A methanol-to-hydrogen purification system

Abstract

The application discloses a methanol hydrogen production purification system, which comprises a molecular sieve runner, a reformer and a hydrogen purifier, the reformer is provided with a methanol water vapor inlet and a reforming mixed gas outlet, the hydrogen purifier is provided with a reforming mixed gas inlet, a purification tail gas outlet and a purified hydrogen outlet, the molecular sieve runner comprises an adsorption zone, a regeneration zone and a purge zone, the reforming mixed gas outlet corresponds to a gas inlet of the molecular sieve runner adsorption zone, and a gas outlet of the molecular sieve runner adsorption zone corresponds to the reforming mixed gas inlet. Through the technical scheme, the land occupation of the purification system is reduced, the hydrogen purification efficiency is improved, the production system failure rate is reduced, the hydrogen recovery rate and the purification purity are improved.

Description

Technical Field

[0001] This invention belongs to the field of methanol-to-hydrogen, and specifically relates to a methanol-to-hydrogen purification system. Background Technology

[0002] Traditional methanol-to-hydrogen production mostly uses the PSA (Pressure Swing Adsorption) method to purify hydrogen. Although this method produces high-purity hydrogen, it requires a large area, has high initial investment costs, and a relatively low hydrogen recovery rate of about 70%. In addition, the PSA method has a large number of valves that need to be switched frequently during operation, resulting in a high failure rate and the need for tower maintenance. This not only increases maintenance costs but also leads to instability in hydrogen production during valve switching or maintenance. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides the following technical solution: a methanol-to-hydrogen purification system, comprising a reformer and a hydrogen purifier. The reformer has a methanol-water vapor inlet and a reformed mixed gas outlet. The hydrogen purifier has a reformed mixed gas inlet, a purified tail gas outlet, and a purified hydrogen outlet. The purification system further includes a molecular sieve rotor, which includes an adsorption zone, a regeneration zone, and a purging zone. The reformed mixed gas outlet corresponds to the gas inlet of the adsorption zone of the molecular sieve rotor, and the gas outlet of the adsorption zone of the molecular sieve rotor corresponds to the reformed mixed gas inlet.

[0004] Preferably, the system further includes a catalyst with a catalyst inlet and a catalyst outlet. The purified exhaust gas outlet is connected to the catalyst inlet, and the gas outlets of the regeneration zone and the purging zone are also corresponding to the catalyst inlet.

[0005] Preferably, the system further includes a heater and a vaporization superheater. The heater has a heater mixture inlet and a heater mixture outlet; the vaporization superheater has a vaporization mixture inlet and a vaporization mixture outlet; the heater mixture outlet is connected to the vaporization mixture inlet, and the vaporization mixture outlet is connected to the methanol steam inlet.

[0006] Preferably, the system further includes a methanation reactor, and the purified hydrogen outlet is connected to the inlet of the methanation reactor.

[0007] Preferably, the reformer is further provided with a reforming heat inlet and a reforming heat outlet, and the vaporization superheater is further provided with a vaporization heat inlet and a vaporization heat outlet; the catalyst outlet is connected to the reforming heat inlet, and the reforming heat outlet is connected to the vaporization heat inlet.

[0008] Preferably, the system further includes a main branch pipe, the vaporization heat outlet is connected to the inlet of the main branch pipe, the main branch pipe includes a first main branch pipe and a second main branch pipe, and the outlet of the second main branch pipe corresponds to the gas inlet of the regeneration zone.

[0009] Preferably, the purification system further includes a reformer heat exchanger, which has a first heat source inlet, a first heat source outlet, a second heat source inlet, and a second heat source outlet. The first heat source inlet is connected to the first heat source outlet, and the second heat source inlet is connected to the second heat source outlet. The heater also has a heater heat inlet and a heater heat outlet. The first heat source inlet is connected to the reformed mixed gas outlet, and the first heat source outlet is connected to the heater heat inlet. The heater heat inlet corresponds to the gas inlet of the adsorption zone. The gas outlet of the adsorption zone corresponds to the second heat source inlet, and the second heat source outlet is connected to the reformed mixed gas inlet.

[0010] Preferably, the purification system further includes a first heat exchanger, a second heat exchanger, and an auxiliary distribution pipe. Both the first and second heat exchangers have a first heat inlet, a first heat outlet, a second heat inlet, and a second heat outlet. The first heat exchanger is located at the junction of the main first branch pipe and the main second branch pipe, and the second heat exchanger is located within the main second branch pipe. The second heat inlet of the first heat exchanger is connected to the vaporization heat outlet via the main distribution pipe. The first heat outlet of the first heat exchanger is connected to the first heat inlet of the second heat exchanger via the main second branch pipe. The second heat outlet of the first heat exchanger is connected to the inlet of the auxiliary distribution pipe. The auxiliary distribution pipe includes an auxiliary first branch pipe and an auxiliary second branch pipe. The second heat outlet of the first heat exchanger is connected to the gas inlet of the auxiliary distribution pipe, the gas outlet of the auxiliary second branch pipe is connected to the first heat inlet of the first heat exchanger, and the first heat outlet of the second heat exchanger corresponds to the gas inlet of the regeneration zone.

[0011] Preferably, the second heat inlet of the second heat exchanger is connected to the purified hydrogen outlet.

[0012] Preferably, the system further includes a booster pump and a circulating compressor. One end of the booster pump is connected to the outlet of the second heat source, and the other end is connected to the inlet of the reformed gas mixture. One end of the circulating compressor is connected to the second heat outlet of the first heat exchanger, and the other end is connected to the first heat inlet of the first heat exchanger. Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1) The composite purification method enables the methanol-to-hydrogen system to produce hydrogen continuously and stably;

[0014] 2) The use of molecular sieve rotors for adsorption of reformed mixed gas makes the adsorption equipment compact, highly integrated, and capable of being skid-mounted.

[0015] 3) By employing a two-stage purification system of molecular sieve rotor and palladium membrane diffusion permeation, the purity of hydrogen can reach 99.999%, while simultaneously increasing the hydrogen recovery rate by 10%.

[0016] 4) The purification system establishes a balanced cycle of thermal energy, which improves the thermal efficiency of the system. Attached Figure Description

[0017] Figure 1 This is a process flow diagram of Embodiment 1 of the present invention.

[0018] Figure 2 This is a process flow diagram of Embodiment 2 of the present invention.

[0019] Figure 3 Process flow diagrams of embodiments 3 and 4 of this invention Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1:

[0022] A purification system for methanol-to-hydrogen production, such as Figure 1As shown, the system includes a reformer 1, a molecular sieve rotor 2, and a hydrogen purifier 3. The reformer 1 is provided with a methanol steam inlet 11 and a reformed mixed gas outlet 12. The molecular sieve rotor 2 is provided with an adsorption zone 21, a regeneration zone 22, and a purging zone 23, wherein the adsorption zone is a room temperature adsorption zone, the regeneration zone is a high temperature regeneration zone, and the purging zone is a cooling purging zone. The hydrogen purifier 3 is provided with a reformed mixed gas inlet 31, a purified tail gas outlet 32, and a purified hydrogen outlet 33. The reformer 1, the molecular sieve rotor 2, and the hydrogen purifier 3 are connected in sequence. During operation, the methanol-water mixture enters the reformer 1 through the methanol-water vapor inlet 11 for reforming. After reaction under the action of the reforming catalyst, the resulting reformed mixture exits the reformer 1 through the reformed mixture outlet 12 and then flows into the adsorption zone 21 of the molecular sieve rotor 2 corresponding to the reformed mixture outlet 12. The reformed mixture flows into the adsorption zone 21 through the gas inlet, where the molecular sieve removes moisture and carbonaceous impurities. The hydrogen-rich gas obtained after treatment in the adsorption zone 21 flows out through the gas outlet of the adsorption zone 21 to the reformed mixture inlet 31 of the corresponding hydrogen purifier 3, and then flows into the hydrogen purifier 3 for purification. The purified hydrogen exits the purifier 3 through the purified hydrogen outlet 33 and is stored. The remaining tail gas after purification exits the purifier 3 through the purified tail gas outlet 32. Preferably, the molecular sieve rotor 2 uses a 5A molecular sieve, and the rotor is driven to rotate by a servo motor and chain. The adsorbed molecular sieves sequentially reach the regeneration zone 22 and the purging zone 23 as the molecular sieve rotor 2 rotates. The molecular sieves undergo decarbonization and dehydration under the high temperature conditions in the regeneration zone 22 to obtain adsorbed tail gas. Then, in the purging zone 23, they are purged by low temperature purging air to obtain reusable molecular sieves. These regenerated molecular sieves then re-enter the adsorption zone 21 under the rotation of the molecular sieve rotor 2.

[0023] Furthermore, the purification system also includes a heater 4 and a vaporization superheater 5. Both the heater 4 and the vaporization superheater 5 are used to heat the methanol-water mixture so that its temperature reaches the requirements of the reforming reaction. During operation, the methanol-water mixture first flows into the heater 4 through the heater mixture inlet 41 for initial heating, then flows to the heater mixture outlet 42 and flows into the vaporization superheater 5 through the vaporization mixture inlet 51 for secondary vaporization and heating. After the methanol-water mixture is heated and vaporized to the required temperature, it flows out of the vaporization superheater 5 through the vaporization mixture outlet 52 and then flows into the reforming reactor 1 through the methanol-water vapor inlet 11.

[0024] Meanwhile, in order to ensure the purity of hydrogen, the purification system is also equipped with a methanation reactor 6. The purified hydrogen flowing out of the purified hydrogen outlet 33 flows into the methanation reactor 6 to react and remove carbon oxides from the purified hydrogen.

[0025] Because the molecular sieve rotor integrates adsorption, regeneration, and purging, it significantly reduces the floor space required compared to adsorption towers. Furthermore, during the impurity removal process, only the rotor needs to rotate to achieve switching between different zones, eliminating the need for the complex valve design of adsorption towers. Moreover, this technical solution yields high-purity hydrogen with a purity of 99.999%. This embodiment not only significantly improves the hydrogen production rate and reduces the production area and system failure rate, but also greatly enhances the recovery rate and purification purity of hydrogen in the hydrogen purifier 3 due to the removal of carbonaceous impurities from the reformed gas by the molecular sieve rotor.

[0026] Example 2:

[0027] Because the hydrogen recovery rate of the existing PSA (Pressure Swing Adsorption) process is only around 70%, this embodiment differs from Embodiment 1 in that a catalyst 7 is also provided in the hydrogen purification system to further improve the utilization rate of hydrogen produced from methanol-to-hydrogen. The catalyst 7 has a catalyst inlet 71 and a catalyst outlet 72. The catalyst 7 is used to burn the adsorption tail gas generated by the molecular sieve rotor 2 and the purification tail gas generated by the hydrogen purifier 3. Therefore, the catalyst inlet 71 is connected to the purification tail gas outlet 32. Simultaneously, the catalyst inlet 71 also corresponds to the regeneration zone 22 and the purging zone 23 of the molecular sieve rotor 2. That is, the gas outlet of the regeneration zone 22 and the gas outlet of the purging zone 23 both correspond to the catalyst inlet 71, allowing the gas flowing out of the regeneration zone 22 and the purging zone 33 to flow to the catalyst inlet 71 and then into the catalyst 7 for combustion. The heat generated from the combustion of the above tail gas is used to provide heat for the reformer 1 and the vaporization superheater 5.

[0028] In this embodiment, such as Figure 2As shown, the reformer 1 is further provided with a reforming heat inlet 13, a reforming heat outlet 14, and a main branch pipe 55, and the vaporization superheater 5 is provided with a vaporization heat inlet 53 and a vaporization heat outlet 54. During operation, the adsorption tail gas and purified tail gas after combustion in the catalyst 7 are called combustion tail gas. The combustion tail gas flows out of the catalyst 7 through the catalyst outlet 72, and then flows into the reformer 1 through the reformer heat inlet 13. The combustion tail gas at 510°C flows into the reformer 1 for heat exchange to provide heat for the reforming reaction. After the heat exchange is completed, the combustion tail gas flows out of the reformer 1 through the reformer heat outlet 14. The temperature of the combustion tail gas flowing out of the reformer 1 is 410°C. Then it flows into the vaporization superheater 5 through the vaporization heat inlet 53 for heat exchange to provide vaporization heat for the methanol-water mixture, and then flows out of the vaporization superheater 5 through the vaporization heat outlet 54. At this time, the temperature of the combustion tail gas flowing out is 150°C, which is called cooling combustion tail gas. Cooling combustion exhaust gas flows into the main branch pipe 55, which includes a first main branch pipe 56 and a second main branch pipe 57. The cooling exhaust gas flowing out of the first main branch pipe 56 goes to the carbon dioxide trap for carbon dioxide recovery. The cooling exhaust gas flowing out of the second main branch pipe 57 flows into the regeneration zone 22 of the molecular sieve rotor 2 through the gas inlet of the regeneration zone 22, and regenerates the molecular sieve that participated in adsorption. The resulting adsorbed exhaust gas and cooling combustion exhaust gas then flow into the catalyst 7 for combustion again.

[0029] In addition, the air used to purge the purging zone 23 of the molecular sieve rotor 2 can be air or a mixture of cooling combustion exhaust gas and air.

[0030] It can be seen that in this embodiment, the hydrogen production utilization rate of the methanol-to-hydrogen system is improved by burning and reusing the remaining hydrogen in the adsorption tail gas and the purifier tail gas.

[0031] Example 3:

[0032] Since the temperature of high-purity hydrogen gas when it exits the methanation reactor 6 and reformer 1 is as high as 410°C, and since the adsorption zone 21 in the molecular sieve rotor 2 needs to operate at room temperature while the regeneration zone 22 needs to operate under high temperature conditions, a thermal circulation system is set up in this hydrogen purification system to improve the thermal efficiency of the system and ensure that the molecular sieve rotor 2 and the purifier 3 can operate normally.

[0033] The difference between this embodiment and embodiment 1 or 2 is that, Figure 3 As shown, the methanol-to-hydrogen purification system is further equipped with a reforming gas heat exchanger 10. The reforming gas heat exchanger 10 is provided with a first heat source inlet 101, a first heat source outlet 102, a second heat source inlet 103, and a second heat source outlet 104. The reforming gas heat exchanger 10 is used to exchange heat between the reformed mixed gas and the hydrogen-rich gas adsorbed by the molecular sieve rotor 2, thereby providing reaction heat for the hydrogen purifier 3.

[0034] Meanwhile, the heater 4 is also provided with a heater heat inlet 43 and a heater heat outlet 44. In this embodiment, after the methanol-to-hydrogen system is turned on and operating stably, the methanol-water mixture continues to flow into the heater 4 through the heater mixture inlet 41 and out of the heater 4 through the heater mixture outlet 42. It then flows into the vaporization superheater 5 through the vaporization mixture inlet 51 to obtain vaporized methanol-water mixture gas. The methanol-water mixture gas flows out through the vaporization mixture outlet 52 and enters the reformer 1 through the methanol-water vapor inlet 11. After the reforming reaction, it obtains reformed mixture gas. The reformed mixture gas flows out of the reformer 1 through the reformed mixture gas outlet 12 and then flows sequentially through the first heat source inlet 11 and the first heat source outlet 12 of the reformed gas heat exchanger 10. At the same time, the hydrogen-rich gas obtained after adsorption by the molecular sieve rotor 2 flows sequentially through the second heat source inlet 103 and the second heat source outlet 104 of the reformed gas heat exchanger 10, thereby completing the heat exchange between the reformed mixture gas at a temperature of 410°C and the hydrogen-rich gas at a temperature of only 40°C. After heat exchange, the temperature of the reformed gas mixture drops to 150°C. It then flows out of the reformed gas heat exchanger 10 from the first heat source outlet 102. The reformed gas mixture flowing out of the first heat source outlet 102 flows to the heater heat inlet 43. The heat of the reformed gas mixture is exchanged in the heater 4 to heat the methanol-water mixture, raising its temperature to 120°C. After heat exchange, the reformed gas mixture is cooled again in the pipeline to 40°C before flowing into the adsorption zone 21. In the adsorption zone 21, moisture and carbon-containing impurities in the reformed gas mixture are removed to obtain hydrogen-rich gas. The molecular sieve that has adsorbed carbon-containing impurities enters the regeneration zone 22 and the purging zone 23 sequentially as the molecular sieve rotor 2 rotates, recovering the adsorbed tail gas and the molecular sieve itself. The adsorbed tail gas obtained from the regeneration zone 22 and the purging zone 23 flows out of the molecular sieve rotor 2 and into the catalyst 7 through the catalyst inlet 71 for catalytic combustion, thereby recovering and utilizing the hydrogen in the adsorbed tail gas. The hydrogen-rich gas obtained by the molecular sieve rotor 2 flows out of the adsorption zone 21 and then into the reformer heat exchanger 10 through the second heat source inlet 103. The temperature of the hydrogen-rich gas after being heated in the reformer heat exchanger 10 can be raised to 390°C. Then it flows into the hydrogen purifier 3 to complete the purification of hydrogen. The purified tail gas flows out of the purifier 3 through the purified tail gas outlet 32 ​​and then flows into the catalytic converter 7 through the catalytic converter inlet 71, so that the hydrogen and methanol in the tail gas can be burned and utilized.

[0035] Since the regeneration zone 22 needs to operate at high temperatures, and the temperature of the reformed gas mixture can reach 410℃, in order to further improve the thermal efficiency of the system, the system is also equipped with a first heat exchanger 8, a second heat exchanger 9, and an auxiliary branch pipe 55'. The first heat exchanger 8 is used to recover waste heat from the adsorption combustion exhaust gas, and the second heat exchanger 9 is used to recover heat from the purified hydrogen. The heat recovered by the first heat exchanger 8 and the second heat exchanger 9 is used to provide heat for the regeneration zone 22 in the molecular sieve rotor 2. Both the first and second heat exchangers are equipped with a first heat inlet, a first heat outlet, a second heat inlet, and a second heat outlet. The auxiliary branch pipe 55' includes an auxiliary first branch pipe 56' and an auxiliary second branch pipe 57'. The first heat exchanger 8 is located at the junction of the main first branch pipe 56 and the main second branch pipe 57. The second heat inlet of the first heat exchanger 8 is connected to the vaporization heat outlet 54 of the vaporization superheater 5 through the main branch pipe 55. The second heat outlet of the first heat exchanger 8 is connected to the first heat inlet of the first heat exchanger 8 through the auxiliary second branch pipe 57'. The second heat exchanger 9 is located on the main second branch pipe 57. The first heat outlet of the first heat exchanger 8 is connected to the first heat inlet of the second heat exchanger 9 through the main second branch pipe.

[0036] The specific workflow is as follows: After reaction in methanation reactor 6, high-purity hydrogen is obtained. The high-purity hydrogen flows into the second heat exchanger 2 through the second heat exchange inlet, undergoes heat exchange, and then flows out through the second heat exchange outlet, where it is collected. The combustion exhaust gas flowing out of vaporization superheater 5 flows into the gas inlet of main branch pipe 55 through vaporization heat outlet 54, and then flows into the second heat inlet of first heat exchanger 8 through main first branch pipe 56 to exchange heat with first heat exchanger 8. Then, it flows out of first heat exchanger 8 through the second heat outlet. The cooled combustion exhaust gas flowing out of first heat exchanger 8 flows into auxiliary branch pipe 55' through main first branch pipe 56. A portion of the cooled exhaust gas flowing into auxiliary branch pipe 55' flows into carbon dioxide capture system through auxiliary first branch pipe 56'. Another portion flows into the auxiliary second branch pipe 57'. This portion of the cooled exhaust gas flows into the first heat inlet of the first heat exchanger 8 through the auxiliary second branch pipe 57' and re-enters the thermal cycle system for recycling. The cooled combustion exhaust gas flows into the first heat exchanger 8 for heat exchange and then flows out from the first heat outlet of the first heat exchanger 8. Then, it flows into the second heat exchanger 9 through the main second branch pipe 57 and the first heat inlet of the second heat exchanger 9 to exchange heat with high-purity hydrogen. Then, it flows out from the first heat outlet of the second heat exchanger 9 and then flows to the regeneration zone 22 of the molecular sieve rotor 2 to discharge the adsorbed exhaust gas in the molecular sieve rotor 2. Then, it flows into the catalyst 7 again for combustion.

[0037] As can be seen in this embodiment, by setting up the reforming gas heat exchanger 10, the first heat exchanger 8 and the second heat exchanger 9, the heat in the system is further recovered and utilized, thereby improving the thermal efficiency of the system.

[0038] Example 4:

[0039] like Figure 3 As shown, the difference between this embodiment and embodiments 1, 2, or 3 is that the system further includes a booster pump 111, a circulating compressor 112, and an air compressor 113. The booster pump 111 is located between the second heat source outlet 104 of the reforming gas heat exchanger 10 and the reforming mixed gas inlet 31 of the hydrogen purifier 3; the circulating compressor 112 is connected between the second heat outlet of the first heat exchanger 8 and the first heat inlet of the first heat exchanger 8; the air compressor 113 is located in the purging zone 23 of the molecular sieve rotor 2 to provide purging air to the purging zone 23.

[0040] It should be noted that the technical features in embodiments 1 to 4 above can be combined arbitrarily, and the resulting technical solutions all fall within the protection scope of this application. Furthermore, in this document, terms such as "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A methanol-to-hydrogen purification system, comprising a reformer and a hydrogen purifier, wherein the reformer has a methanol steam inlet and a reformed mixed gas outlet; and the hydrogen purifier has a reformed mixed gas inlet, a purified tail gas outlet, and a purified hydrogen outlet; characterized in that, The purification system further includes a molecular sieve rotor, which includes an adsorption zone, a regeneration zone, and a purging zone; the reformed mixed gas outlet corresponds to the gas inlet of the adsorption zone of the molecular sieve rotor, and the gas outlet of the adsorption zone of the molecular sieve rotor corresponds to the reformed mixed gas inlet. The purification system also includes a catalyst, a heater, and a vaporization superheater. The catalyst has a catalyst inlet and a catalyst outlet. The purification tail gas outlet is connected to the catalyst inlet. The gas outlets of the regeneration zone and the purging zone are also corresponding to the catalyst inlet. The heater has a heater mixture inlet and a heater mixture outlet. The vaporization superheater has a vaporization mixture inlet and a vaporization mixture outlet. The heater mixture outlet is connected to the vaporization mixture inlet, and the vaporization mixture outlet is connected to the methanol steam inlet. The reformer is further provided with a reforming heat inlet and a reforming heat outlet, and the vaporization superheater is further provided with a vaporization heat inlet and a vaporization heat outlet; the catalyst outlet is connected to the reforming heat inlet, and the reforming heat outlet is connected to the vaporization heat inlet; The purification system also includes a reformer heat exchanger, which has a first heat source inlet, a first heat source outlet, a second heat source inlet, and a second heat source outlet. The first heat source inlet is connected to the first heat source outlet, and the second heat source inlet is connected to the second heat source outlet. The heater also has a heater heat inlet and a heater heat outlet. The first heat source inlet is connected to the reformed mixed gas outlet, and the first heat source outlet is connected to the heater heat inlet. The heater heat inlet corresponds to the gas inlet of the adsorption zone. The gas outlet of the adsorption zone corresponds to the second heat source inlet, and the second heat source outlet is connected to the reformed mixed gas inlet. The purification system also includes a first heat exchanger, a second heat exchanger, an auxiliary branch pipe, and a main branch pipe. The vaporization heat outlet is connected to the inlet of the main branch pipe. The main branch pipe includes a first main branch pipe and a second main branch pipe, and the outlet of the second main branch pipe corresponds to the gas inlet of the regeneration zone. Both the first and second heat exchangers have a first heat inlet, a first heat outlet, a second heat inlet, and a second heat outlet. The first heat exchanger is located at the junction of the first main branch pipe and the second main branch pipe, and the second heat exchanger is located within the second main branch pipe. The second heat inlet of the first heat exchanger... The inlet is connected to the vaporization heat outlet through the main branch pipe; the first heat outlet of the first heat exchanger is connected to the first heat inlet of the second heat exchanger through the main second branch pipe; the second heat outlet of the first heat exchanger is connected to the inlet of the auxiliary branch pipe; the auxiliary branch pipe includes an auxiliary first branch pipe and an auxiliary second branch pipe, the second heat outlet of the first heat exchanger is connected to the gas inlet of the auxiliary branch pipe, the gas outlet of the auxiliary second branch pipe is connected to the first heat inlet of the first heat exchanger, and the first heat outlet of the second heat exchanger corresponds to the gas inlet of the regeneration zone.

2. The purification system as described in claim 1, characterized in that, The purification system also includes a methanation reactor, and the purified hydrogen outlet is connected to the inlet of the methanation reactor.

3. The purification system as described in claim 1, characterized in that, The second heat inlet of the second heat exchanger is connected to the purified hydrogen outlet.

4. The purification system as described in claim 1 or 3, characterized in that, The purification system is also equipped with a booster pump and a circulating compressor. One end of the booster pump is connected to the outlet of the second heat source and the other end is connected to the inlet of the reformed mixed gas. One end of the circulating compressor is connected to the second heat outlet of the first heat exchanger and the other end is connected to the first heat inlet of the first heat exchanger.

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