second concentrated gas to the outside.

In addition, in the gas concentration device according to the second aspect of the present invention, the first concentration section has a first adsorption section that adsorbs and desorbs carbon dioxide from the gas to generate the first concentrated gas, and the second concentration section has a second adsorption section that adsorbs and desorbs carbon dioxide from the first concentrated gas to generate the second concentrated gas, and further includes a pump configured to adjust the pressure in the first concentration section and the pressure in the second concentration section, and a control device that controls the pump and adjusts the pressure in the first concentration section and the pressure in the second concentration section.

In addition, in the gas concentration device according to the third aspect of the present invention, the first concentration section has a first switching section configured to be able to switch the supply destination of the gas, the first adsorption section has a first adsorption tank and a second adsorption tank, the second concentration section has a second switching section configured to be able to switch the supply destination of the first concentrated gas, the second adsorption section has a third adsorption tank and a fourth adsorption tank, and the control device controls the first switching section to switch the supply destination of the gas and controls the second switching section to switch the supply destination of the first concentrated gas.

In addition, in the gas concentration device according to the fourth aspect of the present invention, the volume of gas in the first concentration section is different from the volume of gas in the second concentration section.

In addition, in the gas concentration device according to the fifth aspect of the present invention, the volume of the third adsorption tank or the volume of the fourth adsorption tank is smaller than the volume of the first adsorption tank or the volume of the second adsorption tank.

In addition, in the gas concentration device according to the sixth aspect of the present invention, the volume of the third adsorption tank or the volume of the fourth adsorption tank is less than three-quarters and more than half the volume of the first adsorption tank or the second adsorption tank.

In addition, in the gas concentration device according to the seventh aspect of the present invention, the first concentration section has a first buffer tank that reduces pressure fluctuations within the first concentration section, and the second concentration section has a second buffer tank that reduces pressure fluctuations within the second concentration section, and the volume of the second buffer tank is smaller than the volume of the first buffer tank.

The gas concentration device according to the eighth aspect of the present invention further includes a throttle valve configured to adjust the flow rate of the first concentrated gas.

In addition, in the gas concentration device according to the ninth aspect of the present invention, the first concentration section has a first exhaust valve that exhausts the first concentrated gas, the second concentration section has a second exhaust valve that exhausts the second concentrated gas, and the control device controls the first switching section and the first exhaust valve in conjunction with each other to adjust the timing of exhausting the gas and the first concentrated gas, and controls the second switching section and the second exhaust valve in conjunction with each other to adjust the timing of exhausting the first concentrated gas and the second concentrated gas.

In addition, in the gas concentration device according to the tenth aspect of the present invention, the first concentration section has a first filter that filters the first concentrated gas, and the second concentration section has a second filter that filters the second concentrated gas.

The gas concentration device of the present invention makes it possible to recover carbon dioxide at a higher concentration than when carbon dioxide is recovered from a gas through a one-stage gas concentration process.

1 is a diagram illustrating an example of the overall configuration of a gas concentrating device according to an embodiment of the present invention. 2 is a timing chart showing an example of a process flow in a first concentrating section of the gas concentrating device of FIG. 1 . FIG. 11 is a diagram showing the flow of gas in the first concentrating section at time T11. FIG. 11 is a diagram showing the flow of gas in the first concentrating section at time T14. 4 is a timing chart showing an example of a process flow in a second concentrating section of the gas concentrating device of FIG. 1 .

Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicate descriptions will be omitted.

<Embodiment>
First, a gas concentrating device 1 according to an embodiment of the present invention will be described.

<Overall composition>
FIG. 1 is a diagram illustrating an example of the overall configuration of a gas concentrating device 1 according to an embodiment of the present invention.

As shown in FIG. 1, the gas concentration device 1 includes a gas intake section 10, a pump 9, a water removal tank 12, a first concentration section 2, a second concentration section 5, and a control device 8. Note that the specific configuration of the gas concentration device 1 is not limited to that shown in FIG. 1.

The gas concentration device 1 takes in gas from outside the gas concentration device 1 and generates a second concentrated gas with an increased concentration of carbon dioxide. Note that the gas components whose concentration can be increased by the gas concentration device 1 are not limited to carbon dioxide, but may include nitrogen, oxygen, hydrogen, carbon monoxide, etc.

First, the gas intake section 10 will be described. The gas intake section 10 takes in gas from outside the gas concentration device 1 into the gas concentration device 1. Specifically, the gas intake section 10 supplies gas to the air pump 11 from outside the gas concentration device 1. The gas taken in may be the atmosphere or a separately prepared raw gas.

Next, the pump 9 will be described. The pump 9 is configured to be able to adjust the pressure in the first concentration section 2 and the pressure in the second concentration section 5. Specifically, the gas concentration device 1 as the pump 9 has an air pump 11, a first pressure reduction pump 25, a first boost pump 27, a second pressure reduction pump 55, and a second boost pump 57. The air pump 11 supplies the gas sucked in from the gas intake section 10 to the water removal tank 12.

Next, the water removal tank 12 will be described. The water removal tank 12 removes moisture from the gas sucked in from the air pump 11, and reduces the moisture content in the gas. The gas with reduced moisture content is supplied to the first inlet 20.

Next, the first concentration section 2 will be described. The first concentration section 2 includes a first inlet section 20, a first switching section 21, a first adsorption section 22, a first pressure sensor 29, a first exhaust section 30, a first filter 31, a first check valve 33, a first throttle valve 35, a second throttle valve 37, a first exhaust valve 39, a first buffer tank 41, and a first outlet section 40. The first concentration section 2 generates a first concentrated gas with an increased concentration of carbon dioxide from the gas taken in from outside the gas concentration device 1.

The first inlet section 20 is an intake port that takes in gas from outside the first concentration section 2 into the first concentration section 2. Specifically, gas is supplied from the water removal tank 12 to the first switching section 21.

The first switching unit 21 is configured to be able to switch the supply destination of the gas supplied from the first inlet 20. The first switching unit 21 includes a first solenoid valve 21A, a first solenoid valve 21B, a first solenoid valve 21C, and a first solenoid valve 21D. The gas flow path is controlled by switching between the open state (OPEN) and the closed state (CLOSE) of each solenoid valve, and the supply destination of the gas is switched. In addition, each solenoid valve prevents backflow from the supply side to the intake side, and the side marked IN is the intake side. Specifically, the first solenoid valve 21A is a solenoid valve that controls the supply of gas from the water removal tank 12 to the first adsorption tank 23. The first solenoid valve 21B is a solenoid valve that controls the supply of gas from the water removal tank 12 to the second adsorption tank 24. The first solenoid valve 21C is a solenoid valve that controls the supply of gas from the first adsorption tank 23 to the first filter 31. The first solenoid valve 21D is a solenoid valve that controls the supply of gas from the second adsorption tank 24 to the first filter 31.

The first adsorption section 22 adsorbs and desorbs carbon dioxide from the gas taken in from outside the gas concentration device 1 to generate a first concentrated gas. The first adsorption section 22 is composed of a first adsorption tank 23 and a second adsorption tank 24. The first adsorption tank 23 and the second adsorption tank 24 are tanks to which gas is supplied from the first switching section 21 and which adsorb carbon dioxide from the gas. Gas is alternately supplied to the first adsorption tank 23 and the second adsorption tank 24. A first concentrated gas with an increased carbon dioxide concentration is generated by desorbing the carbon dioxide adsorbed in the first adsorption tank 23 or the second adsorption tank 24. The generated first concentrated gas is supplied to the first filter 31. In addition, the first exhaust gas with a lowered carbon dioxide concentration due to the adsorption of carbon dioxide is exhausted to the outside of the gas concentration device 1 through the first check valve 33A or the first check valve 33B and the first throttle valve 35. The first adsorption tank 23 and the second adsorption tank 24 have a carbon dioxide adsorbent using zeolite. Note that the first adsorption tank 23 and the second adsorption tank 24 may have an adsorbent of, for example, oxygen, hydrogen, carbon monoxide, or nitrogen instead of the carbon dioxide adsorbent.

The first filter 31 filters the first concentrated gas. For example, the first filter 31 filters the adsorbent desorbed from the first adsorption tank 23 and the second adsorption tank 24. The gas filtered by the first filter 31 is supplied to the first pressure reduction pump 25.

The first decompression pump 25 is a pump that decompresses the gas in the first adsorption tank 23 and the second adsorption tank 24. Gas is supplied from the first decompression pump 25 to the first boost pump 27.

The first boost pump 27 is a pump that pressurizes the gas flowing to the buffer tank 41, the third adsorption tank 53, and the fourth adsorption tank 54 of the second concentration section 5.

The first check valve 33 is a valve that prevents backflow from the supply or exhaust side to the intake side. As the first check valve 33, the first check valve 33A, the first check valve 33B, and the first check valve 33C are provided in the first concentration section 2. The first check valve 33A prevents backflow of gas from the first throttle valve 35 side to the first adsorption tank 23 side. The first check valve 33B prevents backflow of gas from the first throttle valve 35 side to the second adsorption tank 24 side. The first check valve 33C prevents backflow of gas from the first buffer tank 41 side to the first boost pump 27 side.

The first buffer tank 41 is a tank that temporarily stores gas and reduces pressure fluctuations and flow rate fluctuations within the first concentration section 2. Specifically, the first buffer tank 41 temporarily stores the first concentrated gas generated in the first adsorption tank 23 or the second adsorption tank 24 and supplies it to the second throttle valve 37.

The first pressure sensor 29 is a sensor that measures pressure. As the first pressure sensor 29, a first pressure sensor 29A, a first pressure sensor 29B, and a first pressure sensor 29C are provided in the first concentration section 2. The first pressure sensor 29A measures the pressure in the first adsorption tank 23, the first pressure sensor 29B measures the pressure in the second adsorption tank 24, and the first pressure sensor 29C measures the pressure in the first buffer tank 41.

The first throttle valve 35 and the second throttle valve 37 are throttle valves configured to adjust the flow rate of the first exhaust gas and the first concentrated gas. The first throttle valve 35 and the second throttle valve 37 are valves that adjust the pressure by adjusting the flow rate of the first exhaust gas and the first concentrated gas. Specifically, the first throttle valve 35 adjusts the flow rate of the first exhaust gas exhausted from the first adsorption tank 23 and the second adsorption tank 24 and exhausts it outside the gas concentration device 1. The second throttle valve 37 adjusts the flow rate of the first concentrated gas supplied from the first buffer tank 41 and supplies it to the second concentration section 5. In the first check valve 33 described above, the smaller the pressure difference between the supply or exhaust side and the intake side, the more likely it is that backflow will occur from the supply or exhaust side to the intake side. By limiting the flow rate in the first throttle valve 35 or the second throttle valve 37 and maintaining the pressure on the supply or exhaust side high, it is possible to suppress the occurrence of backflow. Specifically, the first throttle valve 35 keeps the exhaust side pressure of the first check valve 33A or the first check valve 33B high, thereby preventing the first exhaust gas from flowing back to the first adsorption tank 23 and the second adsorption tank 24.

The second throttle valve 37 also keeps the flow rate of the first concentrated gas supplied from the first concentrator 2 to the second concentrator 5 constant. By keeping the flow rate of the first concentrated gas concentrated in the gas concentration process in the second concentrator 5 constant, the gas concentration process is stabilized and the flow rate of the second concentrated gas exhausted outside the second concentrator 5 is also stabilized. By keeping the flow rate constant, carbon dioxide comes into even contact with the surface of the adsorbent in the second concentrator 5, improving the adsorption efficiency.

The first exhaust section 30 is an exhaust port that exhausts the first exhaust gas, the flow rate of which is adjusted by the first throttle valve 35, outside the gas concentration device 1.

The first exhaust valve 39 is a valve that exhausts the first concentrated gas. The first exhaust valve 39 is provided downstream of the first boost pump 27 and upstream of the first check valve 33C.

The first outlet 40 is an outlet through which the first concentrated gas, the flow rate of which has been adjusted by the second throttle valve 37, is supplied from the first concentration section 2.

Next, the second concentrating section 5 will be described. The second concentrating section 5 includes a second inlet section 50, a second switching section 51, a second adsorption section 52, a second pressure sensor 59, a second exhaust section 60, a second filter 61, a third filter 62, a second check valve 63, a third throttle valve 65, a second exhaust valve 69, a second buffer tank 71, a pressure reducing valve 73, a flowmeter 75, a constant flow valve 77, and a gas exhaust section 70. The second concentrating section 5 generates a second concentrated gas with a higher carbon dioxide concentration from the first concentrated gas.

Of the components of the second concentration section 5, those that are the same as those of the first concentration section 2 will be omitted from the description as appropriate. That is, the second switching section 51 is the first switching section 21, the third adsorption tank 53 and the fourth adsorption tank 54 are the first adsorption tank 23 and the second adsorption tank 24, the second pressure sensor 59 is the first pressure sensor 29, the second exhaust section 60 is the first exhaust section 30, the second filter 61 is the first filter 31, the second check valve 63 is the first check valve 33, the third throttle valve 65 is the first throttle valve 35, the second exhaust valve 69 is the first exhaust valve 39, and the second buffer tank 71 is the first buffer tank 41. Since each of these components can have the same configuration, the description as above will be omitted as appropriate.

The second inlet section 50 is an intake port through which the first concentrated gas supplied from the first outlet section 40 is supplied into the second concentration section 5.

The second pressure reduction pump 55 is a pump that reduces the pressure of the gas in the third adsorption tank 53 and the fourth adsorption tank 54. Gas is supplied from the first pressure reduction pump 25 to the first boost pump 27.

The second boost pump 57 is a pump for pressurizing the second concentrated gas and discharging it outside the gas concentration device 1.

The volume of gas in the first concentration section 2 is different from the volume of gas in the second concentration section 5. Specifically, the volume of gas in the second concentration section 5 is smaller than the volume of gas in the first concentration section 2. Because the volume of gas in the second concentration section 5 is smaller than the volume of gas in the first concentration section 2, the volume of gas that requires pressure control is smaller, and the output of each pump 9 that controls the pressure in the first concentration section 2 can be reduced.

The second adsorption section 52 adsorbs and desorbs carbon dioxide from the first concentrated gas to generate a second concentrated gas. The second adsorption section 52 has a third adsorption tank 53 and a fourth adsorption tank 54. The volume of the third adsorption tank 53 or the volume of the fourth adsorption tank 54 is smaller than the volume of the first adsorption tank 23 or the volume of the second adsorption tank 24. For example, the volume of the third adsorption tank or the volume of the fourth adsorption tank may be half, two-thirds, one-third, three-quarters, four-fifths, or four-thirds of the volume of the first adsorption tank or the second adsorption tank, and preferably, it may be four-fifths or less and one-fifth or more. More preferably, the volume of the third adsorption tank or the fourth adsorption tank is three-quarters or less and half or more of the volume of the first adsorption tank or the second adsorption tank. The first concentrated gas has a higher carbon dioxide concentration than the gas sucked in from outside the gas concentration device 1 in the first concentration section 2, that is, the number of carbon dioxide molecules per specific volume is greater. Therefore, the volume required to concentrate the first concentrated gas in the third adsorption tank 53 or the fourth adsorption tank 54 is smaller than the volume required to concentrate the gas sucked in from outside the gas concentration device 1 in the first adsorption tank 23 or the second adsorption tank 24. The smaller the tank volume, the lower the cost of the tank itself can be compared to when the tank volume is large, and since the volume of gas that requires pressure control is smaller, the output of each pump can be reduced. In other words, the output of the second pressure reduction pump 55 may be smaller than the output of the first pressure reduction pump 25.

The third filter 62 filters the second concentrated gas. For example, the third filter 62 filters out dust particles and the like in the buffer. The gas filtered by the third filter 62 is supplied to the pressure reducing valve 73.

The volume of the second buffer tank 71 is smaller than the volume of the first buffer tank 41. For example, the volume of the second buffer tank 71 may be half, two-thirds, one-third, three-quarters, four-fifths, or four-thirds of the volume of the first buffer tank 41, and preferably is less than four-fifths and more than one-fifth. More preferably, the volume of the second buffer tank 71 is less than three-quarters and more than half the volume of the first buffer tank 41. The smaller the tank volume, the lower the cost of the tank itself can be compared to a case where the tank volume is large, and since the volume of gas requiring pressure control is smaller, the output of each pump can be reduced.

The pressure reducing valve 73 reduces the pressure of the second concentrated gas. The pressure reducing valve 73 may be an electronic expansion valve whose opening is adjustable, or a solenoid valve. When the pressure reducing valve 73 is a solenoid valve, it can be switched between a fully open state and a state in which the opening is reduced so as to reduce the pressure of the second concentrated gas. The second concentrated gas reduced in pressure by the pressure reducing valve 73 is supplied to the flow meter 75.

The flow meter 75 detects the flow rate of the second concentrated gas. The second concentrated gas whose flow rate is detected by the flow meter 75 is supplied to the constant flow valve 77.

The constant flow valve 77 limits the maximum flow rate of the second concentrated gas passing through. The second concentrated gas is supplied from the constant flow valve 77 to the gas exhaust section 70.

The gas exhaust unit 70 exhausts the second concentrated gas from within the gas concentration device 1 to the outside of the gas concentration device 1. The exhausted second concentrated gas may be stored in a tank or the like, or may be used as appropriate.

Next, the control device 8 will be described. The control device 8 controls each part of the gas concentration device 1. The control device 8 is composed of a part or the whole of an analog circuit, or a digital processor or memory. The control device 8 has the following functional blocks: a communication unit 81, a control unit 83, and a memory unit 85.

The communication unit 81 of the control device 8 transmits and receives signals. For example, the communication unit 81 transmits and receives signals to and from the outside of the gas concentration device 1, or transmits and receives signals to and from components within the gas concentration device 1, such as the pressure sensors 29 and 59 and the flow meter 75. The control unit 83 of the control device 8 performs various controls based on signals received by the gas concentration device 1 from the outside or inside, measured values or control target values such as flow rate and pressure stored in the memory unit 85, or various control parameters. The control parameters include, for example, the open/closed state of each solenoid valve of the first switching unit 21 or the second switching unit 51, the open/closed state of the first exhaust valve 39 and the second exhaust valve 69, etc. The memory unit 85 of the control device 8 stores the measured values or control target values, or various control parameters.

The control unit 83 of the control device 8 controls the pump 9 to adjust the pressure in the first concentration unit 2 and the pressure in the second concentration unit 5. Specifically, the control unit 83 controls the first pressure reduction pump 25 and the air pump 11 to adjust the pressure in the first concentration unit 2. The control unit 83 also controls the second pressure reduction pump 55, the first boost pump 27, and the second boost pump 57 to adjust the pressure in the second concentration unit 5. The control unit 83 also controls the first switching unit to switch the supply destination of the gas, and controls the second switching unit to switch the supply destination of the first concentrated gas. Specifically, the control unit 83 controls the opening and closing states of the first solenoid valve 21A, the first solenoid valve 21B, the first solenoid valve 21C, and the first solenoid valve 21D of the first switching unit 21. The control unit 83 controls the opening and closing states of each solenoid valve to control the supply of gas to the first adsorption tank 23 or the second adsorption tank 24, or the supply of gas from the first adsorption tank 23 or the second adsorption tank 24. Similarly, the control unit 83 controls the opening and closing states of the second solenoid valves 51A, 51B, 51C, and 51D of the second switching unit 51 to control the supply destination of the gas to the third adsorption tank 53 or the fourth adsorption tank 54. Furthermore, the control unit 83 controls the first switching unit 21 and the first exhaust valve 39 in cooperation with each other to adjust the timing of exhausting the gas and the first concentrated gas. Specifically, the control unit 83 controls the opening and closing states of each solenoid valve of the first switching unit 21 and the first exhaust valve 39 to adjust the timing of exhausting the gas and the first concentrated gas. Similarly, the control unit 83 controls the second switching unit 51 and the second exhaust valve 69 in cooperation with each other to adjust the timing of exhausting the first concentrated gas and the second concentrated gas.

<Example of operation>
Concentration of gas is performed, for example, as follows. The gas sucked in from outside the gas concentration device 1 by the air pump 11 is supplied to the first adsorption tank 23. The carbon dioxide adsorbent in the first adsorption tank 23 adsorbs carbon dioxide from the gas supplied to the first adsorption tank 23. The first exhaust gas in which carbon dioxide has been adsorbed and the carbon dioxide concentration has been reduced is exhausted to the outside of the gas concentration device 1 through the first exhaust section 30. Next, the pressure of the gas in the first adsorption tank 23 is reduced by the first pressure reducing pump 25, thereby desorbing carbon dioxide from the carbon dioxide adsorbent in the first adsorption tank 23. Since carbon dioxide is desorbed from the adsorbent, the adsorbent can adsorb carbon dioxide again. That is, the carbon dioxide adsorbent is regenerated by desorption of carbon dioxide. The gas containing carbon dioxide desorbed from the first adsorption tank 23 is a first concentrated gas having a higher carbon dioxide concentration than the gas supplied from outside the gas concentration device 1. The first concentrated gas is pressurized by the first boost pump 27 and supplied to the second concentrating section 5. The first concentrated gas introduced into the second concentrating section 5 is supplied to the third adsorption tank 53. The carbon dioxide adsorbent in the third adsorption tank 53 adsorbs carbon dioxide from the gas supplied to the third adsorption tank 53. The second exhaust gas in which carbon dioxide has been adsorbed and the carbon dioxide concentration has been reduced is exhausted to the outside of the gas concentrating device 1 through the second exhaust section 60. Next, the pressure of the gas in the third adsorption tank 53 is reduced by the second decompression pump 55, thereby desorbing the carbon dioxide in the third adsorption tank 53. The gas containing carbon dioxide desorbed from the third adsorption tank 53 is a second concentrated gas having a higher carbon dioxide concentration than the first concentrated gas supplied from the first concentrating section 2. This second concentrated gas is pressurized by the second boost pump 57 and exhausted to the outside of the gas concentrating device 1. The adsorption and desorption of carbon dioxide is carried out alternately between the first adsorption tank 23 and the second adsorption tank 24 and alternately between the third adsorption tank 53 and the fourth adsorption tank 54 .

<Processing flow>
FIG. 2 is a timing chart showing an example of the flow of the process in the first concentrating section 2 of the gas concentrating device 1 of FIG. 1. FIG. 2 shows the open/closed states (OPEN or CLOSE) of the first solenoid valve 21A, the first solenoid valve 21B, the first solenoid valve 21C, and the first solenoid valve 21D of the first switching section 21, and the open/closed state (OPEN or CLOSE) of the first exhaust valve 39, in time series. FIG. 2 also shows which stage the first adsorption tank 23 and the second adsorption tank 24 are in, that is, adsorption, pressure equalization, or desorption, in time series. FIG. 3 is a diagram showing the flow of gas in the first concentrating section 2 at time T11. FIG. 4 is a diagram showing the flow of gas in the first concentrating section 2 at time T14. The flow of carbon dioxide adsorption and desorption alternately performed between the first adsorption tank 23 and the second adsorption tank 24 will be described with reference to FIGS. 1, 2, 3, and 4.

At time T11, the first solenoid valve 21A is open, the first solenoid valve 21B is closed, the first solenoid valve 21C is closed, and the first solenoid valve 21D is open, the first adsorption tank 23 is in an adsorption state, and the second adsorption tank 24 is in a desorption state. As shown in FIG. 3, the gas sucked in from outside the gas concentration device 1 by the air pump 11 is supplied to the first adsorption tank 23. The first adsorption tank 23 adsorbs carbon dioxide from the supplied gas. The first exhaust gas in which carbon dioxide has been adsorbed and the carbon dioxide concentration has been reduced is discharged outside the gas concentration device 1 through the first exhaust section 30. Meanwhile, the pressure of the gas in the second adsorption tank 24 is reduced by the first pressure reduction pump 25, thereby desorbing carbon dioxide from the carbon dioxide adsorbent in the second adsorption tank 24 to generate a first concentrated gas. The first concentrated gas is supplied to the second concentration section 5 through the first outlet section 40. By desorption of carbon dioxide, the carbon dioxide adsorbent in the second adsorption tank 24 is regenerated.

Returning to FIG. 2, at time t111, the first solenoid valve 21B switches to an open state, and the first solenoid valve 21D switches to a closed state. At time T12, the first adsorption tank 23 and the second adsorption tank 24 are in an equal pressure state. The gas sucked in from outside the gas concentration device 1 by the air pump 11 is supplied to the first adsorption tank 23 and the second adsorption tank 24. In addition, the gas in the first adsorption tank 23 flows into the second adsorption tank 24, which was in a reduced pressure state at time T11, and the pressure in the first adsorption tank 23 and the pressure in the second adsorption tank 24 become equal. Here, since the first solenoid valve 21C and the first solenoid valve 21D are in a closed state, the gas is not supplied to the second concentration section 5 side, and the gas is exhausted from the first exhaust section 30.

At time t112, the first solenoid valve 21A switches to a closed state, and the first solenoid valve 21C switches to an open state. At time T13, the first adsorption tank 23 is in a desorption state, and the second adsorption tank 24 is in an adsorption state. The adsorption and desorption states of each tank at time T11 are switched over, and the first concentrated gas is supplied from the first adsorption tank 23 to the first filter 31 side. Also, at time t112, the first exhaust valve 39 also switches to an open state. By opening the first exhaust valve 39, the gas on the intake side of the first check valve 33C is exhausted, and its pressure drops. By lowering the pressure on the intake side of the first check valve 33, the differential pressure between the intake side and the supply side of the first check valve 33C is maintained in a state where the supply side is higher, so that the first check valve 33C can prevent backflow of gas from the supply side to the intake side. This exhaust helps prevent backflow caused by pressure fluctuations when the adsorption and desorption states of each tank switch.

At time t113, the first exhaust valve 39 is switched to a closed state, and exhaust stops. At time T14, the first adsorption tank 23 continues to be in a desorption state, and the second adsorption tank 24 continues to be in an adsorption state. As shown in FIG. 4, the gas sucked in from outside the gas concentration device 1 by the air pump 11 is supplied to the second adsorption tank 24. The second adsorption tank 24 adsorbs carbon dioxide from the supplied gas. The first exhaust gas, in which carbon dioxide has been adsorbed and the carbon dioxide concentration has been reduced, is discharged outside the gas concentration device 1 through the first exhaust section 30. Meanwhile, the pressure of the gas in the first adsorption tank 23 is reduced by the first pressure reduction pump 25, so that carbon dioxide is desorbed from the carbon dioxide adsorbent in the first adsorption tank 23 to generate a first concentrated gas. The first concentrated gas is supplied to the second concentration section 5 through the first outlet section 40. The carbon dioxide adsorbent in the first adsorption tank 23 is regenerated by the desorption of carbon dioxide.

Returning to FIG. 2, at time t114, the first solenoid valve 21A switches to an open state, and the first solenoid valve 21C switches to a closed state. At time T15, the first adsorption tank 23 and the second adsorption tank 24 are in an equal pressure state. The gas sucked in from outside the gas concentration device 1 by the air pump 11 is supplied to the first adsorption tank 23 and the second adsorption tank 24. In addition, the gas in the second adsorption tank 24 flows into the first adsorption tank 23, which was in a reduced pressure state at time T11, and the pressure in the first adsorption tank 23 and the pressure in the second adsorption tank 24 become equal. Here, since the first solenoid valve 21C and the first solenoid valve 21D are in a closed state, the gas is not supplied to the second concentration section 5 side, and the gas is exhausted from the first throttle valve 35 side.

At time t115, the first solenoid valve 21B switches to the closed state, and the first solenoid valve 21D switches to the open state. At time T16, the first adsorption tank 23 is in the adsorption state, and the second adsorption tank 24 is in the desorption state. The adsorption and desorption states of each tank at time T14 are switched, and the first concentrated gas is supplied from the second adsorption tank 24 to the first filter 31 side. Also, at time t115, the first exhaust valve 39 switches to the open state.

At time t116, the first exhaust valve 39 switches to the closed state, and exhaust stops. Here, as in the case of T11, the first solenoid valve 21A is open, the first solenoid valve 21B is closed, the first solenoid valve 21C is closed, and the first solenoid valve 21D is open, the first adsorption tank 23 is in the adsorption state, and the second adsorption tank 24 is in the desorption state.

By repeating the above process, carbon dioxide adsorption and desorption are alternately performed in the first adsorption tank 23 and the second adsorption tank 24 of the first concentration section 2, and the first concentrated gas is generated. Here, the adsorption and desorption of carbon dioxide is controlled by switching the first switching section 21 and adjusting the pressure inside the gas concentration device 1 by the air pump 11 and the first pressure reduction pump 25.

Figure 5 is a timing chart showing an example of the process flow in the second concentrating section 5 of the gas concentrating device 1 of Figure 1. Figure 5 shows the open/closed states (OPEN or CLOSE) of the second solenoid valves 51A, 51B, 51C, and 51D of the second switching section 51, and the open/closed state (OPEN or CLOSE) of the second exhaust valve 69, in chronological order. Figure 5 also shows which stage the third adsorption tank 53 and the fourth adsorption tank 54 are in, adsorption, pressure equalization, or desorption, in chronological order.

5, the flow of carbon dioxide adsorption and desorption in the second concentrator 5 overlaps with the flow of carbon dioxide adsorption and desorption in the first concentrator 2, and the description thereof will be omitted as appropriate. Each component of the second concentrator 5 can be replaced with each component corresponding to the first concentrator 2. That is, the same configuration can be adopted as the air pump 11 as the first boost pump 27, the first suction tank 23 as the third suction tank 53, the second suction tank 24 as the fourth suction tank 54, the first solenoid valve 21A as the second solenoid valve 51A, the first solenoid valve 21B as the second solenoid valve 51B, the first solenoid valve 21C as the second solenoid valve 51C, the first solenoid valve 21D as the second solenoid valve 51D, the first check valve 33C as the second check valve 63C, the first exhaust valve 39 as the second exhaust valve 69, times T11 to T16 as times T21 to T26, and times t100 to t126 as times t200 to t226, so duplicated explanations will be omitted as appropriate.

Similar to the first concentration section 2, carbon dioxide adsorption and desorption are alternately performed in the third adsorption tank 53 and the fourth adsorption tank 54 of the second concentration section 5 to generate a second concentrated gas. Here, the adsorption and desorption of carbon dioxide in the second adsorption section 52 of the second concentration section 5 is controlled by switching the second switching section 51 and adjusting the pressure in the second concentration section 5 by the first boost pump 27 and the second pressure reduction pump 55.

<Action and effect>
As described above, the gas concentration device 1 of this embodiment comprises a gas intake section 10 that takes in gas, a first concentration section 2 that generates a first concentrated gas having an increased concentration of carbon dioxide from the taken-in gas, a second concentration section 5 that generates a second concentrated gas having an even higher concentration of carbon dioxide from the first concentrated gas, and a gas exhaust section 70 that exhausts the second concentrated gas to the outside.

With this configuration, gas concentration is performed in two stages, making it possible to recover carbon dioxide at a higher concentration than when carbon dioxide is recovered from gas through a single-stage gas concentration process.

In addition, in the gas concentration device 1, the first concentration section 2 has a first adsorption section 22 that adsorbs and desorbs carbon dioxide from the gas to generate a first concentrated gas, and the second concentration section 5 has a second adsorption section 52 that adsorbs and desorbs carbon dioxide from the first concentrated gas to generate a second concentrated gas, and further includes a pump 9 that is configured to adjust the pressure in the first concentration section 2 and the pressure in the second concentration section 5, and a control device 8 that controls the pump 9 and adjusts the pressure in the first concentration section 2 and the pressure in the second concentration section 5.

This configuration allows gas containing carbon dioxide to be obtained more quickly than when gas concentration is performed by thermal control.

In addition, in the gas concentration device 1, the first concentration section 2 has a first switching section 21 configured to be able to switch the supply destination of the gas, the first adsorption section 22 has a first adsorption tank 23 and a second adsorption tank 24, the second concentration section 5 has a second switching section 51 configured to be able to switch the supply destination of the first concentrated gas, the second adsorption section 52 has a third adsorption tank 53 and a fourth adsorption tank 54, and the control device 8 controls the first switching section 21 to switch the supply destination of the gas and controls the second switching section 51 to switch the supply destination of the first concentrated gas.

With this configuration, gas can be concentrated alternately in the two adsorption tanks of each concentration section, making gas concentration more efficient than when each concentration section has only one adsorption tank.

In addition, in the gas concentration device 1, the volume of gas in the first concentration section 2 is different from the volume of gas in the second concentration section 5.

According to this configuration, when the volume of gas in the second concentration section is larger than the volume of gas in the first concentration section, a larger amount of second concentrated gas can be obtained compared to when the volume of gas in the second concentration section is the same as the volume of gas in the first concentration section, and when the volume of gas in the second concentration section is smaller than the volume of gas in the first concentration section, the size of the device can be reduced and costs can be reduced.

In addition, in the gas concentration device 1, the volume of the third adsorption tank 53 or the volume of the fourth adsorption tank 54 is smaller than the volume of the first adsorption tank 23 or the volume of the second adsorption tank 24.

With this configuration, compared to when the adsorption tank has a large volume, it is possible to reduce the cost of the tank itself, and because the volume of gas that requires pressure control is also small, it is also possible to reduce the output of the pump used for pressure control.

In addition, in the gas concentration device 1, the volume of the third adsorption tank 53 or the volume of the fourth adsorption tank 54 is less than three-quarters and more than half the volume of the first adsorption tank 23 or the second adsorption tank 24.

With this configuration, compared to when the adsorption tank has a large volume, it is possible to reduce the cost of the tank itself, and because the volume of gas that requires pressure control is also small, it is also possible to reduce the output of the pump used for pressure control.

In addition, in the gas concentration device 1, the first concentration section 2 has a first buffer tank 41 that reduces pressure fluctuations within the first concentration section 2, and the second concentration section 5 has a second buffer tank 71 that reduces pressure fluctuations within the second concentration section 5, and the volume of the second buffer tank 71 is smaller than the volume of the first buffer tank 41.

With this configuration, compared to when the volume of the buffer tank is large, it is possible to reduce the cost of the buffer tank itself, and because the volume of gas that requires pressure control is also small, it is also possible to reduce the output of the pump used for pressure control.

In addition, the gas concentration device 1 further includes a throttle valve that is configured to adjust the flow rate of the first concentrated gas.

With this configuration, the gas concentration process in the second concentration section is stable, and the flow rate of the second concentrated gas exhausted outside the second concentration section is also stable, compared to when the flow rate of the first concentrated gas fluctuates unstably.

In addition, in the gas concentration device 1, the first concentration section 2 has a first exhaust valve 39 that exhausts the first concentrated gas, and the second concentration section 5 has a second exhaust valve 69 that exhausts the second concentrated gas, and the control device 8 controls the first switching section 21 and the first exhaust valve 39 in conjunction with each other to adjust the timing of exhausting the gas and the first concentrated gas, and controls the second switching section 51 and the second exhaust valve 69 in conjunction with each other to adjust the timing of exhausting the first concentrated gas and the second concentrated gas.

This configuration can reduce pressure fluctuations within the gas concentration device compared to when exhaust is not performed.

In addition, in the gas concentration device 1, the first concentration section 2 has a first filter 31 that filters the first concentrated gas, and the second concentration section 5 has a second filter 61 that filters the second concentrated gas.

This configuration makes it possible to prevent desorbed adsorbents and other substances from being mixed into the collected gas, compared to when there is no filter.

<Modification>
The present invention is not limited to the above-described embodiment. In other words, the above-described specific example may be modified by a person skilled in the art as appropriate, and the modifications may be included within the scope of the present invention as long as they include the features of the present invention. In addition, the elements of the above-described embodiment and the following modifications may be combined to the extent technically possible, and the combination of these may be included within the scope of the present invention as long as they include the features of the present invention.

For example, although the embodiment has been described as an example of a gas concentration device 1 that performs gas concentration in two stages, the gas concentration device 1 may also be configured to perform gas concentration in three stages. For example, the gas concentration device 1 may further include a third concentration section that generates a third concentrated gas with an increased carbon dioxide concentration from the second concentrated gas. In this case, a gas containing a higher concentration of carbon dioxide can be obtained compared to the case of gas concentration in two stages.

In the embodiment, gas concentration is performed by controlling the pressure of parallel adsorption tanks, but other methods of gas concentration, such as chemical adsorption, chemical absorption, membrane separation, and cryogenic separation, may also be used. For example, gas concentration by thermal control may be performed in two stages.

In addition, in the embodiment, the volume of the third adsorption tank 53 or the volume of the fourth adsorption tank 54 is smaller than the volume of the first adsorption tank 23 or the volume of the second adsorption tank 24, but the volume of the third adsorption tank 53 or the volume of the fourth adsorption tank 54 may be the same as the volume of the first adsorption tank 23 or the volume of the second adsorption tank 24, or may be larger. When the volume of the third adsorption tank 53 or the volume of the fourth adsorption tank 54 is large, more second concentrated gas can be obtained in one cycle of carbon dioxide adsorption and desorption.

In addition, the adsorption and desorption times T21, T23, T24, or T26 in the second concentration section 5 may be longer, the same, or shorter than the adsorption and desorption times T11, T13, T24, and T26 in the first concentration section 2. For example, the time T24 at which the third adsorption tank 53 is in a desorption state may be longer, shorter, or the same as the time T14 at which the first adsorption tank 23 is in a desorption state. For example, by setting each of the times T11 to T16 shorter, gas concentration can be performed at a higher speed. For example, when comparing the time required to reach adsorption breakthrough in one stage to obtain a desired carbon dioxide concentration from the carbon dioxide concentration in the atmosphere and the total time required for the first concentrated gas and the second concentrated gas to reach adsorption breakthrough in two stages, the latter may be faster. In addition, the pressure controlled in the first concentration section 2 and the pressure controlled in the second concentration section 5 may be the same pressure or different pressures. For example, the pressure in the third adsorption tank 53 at time T24 when the third adsorption tank 53 is in the desorption state may be higher, lower, or the same as the pressure in the first adsorption tank 23 at time T14 when the first adsorption tank 23 is in the desorption state. Furthermore, for example, the first cycle, which is the total time from T11 to T16 of the first concentrating section 2, may be longer, shorter, or the same as the second cycle, which is the total time from T21 to T26 of the second concentrating section 5. The above time, pressure, cycle, etc. may be adjusted according to the desired carbon dioxide concentration, yield, yield stability, etc. In addition, the timing of exhaust by opening and closing the first exhaust valve 39 or the second exhaust valve 69 may also be adjusted according to the above time and pressure changes. By adjusting the exhaust timing, the pressure balance in the gas concentrating device 1 can be stabilized.

In addition, while the second throttle valve 37 for adjusting the flow rate of the first concentrated gas is provided in the first concentration section 2 as an example, the second throttle valve 37 may be provided in the second concentration section 5, or may be provided independently of the first concentration section 2 and the second concentration section 5. In addition, the flow rate may be changed in response to the opening and closing of the first switching section 21 and the second switching section 51, and the change in pressure caused by the pump 9.

In addition, while the control unit 83 controls the pressure in the first concentration unit 2 and the pressure in the second concentration unit 5 at independent timings, the timings of the two stages of gas concentration may be controlled in conjunction with each other.

The volume of the first adsorption tank 23 and the volume of the second adsorption tank 24 may be the same, or one of them may be larger. The volume of the third adsorption tank 53 and the volume of the fourth adsorption tank 54 may be the same, or one of them may be larger.

In addition, in this embodiment, the first concentration section 2 and the second concentration section 5 each have two adsorption tanks as an example, but the number of adsorption tanks in each concentration section may be one or three or more. For example, the first concentration section 2 may have three adsorption tanks, and the second concentration section 5 may have four adsorption tanks.

In addition, although the configuration in which the volume of gas in the second concentrator 5 is smaller than the volume of gas in the first concentrator 2 has been shown as an example, the volume of gas in the second concentrator 5 may be larger than or the same as the volume of gas in the first concentrator 2. If the volume of gas in the second concentrator 5 is larger than the volume of gas in the first concentrator 2, more second concentrated gas can be obtained in one cycle of carbon dioxide adsorption and desorption. In addition, although the configuration in which the volumes of the adsorption tanks 23, 24, 53, and 54 and the buffer tanks 41 and 71 are different has been shown as an example, for example, the volumes of the members constituting the flow paths in the gas concentration device 1 may be different. For example, the gas volume may be different depending on the diameter of the tubes, hoses, connectors constituting the flow paths in the gas concentration device 1.

Furthermore, the flow meter 75 may be provided, for example, before or after the first throttle valve 35, the second throttle valve 37, and the third throttle valve 65. The control device 8 may control each solenoid valve or each pump based on the measured flow rate, and adjust the pressure within the gas concentration device 1 and the supply destination of the gas or each concentrated gas.

1: Gas concentrator 2: First concentrator 5: Second concentrator 10: Gas intake section 70: Gas exhaust section

Claims (7)

A gas intake section for taking in gas;
a first concentration section for generating a first concentrated gas having an increased concentration of carbon dioxide from the introduced gas;
a second concentration section for generating a second concentrated gas having a further increased concentration of carbon dioxide from the first concentrated gas;
a gas exhaust section that exhausts the second concentrated gas to the outside;
A pump configured to be able to adjust the pressure in the first concentration section and the pressure in the second concentration section;
a control device that controls the pump and adjusts the pressure in the first concentration section and the pressure in the second concentration section;
a throttle valve configured to adjust a flow rate of the first concentrated gas supplied from the first concentration section to the second concentration section;
Equipped with
the first concentration unit includes a first adsorption unit having a first adsorption tank and a second adsorption tank, which adsorbs and desorbs carbon dioxide from the gas to generate the first concentrated gas, and a first switching unit configured to be able to switch a supply destination of the gas,
the second concentration unit includes a second adsorption unit having a third adsorption tank and a fourth adsorption tank, which adsorbs and desorbs carbon dioxide from the first concentrated gas to generate the second concentrated gas, and a second switching unit configured to be able to switch a supply destination of the first concentrated gas;
The control device controls the first switching unit to switch the supply destination of the gas, and controls the second switching unit to switch the supply destination of the first concentrated gas.
Gas concentrator. The volume of the gas in the first concentration section is different from the volume of the gas in the second concentration section.
The gas concentrating device according to claim 1 . The volume of the third adsorption tank or the volume of the fourth adsorption tank is smaller than the volume of the first adsorption tank or the volume of the second adsorption tank.
3. The gas concentrating device according to claim 2 . The volume of the third adsorption tank or the volume of the fourth adsorption tank is equal to or less than three-quarters and equal to or more than one-half of the volume of the first adsorption tank or the second adsorption tank.
The gas concentrating device according to claim 3 . the first enrichment section has a first buffer tank that reduces pressure fluctuations in the first enrichment section,
the second enrichment section has a second buffer tank that reduces pressure fluctuations in the second enrichment section,
The volume of the second buffer tank is smaller than the volume of the first buffer tank.
The gas concentrating device according to claim 1 . the first concentrating section has a first exhaust valve that exhausts the first concentrated gas,
the second concentrating section has a second exhaust valve that exhausts the second concentrated gas,
The control device controls the first switching unit and the first exhaust valve in cooperation with each other to adjust the timing of exhaust of the gas and the exhaust of the first concentrated gas, and controls the second switching unit and the second exhaust valve in cooperation with each other to adjust the timing of exhaust of the first concentrated gas and the exhaust of the second concentrated gas.
The gas concentrating device according to claim 1 . the first concentration section has a first filter that filters the first concentrated gas,
The second concentration section has a second filter that filters the second concentrated gas.
The gas concentrating device according to claim 1 .

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