Heat exchange type adsorption system and method for hydrogen purification

Abstract

The invention discloses a heat exchange type adsorption system and method for hydrogen purification, the heat exchange type adsorption system for hydrogen purification comprises a first adsorber and a second adsorber, the first adsorber is internally provided with a first heat exchange pipe, the second adsorber is internally provided with a second heat exchange pipe, and the first heat exchange pipe and the second heat exchange pipe are communicated with each other. Desorption gas enters the first heat exchange pipe and the second heat exchange pipe through the first heat exchange medium inlet and the second heat exchange medium inlet respectively to heat the adsorbent, so that the adsorbed CO and H2S are desorbed from the adsorbent, the adsorbent can be recycled and cannot be consumed, and the service life of the adsorbent is prolonged. The content of CO in the obtained hydrogen product is stably lower than 0.2 ppm for a long time, and the problems that the energy conversion efficiency is reduced, the service life of a battery is shortened and even the battery is completely inactivated due to the fact that CO is adsorbed on a platinum electrode and hinders the electrochemical reaction of H2 are solved.

Description

Technical Field

[0001] The present application belongs to the technical field of hydrogen preparation, and specifically relates to a heat exchange adsorption system and method for hydrogen purification. Background Art

[0002] Fuel cell technology is mainly based on the proton exchange membrane fuel cell (PEMFC), which has the most mature technology and the highest degree of industrialization. Proton exchange membrane fuel cells (PEMFC) have the advantages of high power generation efficiency, environmental friendliness, and a wide range of hydrogen fuel sources. They have broad application prospects in fixed power stations, vehicle power supplies, portable power supplies, aerospace, and other fields, and have received great attention from governments around the world. On the electrode catalyst of PEMFC, the precious metal Pt supported as a catalyst is very sensitive to CO and sulfur. When there are too many trace impurities in hydrogen, compounds such as C and S have irreversible poisoning effects on the electrodes. Therefore, the requirements for impurities in hydrogen are very high, especially the adsorption of CO by precious metal electrodes such as platinum and palladium is greater than that of H2, so that CO adsorbed on the platinum electrode hinders the electrochemical reaction of H2, reduces energy conversion efficiency, shortens the battery life, and even completely deactivates. Hydrogen fuel cells have very high requirements for hydrogen quality. Before hydrogen is refueled, it must be purified to remove impurities.

[0003] At present, the domestic hydrogen purification is mainly based on pressure swing adsorption. According to the standards of industrial hydrogen, hydrogen from various sources is purified. However, the efficiency of using traditional pressure swing adsorption process to purify raw hydrogen to meet the requirements of fuel cell hydrogen is relatively low. The requirement of total sulfur (calculated as H2S) content below 4ppb (parts per billion, abbreviated as ppb, one billionth) is relatively easy to achieve, but due to the consumption of adsorbent, the CO content in hydrogen is difficult to reach the standard of less than 0.2ppm (parts per million, abbreviated as ppm, one millionth) for a long time. At present, there is a lack of more efficient and economical hydrogen purification technology and equipment in the market, especially it is extremely difficult to keep the CO content in hydrogen stable below 0.2ppm for a long time. Summary of the invention

[0004] In order to solve the technical problem that the hydrogen purification process in the prior art consumes adsorbent, making it difficult for the CO content in the obtained hydrogen to stably reach the standard of less than 0.2ppm for a long time, the adsorption effect of precious metal electrodes such as platinum and palladium on CO is greater than that on H2, so that CO adsorbed on the platinum electrode hinders the electrochemical reaction of H2, reduces the energy conversion efficiency, shortens the battery life, and even completely inactivates the battery, the present application provides a heat exchange adsorption system and method for hydrogen purification.

[0005] In a first aspect of the present application, there is provided a heat exchange adsorption system for hydrogen purification, comprising a first adsorber and a second adsorber;

[0006] Adsorbents are disposed inside the first adsorber and the second adsorber, and the adsorbents are used to adsorb CO and H2S in the raw hydrogen;

[0007] A first heat exchange tube is provided inside the first adsorber for heating and desorbing the adsorbent in the first adsorber; a first raw gas inlet, a first product gas outlet and a first heat exchange medium inlet are provided on the outer wall of the first adsorber, and the first heat exchange medium inlet is connected to the first heat exchange tube;

[0008] A second heat exchange tube is provided inside the second adsorber for heating and desorbing the adsorbent in the second adsorber; a second raw gas inlet, a second product gas outlet, and a second heat exchange medium inlet are provided on the outer wall of the second adsorber, the second product gas outlet is connected to the first product gas outlet, and the second heat exchange medium inlet is connected to the second heat exchange tube;

[0009] During the adsorption process, the first raw gas inlet and the second raw gas inlet respectively introduce raw hydrogen into the first adsorber and the second adsorber, the adsorbent adsorbs CO and H2S, and the obtained product hydrogen flows out from the first product gas outlet and the second product gas outlet;

[0010] During the desorption process, the desorbed gas enters the first heat exchange tube and the second heat exchange tube through the first heat exchange medium inlet and the second heat exchange medium inlet respectively, and heats the adsorbent to desorb the adsorbed CO and H2S from the adsorbent;

[0011] The adsorption and desorption of the first adsorber and the second adsorber are performed alternately, and one of the first product gas outlet and the second product gas outlet conveys part of the product hydrogen to the other, so as to purge the desorbed CO and H2S, so that CO and H2S flow out from the first raw gas inlet and the second raw gas inlet to the exhaust gas treatment pipeline.

[0012] In some embodiments, the first raw gas inlet and the second raw gas inlet are connected to the hydrogen feed main pipeline through a first feed branch pipe and a second feed branch pipe respectively, the first feed branch pipe is provided with a first intake valve, and the second feed branch pipe is provided with a second intake valve;

[0013] The first product gas outlet and the second product gas outlet are connected to the product discharge main pipeline through the first discharge branch pipe and the second discharge branch pipe respectively, the first discharge branch pipe is provided with a first gas outlet valve, the second discharge branch pipe is provided with a second gas outlet valve, a reflux pipeline is connected between the second discharge branch pipe between the first product gas outlet and the first gas outlet valve and the first discharge branch pipe between the second product gas outlet and the second gas outlet valve, and a reflux valve and a reversing valve are provided on the reflux pipeline;

[0014] The first product gas outlet and the second product gas outlet are connected to the exhaust gas recovery main pipeline through the first exhaust gas recovery branch pipe and the second exhaust gas recovery branch pipe respectively; the first exhaust gas recovery branch pipe is connected to the first discharge branch pipe between the first outlet valve and the first product gas outlet, and the first exhaust gas recovery branch pipe is provided with a first exhaust gas valve; the second exhaust gas recovery branch pipe is connected to the second outlet valve and the second product gas outlet diameter second discharge branch pipe, and the second exhaust gas recovery branch pipe is provided with a second exhaust gas valve;

[0015] During the adsorption process, the first exhaust valve and the second exhaust valve are closed, the first intake valve, the second intake valve, the first outlet valve and the second outlet valve are opened, the raw hydrogen enters the first adsorber and the second adsorber through the first feed branch pipe and the second feed branch pipe respectively, and the product hydrogen flows out of the first adsorber and the second adsorber through the first discharge branch pipe and the second discharge branch pipe respectively;

[0016] During the desorption process, the reflux valve and the reversing valve are opened, and the product hydrogen generated by adsorption in the first adsorber enters the second product gas outlet through the first product gas outlet, and the CO and H2S desorbed by the adsorbent in the second adsorber are purged, so that CO and H2S flow out from the second raw gas inlet to the waste gas treatment pipeline; or, the product hydrogen generated by adsorption in the second adsorber enters the first product gas outlet through the second product gas outlet, and the CO and H2S desorbed by the adsorbent in the first adsorber are purged, so that CO and H2S flow out from the first raw gas inlet to the waste gas treatment pipeline.

[0017] In some embodiments, during the adsorption process, when the adsorbent is saturated with adsorption, the first air inlet valve, the second air inlet valve, the first air outlet valve and the second air outlet valve are closed, the first exhaust valve and the second exhaust valve are opened, and the gas in the first adsorber and the second adsorber flows out from the first raw gas inlet and the second raw gas inlet to the exhaust gas treatment pipeline, respectively, and the pressure in the first adsorber and the second adsorber is reduced to a preset pressure threshold.

[0018] In some embodiments, after the CO and H2S in the adsorbent are completely desorbed, desorption gas is continuously introduced into the first heat exchange tube and the second heat exchange tube through the first heat exchange medium inlet and the second heat exchange medium inlet to reduce the temperature in the first adsorber and the second adsorber to a preset adsorption temperature, which is 20 to 40°C.

[0019] In some embodiments, during the desorption process, after the CO and H2S to be desorbed are completely purged into the exhaust gas treatment pipeline, the first exhaust valve and the second exhaust valve are closed, and the first product gas outlet and the second product gas outlet, one of them deliver part of the product hydrogen to the other, so that the internal pressure thereof is increased to a preset adsorption pressure, and the preset adsorption pressure is 1-3 MPa.

[0020] In some embodiments, a desorbed gas supply device and a desorbed gas recovery device are also included, the first heat exchange medium inlet is connected to the desorbed gas supply device, and a first heat exchange medium outlet is also provided on the outer wall of the first adsorber, the first heat exchange medium outlet is respectively connected to the first heat exchange tube and the desorbed gas recovery device for recycling the desorbed gas; the second heat exchange medium inlet is connected to the desorbed gas supply device through a second medium entry branch pipe, and a second heat exchange medium outlet is also provided on the outer wall of the second adsorber, the second heat exchange medium outlet is respectively connected to the second heat exchange tube and the desorbed gas recovery device for recycling the desorbed gas.

[0021] In a second aspect of the present application, a heat exchange adsorption method for hydrogen purification is provided, using the heat exchange adsorption system for hydrogen purification described in the first aspect, comprising:

[0022] Adsorbing CO and H2S in the raw hydrogen introduced from the first raw gas inlet and the second raw gas inlet by the adsorbent, and the obtained product hydrogen flows out from the first product gas outlet and the second product gas outlet;

[0023] By introducing desorption gas into the first heat exchange tube and the second heat exchange tube to heat the adsorbent, the adsorbed CO and H2S are desorbed from the adsorbent;

[0024] The adsorption and desorption of the first adsorber and the second adsorber are performed alternately, and the first product gas outlet and the second product gas outlet, one of them convey part of the product hydrogen to the other, so as to purge the desorbed CO and H2S, so that CO and H2S flow out from the first raw gas inlet and the second raw gas inlet to the exhaust gas treatment pipeline.

[0025] In some embodiments, after the desorbed CO and H2S are desorbed from the adsorbent by introducing desorbed gas into the first heat exchange tube and the second heat exchange tube to heat the adsorbent, the method further includes: continuing to introduce desorbed gas into the first heat exchange tube and the second heat exchange tube through the first heat exchange medium inlet and the second heat exchange medium inlet to reduce the temperature in the first adsorber and the second adsorber to a preset adsorption temperature, wherein the preset adsorption temperature is 20 to 40°C.

[0026] In some embodiments, after allowing CO and H2S to flow out from the first raw gas inlet and the second raw gas inlet to the exhaust gas treatment pipeline, the method further includes: closing the first exhaust valve and the second exhaust valve, and the first product gas outlet and the second product gas outlet, one of which delivers part of the product hydrogen to the other, so that the internal pressure thereof is increased to a preset adsorption pressure, and the preset adsorption pressure is 1-3MPa.

[0027] In some embodiments, the adsorption of CO and H2S in the raw hydrogen introduced from the first raw gas inlet and the second raw gas inlet by the adsorbent includes: when the adsorbent is saturated with adsorption, the first air inlet valve, the second air inlet valve, the first air outlet valve and the second air outlet valve are closed, the first exhaust valve and the second exhaust valve are opened, and the gas in the first adsorber and the second adsorber flows out from the first raw gas inlet and the second raw gas inlet to the exhaust gas treatment pipeline respectively, and the pressure in the first adsorber and the second adsorber is reduced to a preset pressure threshold.

[0028] The heat exchange adsorption system for hydrogen purification provided according to one or more embodiments of the present application has the following beneficial effects compared with the prior art:

[0029] The desorbed gas enters the first heat exchange tube and the second heat exchange tube through the first heat exchange medium inlet and the second heat exchange medium inlet respectively, and the adsorbent is heated to desorb the adsorbed CO and H2S from the adsorbent, so that the adsorbent can be reused and will not be consumed, so that the CO content in the obtained hydrogen product can reach the standard of less than 0.2ppm stably for a long time, avoiding the problem that CO adsorbed on the platinum electrode hinders the electrochemical reaction of H2, resulting in reduced energy conversion efficiency, shortened battery life, and even complete deactivation of the battery; the adsorption and desorption of the first adsorber and the second adsorber are alternately performed, and one of the first product gas outlet and the second product gas outlet conveys part of the product hydrogen to the other for purging the desorbed CO and H2S, so that CO and H2S flow out from the first raw gas inlet and the second raw gas inlet to the exhaust gas treatment pipeline, so that the adsorption and desorption of the first adsorber and the second adsorber can be cyclically performed, which is conducive to the reuse of the adsorbent. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The structure diagram of the heat exchange adsorption system for hydrogen purification in an embodiment of the present invention is shown;

[0031] Figure 2 The structure schematic diagram of the first adsorber of the heat exchange adsorption system for hydrogen purification in an embodiment of the present invention is shown;

[0032] Figure 3 A schematic flow chart of a heat exchange adsorption method for purifying hydrogen in an embodiment of the present invention is shown.

[0033] The reference numerals in the above drawings are: 100-first adsorber, 110-tank body, 111-first heat exchange tube, 112-first raw gas inlet, 113-first product gas outlet, 114-first heat exchange medium inlet, 115-first heat exchange medium outlet, 116-lower distributor, 117-ceramic ball, 118-thermometer port, 119-ear seat, 120-wire screen, 121-hand hole, 122-upper distributor, 130-first air inlet valve, 140-first An outlet valve, 150-a first waste gas valve; 200-a second adsorber, 211-a second heat exchange tube, 212-a second raw gas inlet, 213-a second product gas outlet, 214-a second heat exchange medium inlet, 215-a second heat exchange medium outlet, 230-a second air inlet valve, 240-a second outlet valve, 250-a second waste gas valve; 300-a reflux valve; 400-a reversing valve; 500-a desorption gas supply device; 600-a desorption gas recovery device; 700-a heater. DETAILED DESCRIPTION

[0034] In order to make the technical personnel in the technical field to which the present application belongs to understand the present application more clearly, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0035] Before introducing the specific embodiments, several hydrogen purification methods are briefly introduced. The main hydrogen purification methods include cryogenic separation, adsorption (pressure swing adsorption, temperature swing adsorption), catalytic deoxygenation, membrane separation, etc. Cryogenic separation is low-temperature separation, which uses the boiling point difference of different substances to separate other component gases contained in hydrogen through low-temperature liquefaction. This technology is suitable for occasions where the hydrogen purification degree is not high, and cryogenic separation technology is a high-energy separation process. Adsorption is a method of achieving adsorption and desorption of adsorbents by utilizing the different adsorption capacities of adsorbents under different states. Adsorption is divided into two types: pressure swing adsorption and temperature swing adsorption. Pressure swing adsorption has the advantages of low energy consumption, high product purity and flexible adjustment, simple process flow and the ability to separate multiple gases, high degree of automation, simple operation, and long adsorbent use cycle. The biggest disadvantage is the low product recovery rate. Temperature swing adsorption utilizes the characteristics of adsorbents that have a large adsorption capacity for adsorbents at low temperatures and a small adsorption capacity at high temperatures, so that the mixed gas passes through the adsorbent bed at a relatively low temperature, and the impurities therein are adsorbed by the adsorbent. When the adsorption is saturated, the adsorbent no longer has adsorption capacity. At this time, the adsorbent bed is heated, and the adsorbed impurities are desorbed therefrom. At the same time, the adsorbent is regenerated for use in cyclic adsorption. It is characterized by a large processing capacity, especially suitable for industrial hydrogen re-purification, low operating cost, greatly saved power costs, small footprint, and simple operation. The embodiment of the present application adopts temperature swing adsorption.

[0036] In the first embodiment of the present application, refer to Figure 1 and Figure 2 As shown, a heat exchange adsorption system for hydrogen purification is provided, comprising a first adsorber 100 and a second adsorber 200;

[0037] The first adsorber 100 and the second adsorber 200 are both provided with an adsorbent for adsorbing CO and H2S in the raw hydrogen. The adsorbent may be a molecular sieve, which (also known as synthetic zeolite) is a microporous crystal of aluminosilicate. It is composed of a basic framework structure of silicon-oxygen and aluminum-oxygen tetrahedrons, and metal cations (such as Na + , K + , Ca 2+ , Li + etc.) to balance the excess negative charge in the crystal. Molecular sieve is a material containing precise and single tiny pores that can be used to adsorb gases or liquids. Molecules small enough can be adsorbed through the pores, while larger molecules cannot.

[0038] A first heat exchange tube 111 is provided inside the first adsorber 100 for heating and desorbing the adsorbent in the first adsorber 100; a first raw gas inlet 112, a first product gas outlet 113 and a first heat exchange medium inlet 114 are provided on the outer wall of the first adsorber 100, and the first heat exchange medium inlet 114 is connected to the first heat exchange tube 111; the first heat exchange tube 111 is provided inside the first adsorber 100, and can directly heat the adsorbent in the first adsorber 100, and the first adsorber 100 can keep the first heat exchange tube 111 warm, thereby achieving energy-saving and high-efficiency effects.

[0039] The first adsorber 100 and the second adsorber 200 have the same structure. In this embodiment, the first adsorber 100 is taken as an example for illustration:

[0040] like Figure 2 As shown, the first adsorber 100 includes a sealed tank body 110, a first raw gas inlet 112 is arranged above the top of the tank body 110, a first product gas outlet 113 is arranged below the bottom of the tank body 110, a first heat exchange tube 111 is arranged inside the tank body 110, two ends of the first heat exchange tube 111 are respectively connected to a first heat exchange medium inlet 114 and a first heat exchange medium outlet 115, an adsorbent is arranged inside the tank body 110, the first heat exchange medium inlet 114 is arranged above the side wall of the tank body 110, the first heat exchange medium outlet 115 is arranged below the side wall of the tank body 110, and the bottom of the inner wall of the tank body 110 A lower distributor 116 is provided, which is connected to the first raw gas inlet 112, a ceramic ball 117 is provided at the bottom of the inner wall of the tank body 110, a thermometer port 118 for installing a thermometer is provided on the outer wall of the tank body 110, an ear seat 119 for installing and fixing the first adsorber 100 is provided on the outer wall of the tank body 110, a wire mesh 120 is provided on the top of the inner wall of the tank body 110, the ceramic ball 117 is carried on the wire mesh 120, a hand hole 121 is provided on the top of the tank body 110, the hand hole 121 is connected to the first product gas outlet 113, and an upper distributor 122 is provided in the hand hole 121.

[0041] A second heat exchange tube 211 is provided inside the second adsorber 200 for heating and desorbing the adsorbent in the second adsorber 200; a second raw gas inlet 212, a second product gas outlet 213 and a second heat exchange medium inlet 214 are provided on the outer wall of the second adsorber 200, the second product gas outlet 213 is connected to the first product gas outlet 113, and the second heat exchange medium inlet 214 is connected to the second heat exchange tube 211; the second heat exchange tube 211 is provided inside the second adsorber 200, and can directly heat the adsorbent in the second adsorber 200, and the second adsorber 200 can keep the second heat exchange tube 211 warm, which can achieve energy-saving and high-efficiency effects.

[0042] During the adsorption process, the first raw gas inlet 112 and the second raw gas inlet 212 introduce raw hydrogen into the first adsorber 100 and the second adsorber 200 respectively, and the adsorbent adsorbs CO and H2S, and the obtained product hydrogen flows out from the first product gas outlet 113 and the second product gas outlet 213.

[0043] During the desorption process, the desorbed gas enters the first heat exchange tube 111 and the second heat exchange tube 211 through the first heat exchange medium inlet 114 and the second heat exchange medium inlet 214 respectively, and heats the adsorbent to desorb the adsorbed CO and H2S from the adsorbent; the desorbed gas can be the tail gas generated by other sections, or an inert gas such as nitrogen. The desorbed gas is heated in advance and then enters the first heat exchange tube 111 and the second heat exchange tube 211; here, the adsorbent is heated to 160-200°C by the desorbed gas to desorb CO and H2S from the adsorbent.

[0044] Adsorption and desorption of the first adsorber 100 and the second adsorber 200 are performed alternately, and the first product gas outlet 113 and the second product gas outlet 213, one of which conveys part of the product hydrogen to the other, are used to purge the desorbed CO and H2S, so that CO and H2S flow out from the first raw gas inlet 112 and the second raw gas inlet 212 to the exhaust gas treatment pipeline.

[0045] The embodiment of the present application provides a heat exchange adsorption system for hydrogen purification, wherein the desorbed gas enters the first heat exchange tube 111 and the second heat exchange tube 211 through the first heat exchange medium inlet 114 and the second heat exchange medium inlet 214, respectively, and the adsorbent is heated to desorb the adsorbed CO and H2S from the adsorbent, so that the adsorbent can be reused and will not be consumed, so that the CO content in the obtained hydrogen is difficult to stably reach the standard of less than 0.2ppm for a long time, thereby avoiding the adsorption of CO on the platinum electrode to hinder the electrochemical reaction of H2 and cause the energy conversion efficiency to decrease. The problem of low, shortened battery life, or even completely deactivating the battery is solved; the adsorption and desorption of the first adsorber 100 and the second adsorber 200 are carried out alternately, and the first product gas outlet 113 and the second product gas outlet 213, one of which conveys part of the product hydrogen to the other, is used to purge the desorbed CO and H2S, so that CO and H2S flow out from the first raw gas inlet 112 and the second raw gas inlet 212 to the exhaust gas treatment pipeline, so that the adsorption and desorption of the first adsorber 100 and the second adsorber 200 can be cyclically carried out, which is beneficial to the reuse of the adsorbent.

[0046] In some embodiments, the first raw gas inlet 112 and the second raw gas inlet 212 are connected to the hydrogen feed main pipeline through a first feed branch pipe and a second feed branch pipe, respectively. The first feed branch pipe is provided with a first intake valve 130, and the second feed branch pipe is provided with a second intake valve 230;

[0047] The first product gas outlet 113 and the second product gas outlet 213 are connected to the product discharge main pipeline through the first discharge branch pipe and the second discharge branch pipe respectively, the first discharge branch pipe is provided with a first gas outlet valve 140, the second discharge branch pipe is provided with a second gas outlet valve 240, a reflux pipeline is connected between the second discharge branch pipe between the first product gas outlet 113 and the first gas outlet valve 140 and the first discharge branch pipe between the second product gas outlet 213 and the second gas outlet valve 240, and a reflux valve 300 and a reversing valve 400 are provided on the reflux pipeline;

[0048] The first product gas outlet 113 and the second product gas outlet 213 are connected to the exhaust gas recovery main pipeline through the first exhaust gas recovery branch pipe and the second exhaust gas recovery branch pipe respectively. The first exhaust gas recovery branch pipe is connected to the first discharge branch pipe between the first outlet valve 140 and the first product gas outlet 113, and the first exhaust gas valve 150 is provided on the first exhaust gas recovery branch pipe; the second exhaust gas recovery branch pipe is connected to the second outlet valve 240 and the second product gas outlet 213 diameter second discharge branch pipe, and the second exhaust gas recovery branch pipe is provided with a second exhaust gas valve 250;

[0049] During the adsorption process, the first exhaust valve 150 and the second exhaust valve 250 are closed, the first intake valve 130, the second intake valve 230, the first outlet valve 140 and the second outlet valve 240 are opened, the raw hydrogen enters the first adsorber 100 and the second adsorber 200 through the first feed branch pipe and the second feed branch pipe respectively, and the product hydrogen flows out of the first adsorber 100 and the second adsorber 200 through the first discharge branch pipe and the second discharge branch pipe respectively;

[0050] During the desorption process, the reflux valve 300 and the reversing valve 400 are opened, and the product hydrogen generated by adsorption in the first adsorber 100 enters the second product gas outlet 213 through the first product gas outlet 113, and the CO and H2S desorbed from the adsorbent in the second adsorber 200 are purged, so that CO and H2S flow out from the second raw gas inlet 212 to the waste gas treatment pipeline; or, the product hydrogen generated by adsorption in the second adsorber 200 enters the first product gas outlet 113 through the second product gas outlet 213, and the CO and H2S desorbed from the adsorbent in the first adsorber 100 are purged, so that CO and H2S flow out from the first raw gas inlet 112 to the waste gas treatment pipeline.

[0051] In this embodiment, by alternately performing adsorption and desorption in the first adsorber 100 and the second adsorber 200 , continuous input of raw hydrogen and continuous output of product hydrogen can be achieved.

[0052] In some embodiments, during the adsorption process, when the adsorbent is saturated with adsorption, the first air inlet valve 130, the second air inlet valve 230, the first air outlet valve 140 and the second air outlet valve 240 are closed, the first exhaust valve 150 and the second exhaust valve 250 are opened, and the gas in the first adsorber 100 and the second adsorber 200 flows out from the first raw gas inlet 112 and the second raw gas inlet 212 to the exhaust gas treatment pipeline, respectively, and the pressure in the first adsorber 100 and the second adsorber 200 is reduced to a preset pressure threshold. The adsorbent loading amount and adsorption time are designed according to the gas components, and the adsorption is considered to be saturated when the adsorption time is reached. The gas in the first adsorber 100 and the second adsorber 200 flows out from the first raw gas inlet 112 and the second raw gas inlet 212 to the exhaust gas treatment pipeline respectively, realizing reverse decompression and reducing the pressure to a preset pressure threshold, which is beneficial to the desorption of impurities. Reverse decompression is beneficial to the faster desorption of gas impurities in the first adsorber 100 and the second adsorber 200 from the bottom of the first adsorber 100 and the second adsorber 200, which is beneficial to prevent the upper adsorbent from being contaminated.

[0053] In some embodiments, after CO and H2S in the adsorbent are completely desorbed, desorbed gas is continuously introduced into the first heat exchange tube 111 and the second heat exchange tube 211 through the first heat exchange medium inlet 114 and the second heat exchange medium inlet 214 to reduce the temperature in the first adsorber 100 and the second adsorber 200 to a preset adsorption temperature, which is 20 to 40° C. The desorbed gas introduced here is pre-cooled, and the low-temperature desorbed gas is introduced into the first heat exchange tube 111 and the second heat exchange tube 211 to reduce the temperature in the first adsorber 100 and the second adsorber 200 to the preset adsorption temperature, so as to prepare for the next cycle of adsorption treatment.

[0054] In some embodiments, during the desorption process, after the CO and H2S to be desorbed are completely purged to the waste gas treatment pipeline, the first waste gas valve 150 and the second waste gas valve 250 are closed, and the first product gas outlet 113 and the second product gas outlet 213, one of them delivers part of the product hydrogen to the other, so that its internal pressure is increased to a preset adsorption pressure, and the preset adsorption pressure is 1-3MPa. Through the first adsorption tower and the second adsorption tower, one of them delivers part of the product hydrogen to the other, so that the internal pressure of the other is increased to the preset adsorption pressure, so as to prepare for the next cycle of adsorption treatment.

[0055] In some embodiments, the heat exchange adsorption system for hydrogen purification also includes a desorption gas supply device 500 and a desorption gas recovery device 600, the first heat exchange medium inlet 114 is connected to the desorption gas supply device 500, and a first heat exchange medium outlet 115 is also provided on the outer wall of the first adsorber 100, and the first heat exchange medium outlet 115 is respectively connected to the first heat exchange pipe 111 and the desorption gas recovery device 600 for recycling the desorption gas; the second heat exchange medium inlet 214 is connected to the desorption gas supply device 500 through the second medium into the branch pipe, and a second heat exchange medium outlet 215 is also provided on the outer wall of the second adsorber 200, and the second heat exchange medium outlet 215 is respectively connected to the second heat exchange pipe 211 and the desorption gas recovery device 600 for recycling the desorption gas. In actual use, a heater 700 is provided between the desorption gas supply device 500 and the first heat exchange medium inlet 114. When high-temperature desorption gas is required to heat the adsorbent, the heater 700 is turned on to heat the desorption gas. When the first adsorber 100 is cooled, the heater 700 is turned off and desorption gas at room temperature is introduced.

[0056] In the second embodiment of the present application, refer to Figure 3 As shown, a heat exchange adsorption method for hydrogen purification is provided, using the heat exchange adsorption system for hydrogen purification of the first aspect embodiment, comprising:

[0057] Step S1: adsorbing CO and H2S in the raw hydrogen introduced from the first raw gas inlet 112 and the second raw gas inlet 212 by an adsorbent, and the obtained product hydrogen flows out from the first product gas outlet 113 and the second product gas outlet 213;

[0058] Step S2: introducing desorption gas into the first heat exchange tube 111 and the second heat exchange tube 211 to heat the adsorbent and desorb the adsorbed CO and H2S from the adsorbent;

[0059] Step S3: The adsorption and desorption of the first adsorber 100 and the second adsorber 200 are performed alternately, and the first product gas outlet 113 and the second product gas outlet 213, one of them conveys part of the product hydrogen to the other, so as to purge the desorbed CO and H2S, so that CO and H2S flow out from the first raw gas inlet 112 and the second raw gas inlet 212 to the exhaust gas treatment pipeline.

[0060] The present embodiment provides a heat exchange adsorption method for hydrogen purification, which heats the adsorbent by introducing desorption gas into the first heat exchange tube 111 and the second heat exchange tube 211 to desorb the adsorbed CO and H2S from the adsorbent, so that the adsorbent can be reused and will not be consumed, so that the CO content in the obtained hydrogen can reach a standard of less than 0.2ppm for a long time, thereby avoiding the problem that CO adsorbed on the platinum electrode hinders the electrochemical reaction of H2, thereby reducing the energy conversion efficiency, shortening the battery life, and even completely deactivating the battery; the adsorption and desorption of the first adsorber 100 and the second adsorber 200 are alternately performed, and the first product gas outlet 113 and the second product gas outlet 213, one of which conveys part of the product hydrogen to the other, is used to purge the desorbed CO and H2S, so that CO and H2S flow out from the first raw gas inlet 112 and the second raw gas inlet 212 to the exhaust gas treatment pipeline, so that the adsorption and desorption of the first adsorber 100 and the second adsorber 200 can be cyclically performed, which is conducive to the reuse of the adsorbent.

[0061] In some embodiments, in step S2, after the desorbed CO and H2S are desorbed from the adsorbent by passing desorbed gas into the first heat exchange tube 111 and the second heat exchange tube 211 to heat the adsorbent, the process further includes: continuing to pass desorbed gas into the first heat exchange tube 111 and the second heat exchange tube 211 through the first heat exchange medium inlet 114 and the second heat exchange medium inlet 214 to reduce the temperature in the first adsorber 100 and the second adsorber 200 to a preset adsorption temperature, which is 20 to 40° C. The desorbed gas passed in here is cooled in advance, and the low-temperature desorbed gas is passed into the first heat exchange tube 111 and the second heat exchange tube 211 to reduce the temperature in the first adsorber 100 and the second adsorber 200 to the preset adsorption temperature, so as to prepare for the next cycle of adsorption treatment.

[0062] In some embodiments, in step S3, after CO and H2S are made to flow out from the first raw gas inlet 112 and the second raw gas inlet 212 to the waste gas treatment pipeline, the first waste gas valve 150 and the second waste gas valve 250 are closed, and the first product gas outlet 113 and the second product gas outlet 213 are used to deliver part of the product hydrogen to the other, so that the internal pressure of the first product gas outlet 113 and the second product gas outlet 213 are increased to a preset adsorption pressure of 1-3 MPa. Through the first adsorption tower and the second adsorption tower, one of them delivers part of the product hydrogen to the other, so that the internal pressure of the other is increased to the preset adsorption pressure, so as to prepare for the adsorption treatment of the next cycle.

[0063] In some embodiments, in step S1, the adsorbent is used to adsorb CO and H2S in the raw hydrogen introduced from the first raw gas inlet 112 and the second raw gas inlet 212, including: when the adsorbent is saturated with adsorption, the first air inlet valve 130, the second air inlet valve 230, the first air outlet valve 140 and the second air outlet valve 240 are closed, the first exhaust valve 150 and the second exhaust valve 250 are opened, and the gas in the first adsorber 100 and the second adsorber 200 flows out from the first raw gas inlet 112 and the second raw gas inlet 212 to the exhaust gas treatment pipeline, respectively, and the pressure in the first adsorber 100 and the second adsorber 200 is reduced to a preset pressure threshold. The adsorbent loading amount and adsorption time are designed according to the gas components, and the adsorption is considered to be saturated when the adsorption time is reached. The gas in the first adsorber 100 and the second adsorber 200 flows out from the first raw gas inlet 112 and the second raw gas inlet 212 to the exhaust gas treatment pipeline respectively, realizing reverse decompression and reducing the pressure to a preset pressure threshold, which is beneficial to the desorption of impurities. Reverse decompression is beneficial to faster desorption of gas impurities in the tower from the bottom of the tower, which is beneficial to preventing the adsorbent in the upper layer from being contaminated.

[0064] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0065] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise" and "counterclockwise" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0066] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0067] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0068] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A heat exchange adsorption system for hydrogen purification, characterized in that: including a first adsorber and a second adsorber; Adsorbents are disposed inside the first adsorber and the second adsorber, and the adsorbents are used to adsorb CO and H2S in the raw hydrogen; A first heat exchange tube is provided inside the first adsorber for heating and desorbing the adsorbent in the first adsorber; a first raw gas inlet, a first product gas outlet and a first heat exchange medium inlet are provided on the outer wall of the first adsorber, and the first heat exchange medium inlet is connected to the first heat exchange tube; A second heat exchange tube is provided inside the second adsorber for heating and desorbing the adsorbent in the second adsorber; a second raw gas inlet, a second product gas outlet, and a second heat exchange medium inlet are provided on the outer wall of the second adsorber, the second product gas outlet is connected to the first product gas outlet, and the second heat exchange medium inlet is connected to the second heat exchange tube; During the adsorption process, the first raw gas inlet and the second raw gas inlet respectively introduce raw hydrogen into the first adsorber and the second adsorber, the adsorbent adsorbs CO and H2S, and the obtained product hydrogen flows out from the first product gas outlet and the second product gas outlet; During the desorption process, the desorbed gas enters the first heat exchange tube and the second heat exchange tube through the first heat exchange medium inlet and the second heat exchange medium inlet respectively, and heats the adsorbent to desorb the adsorbed CO and H2S from the adsorbent; The adsorption and desorption of the first adsorber and the second adsorber are performed alternately, and one of the first product gas outlet and the second product gas outlet conveys part of the product hydrogen to the other, so as to purge the desorbed CO and H2S, so that CO and H2S flow out from the first raw gas inlet and the second raw gas inlet to the exhaust gas treatment pipeline.

2. The heat exchange adsorption system for hydrogen purification according to claim 1, characterized in that: The first raw gas inlet and the second raw gas inlet are connected to the hydrogen feed main pipeline through a first feed branch pipe and a second feed branch pipe respectively, the first feed branch pipe is provided with a first intake valve, and the second feed branch pipe is provided with a second intake valve; The first product gas outlet and the second product gas outlet are connected to the product discharge main pipeline through the first discharge branch pipe and the second discharge branch pipe respectively, the first discharge branch pipe is provided with a first gas outlet valve, the second discharge branch pipe is provided with a second gas outlet valve, a reflux pipeline is connected between the second discharge branch pipe between the first product gas outlet and the first gas outlet valve and the first discharge branch pipe between the second product gas outlet and the second gas outlet valve, and a reflux valve and a reversing valve are provided on the reflux pipeline; The first product gas outlet and the second product gas outlet are connected to the exhaust gas recovery main pipeline through the first exhaust gas recovery branch pipe and the second exhaust gas recovery branch pipe respectively; the first exhaust gas recovery branch pipe is connected to the first discharge branch pipe between the first outlet valve and the first product gas outlet, and the first exhaust gas recovery branch pipe is provided with a first exhaust gas valve; the second exhaust gas recovery branch pipe is connected to the second outlet valve and the second product gas outlet diameter second discharge branch pipe, and the second exhaust gas recovery branch pipe is provided with a second exhaust gas valve; During the adsorption process, the first exhaust valve and the second exhaust valve are closed, the first intake valve, the second intake valve, the first outlet valve and the second outlet valve are opened, the raw hydrogen enters the first adsorber and the second adsorber through the first feed branch pipe and the second feed branch pipe respectively, and the product hydrogen flows out of the first adsorber and the second adsorber through the first discharge branch pipe and the second discharge branch pipe respectively; During the desorption process, the reflux valve and the reversing valve are opened, and the product hydrogen generated by adsorption in the first adsorber enters the second product gas outlet through the first product gas outlet, and the CO and H2S desorbed by the adsorbent in the second adsorber are purged, so that CO and H2S flow out from the second raw gas inlet to the waste gas treatment pipeline; or, the product hydrogen generated by adsorption in the second adsorber enters the first product gas outlet through the second product gas outlet, and the CO and H2S desorbed by the adsorbent in the first adsorber are purged, so that CO and H2S flow out from the first raw gas inlet to the waste gas treatment pipeline.

3. The heat exchange adsorption system for hydrogen purification according to claim 2, characterized in that: During the adsorption process, when the adsorbent is saturated with adsorption, the first air inlet valve, the second air inlet valve, the first air outlet valve and the second air outlet valve are closed, the first exhaust valve and the second exhaust valve are opened, and the gas in the first adsorber and the second adsorber flows out from the first raw gas inlet and the second raw gas inlet to the exhaust gas treatment pipeline respectively, reducing the pressure in the first adsorber and the second adsorber to a preset pressure threshold.

4. The heat exchange adsorption system for hydrogen purification according to claim 3, characterized in that: After the CO and H2S in the adsorbent are completely desorbed, desorption gas is continuously introduced into the first heat exchange tube and the second heat exchange tube through the first heat exchange medium inlet and the second heat exchange medium inlet to reduce the temperature in the first adsorber and the second adsorber to a preset adsorption temperature, which is 20 to 40°C.

5. The heat exchange adsorption system for hydrogen purification according to claim 1, characterized in that: During the desorption process, after the desorbed CO and H2S are completely purged into the exhaust gas treatment pipeline, the first exhaust valve and the second exhaust valve are closed, and the first product gas outlet and the second product gas outlet, one of them deliver part of the product hydrogen to the other, so that its internal pressure is increased to the preset adsorption pressure, and the preset adsorption pressure is 1-3MPa.

6. The heat exchange adsorption system for hydrogen purification according to claim 4, characterized in that: It also includes a desorbed gas supply device and a desorbed gas recovery device, the first heat exchange medium inlet is connected to the desorbed gas supply device, and a first heat exchange medium outlet is also provided on the outer wall of the first adsorber, the first heat exchange medium outlet is respectively connected to the first heat exchange tube and the desorbed gas recovery device for recycling the desorbed gas; the second heat exchange medium inlet is connected to the desorbed gas supply device through a second medium entry branch pipe, and a second heat exchange medium outlet is also provided on the outer wall of the second adsorber, the second heat exchange medium outlet is respectively connected to the second heat exchange tube and the desorbed gas recovery device for recycling the desorbed gas.

7. A heat exchange adsorption method for hydrogen purification, using the heat exchange adsorption system for hydrogen purification according to any one of claims 1 to 6, characterized in that: include: Adsorbing CO and H2S in the raw hydrogen introduced from the first raw gas inlet and the second raw gas inlet by the adsorbent, and the obtained product hydrogen flows out from the first product gas outlet and the second product gas outlet; By introducing desorption gas into the first heat exchange tube and the second heat exchange tube to heat the adsorbent, the adsorbed CO and H2S are desorbed from the adsorbent; The adsorption and desorption of the first adsorber and the second adsorber are performed alternately, and the first product gas outlet and the second product gas outlet, one of them convey part of the product hydrogen to the other, so as to purge the desorbed CO and H2S, so that CO and H2S flow out from the first raw gas inlet and the second raw gas inlet to the exhaust gas treatment pipeline.

8. The heat exchange adsorption method for hydrogen purification according to claim 7, characterized in that: After the desorbed CO and H2S are desorbed from the adsorbent by introducing desorbed gas into the first heat exchange tube and the second heat exchange tube to heat the adsorbent, the method further includes: continuing to introduce desorbed gas into the first heat exchange tube and the second heat exchange tube through the first heat exchange medium inlet and the second heat exchange medium inlet to reduce the temperature in the first adsorber and the second adsorber to a preset adsorption temperature, which is 20 to 40°C.

9. The heat exchange adsorption method for hydrogen purification according to claim 7, characterized in that: After allowing CO and H2S to flow out from the first raw gas inlet and the second raw gas inlet to the exhaust gas treatment pipeline, the method further includes: closing the first exhaust valve and the second exhaust valve, and the first product gas outlet and the second product gas outlet, one of which transports part of the product hydrogen to the other, so that the internal pressure thereof is increased to a preset adsorption pressure, and the preset adsorption pressure is 1-3MPa.

10. The heat exchange adsorption method for hydrogen purification according to claim 7, characterized in that: The adsorption of CO and H2S in the raw hydrogen introduced from the first raw gas inlet and the second raw gas inlet by the adsorbent includes: when the adsorbent is saturated with adsorption, the first air inlet valve, the second air inlet valve, the first air outlet valve and the second air outlet valve are closed, the first exhaust valve and the second exhaust valve are opened, and the gas in the first adsorber and the second adsorber flows out from the first raw gas inlet and the second raw gas inlet to the exhaust gas treatment pipeline respectively, and the pressure in the first adsorber and the second adsorber is reduced to a preset pressure threshold.

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