CN116395637A - A tail gas recovery device - Google Patents

Abstract

The invention discloses a tail gas recovery device which comprises pressurizing equipment, a gas adsorption separator, buffering equipment and a purifier which are connected in sequence, so as to recover and purify tail gas; the pressurizing equipment is used for pressing the tail gas into the gas adsorption separator, the gas adsorption separator is used for adsorbing moisture and impurities in the tail gas, the buffering equipment is used for storing and releasing the tail gas, and the purifier is used for purifying the tail gas. The invention realizes the recovery of the hydrogen in the tail gas by using the tail gas recovery device.

Description

A kind of tail gas recovery device

technical field

The invention relates to the technical field of tail gas treatment, in particular to a tail gas recovery device.

Background technique

At present, in the epitaxial growth of semiconductor materials and the manufacturing process of light-emitting diode chips, the main process is metal-organic chemical vapor deposition (MOCVD). The special gases required for production in the process flow are high-purity NH ₃ and SiH ₄ . The gases are high-purity N ₂ and H ₂ . Since the special gas in the MOCVD system does not fully participate in the reaction, the tail gas contains toxic and harmful substances, so the tail gas after the reaction must be treated, and most of it will be discharged to the tail gas after the production is completed.

Existing MOCVD equipment tail gas recovery often uses water spray absorption, membrane group circulation absorption, sulfuric acid acid-base neutralization absorption, etc., but the above methods only recover NH ₃ in the tail gas, and the hydrogen in the tail gas is not Effective recovery will result in a waste of energy, and there are certain safety risks in the hydrogen discharge process, which may seriously cause major production accidents.

Therefore, how to recover the hydrogen in the tail gas is a technical problem to be solved by those skilled in the art.

Contents of the invention

In view of this, the object of the present invention is to provide a tail gas recovery device to recover the hydrogen in the tail gas.

In order to achieve the above object, the present invention provides the following technical solutions:

A tail gas recovery device, including sequentially connected pressurization equipment, gas adsorption separator, buffer equipment and purifier, to recover and purify the tail gas;

The pressurization equipment is used to inject the tail gas into the gas adsorption separator, the gas adsorption separator is used to absorb the moisture and impurities in the tail gas, the buffer device is used to store and release the tail gas, and the purifier is used to purify the tail gas.

Optionally, in the above tail gas recovery device, the buffer device includes a buffer tank, and when the buffer device is in the first state, the buffer tank is used to store the tail gas;

When the buffer device is in the second state, the buffer tank releases tail gas, and the purifier performs purification treatment on the tail gas in the buffer tank.

Optionally, in the above exhaust gas recovery device, the buffer device further includes a bypass valve, a first isolation valve and a second isolation valve,

The buffer tank is set in the first branch, and the first block valve and the second block valve are respectively set on both sides of the buffer tank to control the on-off of the first branch; the bypass valve is set in the second branch to control the On-off of two branches;

The bypass valve and the first isolation valve are opened, the second isolation valve is closed, and the buffer device is in the first state;

The second isolation valve is opened, the bypass valve and the first isolation valve are closed, and the buffer device is in the second state.

Optionally, in the above tail gas recovery device, the purifier includes a primary hydrogen purifier and a cryogenic purifier, and the primary hydrogen purifier and cryogenic purifier are sequentially arranged downstream of the buffer device.

Optionally, the above tail gas recovery device further includes gas-water separation equipment, which is arranged upstream of the gas adsorption separator to separate gas and moisture in the tail gas.

Optionally, in the above-mentioned tail gas recovery device, filtering equipment is also included to filter impurities in the tail gas.

Optionally, in the above exhaust gas recovery device, the filtering device includes a coarse filter and a fine filter, the coarse filter is arranged upstream of the pressurizing device, and the fine filter is arranged downstream of the coarse filter and upstream of the gas adsorption separator.

Optionally, in the above exhaust gas recovery device, the coarse filter includes a first coarse filter and a second coarse filter, and when one of the first coarse filter and the second coarse filter is in working condition, the other is in non-working condition; and/or,

The fine filter includes a first fine filter and a second fine filter, and when one of the first fine filter and the second fine filter is in a working state, the other is in a non-working state.

Optionally, in the above-mentioned tail gas recovery device, gas analysis equipment is also included, and the gas analysis equipment is arranged downstream of the purifier to detect the purity of hydrogen in the tail gas.

Optionally, in the above-mentioned tail gas recovery device, a tail gas flow regulating device is also included, and the tail gas flow regulating device is used to control the discharge of tail gas.

The tail gas recovery device provided by the present invention includes sequentially connected pressurization equipment, gas adsorption separator, buffer equipment and purifier to recover and purify the tail gas, and the tail gas containing hydrogen enters the gas adsorption separator after being pressurized by the pressurization device , The gas adsorption separator can absorb and remove most of the water in the tail gas, and adsorb the impurities to the PPM level. After being buffered by the buffer equipment, the purifier purifies the tail gas, thereby obtaining hydrogen that meets the process standard, and realizes the recovery of hydrogen in the tail gas.

In addition, when the upstream equipment needs to be overhauled or maintained, the existence of the buffer device ensures the stability and continuity of gas consumption for the equipment located downstream of the buffer device.

Moreover, the hydrogen in the tail gas is recycled by using the tail gas recovery device provided by the present invention, and the recovered hydrogen can be reused as fuel and process raw materials. Hydrogen replaces natural gas as fuel to treat process organic waste gas to realize the reuse of hydrogen and avoid energy waste.

When the tail gas recovery device provided by the present invention is used to recover the tail gas produced by epitaxial MOCVD equipment, because the gas in the epitaxial MOCVD tail gas has fewer types, high purity, easy recovery, and high recovery efficiency, the cost of recovery and use can be greatly reduced, and the tail gas recovery The device uses physical methods to recover hydrogen without auxiliary fuel and combustion reaction, which increases the stability and safety of the overall device and reduces energy consumption.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the overall structural diagram of the tail gas recovery device disclosed in the embodiment of the present invention;

Fig. 2 is a structural diagram of an exhaust gas recovery device disclosed in an embodiment of the present invention for waste gas treatment;

in:

101 is the first coarse filter; 102 is the second coarse filter;

200 is pressurized equipment;

300 is gas-water separation equipment;

401 is the first fine filter; 402 is the second fine filter;

500 is a gas adsorption separator;

601 is a buffer tank; 602 is a bypass valve; 603 is a first isolation valve; 604 is a second isolation valve;

701 is a primary hydrogen purifier; 702 is a cryogenic purifier;

800 is an exhaust gas regulating device;

900 is exhaust gas treatment equipment.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings 1-2 in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Example. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making novel efforts belong to the scope of protection of the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only In order to facilitate the description of the present invention and simplify the description, it does not indicate or imply that the referred position or element must have a specific orientation, be constructed and operate in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance.

As shown in Figure 1, the tail gas recovery device disclosed in the present invention includes pressurized equipment 200, gas adsorption separator 500, buffer equipment and purifiers connected in sequence to recover and purify tail gas; pressurized equipment 200 is used to Air pressure enters the gas adsorption separator 500, the gas adsorption separator 500 is used to absorb moisture and impurities in the tail gas, the buffer equipment is used to store and release the tail gas, and the purifier is used to purify the tail gas.

The tail gas recovery device provided by the present invention includes a pressurization device 200, a gas adsorption separator 500, a buffer device and a purifier connected in sequence to recover and purify the tail gas, and the tail gas containing hydrogen enters the gas after being pressurized by the pressurization device 200 The adsorption separator 500, the gas adsorption separator 500 can adsorb and remove most of the water in the tail gas, and adsorb the impurities to the PPM level. After being buffered by the buffer equipment, the purifier purifies the tail gas, thereby obtaining hydrogen that meets the process standard, and realizes the recovery of hydrogen in the tail gas.

In addition, when the upstream equipment needs to be overhauled or maintained, the existence of the buffer device ensures the stability and continuity of gas consumption for the equipment located downstream of the buffer device.

Moreover, the hydrogen in the tail gas is recycled by using the tail gas recovery device provided by the present invention, and the recovered hydrogen can be reused as fuel and process raw materials. For example, when the waste gas is subjected to RTO treatment, hydrogen can be used instead of natural gas as fuel. The organic waste gas of the process is treated to realize the reuse of hydrogen and avoid the waste of energy.

When the tail gas recovery device provided by the present invention is used to recover the tail gas produced by epitaxial MOCVD equipment, because the gas in the epitaxial MOCVD tail gas has fewer types, high purity, easy recovery, and high recovery efficiency, the cost of recovery and use can be greatly reduced, and the tail gas recovery The device uses physical methods to recover hydrogen without auxiliary fuel and combustion reaction, which increases the stability and safety of the overall device and reduces energy consumption.

In order to optimize the above-mentioned technical scheme, the buffer equipment includes a buffer tank 601, so that when the buffer equipment is in the first state, the buffer tank 601 is used to store the tail gas; The tail gas in the tank 601 is purified.

The buffer tank 601 is used as an intermediary container, and when the buffer device is in the first state, the buffer tank 601 is used as a storage device for storing exhaust gas treated by equipment upstream of the buffer tank 601 . When the buffer device is in the second state, the buffer tank 601 acts as a release device to release the exhaust gas stored in the first state. The existence of the buffer device ensures the stability and continuity of the gas consumption of the equipment downstream of the buffer device, and facilitates the repair and maintenance of the equipment upstream of the buffer device.

Specifically, as shown in Figure 1, there are two branches at the buffer equipment, the first isolation valve 603, the second isolation valve 604 and the buffer tank 601 are located in the first branch, and the first isolation valve 603 and the second isolation valve 604 are respectively arranged on both sides of the buffer tank 601, and the bypass valve 602 is located in the second branch. The first isolation valve 603, the second isolation valve 604 and the bypass valve 602 work together to control the switching between the first state and the second state of the buffer device.

The first block valve 603 is located upstream of the buffer tank 601, the first block valve 603 and the bypass valve 602 are opened, and the second block valve 604 is closed, so that the first branch is closed, the second branch is opened, and the buffer device is in the first state . Part of the tail gas treated by the equipment upstream of the buffer tank 601 reaches the buffer tank 601 through the first isolation valve 603 and fills up the buffer tank 601 , and part of it passes through the bypass valve 602 to the purifier through the second branch.

Close the first isolation valve 603 and the bypass valve 602, open the second isolation valve 604, so that the first branch is opened, the second branch is closed, and the buffer device is in the second state. Because the first isolation valve 603 is closed, the equipment located upstream of the buffer tank 601 no longer provides treated exhaust gas, and the second isolation valve 604 is opened, so that the buffer tank 601 can release the exhaust gas stored in the first state, and the exhaust gas passes through the second isolation The valve 604 reaches the purifier through the first branch, so that even when the equipment upstream of the buffer tank 601 is overhauled or maintained, the purifier can work uninterrupted, which improves the work efficiency.

In order to improve the purification degree of hydrogen and reduce the content of impurities in hydrogen, the purifier includes a primary hydrogen purifier 701 and a cryogenic purifier 702, and the primary hydrogen purifier 701 and cryogenic purifier 702 are arranged in sequence downstream of the buffer equipment, so as to Purify the exhaust gas. The primary purifier can reduce the impurities in the tail gas to the PPB level, and the gas after the primary purification enters the cryogenic purifier 702 to further absorb the impurities in the gas, and finally reduce the impurities in the gas to below 1PPB, reaching the process Hydrogen usage standards for use in downstream machines. The use of two-stage purifiers in different forms ensures that the impurities in the tail gas are separated to obtain high-purity producible hydrogen, which improves the stability of the gas supply. It should be noted that the purifier used in the present invention is an adsorption purifier, which has smaller pressure loss and lower energy consumption than palladium membrane purifiers.

If the exhaust gas contains a large amount of impurities, the impurities will cause wear and damage to all parts of the exhaust gas recovery device. In order to reduce impurities entering downstream equipment and prolong the service life of the exhaust gas recovery device, filter equipment is installed to remove impurities in the exhaust gas.

Specifically, due to the difference in filtration accuracy, the filtration equipment includes a coarse filter and a fine filter. The coarse filter can filter out large solid particles in the tail gas. Non-polar or weakly polar impurity components in water. On the basis of the coarse filter, the fine filter can filter out small particles of impurities in the exhaust gas, and the fine filter can be used for chemical adsorption to perform fine purification of the exhaust gas and remove polar impurities dissolved in water. Wherein, in order to avoid damage to the pressurized equipment 200 and the gas adsorption separator 500 by impurities, the coarse filter is arranged upstream of the pressurized equipment 200 , and the fine filter is arranged downstream of the coarse filter and upstream of the gas adsorption separator 500 .

Because the filter element of the filter needs to be replaced in time, in order to ensure that the exhaust gas recovery device can continue to work, the number of coarse filters is set to two, and the first coarse filter 101 and the second coarse filter 102 are respectively connected to the exhaust gas treatment process. When one of the first coarse filter 101 and the second coarse filter 102 is in the working state, the other is in the non-working state. The first coarse filter 101 and the second coarse filter 102 are one for use and one for backup, so that when one coarse filter works normally, the other can be inspected or rotated to complete the replacement of the filter element. Similarly, the fine filters can be set as a first fine filter 401 and a second fine filter 402, realizing one for use and one for standby.

In an embodiment of the present invention, a gas-water separation device 300 can be installed upstream of the gas adsorption separator 500 to separate the gas and moisture in the tail gas. The separation of gas and moisture reduces the operation of the adsorbent in the gas purification process. The load increases the service life of the adsorbent of the purifier.

The gas adsorption and separation method usually adopts two cycle processes of temperature swing adsorption or pressure swing adsorption, and a pressure swing adsorber is used in the present invention. The products of pressure swing adsorption are of high purity, and can generally work at room temperature and low pressure. No heating is required during bed regeneration, which reduces energy consumption. In addition, the equipment of pressure swing adsorption is simple, easy to operate and maintain, and can be continuously Cyclic operation to achieve complete automation. In the process of pressure swing adsorption, most of the water in the gas and the remaining impurities not removed in the filtration stage can be removed, and the impurities can be adsorbed to the PPM level.

Gas analysis equipment can be installed at the end of the tail gas recovery device as shown in Figure 1 to detect the purity of hydrogen in the gas purified by the purifier. If the hydrogen meets the process use standard, it can be directly collected or used. If the hydrogen does not meet the process use standard, it means that there is a problem in the upstream tail gas treatment process. At this time, the equipment needs to be repaired.

As shown in Figure 2, the tail gas recovery device provided by the present invention can be used in RTO process treatment. At present, with the continuous improvement of the industrialization level of semiconductor production enterprises, the environmental protection policy has stricter control on the emission of organic pollution waste gas, so the zeolite runner + RTO process treatment method has been introduced into semiconductor production enterprises. In the process flow, after the VOCs waste gas passes through the zeolite concentration wheel, it can be effectively absorbed in the zeolite to achieve the purpose of removal. The volatile organic gases adsorbed by zeolite are cleaned and discharged directly into the atmosphere through the chimney, and the adsorbed volatile organic compounds are transported to the desorption zone, where a small stream of heating gas is used to desorb the volatile organic compounds. After desorption, the zeolite wheel rotates to the adsorption area to continuously adsorb volatile organic gases. The desorbed concentrated organic waste gas is sent to the incinerator for combustion, converted into carbon dioxide and water vapor, and then discharged into the atmosphere. In this process, natural gas can be used as fuel, but the natural gas needs to be re-purchased, and the cost of pipeline engineering and natural gas purchase is high, so in the present invention, the hydrogen that has not been effectively treated in the tail gas of this type of industrial production process can be processed Recycling, using hydrogen as fuel, avoiding waste of energy. After the buffer equipment, waste gas treatment equipment 900 is installed to use hydrogen instead of natural gas as fuel to realize the treatment of waste gas.

In an embodiment of the present invention, a tail gas regulating device 800 is provided upstream of the exhaust gas treatment equipment 900 , and the adjustment is performed according to the hydrogen demand required by the exhaust gas treatment equipment 900 . The tail gas regulating device 800 can be installed upstream of the pressurizing equipment 200, so that the downstream equipment and pipelines can be reduced in level and specification, greatly reducing the construction cost. Alternatively, the tail gas regulating device 800 is arranged between the buffer equipment and the exhaust gas treatment equipment 900, so that the gas enters the exhaust gas treatment equipment 900 according to demand.

It should be noted that the tail gas recovery device provided by the present invention can be used in the technical field of tail gas treatment or other fields. Other fields refer to any field except the field of tail gas treatment technology. The above is only an example, and does not limit the application field of the tail gas recovery device provided by the present invention.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

In the description of this specification, descriptions referring to the terms "one embodiment", "example", "specific example" and the like mean that specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment of the present invention. In an embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the invention disclosed above are only to help illustrate the invention. The preferred embodiments do not exhaust all details nor limit the invention to only specific embodiments. Obviously, many modifications and variations can be made based on the contents of this specification. This description selects and specifically describes these embodiments in order to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. The invention is to be limited only by the claims, along with their full scope and equivalents.

Claims (10)

1. A tail gas recovery device, characterized in that, comprises sequentially connected pressurization equipment (200), gas adsorption separator (500), buffer equipment and a purifier, to recover and purify tail gas; The pressurizing device (200) is used to pressurize the tail gas into the gas adsorption separator (500), and the gas adsorption separator (500) is used to adsorb moisture and impurities in the tail gas, and the buffer The equipment is used to store and release the tail gas, and the purifier is used to purify the tail gas. 2. The tail gas recovery device according to claim 1, characterized in that, the buffer device comprises a buffer tank (601), and when the buffer device is in the first state, the buffer tank (601) is used to store the exhaust gas; When the buffer device is in the second state, the buffer tank (601) releases the tail gas, and the purifier performs purification treatment on the tail gas in the buffer tank (601). 3. The tail gas recovery device according to claim 2, characterized in that, the buffer device further comprises a bypass valve (602), a first isolation valve (603) and a second isolation valve (604), The buffer tank (601) is arranged in the first branch, and the first isolation valve (603) and the second isolation valve (604) are respectively arranged on both sides of the buffer tank (601) to control the The on-off of the first branch; the bypass valve (602) is arranged in the second branch to control the on-off of the second branch; The bypass valve (602) and the first isolation valve (603) are opened, the second isolation valve (604) is closed, and the buffer device is in the first state; The second isolation valve (604) is open, the bypass valve (602) and the first isolation valve (603) are closed, and the buffer device is in the second state. 4. tail gas recovery device as claimed in claim 1, is characterized in that, described purifier comprises primary hydrogen purifier (701) and cryogenic purifier (702), and described primary hydrogen purifier (701) and The cryogenic purifier (702) is sequentially arranged downstream of the buffer device. 5. The tail gas recovery device according to claim 1, characterized in that, it also comprises a gas-water separation device (300), and the gas-water separation device (300) is arranged upstream of the gas adsorption separator (500) to Gas and moisture in the tail gas are separated. 6. The tail gas recovery device according to claim 1, further comprising filtering equipment to filter impurities in the tail gas. 7. The tail gas recovery device according to claim 6, characterized in that, the filtering device comprises a coarse filter and a fine filter, the coarse filter is arranged upstream of the pressurizing device (200), and the fine filter A filter is arranged downstream of the coarse filter and upstream of the gas adsorption separator (500). 8. The tail gas recovery device according to claim 7, characterized in that, the coarse filter comprises a first coarse filter (101) and a second coarse filter (102), and in the first coarse filter (102) 101) and one of the second coarse filter (102) is in a working state, the other is in a non-working state; and/or, The fine filter comprises a first fine filter (401) and a second fine filter (402), and one of the first fine filter (401) and the second fine filter (402) is at When one is working, the other is not working. 9. The tail gas recovery device according to claim 1, further comprising a gas analysis device, the gas analysis device is arranged downstream of the purifier to detect the purity of hydrogen in the tail gas. 10. The tail gas recovery device according to any one of claims 1-9, further comprising a tail gas flow regulating device (800), and the tail gas flow regulating device (800) is used to control the emission of the tail gas .

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