Biomass pyrolysis gas self-heating reforming hydrogen production system

Abstract

The invention relates to the technical field of pyrolysis gas treatment, in particular to a biomass pyrolysis gas self-heating reforming hydrogen production system which comprises a pyrolysis gas reforming hydrogen production subsystem and a thermochemical self-heating subsystem. Wherein the pyrolysis gas reforming hydrogen production subsystem can realize reforming quality improvement of pyrolysis gas to obtain high-purity hydrogen. On one hand, the thermochemical self-heating subsystem provides energy for the reforming hydrogen production reaction through an exothermic reaction of calcium oxide and carbon dioxide, and continuous and efficient operation of the reforming hydrogen production reaction is achieved; on the other hand, primary separation and quality improvement of the reformed gas can be realized, and the energy of the pyrolysis gas which is difficult to store and transport and has low utilization value is stored in calcium oxide. Through organic coupling of biomass pyrolysis gas reforming hydrogen production and thermochemical heat storage, self-heat-supply upgrading utilization of biomass pyrolysis gas and low-cost preparation of green hydrogen are achieved, and the device has the advantages of being high in energy utilization rate, high in treatment efficiency, convenient to operate and control, high in applicability and the like.

Description

Technical Field

[0001] The invention relates to the technical field of pyrolysis gas treatment, and in particular to a biomass pyrolysis gas self-heating reforming hydrogen production system. Background Art

[0002] With social progress and economic development, people pay more and more attention to the clean use of energy. Under the "dual carbon" goal, the green and low-carbon transformation of energy is getting more and more attention. Biomass is the only renewable resource that can achieve negative carbon emissions during its utilization, and is considered to be the best choice to replace fossil resources. However, the direct combustion efficiency of biomass is low and the pollutant emissions are more serious. Biomass pyrolysis refers to the process of decomposing biomass into pyrolysis oil, biochar and pyrolysis gas through thermochemical conversion under anaerobic or anoxic conditions. Biomass pyrolysis technology can efficiently convert biomass energy into various fuel substances or energy products, thereby reducing human dependence on fossil energy and alleviating environmental pollution problems caused by fossil energy consumption.

[0003] There are many ways to utilize pyrolysis oil and pyrolysis char, but the composition of pyrolysis gas is relatively complex and difficult to store, and it is usually directly burned as a fuel for heat supply. This utilization method cannot fully utilize the potential of pyrolysis gas, resulting in waste of pyrolysis products. Pyrolysis gas is rich in hydrocarbon products such as methane and ethane, which can be directly used as a raw material for steam catalytic reforming to produce hydrogen, realizing low-cost, green and efficient preparation of hydrogen. Carbon dioxide in pyrolysis gas can be used as a feed gas for the calcium oxide / calcium carbonate thermochemical energy storage system, which can not only reduce the concentration of carbon dioxide in the reforming product, achieve preliminary purification of hydrogen, reduce carbon emissions, but also provide the required reaction heat for the reforming reaction, and reduce the input of external energy. For other combustible components contained in pyrolysis gas, combustion provides heat for the calcium oxide / calcium carbonate thermochemical energy storage system, converts thermal energy into chemical energy, and realizes efficient storage and transportation of energy. How to organically combine the two systems is the key to further promote the development of related technologies. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a biomass pyrolysis gas self-heating reforming hydrogen production system to effectively solve the problem of waste heat recovery in the hydrogen production process and realize self-heating of biomass pyrolysis gas reforming hydrogen production.

[0006] (II) Technical solution

[0007] In order to achieve the above-mentioned object, the biomass pyrolysis gas self-heating reforming hydrogen production system of the present invention comprises: a pyrolysis gas reforming hydrogen production subsystem and a thermochemical self-heating subsystem;

[0008] The pyrolysis gas reforming hydrogen production subsystem comprises a biomass pyrolysis device, a three-way valve, a steam reforming reactor, a water storage tank, a first heat exchanger, a water-gas shift reactor, a second heat exchanger, a pressure swing adsorber and a hydrogen storage tank; the gas phase product outlet of the biomass pyrolysis device, the left and right passages of the three-way valve, the gas inlet of the steam reforming reactor, the hot fluid inlet and outlet of the first heat exchanger, and the gas inlet of the water-gas shift reactor are connected in sequence, and the water storage tank, the cold fluid inlet and outlet of the first heat exchanger, and the water vapor inlet of the steam reforming reactor are connected in sequence;

[0009] The thermochemical self-heating subsystem includes a carbonation reactor, a third heat exchanger, a calcium carbonate storage bin, a calcium oxide storage bin, a fourth heat exchanger, a fifth heat exchanger, a calcination reactor and a carbon dioxide storage tank; the gas outlet of the water-gas shift reactor, the cold fluid inlet and outlet of the second heat exchanger, the gas inlet and outlet of the carbonation reactor, the hot fluid inlet and outlet of the second heat exchanger, the feed port of the pressure swing adsorber, and the hydrogen storage tank are connected in sequence; the solid outlet of the carbonation reactor, the hot fluid inlet and outlet of the third heat exchanger, and the calcium carbonate storage bin inlet are connected in sequence; the calcium oxide storage bin outlet, the cold fluid inlet and outlet of the third heat exchanger, and the solid inlet of the carbonation reactor are connected in sequence; the calcium carbonate storage bin outlet, the fourth heat exchanger low-temperature feed port, the fifth heat exchanger low-temperature feed port, and the solid inlet of the calcination reactor are connected in sequence, and the solid outlet of the calcination reactor, the hot fluid inlet and outlet of the fourth heat exchanger, and the calcium oxide storage bin inlet are connected in sequence; the gas outlet of the calcination reactor, the hot fluid inlet and outlet of the fifth heat exchanger, and the carbon dioxide storage tank are connected in sequence;

[0010] The thermochemical self-heating subsystem also includes a sixth heat exchanger, a seventh heat exchanger, a burner, an eighth heat exchanger and an exhaust gas treatment device; the sixth heat exchanger is placed inside the carbonation reactor, the seventh heat exchanger is placed inside the steam reforming reactor, and the sixth heat exchanger is connected to the seventh heat exchanger; the eighth heat exchanger is placed inside the calcination reactor; the pressure swing adsorber analysis gas outlet and the third passage of the three-way valve are connected to the burner in parallel; the burner flue gas outlet, the eighth heat exchanger, and the exhaust gas treatment device are connected in sequence.

[0011] Optionally, a water pump is provided in the pipeline between the water storage tank and the first heat exchanger;

[0012] The pipeline between the calcium carbonate storage bin outlet and the low-temperature feed port of the fourth heat exchanger is provided with a first screw feeder;

[0013] The pipeline between the calcium oxide storage bin outlet and the third heat exchanger is provided with a second screw feeder.

[0014] Optionally, the biomass pyrolysis device is operated in an air-tight state or in an air state where the oxygen content does not exceed 5%, and the pyrolysis gas components produced include hydrogen, carbon dioxide, carbon monoxide, C n H m .

[0015] Optionally, the steam reforming reactor is equipped with a nickel-based catalyst, and the reaction temperature is 700-800°C; the water-gas shift reactor is equipped with an iron-chromium-based catalyst, and the reaction temperature is 400-450°C.

[0016] Optionally, the gaseous product of the water-gas shift reactor includes hydrogen, carbon dioxide and water vapor; and the carbon dioxide content in the gas entering the pressure swing adsorber is reduced to below 5%.

[0017] Optionally, the temperature of the gas product of the water-gas shift reactor after being preheated by the second heat exchanger is 600-700°C.

[0018] Optionally, the reaction temperature in the carbonation reactor is 800-900°C.

[0019] Optionally, when the heat released by the complete combustion of the analytical gas produced by the pressure swing adsorber is insufficient to complete the calcination reaction in the calcination reactor, the three-way valve can adjust the pyrolysis gas flow rate, and part of the pyrolysis gas produced by the biomass pyrolysis device is directly burned in the burner and the flue gas generated directly provides heat for the calcination reactor.

[0020] Optionally, the reaction temperature of the calcination reactor is 650°C to 750°C.

[0021] Optionally, the calcium carbonate from the calcium carbonate storage bin is preheated by the fourth heat exchanger and the fifth heat exchanger and then passed to the calcination reactor to obtain calcium oxide and carbon dioxide with a purity of more than 99%, which are stored in the calcium oxide storage bin and the carbon dioxide storage tank, respectively.

[0022] (III) Beneficial effects

[0023] The technical solution of the present invention provides a biomass pyrolysis gas self-heating reforming hydrogen production system. The pyrolysis gas reforming hydrogen production subsystem and the thermochemical self-heating subsystem cooperate with each other to effectively solve the problem of waste heat recovery in the hydrogen production process, realize the self-heating of biomass pyrolysis gas reforming hydrogen production, and upgrade the low-grade carbon dioxide produced in the pyrolysis system, giving full play to the carbon emission reduction properties of biomass. Among them, the pyrolysis gas reforming hydrogen production subsystem can realize the reforming and upgrading of pyrolysis gas to obtain high-purity hydrogen. On the one hand, the thermochemical self-heating subsystem provides energy for the reforming hydrogen production reaction through the exothermic reaction of calcium oxide and carbon dioxide, realizing the continuous and efficient operation of the reforming hydrogen production reaction; on the other hand, it can realize the preliminary separation and upgrading of the reformed gas, and store the low-utilization value pyrolysis gas energy that is difficult to store and transport in calcium oxide. The present invention realizes self-heating and quality-improving utilization of biomass pyrolysis gas and low-cost preparation of green hydrogen through the organic coupling of biomass pyrolysis gas reforming hydrogen production and thermochemical heat storage, and has the advantages of high energy utilization rate, high processing efficiency, convenient control, strong applicability, etc.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention utilizes the gas phase product of biomass pyrolysis to prepare hydrogen, thereby increasing the energy density of the gas and completing the high value-added conversion of resources.

[0026] (2) The present invention adopts a calcium carbonate / calcium oxide heat storage and release cycle to achieve self-heating of the pyrolysis gas steam reforming hydrogen production system, which has the advantages of wide sources, safety and non-toxicity. It also rationally utilizes the reaction sensible heat carried by the calcium carbonate, calcium oxide, carbon dioxide in the heat storage system and the analysis gas after pressure swing adsorption in the hydrogen production system through a heat exchanger, thereby significantly improving the energy utilization rate.

[0027] (3) The present invention directly introduces the mixed gas after steam reforming of biomass pyrolysis gas into the carbonation reactor to participate in the carbonation reaction, and reconverts it into high-purity carbon dioxide in the calcination reactor, thereby improving the grade of carbon dioxide in the flue gas, driving the resource recycling of carbon dioxide, and realizing the capture, utilization and storage of carbon dioxide in the biomass pyrolysis flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the principle of the biomass pyrolysis gas self-heating reforming hydrogen production system of the present invention.

[0029] [Description of Reference Numerals]

[0030] 1: Biomass pyrolysis device; 2: Three-way valve; 3: Steam reforming reactor; 4: Water storage tank; 5: First heat exchanger; 6: Water-gas shift reactor; 7: Second heat exchanger; 8: Pressure swing adsorber; 9: Hydrogen storage tank; 10: Carbonation reactor; 11: Third heat exchanger; 12: Calcium carbonate storage bin; 13: Calcium oxide storage bin; 14: Fourth heat exchanger; 15: Fifth fourth heat exchanger; 16: Calcination reactor; 17: Carbon dioxide storage tank; 18: Sixth heat exchanger; 19: Seventh heat exchanger; 20: Burner; 21: Eighth heat exchanger; 22: Tail gas treatment device. DETAILED DESCRIPTION

[0031] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0032] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0033] In addition, in the present invention, descriptions such as "first", "second", etc. are only used 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 at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0034] In the present invention, 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; "connection" can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] See also Figure 1 The present invention provides a biomass pyrolysis gas self-heating reforming hydrogen production system, which includes a pyrolysis gas reforming hydrogen production subsystem and a thermochemical self-heating subsystem (ie, a calcium carbonate / calcium oxide heat storage subsystem).

[0036] The pyrolysis gas reforming hydrogen production subsystem includes a biomass pyrolysis device 1, a three-way valve 2, a steam reforming reactor 3, a water storage tank 4, a first heat exchanger 5, a water gas shift reactor 6, a second heat exchanger 7, a pressure swing adsorber 8 and a hydrogen storage tank 9. The gas phase product outlet of the biomass pyrolysis device 1, the left and right passages of the three-way valve 2, the gas inlet of the steam reforming reactor 3, the hot fluid inlet and outlet of the first heat exchanger 5, and the gas inlet of the water gas shift reactor 6 are connected in sequence, and the water storage tank 4 (with desalted water inside), the cold fluid inlet and outlet of the first heat exchanger 5, and the water vapor inlet of the steam reforming reactor 3 are connected in sequence.

[0037] The thermochemical self-heating subsystem includes a carbonation reactor 10 , a third heat exchanger 11 , a calcium carbonate storage bin 12 , a calcium oxide storage bin 13 , a fourth heat exchanger 14 , a fifth heat exchanger 15 , a calcination reactor 16 and a carbon dioxide storage tank 17 . The gas outlet of the water-gas shift reactor 6, the cold fluid inlet and outlet of the second heat exchanger 7, the gas inlet and outlet of the carbonation reactor 10, the hot fluid inlet and outlet of the second heat exchanger 7, the feed port of the pressure swing adsorber 8, and the hydrogen storage tank 9 are connected in sequence; the solid outlet of the carbonation reactor 10, the hot fluid inlet and outlet of the third heat exchanger 11, and the inlet of the calcium carbonate storage bin 12 are connected in sequence; the outlet of the calcium oxide storage bin 13, the cold fluid inlet and outlet of the third heat exchanger 11, and the solid inlet of the carbonation reactor 10 are connected in sequence to provide raw material calcium oxide for the carbonation reaction; the outlet of the calcium carbonate storage bin 12, the low-temperature feed port of the fourth heat exchanger 14, the low-temperature feed port of the fifth heat exchanger 15, and the solid inlet of the calcination reactor 16 are connected in sequence to provide raw material calcium carbonate for the decomposition reaction; the solid outlet of the calcination reactor 16, the hot fluid inlet and outlet of the fourth heat exchanger 14, and the inlet of the calcium oxide storage bin 13 are connected in sequence to form a closed loop; the gas outlet of the calcination reactor 16, the hot fluid inlet and outlet of the fifth heat exchanger 15, and the carbon dioxide storage tank 17 are connected in sequence, and the carbon dioxide is stored after recovering the waste heat. Among them, the biomass pyrolysis device 1, the steam reforming reactor 3, the water-gas shift reactor 6, the pressure swing adsorber 8, the carbonation reactor 10 and the calcination reactor 16 are all existing devices.

[0038] The thermochemical self-heating subsystem also includes a sixth heat exchanger 18, a seventh heat exchanger 19, a burner 20, an eighth heat exchanger 21 and an exhaust gas treatment device 22. The sixth heat exchanger 18 is placed inside the carbonation reactor 10 to collect a large amount of heat released by the carbonation reaction. The seventh heat exchanger 19 is placed inside the steam reforming reactor 3. The sixth heat exchanger 18 and the seventh heat exchanger 19 are connected to form a small circulation loop to provide heat for the steam reforming hydrogen production reaction; the eighth heat exchanger 21 is placed inside the calcination reactor 16 to provide heat for the calcium carbonate decomposition reaction, and then connected to the exhaust gas treatment device 22; the analytical gas outlet of the pressure swing adsorber 8 is connected to the burner 20 in parallel with the third passage of the three-way valve 2; the flue gas outlet of the burner 20, the eighth heat exchanger 21, and the exhaust gas treatment device 22 are connected in sequence.

[0039] In addition, in order to enable the whole system to operate efficiently, a water pump A is provided in the pipeline between the water storage tank 4 and the first heat exchanger 5; a first screw feeder B is provided in the pipeline between the outlet of the calcium carbonate storage bin 12 and the low-temperature feed port of the fourth heat exchanger 14; and a second screw feeder C is provided in the pipeline between the outlet of the calcium oxide storage bin 13 and the third heat exchanger 11. Among them, the water pump A, the first screw feeder B and the first screw feeder C are all existing devices.

[0040] In the above system, the biomass pyrolysis device 1 is operated in a state of being isolated from air or supplied with a small amount of air (a small amount of air means that the oxygen content of the gas introduced into the biomass pyrolysis device 1 does not exceed 5%), and the pyrolysis gas components produced include hydrogen, carbon dioxide, carbon monoxide, C n H m (hydrocarbons), etc. In addition, the steam reforming reactor 3 is equipped with a nickel-based catalyst, and the reaction temperature is 700-800°C; the water gas shift reactor 6 is equipped with an iron-chromium-based catalyst, and the reaction temperature is 400-450°C.

[0041] Furthermore, the gaseous products of the water-gas shift reactor 6 include hydrogen, carbon dioxide, and water vapor. After the calcium oxide from the calcium oxide storage bin 13 is preheated by the third heat exchanger 11, it is passed into the carbonation reactor 10 together with the gaseous products of the water-gas shift reactor 6. The carbon dioxide is absorbed by the calcium oxide and releases a large amount of heat energy, which is supplied to the steam reforming reactor 3 through the heat exchanger. At this time, the gaseous products are preliminarily purified so that the carbon dioxide content in the gas entering the pressure swing adsorber 8 is reduced to less than 5%. The gaseous products of the water-gas shift reactor 6 are preheated by the second heat exchanger 7 to a temperature of 600 to 700°C, wherein the second heat exchanger 7 recovers the sensible heat of the gas that has not undergone the carbonation reaction, and is used to preheat the gaseous products from the water-gas shift reactor 6 to make it close to the carbonation reaction temperature. The reaction temperature in the carbonation reactor 10 is 800 to 900°C.

[0042] In a preferred embodiment, when the heat released by the complete combustion of the analytical gas generated by the pressure swing adsorber 8 is insufficient to completely carry out the calcination reaction in the calcination reactor 16, the three-way valve 2 can adjust the pyrolysis gas flow rate, and the flue gas generated by the partial pyrolysis gas generated by the biomass pyrolysis device 1 directly burns in the burner 20 to directly provide heat for the calcination reactor 16. The reaction temperature of the calcination reactor 16 is 650°C to 750°C. The calcium carbonate from the calcium carbonate storage bin 12 is preheated by the fourth heat exchanger 14 and the fifth heat exchanger 15 and then passed to the calcination reactor 16 to obtain calcium oxide and carbon dioxide with a purity of more than 99%, which can be stored in the calcium oxide storage bin 13 and the carbon dioxide storage tank 17, respectively.

[0043] In the above system, during heat release, the calcium oxide from the calcium oxide storage bin 13 is preheated in the third heat exchanger 11 and then passed to the carbonation reactor 10, the carbon dioxide in the pyrolysis gas is absorbed by the calcium oxide and releases a large amount of heat, providing heat to the steam reforming reactor 3, and the remaining low-temperature gas is separated and purified by the pressure swing adsorber 8 and then burned in the burner 20 with part of the pyrolysis gas diverted from the three-way valve 2 to provide heat for the calcination reactor 16. During heat storage, the calcium carbonate from the calcium carbonate storage bin 12 is preheated in the fourth heat exchanger 14 and the fifth heat exchanger 15 respectively and then passed to the calcination reactor 16 to obtain calcium oxide and high-purity carbon dioxide, which are stored in the calcium oxide storage bin 13 and the carbon dioxide storage tank 17 respectively.

[0044] On the hydrogen production side, the pyrolysis gas produced by the biomass pyrolysis device 1 reacts with water vapor in the steam reforming reactor 3 C n H m +nH2O→nCO+(n+2m)H2, and then enter the water gas shift reactor 6 to react CO+H2O→CO2+H2. At this time, the main components of the mixed gas are hydrogen, carbon dioxide, and water vapor. The mixed gas enters the carbonation reactor 10, and calcium oxide, as a carbon dioxide adsorbent, can remove most of the carbon dioxide in the mixed gas. The pressure swing adsorber 8 separates the hydrogen in the remaining gas from the rest of the gas and stores the hydrogen in the hydrogen storage tank 9.

[0045] On the self-heating side, the high-temperature gas produced by the steam reforming reactor 3 passes through the first heat exchanger 5 to heat the desalted water in the water storage tank 4, providing raw water vapor for the steam reforming reactor 3; the mixed gas containing carbon dioxide produced by the water-gas shift reactor 6 enters the carbonation reactor 10, undergoes a synthesis reaction with calcium oxide, converts chemical energy into thermal energy, and the released heat is used to heat the steam reforming reactor 3 through the heat exchanger; the second heat exchanger 7 recovers the sensible heat of the gas that has not undergone the carbonation reaction, and is used to preheat the gas product produced by the water-gas shift reactor 6 to make it close to the carbonation reaction temperature; after releasing the heat, the sensible heat of the synthetic product calcium carbonate is The heat is passed through the third heat exchanger 11 to preheat the calcium oxide fed later; the pressure swing adsorber 8 burns the remaining gas after hydrogen separation and part of the pyrolysis gas diverted by the three-way valve 2 in the burner 20 to provide heat for the decomposition reaction, and the calcium carbonate in the calcination reactor 16 absorbs heat energy to decompose, and the heat energy is converted into chemical energy in calcium oxide and carbon dioxide; after storing the heat, the high-temperature calcium oxide produced by the decomposition is passed through the fourth heat exchanger 14 to preheat the calcium carbonate fed later for the first time, and the high-temperature carbon dioxide produced by the decomposition is passed through the fifth heat exchanger 15 to preheat the preheated medium-temperature calcium carbonate for the second time, thereby realizing self-heating of the system.

[0046] In the above technical scheme, the pyrolysis gas reforming hydrogen production subsystem and the thermochemical self-heating subsystem cooperate with each other to effectively solve the problem of waste heat recovery in the hydrogen production process, realize the self-heating of biomass pyrolysis gas reforming hydrogen production, and upgrade the low-grade carbon dioxide produced in the pyrolysis system, giving full play to the carbon emission reduction properties of biomass. Among them, the pyrolysis gas reforming hydrogen production subsystem can realize the reforming and upgrading of pyrolysis gas to obtain high-purity hydrogen. On the one hand, the thermochemical self-heating subsystem provides energy for the reforming hydrogen production reaction through the exothermic reaction of calcium oxide and carbon dioxide, realizing the continuous and efficient operation of the reforming hydrogen production reaction; on the other hand, it can realize the preliminary separation and upgrading of the reformed gas, and store the low-utilization value pyrolysis gas energy that is difficult to store and transport in calcium oxide. The present invention realizes the self-heating and quality-improving utilization of biomass pyrolysis gas and the low-cost preparation of green hydrogen through the organic coupling of biomass pyrolysis gas reforming hydrogen production and thermochemical heat storage, and has the advantages of high energy utilization, high processing efficiency, convenient control, and strong applicability.

[0047] It should be understood that the above description of the specific embodiments of the present invention is only for illustrating the technical route and features of the present invention, and its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, but the present invention is not limited to the above specific implementation methods. Any changes or modifications made within the scope of the claims of the present invention should be included in the protection scope of the present invention.

Claims

1. A biomass pyrolysis gas self-heating reforming hydrogen production system, characterized in that: It includes a pyrolysis gas reforming hydrogen production subsystem and a thermochemical self-heating subsystem; The pyrolysis gas reforming hydrogen production subsystem comprises a biomass pyrolysis device (1), a three-way valve (2), a steam reforming reactor (3), a water storage tank (4), a first heat exchanger (5), a water-gas shift reactor (6), a second heat exchanger (7), a pressure swing adsorber (8) and a hydrogen storage tank (9); the gas phase product outlet of the biomass pyrolysis device (1), the left and right passages of the three-way valve (2), the gas inlet of the steam reforming reactor (3), the hot fluid inlet and outlet of the first heat exchanger (5), and the gas inlet of the water-gas shift reactor (6) are connected in sequence, and the water storage tank (4), the cold fluid inlet and outlet of the first heat exchanger (5), and the water vapor inlet of the steam reforming reactor (3) are connected in sequence; The thermochemical self-heating subsystem comprises a carbonation reactor (10), a third heat exchanger (11), a calcium carbonate storage bin (12), a calcium oxide storage bin (13), a fourth heat exchanger (14), a fifth heat exchanger (15), a calcination reactor (16) and a carbon dioxide storage tank (17); the gas outlet of the water-gas shift reactor (6), the cold fluid inlet and outlet of the second heat exchanger (7), the gas inlet and outlet of the carbonation reactor (10), the hot fluid inlet and outlet of the second heat exchanger (7), the feed inlet of the pressure swing adsorber (8) and the hydrogen storage tank (9) are connected in sequence; the solid outlet of the carbonation reactor (10), the hot fluid inlet and outlet of the third heat exchanger (11), the calcium carbonate storage bin (12), the calcium oxide storage bin (13), the fourth heat exchanger (14), the fifth heat exchanger (15), the calcination reactor (16) and the carbon dioxide storage tank (17) are connected in sequence; The inlet of the storage bin (12) is connected in sequence; the outlet of the calcium oxide storage bin (13), the cold fluid inlet and outlet of the third heat exchanger (11), and the solid inlet of the carbonation reactor (10) are connected in sequence; the outlet of the calcium carbonate storage bin (12), the low-temperature feed inlet of the fourth heat exchanger (14), the low-temperature feed inlet of the fifth heat exchanger (15), and the solid inlet of the calcination reactor (16) are connected in sequence; the solid outlet of the calcination reactor (16), the hot fluid inlet and outlet of the fourth heat exchanger (14), and the inlet of the calcium oxide storage bin (13) are connected in sequence; the gas outlet of the calcination reactor (16), the hot fluid inlet and outlet of the fifth heat exchanger (15), and the carbon dioxide storage tank (17) are connected in sequence; The thermochemical self-heating subsystem further comprises a sixth heat exchanger (18), a seventh heat exchanger (19), a burner (20), an eighth heat exchanger (21) and an exhaust gas treatment device (22); the sixth heat exchanger (18) is disposed inside the carbonation reactor (10), the seventh heat exchanger (19) is disposed inside the steam reforming reactor (3), and the sixth heat exchanger (18) is connected to the seventh heat exchanger (19); the eighth heat exchanger (21) is disposed inside the calcination reactor (16); the desorption gas outlet of the pressure swing adsorber (8) and the third passage of the three-way valve (2) are connected in parallel to the burner (20); the flue gas outlet of the burner (20), the eighth heat exchanger (21) and the exhaust gas treatment device (22) are connected in sequence.

2. The biomass pyrolysis gas self-heating reforming hydrogen production system according to claim 1, characterized in that: The pipeline between the water storage tank (4) and the first heat exchanger (5) is provided with a water pump (A); A first screw feeder (B) is provided in the pipeline between the outlet of the calcium carbonate storage bin (12) and the low-temperature feed port of the fourth heat exchanger (14); The pipeline between the outlet of the calcium oxide storage bin (13) and the third heat exchanger (11) is provided with a second screw feeder (C).

3. The biomass pyrolysis gas self-heating reforming hydrogen production system according to claim 1, characterized in that: The biomass pyrolysis device (1) is operated in an air-tight state or in an air state where the oxygen content does not exceed 5%, and the pyrolysis gas components produced include hydrogen, carbon dioxide, carbon monoxide, C n H m .

4. The biomass pyrolysis gas self-heating reforming hydrogen production system according to claim 1, characterized in that: The steam reforming reactor (3) is filled with a nickel-based catalyst, and the reaction temperature is 700-800°C; the water-gas shift reactor (6) is filled with an iron-chromium-based catalyst, and the reaction temperature is 400-450°C.

5. The biomass pyrolysis gas self-heating reforming hydrogen production system according to claim 1, characterized in that: The gaseous products of the water-gas shift reactor (6) include hydrogen, carbon dioxide and water vapor; the carbon dioxide content in the gas entering the pressure swing adsorber (8) is reduced to less than 5%.

6. The biomass pyrolysis gas self-heating reforming hydrogen production system according to claim 1, characterized in that: The temperature of the gas product of the water-gas shift reactor (6) is 600-700° C. after being preheated by the second heat exchanger (7).

7. The biomass pyrolysis gas self-heating reforming hydrogen production system according to claim 1, characterized in that: The reaction temperature in the carbonation reactor (10) is 800-900°C.

8. The biomass pyrolysis gas self-heating reforming hydrogen production system according to claim 1, characterized in that: When the heat released by the complete combustion of the decomposition gas generated by the pressure swing adsorber (8) is insufficient to completely carry out the calcination reaction in the calcination reactor (16), the three-way valve (2) can adjust the flow rate of the pyrolysis gas, and the flue gas generated by the direct combustion of part of the pyrolysis gas generated by the biomass pyrolysis device (1) in the burner (20) directly supplies heat to the calcination reactor (16).

9. The biomass pyrolysis gas self-heating reforming hydrogen production system according to claim 1, characterized in that: The reaction temperature of the calcination reactor (16) is 650°C to 750°C.

10. The biomass pyrolysis gas self-heating reforming hydrogen production system according to claim 1, characterized in that: The calcium carbonate from the calcium carbonate storage bin (12) is preheated in the fourth heat exchanger (14) and the fifth heat exchanger (15) and then passed to the calcination reactor (16) to obtain calcium oxide and carbon dioxide with a purity of more than 99%, which are stored in the calcium oxide storage bin (13) and the carbon dioxide storage tank (17), respectively.

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