Compact biomass gasification and chemical looping hydrogen production device and method

Abstract

The invention relates to a compact biomass gasification and chemical-looping hydrogen production device, which takes a chemical-looping hydrogen production reactor based on an oxygen ion conduction membrane as a core component to replace a traditional double-reactor / three-reactor chemical-looping hydrogen production device, so that the circulation loss of an oxygen carrier is avoided, and the compact arrangement of the biomass chemical-looping hydrogen production device is realized. The device specifically comprises a biomass gasification furnace, a cyclone separator, a water vapor generator, a chemical looping hydrogen production reactor based on an oxygen ion conduction membrane and a condenser. Compared with the prior art, through coupling of a biomass gasification process and the chemical looping hydrogen production reactor based on the oxygen ion conduction membrane, abrasion caused by oxygen carrier circulation is avoided, and the equipment size of the biomass gasification and chemical looping hydrogen production processes is greatly reduced; and a technical basis is provided for mobile biomass gasification and chemical looping hydrogen production equipment.

Description

Technical Field

[0001] This invention relates to the field of biomass chemical chain hydrogen production, and in particular to a compact biomass gasification and chemical chain hydrogen production apparatus and method. Background Technology

[0002] Biomass chemical looping hydrogen production refers to the production of hydrogen using biomass, which is one of the ways to achieve low-carbon and high-value utilization of biomass energy. Biomass gasification technology is an effective method for producing hydrogen, usually using air, water vapor, or oxygen as gasifying agents. However, this method suffers from high tar concentration and low hydrogen concentration, which has become a bottleneck and major obstacle limiting biomass gasification technology.

[0003] Biomass chemical looping hydrogen production technology is an application of chemical looping technology in the field of biomass energy utilization. Combining biomass gasification with chemical looping hydrogen production can effectively produce high-purity hydrogen. Generally, biomass chemical looping hydrogen production devices produce high-purity hydrogen by circulating an oxygen carrier between two reactors (fuel reactor and steam reactor) or three reactors (fuel reactor, steam reactor, and air reactor).

[0004] However, traditional biomass chemical looping hydrogen production, using dual or triple looping reactors, suffers from problems such as large footprint, high operating and maintenance costs, and significant oxygen carrier circulation losses leading to unstable hydrogen production efficiency and low hydrogen purity. These issues have become bottlenecks and major obstacles restricting biomass chemical looping hydrogen production technology. For example, patent application CN115321478A discloses a biomass pyrolysis chemical looping hydrogen production process, employing a biomass pyrolysis chemical looping hydrogen production device consisting of a cyclone pyrolysis reactor, a bubble bed gasification reactor, and a hydrogen production reactor. It achieves coupling of biomass pyrolysis and chemical looping hydrogen production by circulating oxygen carriers to provide heat and catalysis, forming a self-heating cycle, reducing external heat input, and utilizing the oxygen carrier as both heat-carrying particles and a catalyst. Patent application CN115432667 discloses a biomass gasification-chemical looping hydrogen production device and method. The device includes a biomass gasification unit, a chemical looping hydrogen production unit, and a heat exchange unit. The chemical looping hydrogen production unit includes a first fixed-bed reactor and a second fixed-bed reactor. This invention combines biomass gasification and chemical looping hydrogen production, employing a dual fixed-bed reactor. By switching the reaction gas / tail gas valves, the biomass gasification-chemical looping hydrogen production process is made continuous, simplifying the biomass chemical looping hydrogen production system and reducing the difficulty of system operation and control. Through a reasonable layout of the heat exchange system, the tail gas and reaction gas of each reaction stage are directly exchanged for heat. It can be seen that both use dual or triple chemical looping reactors, which have high losses and are unstable.

[0005] Therefore, there is an urgent need to develop a compact, highly stable, and efficient method for producing high-purity hydrogen from biomass to improve hydrogen production efficiency. Summary of the Invention

[0006] The purpose of this invention is to provide a compact biomass gasification and chemical looping hydrogen production device to address the shortcomings of existing technologies, thereby solving the problems of complex biomass gasification and chemical looping hydrogen production equipment, low integration, severe wear of oxygen carrier, and unstable hydrogen yield.

[0007] The objective of this invention can be achieved through the following technical solution: a compact biomass gasification and chemical looping hydrogen production device, comprising a biomass gasification furnace, a cyclone separator, a steam generator, and a chemical looping hydrogen production reactor. The chemical looping hydrogen production reactor is a cation-conducting membrane-based chemical looping hydrogen production reactor. The reactor has a hollow cylindrical oxygen ion conducting membrane inside, which divides the internal cavity of the reactor into an internal fuel side and an external hydrogen production side. The fuel section inlet is connected to the cyclone separator, and the hydrogen production section inlet is connected to the steam generator.

[0008] Furthermore, the biomass gasifier is equipped with a biomass feeding device at the top, an ash discharge outlet at the bottom, and a bottom gas inlet connected to an air compressor.

[0009] Furthermore, the gas outlet at the top of the biomass gasifier is connected to a cyclone separator, and a high-temperature tar removal device is installed on the connecting pipe.

[0010] Furthermore, the chemical loop hydrogen production reactor has a steam inlet at the bottom, which is connected to a steam generator, and a hydrogen outlet at the top, which is connected to a condenser.

[0011] Furthermore, the condenser is provided with a water inlet for a steam generator and a liquid outlet, wherein the liquid outlet is connected to the steam generator.

[0012] Furthermore, the hollow cylindrical oxygen ion conducting membrane is a hollow cylinder disposed within the cavity of the chemical looping hydrogen production reactor. The interior of the hollow cylinder forms a fuel zone, and the outer wall of the hollow cylinder and the inner wall of the chemical looping hydrogen production reactor form a hydrogen production zone.

[0013] Furthermore, the hollow cylindrical oxygen ion conducting membrane is made of oxygen ion conducting membrane material, with its top connected to a cyclone separator and its bottom connected to the CO2 and H2O product outlets.

[0014] Furthermore, the bottom of the cyclone separator is provided with a cyclone separator ash outlet.

[0015] The present invention also relates to a hydrogen production method using the aforementioned compact biomass gasification and chemical looping hydrogen production device, comprising the following steps: S1. Biomass is gasified in a biomass gasifier. The resulting syngas is tar removed by a tar removal device and then further separated into gas and solid by a cyclone separator. The biomass gasifier uses a fixed-bed gasifier, where biomass is pyrolyzed and gasified to produce syngas (mainly CO and H2), as well as C1-C5 low-carbon hydrocarbons and tar (C2). n H m O z The main reaction formulas are as follows: Biomass + O2 → C + CO + H2 + C n H m O z In the tar removal zone, tar is converted into syngas and low-carbon hydrocarbons. The main reaction formulas are as follows: C n H m O z +O2→CO+H2 S2. The separated syngas is fed into the fuel zone inside the chemical looping hydrogen reactor, where it undergoes CO + O2 reactions. 2- →CO2 + 2e - and H2+O 2- →H₂O + 2e - reaction; The steam generated by the steam generator is introduced into the hydrogen production zone, where H2O + 2e- occurs. - →H2+O 2- The reaction proceeds, and high-purity H2 is discharged after being condensed in a condenser.

[0016] The chemical looping hydrogen production reactor consists of a cylindrical reactor interior and a concentric cylindrical oxygen ion conducting membrane inside the reactor. The cylindrical oxygen ion conducting membrane is cylindrical and nested inside the cylindrical reactor, dividing the chemical looping hydrogen production reactor into an internal fuel zone and an external hydrogen production zone.

[0017] Furthermore, hydrogen production reactions continue to occur in the hydrogen production zone, and oxygen ions are continuously conducted through the hollow cylindrical oxygen ion conduction membrane to the fuel zone to undergo the oxidation reaction of syngas. At the same time, the oxidation reaction of syngas continuously provides electrons for the hydrogen production reaction.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention innovatively integrates a chemical loop hydrogen production reactor based on an oxygen ion conduction membrane with a biomass gasification furnace, avoiding the wear of the oxygen carrier caused by circulation in traditional biomass gasification and dual- or triple-reactor chemical loop hydrogen production devices. This reduces the footprint and simplifies system operation and maintenance. The reason this invention can achieve the hydrogen production effect required by traditional technologies (which typically require 2-3 reactors) is because it uses an oxygen ion separation membrane to divide the hydrogen production reactor into a fuel zone and a hydrogen production zone, allowing only oxygen ions to pass freely. This replaces the traditional fuel reaction chamber and steam reaction chamber (or fuel reaction chamber, steam reaction chamber, and air reaction chamber). The fuel zone consumes oxygen ions to generate electrons; the hydrogen production zone consumes electrons to generate hydrogen. The hydrogen zone contains only hydrogen and water vapor, facilitating separation and producing high-purity hydrogen.

[0019] 2. This invention significantly reduces the footprint of the equipment and saves land resources by using a compact biomass gasification and chemical looping hydrogen production device, which consists of a reactor, separator, and hydrogen generator.

[0020] 3. Both the biomass gasification furnace and the chemical looping hydrogen production reactor based on the oxygen ion conduction membrane in this invention are equipped with ash outlets at the bottom, which can promptly discharge the solids produced by the reaction and effectively reduce the risk of equipment blockage. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention.

[0022] The diagram is labeled as follows: 1. Air compressor; 2. Biomass feeding device; 3. Biomass gasifier; 4. Ash outlet of biomass gasifier; 5. Tar removal device; 6. Cyclone separator; 7. Ash outlet of cyclone separator; 8. Water inlet of steam generator; 9. Steam generator; 10. Gas outlet of cyclone separator; 11. Chemical looping hydrogen production reactor; 11.1 Hollow cylindrical oxygen ion conducting membrane; 11.2 Fuel zone; 11.3 Hydrogen production zone; 12. Product outlet; 13. Condenser; 14. Gas outlet of condenser; 15. Liquid outlet of condenser. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0024] Example 1 like Figure 1 As shown, the compact biomass gasification and chemical looping hydrogen production device of this embodiment includes: a biomass gasifier 3, a cyclone separator 6, a steam generator 9, and a chemical looping hydrogen production reactor 11. The biomass gasifier 3 is equipped with a biomass feeding device 2 at the top and an ash discharge outlet 4 at the bottom, and the bottom gas inlet is connected to the air compressor 1; the top gas outlet of the biomass gasifier 3 is connected to the cyclone separator 6, and a high-temperature tar removal device 5 is installed on the connecting pipeline. The cyclone separator 6 has an ash outlet 7 at the bottom and a gas outlet 10 at the top. The chemical looping hydrogen production reactor 11 is a cylindrical reactor with a concentric hollow cylindrical oxygen ion conducting membrane 11.1 inside. The hollow cylindrical oxygen ion conducting membrane 11.1 is nested inside the cylindrical reactor, dividing the reactor into an internal fuel zone 11.2 and an external hydrogen production zone 11.3. Specifically, the hollow cavity inside the hollow cylindrical oxygen ion conducting membrane 11.1 constitutes the fuel zone 11.2, and the area between the outer wall of the hollow cylindrical oxygen ion conducting membrane 11.1 and the inner wall of the chemical looping hydrogen production reactor 11 forms the hydrogen production zone 11.3. The hollow cylindrical oxygen ion conducting membrane 11.1 is made of oxygen ion conducting membrane material. Its top has a synthesis gas inlet connected to a cyclone separator 6, and its bottom is connected to a product outlet 12. The lower part of the outer shell of the chemical looping hydrogen production reactor 11 has a steam inlet connected to a steam generator 9, and the upper part has a hydrogen outlet connected to a condenser 13.

[0025] The side wall of the steam generator 9 is provided with a steam generator water inlet 8, and the bottom is connected to the steam inlet of the chemical loop hydrogen production reactor 11; The condenser 13 is provided with a condenser gas outlet 14 and a liquid outlet 15, wherein the liquid outlet 15 is connected to the water inlet 8 of the steam generator 9. The method for producing hydrogen using the above-mentioned apparatus is as follows: S1. Sufficient biomass feedstock is added to the biomass gasifier 3 through the biomass feeding device 2, and the air compressor 1 is adjusted to provide sufficient air to the biomass gasifier 3 to maximize carbon conversion rate and gasification efficiency. In this embodiment, straw is used as raw material for the experiment, with a feeding rate of 5 kg / h; the air compressor 1 inputs air to the biomass gasifier 3 at a rate of 60 L / min. In biomass gasifier 3, biomass undergoes pyrolysis and gasification under the action of a gasifying agent (air), producing syngas (mainly CO and H2), as well as C1-C5 low-carbon hydrocarbons and tar (C n H m O z The main reaction formulas are as follows: Biomass + O2 → C + CO + CO2 + H2 + C n H m O z S2. Ash produced by biomass gasifier 3 is discharged from ash outlet 4, producing syngas (mainly CO and H2), as well as C1-C5 low-carbon hydrocarbons and tar (C n H m O z The biomass tar enters the tar removal unit 5, where it is cracked into syngas and low-carbon hydrocarbons. The main reaction formulas are as follows: C n H m O z +O2→CO+H2 S3. Syngas and low-carbon hydrocarbons undergo further gas-solid separation in cyclone separator 6. The separated ash is discharged through the ash outlet 7 of the cyclone separator, while the separated syngas enters the fuel zone 11.2 of the chemical looping hydrogen reactor 11, where it reacts fully with oxygen ions transferred by the hollow cylindrical oxygen ion conducting membrane 11.1 to produce CO2 and H2O and release electrons. Simultaneously, water vapor enters the hydrogen production zone 11.3 of the chemical looping hydrogen reactor 11, where it combines with electrons transferred by the hollow cylindrical oxygen ion conducting membrane 11.1 to release H2 and oxygen ions. The main reactions that occur are as follows: Fuel zone: CO+O 2- →CO2 + 2e - H2+O 2- →H₂O + 2e - CH4+ 4O 2- →CO2 + 2H2O + 8e - Hydrogen production zone: H2O + 2e - →H2+O 2- The CO2 and H2O produced in the fuel zone are discharged from the CO2 and H2O outlet 12, and the hydrogen produced in the hydrogen production zone is discharged from the hydrogen outlet on the side wall and enters the condenser 13. The oxygen ion conduction membrane continuously consumes oxygen ions and generates electrons in the fuel zone and moves to the hydrogen production zone. The hydrogen production zone continuously consumes electrons and generates oxygen ions and moves to the fuel zone, thus achieving a highly efficient, continuous and stable hydrogen production reaction.

[0026] S4. Hydrogen gas is condensed by condenser 13 to produce high-purity H2 (purity greater than 99%), which is discharged from condenser gas outlet 14. The water condensed by condenser 13 is reintroduced into steam generator 9 from condenser liquid outlet 15 for circulation.

[0027] This invention couples biomass gasification with a chemical looping hydrogen production reactor based on an oxygen ion conduction membrane, avoiding the circulation of solid oxygen carriers, improving the stability and purity of hydrogen production, and greatly reducing the equipment size of biomass gasification and chemical looping hydrogen production processes, thus providing a technical basis for mobile biomass gasification and chemical looping hydrogen production equipment.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compact biomass gasification and chemical looping hydrogen production device, comprising a biomass gasifier (3), a cyclone separator (6), a steam generator (9), and a chemical looping hydrogen production reactor (11), characterized in that: The chemical chain hydrogen production reactor (11) is a chemical chain hydrogen production reactor based on a cation conduction membrane. The chemical chain hydrogen production reactor (11) is provided with a hollow cylindrical oxygen ion conduction membrane (11.1). The hollow cylindrical oxygen ion conduction membrane (11.1) divides the internal cavity of the chemical chain hydrogen production reactor (11) into an internal fuel side (11.2) and an external hydrogen production side (11.3). The inlet of the fuel zone (11.2) is connected to the cyclone separator (6), and the inlet of the hydrogen production zone (11.3) is connected to the steam generator (9).

2. The compact biomass gasification and chemical looping hydrogen production device according to claim 1, characterized in that: The biomass gasifier (3) has a biomass feeding device (2) at the top and an ash discharge outlet (4) at the bottom, and the bottom gas inlet is connected to an air compressor (1).

3. The compact biomass gasification and chemical looping hydrogen production device according to claim 1, characterized in that: The top gas outlet of the biomass gasifier (3) is connected to a cyclone separator (6), and a high-temperature tar removal device (5) is installed on the connecting pipe.

4. A compact biomass gasification and chemical looping hydrogen production device according to claim 1, characterized in that: The chemical chain hydrogen production reactor (11) has a steam inlet at the bottom, which is connected to a steam generator (9), and a hydrogen outlet at the top, which is connected to a condenser (13).

5. A compact biomass gasification and chemical looping hydrogen production device according to claim 4, characterized in that: The condenser (13) is provided with a condenser gas outlet (14) and a liquid outlet (15), wherein the liquid outlet (15) is connected to the steam generator (9).

6. A compact biomass gasification and chemical looping hydrogen production device according to claim 1, characterized in that: The hollow cylindrical oxygen ion conducting membrane (11.1) is a hollow cylinder installed in the cavity of the chemical chain hydrogen production reactor (11). The interior of the hollow cylinder forms a fuel zone (11.2), and the outer wall of the hollow cylinder and the inner wall of the chemical chain hydrogen production reactor (11) form a hydrogen production zone (11.3).

7. A compact biomass gasification and chemical looping hydrogen production device according to claim 6, characterized in that: The hollow cylindrical oxygen ion conducting membrane (11.1) is made of oxygen ion conducting membrane, with its top connected to the cyclone separator (6) and its bottom connected to the CO2 and H2O outlets (12).

8. A compact biomass gasification and chemical looping hydrogen production device according to claim 1, characterized in that: The bottom of the cyclone separator (3) is provided with a cyclone separator ash outlet (7).

9. A method for producing hydrogen using a compact biomass gasification and chemical looping hydrogen production device as described in any one of claims 1-8, characterized in that: Biomass is gasified in a biomass gasifier (3), and the resulting syngas is detarted by a tar removal device (5) and then further separated into gas and solid by a cyclone separator (6). The separated syngas is fed into the fuel zone (11.2) inside the chemical looping hydrogen reactor (11), where the syngas undergoes CO + O2 reaction. 2- →CO2 + 2e - and H2+O 2- →H₂O + 2e - reaction; The steam generated by the steam generator (9) is introduced into the hydrogen production zone (11.3), where H2O + 2e- is generated. - →H2+O 2- The reaction is condensed by condenser (13) and then discharged as high-purity H2.

10. The hydrogen production method according to claim 9, characterized in that: Hydrogen production reaction continues to occur in the hydrogen production zone (11.3). Oxygen ions are continuously conducted through the hollow cylindrical oxygen ion conduction membrane (11.1) to the fuel zone (11.2) to undergo the oxidation reaction of syngas. At the same time, the oxidation reaction of syngas continuously provides electrons for the hydrogen production reaction.

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