System and method for producing hydrogen by adsorbing enhanced biomass gasification based on magnetic separator

Abstract

The invention provides a system and a method for adsorption-enhanced biomass gasification hydrogen production based on a magnetic separator, and belongs to the field of biomass hydrogen production. A magnetic separator and a flow divider are introduced into the system; in the fuel reactor, biomass reacts with water vapor to generate hydrogen-rich gas and CO2; cO2 is adsorbed by CaO to generate CaCO3, and the oxidation-state magnetic oxygen carrier is reduced to obtain a reduction-state magnetic oxygen carrier; after hydrogen-rich gas, a calcium-based adsorbent containing CaCO3 and a reduction-state magnetic oxygen carrier are subjected to gas-solid separation in a first cyclone separator, solid bed materials enter a magnetic separator; separating by a magnetic separator, introducing CaCO3 into a calcining reactor, and introducing a reduction-state magnetic oxygen carrier into an air reactor; caCO3 in the calcination reactor generates CaO and CO2, a reduction-state magnetic oxygen carrier in the air reactor is oxidized to an oxidation state, and the oxidation state magnetic oxygen carrier is shunted to the calcination reactor and the fuel reactor through the shunt. According to the invention, self-heat balance and regulation and control of the magnetic oxygen carrier and the calcium-based adsorbent in the fuel reactor are realized.

Description

Technical Field

[0001] This invention belongs to the field of biomass hydrogen production, specifically relating to a system and method for adsorption-enhanced biomass gasification hydrogen production based on a magnetic separator. Background Technology

[0002] Hydrogen is an ideal clean energy source; it is non-toxic, odorless, and produces only pure water when it reacts with oxygen, causing no pollution to the environment. Currently, using fossil fuels to produce hydrogen is the mainstream method. However, due to the finite nature of fossil fuels and their significant environmental impact, finding new raw materials and methods for hydrogen production has become particularly important. Biomass hydrogen production has attracted much attention due to its renewable nature and abundant reserves.

[0003] Currently, research on hydrogen production from biomass is mainly divided into two categories: thermochemical conversion and biological methods. Due to the influence of factors such as temperature and pH, the conversion efficiency of biological methods is low. In contrast, thermochemical conversion methods are more suitable for large-scale hydrogen production.

[0004] In existing technologies, biomass hydrogen production processes based on thermochemical conversion generally employ circulating fluidized beds as reactors. Under the combined action of catalysts and adsorbents, biomass feedstocks are converted into hydrogen-rich syngas. However, existing adsorption-enhanced biomass gasification hydrogen production methods have the following drawbacks: The CaO calcined in the calcination reactor enters the high-temperature air reactor along with the reduced oxygen carrier (OC). This leads to unnecessary high-temperature sintering of calcium oxide. Simultaneously, all the high-temperature oxygen carrier exiting the air reactor enters the fuel reactor, potentially resulting in excessive consumption of reducing gases and a decrease in hydrogen yield. Furthermore, this fixed-stream distribution can lead to insufficient or excessive heat in the system, requiring external heating or causing energy waste. Therefore, regulating the high-temperature oxygen carrier entering the fuel reactor, i.e., regulating the OC / CaO ratio, to achieve system self-heating balance is particularly important. Summary of the Invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, the present invention aims to provide a system and method for adsorption-enhanced biomass gasification hydrogen production based on a magnetic separator. The system employs a three-bed configuration consisting of a fuel reactor, a calcination reactor, and an air reactor. Adsorption-enhanced chemical looping gasification of biomass is achieved in the fuel reactor, biomass gasification hydrogen production is achieved in the calcination reactor, and catalyst regeneration is achieved in the air reactor. A magnetic separator is introduced after the fuel reactor to separate the iron-based oxygen carrier from the Ca-based adsorbent. Simultaneously, a splitter is introduced after the air reactor to achieve continuous regulation of the OC / CaO ratio and control of the system's self-heating balance, thereby improving hydrogen production efficiency and achieving self-heating balance.

[0006] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0007] In a first aspect, embodiments of the present invention provide an adsorption-enhanced biomass gasification hydrogen production system based on a magnetic separator. The system includes a fuel reactor 2, a calcination reactor 3, an air reactor 4, a first cyclone separator 5, a second cyclone separator 6, a third cyclone separator 7, a magnetic separator 8, a diverter 16, and a steam generator 17; wherein...

[0008] The discharge port of the fuel reactor 2 is connected to the first cyclone separator 5; the first gas outlet of the first cyclone separator 5 is connected to the steam generator 17, and the lower discharge port is connected to the magnetic separator 8.

[0009] The magnetic branch of the magnetic separator 8 is connected to the air reactor 4, and the non-magnetic branch is connected to the calcination reactor 3; the separation effect of the magnetic separator for different magnetic oxygen carriers (OC) is adjusted by the magnetic force and the chain speed.

[0010] The discharge port of the calcination reactor 3 is connected to the second cyclone separator 6; the second gas outlet of the second cyclone separator 6 is connected to the steam generator 17, and the lower discharge port is connected to the fuel reactor 2; the discharge port of the air reactor 4 is connected to the third cyclone separator 7; the third gas outlet of the third cyclone separator 7 is connected to the steam generator 17, and the lower discharge port is connected to the distributor 16.

[0011] The distributor 16 includes three branches: the first branch is connected to the calcination reactor 3, the second branch is connected to the fuel reactor 2, and the third branch serves as the magnetic oxygen carrier OC outlet 19.

[0012] In a preferred embodiment of the present invention, the steam generator 17 is provided with a second water inlet 18, and the steam outlet is connected to the steam inlet of the fuel reactor 2; high-temperature H2, CO2 and N2 flow through the steam generator 17 through three channels from the first to the third gas outlets, respectively, and exchange heat with the low-temperature water entering through the second water inlet 18 to form steam.

[0013] In a preferred embodiment of the present invention, the magnetic branch of the magnetic separator 8 is used to transport the separated reduced magnetic OC; the non-magnetic branch is used to transport the calcium-based adsorbent CaCO3 formed after adsorbing CO2.

[0014] In a preferred embodiment of the present invention, the calcium-based adsorbent comprises limestone and / or dolomite; the calcium-based adsorbent is granular with a particle size of 20~500μm.

[0015] In a preferred embodiment of the present invention, the magnetic OC includes two states: a reduced state and an oxidized state, which are realized by using iron-based oxygen carrier Fe-OC particles; the iron-based oxygen carrier is an iron-containing mineral, including magnetite, ilmenite and / or manganese iron ore; the Fe-OC particles have a particle size of 20~500μm.

[0016] In a preferred embodiment of the present invention, the fuel reactor 2, the calcination reactor 3, and the air reactor 4 are respectively provided with a first fluid inlet 9, a second fluid inlet 10, and a third fluid inlet 11; wherein, the first fluid inlet 9 introduces water vapor into the fuel reactor 2; the second fluid inlet 10 introduces CO2 into the calcination reactor 3; and the third fluid inlet 11 introduces air into the air reactor 4.

[0017] Secondly, embodiments of the present invention also provide a hydrogen production method using the adsorption-enhanced biomass gasification hydrogen production system based on a magnetic separator as described above, the method comprising:

[0018] A predetermined amount of calcium-based adsorbent and oxidized magnetic OC are introduced through the feed inlet and fed into a three-bed circulation system; after stabilization, a predetermined amount of crushed biomass is introduced into the fuel reactor.

[0019] A calcium-based adsorbent, or a combination of calcium-based adsorbent and oxidized magnetic OC, circulating between the calcination reactors is introduced into the fuel reactor. Oxidized magnetic OC circulating between the air reactors is also introduced, along with steam. Under fluidization, biomass and steam mix and undergo adsorption-enhanced chemical looping gasification under the influence of the oxidized magnetic OC, generating CO2 and hydrogen-rich syngas. CO2 is adsorbed by the calcium-based adsorbent to form CaCO3, and the oxidized magnetic OC is reduced to a reduced magnetic OC. The hydrogen-rich gas, the CaCO3-containing calcium-based adsorbent, and the reduced magnetic OC then enter the first cyclone separator.

[0020] Hydrogen-rich gas, calcium-based adsorbent containing CaCO3, and reduced magnetic OC are separated into gas and solid in the first cyclone separator. The hydrogen-rich gas is introduced into the steam generator through the first gas outlet, and the solid bed material enters the magnetic separator through the lower discharge port of the first cyclone separator.

[0021] In the magnetic separator, reduced magnetic OC and non-magnetic calcium-based adsorbent containing CaCO3 are screened and separated. The calcium-based adsorbent containing CaCO3 is fed into the calcination reactor through the non-magnetic branch, while the reduced magnetic OC is fed into the air reactor through the magnetic branch.

[0022] In the calcination reactor, the CaO and CO2 generated by calcining CaCO3 in the calcium-based adsorbent are separated into gas and solid by the second cyclone separator. The CO2 is fed into the steam generator, and the calcium-based adsorbent is returned to the fuel reactor. Air is introduced into the air reactor, and the reduced magnetic OC is oxidized to the oxidized magnetic OC, which carries heat into the splitter.

[0023] The diverter directs the high-temperature oxidized magnetic OC to the calcination reactor, fuel reactor, or outside the system, supplementing the calcination reactor with heat and achieving self-heating balance, while simultaneously regulating the magnetic OC and calcium-based adsorbent in the fuel reactor.

[0024] In a preferred embodiment of the present invention, the diverter divides the high-temperature oxidized magnetic OC flowing out of the air reactor into three streams; the first stream is diverted to the calcination reactor to balance the heat load required in the calcination reactor, and after heat exchange, it is mixed with the decomposed calcium-based adsorbent and then enters the fuel reactor; the second stream is diverted to the fuel reactor to achieve the self-heating balance of the fuel reactor; the third stream is diverted to the magnetic OC outlet to achieve the controllable discharge of magnetic OC, thereby realizing the ratio regulation of magnetic OC and calcium-based adsorbent.

[0025] In a preferred embodiment of the present invention, the fuel reactor is further provided with a first fluid inlet; water vapor is introduced through the fluid inlet, and together with the steam generated in the steam generator, it provides steam for the water-gas reaction.

[0026] In a preferred embodiment of the present invention, the oxidized magnetic OC in the calcination reactor is mixed with the decomposed calcium-based adsorbent and then enters the fuel reactor.

[0027] The technical solutions provided in the embodiments of the present invention have the following beneficial effects:

[0028] The provided system and method for adsorption-enhanced biomass gasification hydrogen production based on magnetic separators utilizes CaO to adsorb CO2 in situ in a fuel reactor, driving the water-gas reaction towards hydrogen production to generate high-concentration hydrogen and improve hydrogen yield. In the fuel reactor, CO2 reacts with a calcium-based adsorbent to generate CaCO3. After calcination in the calcination reactor, the CaCO3 is discharged as high-concentration CO2 through the upper outlet of a second cyclone separator, thus achieving in-situ CO2 capture. The magnetic separator separates magnetic OC from the calcium-based adsorbent bed, allowing the oxidation of magnetic OC and the calcination of CaCO3 to occur in their respective reactors. Simultaneously, the ratio of magnetic OC to calcium-based adsorbent is controlled, thereby regulating the system's self-heating balance and hydrogen production. Combined with a splitter, the sensible heat of the high-temperature exhaust gas is recovered and utilized, improving energy utilization efficiency.

[0029] Of course, implementing any product or method of the present invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the system structure for adsorption-enhanced biomass gasification hydrogen production based on a magnetic separator, as described in an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the magnetic separator in the system described in the embodiment of the present invention;

[0033] Figure 3 This is a graph showing the trend of hydrogen concentration with temperature in a specific application example of the present invention;

[0034] Figure 4 This is a graph showing the trend of hydrogen concentration with S / C in a specific application example of the present invention;

[0035] Figure 5 This is a graph showing the trend of hydrogen concentration with Fe-OC / C in a specific application example of the present invention;

[0036] Figure 6 This is a graph showing the trend of hydrogen concentration and yield with Fe-OC / CaO in a specific application example of the present invention.

[0037] Figure 7 This is a comparison chart of hydrogen production rate and system net heat with and without the use of a magnetic separator in specific embodiments of the present invention.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1-Feed inlet; 2-Fuel reactor; 3-Calcination reactor; 4-Air reactor; 5-First cyclone separator; 6-Second cyclone separator; 7-Third cyclone separator; 8-Magnetic separator; 9-First fluid inlet; 10-Second fluid inlet; 11-Third fluid inlet; 12-Third gas outlet; 13-Second gas outlet; 14-First gas outlet; 15-First water inlet; 16-Diverter; 17-Steam generator; 18-Second water inlet; 19-Fe-OC outlet. Detailed Implementation

[0040] 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 a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can also be combined with each other.

[0041] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of the embodiments of the present invention, the terms "first," "second," "third," "fourth," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, sometimes a subscript such as W1 may be written in a non-subscript form such as W1, and their meanings are consistent unless the distinction is emphasized.

[0042] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0043] To address the problem of adsorption-enhanced biomass gasification for hydrogen production, this invention provides a system and method for adsorption-enhanced biomass gasification based on a magnetic separator. The system employs a fuel reactor, a calcination reactor, an air reactor, a cyclone separator, and a steam generator, while simultaneously introducing a magnetic separator and a flow divider. This effectively converts biomass into hydrogen while simultaneously capturing CO2. The introduction of the magnetic separator enables magnetic separation of the calcium-based adsorbent and the magnetic oxygen carrier (OC). In this embodiment, the magnetic oxygen carrier is exemplified by the iron-based oxygen carrier Fe-OC and the calcium-based adsorbent CaO. This allows for the regulation of Fe-OC and CaO, enabling separate calcination regeneration of the calcium-based adsorbent and oxidation regeneration of the iron-based oxygen carrier. This not only increases the hydrogen concentration but also achieves continuous and stable operation. Furthermore, by regulating the flow rate of the air stream flowing from the air reactor to the calcination reactor through the flow divider, self-heating equilibrium operation can be achieved, providing a highly efficient, environmentally friendly, and economical new approach for biomass hydrogen production.

[0044] like Figure 1As shown, the adsorption-enhanced biomass gasification hydrogen production system based on magnetic separator includes a fuel reactor 2, a calcination reactor 3, an air reactor 4, a first cyclone separator 5, a second cyclone separator 6, a third cyclone separator 7, a magnetic separator 8, a diverter 16, and a steam generator 17.

[0045] The fuel reactor 2 is equipped with a biomass inlet 1, and its outlet is connected to a first cyclone separator 5. The first cyclone separator 5 has a first gas outlet 14, which is connected to a steam generator 17, and its lower outlet is connected to a magnetic separator 8. The steam generator 17 is equipped with a second water inlet 18, and its steam outlet is connected to the steam inlet of the fuel reactor 2. After the biomass enters the fuel reactor 2 through the inlet 1, it reacts with the high-temperature gas from the steam generator 17, undergoing thermal decomposition in the fuel reactor 2 to generate CO2, tar, biochar, etc. The resulting mixture is separated by the first cyclone separator 5, with the gas phase discharged and the separated biochar and other solid phases entering the magnetic separator. The first gas outlet 14 outputs high-temperature H2.

[0046] like Figure 2 As shown, the magnetic separator 8 separates the magnetic and non-magnetic components in the solid bed material separated by the first cyclone separator 5 using magnetic separation, resulting in magnetic bed material (reduced magnetic oxygen carrier, such as reduced Fe-OC) and non-magnetic bed material (calcium carbonate). The magnetic separator 8 is equipped with a first water inlet 15, with a magnetic branch connected to the air reactor 4 and a non-magnetic branch connected to the calcination reactor 3. The solid components generated in the fuel reactor 2 are separated by magnetic separation in the magnetic separator 8, achieving the separation of the iron-based catalyst and the Ca-based bed material.

[0047] The discharge port of the calcination reactor 3 is connected to the second cyclone separator 6; the second cyclone separator 6 has a second gas outlet 13, which is connected to the steam generator 17, and its lower discharge port is connected to the fuel reactor 2. The second gas outlet 13 outputs high-temperature CO2 gas.

[0048] The outlet of the air reactor 4 is connected to the third cyclone separator 7; the third cyclone separator 7 has a third gas outlet 12 connected to the steam generator 17, and a lower outlet connected to the distributor 16. The third gas outlet 12 outputs high-temperature N2 gas. High-temperature H2, CO2, and N2 flow through the steam generator through three channels respectively, and exchange heat with the low-temperature water entering through the second feedwater inlet 18 to form steam.

[0049] The splitter 16 includes three branches, wherein the first branch is connected to the calcination reactor 3, the second branch is connected to the fuel reactor 2, and the flow rate of the gas entering the first and second branches is adjusted, and the third branch serves as the magnetic oxygen carrier OC outlet 19, thereby realizing the control of magnetic OC.

[0050] In one executable embodiment, the fuel reactor 2, calcination reactor 3, and air reactor 4 are respectively provided with a first fluid inlet 9, a second fluid inlet 10, and a third fluid inlet 11. The first fluid inlet 9 introduces steam into the fuel reactor 2; the second fluid inlet 10 introduces CO2 into the calcination reactor 3; and the third fluid inlet 11 introduces air into the air reactor 4. Preferably, the first to third fluid inlets are respectively introduced by blowers.

[0051] The magnetic OC comprises both reduced and oxidized states; it is implemented using iron-based oxygen carrier Fe-OC particles, including iron-bearing minerals such as magnetite, ilmenite, and manganese iron ore; the Fe-OC particle size is 20–500 μm (Geldart A and B type particles). The adsorbent is implemented using Ca-based adsorbent particles, including limestone and dolomite; the Ca-based adsorbent particle size is 20–500 μm (Geldart A and B type particles).

[0052] Preferably, the biomass includes, but is not limited to, straw, waste crops, biomass waste, municipal solid waste, and bio-oil.

[0053] Based on the aforementioned adsorption-enhanced biomass gasification hydrogen production system using a magnetic separator, this embodiment of the invention also provides a method for adsorption-enhanced biomass gasification hydrogen production using a magnetic separator, the method comprising the following steps:

[0054] Step S1: A predetermined amount of adsorbent CaO and oxidized Fe-OC are introduced through feed inlet 1 and enter the three-bed circulation; after stabilization, a predetermined amount of crushed biomass is introduced into fuel reactor 2; here, the three-bed circulation refers to the circulation of bed material in fuel reactor 2, calcination reactor 3, and air reactor 4.

[0055] In step S2, CaO, or a mixture of CaO and oxidized Fe-OC, which circulates between the calcination reactor 3, is introduced into the fuel reactor 2. Simultaneously, oxidized Fe-OC circulating between the air reactor 4 is introduced, along with steam generated by the steam generator 17. Under fluidization, biomass and steam mix and undergo adsorption-enhanced chemical looping gasification under the action of the oxidized oxygen carrier, generating CO2 and hydrogen-rich syngas. The hydrogen-rich syngas contains not only hydrogen but also CO and CH4. At this point, the participation of oxidized Fe-OC in the reaction process promotes tar cracking. Specifically, CO2 is adsorbed by CaO to generate CaCO3, thus promoting the water-gas reaction in the forward direction. Oxidized Fe-OC is reduced to reduced Fe-OC, significantly altering the biomass reaction process, reducing tar production, and promoting small molecule reforming. The hydrogen-rich gas, CaCO3, and reduced Fe-OC enter the first cyclone separator 5.

[0056] In step S3, the hydrogen-rich gas, CaCO3, and reduced Fe-OC generated in the fuel reactor 2 are separated into gas and solid phases in the first cyclone separator 5. The hydrogen-rich gas is fed into the steam generator 17 through the first gas outlet 14 and is collected after exchanging heat with the feed water. The CaCO3 and reduced Fe-OC enter the magnetic separator 8 through the lower outlet of the first cyclone separator 5.

[0057] In step S4, the solid bed material containing reduced Fe-OC and CaCO3 is separated from the non-magnetic CaCO3 by the magnetic separator 8. The CaCO3 is fed into the calcination reactor 3 through the non-magnetic branch, while the magnetic reduced Fe-OC is fed into the air reactor 4 through the magnetic branch.

[0058] In step S5, the CaO and CO2 generated by calcining CaCO3 in calcination reactor 3 are separated into gas and solid by the second cyclone separator 6. The CO2 gas is introduced into the steam generator 17 through the second gas outlet 13, and the low-temperature CO2 obtained after heat exchange is captured; the CaO is returned to the fuel reactor.

[0059] In step S6, the reduced Fe-OC in air reactor 4 undergoes an oxidation reaction with oxygen in the air to generate oxidized Fe-OC, thus regenerating the oxygen carrier. The oxidation reaction of the magnetic oxygen carrier is an exothermic reaction, making it possible to achieve self-heating equilibrium operation of the system. The process of the magnetic oxygen carrier changing from a reduced state to an oxidized state is exothermic, and the generated oxidized Fe-OC carries the heat and enters the splitter 16.

[0060] In step S7, the distributor 16 diverts the high-temperature oxidized Fe-OC flowing out of the air reactor 4 into three streams. The first stream is diverted to the calcination reactor 3 to balance the required heat load in the calcination reactor 3. After heat exchange, it mixes with the decomposed CaO and then enters the fuel reactor. The second stream is diverted to the fuel reactor 2 to achieve self-heating balance in the fuel reactor 2. The third stream is diverted to the Fe-OC outlet 19, where its flow rate can be zero. The Fe-OC is controlled to be discharged through the Fe-OC outlet 19, thereby achieving the ratio regulation of Fe-OC and CaO. Since the fuel reactor 2 itself is heat-sustainable, regulating the stream entering the calcination reactor 3 is particularly important.

[0061] The adsorption-enhanced biomass gasification hydrogen production system based on a magnetic separator, as described in this embodiment of the invention, was constructed using Aspen Plus chemical simulation software, and the method was executed. During the simulation, the biomass feed rate was set to 24 kg / h, and the relationships between the FR temperature, S / C vapor-to-carbon ratio, CaO / C, and OC / CaO ratio and hydrogen concentration and yield were investigated. Figures 3 to 7As shown, the simulation results indicate that the optimal operating temperature is 700℃, and the optimal S / C ratio is 1. The magnetic separator plays a significant role in controlling the OC / CaO ratio, thereby regulating the hydrogen concentration and yield. At a temperature of 700℃, S / C=1, and OC / CaO=0.5, a hydrogen concentration of approximately 55% and a hydrogen yield of approximately 1.01 kmol / h are achieved. Comparing the hydrogen yield of the system with and without the magnetic separator under self-heating equilibrium conditions, the system achieves the highest hydrogen yield of 1.01 kmol / h with the magnetic separator, while the hydrogen yield without the magnetic separator is 0.82 kmol / h. The above simulation parameters are used to guide scale-up and operational settings. Specific values ​​will be adjusted within the above window based on factors such as biomass type and particle size, magnetic oxygen carrier / adsorbent ratio, and gas-solid contact efficiency. If the model is scaled up to industrial scale with a biomass feed rate of 1000 kg / h, theoretically, 84.23 kg / h of hydrogen will be produced.

[0062] As can be seen from the above technical solutions, the system and method for adsorption-enhanced biomass gasification hydrogen production based on magnetic separator provided in this invention achieves high-concentration hydrogen production by in-situ adsorbing CO2 with CaO in the fuel reactor, thereby driving the water-gas reaction towards hydrogen production and increasing hydrogen yield. In the fuel reactor, CO2 reacts with CaO to generate CaCO3. After calcination in the calcination reactor, high-concentration CO2 is output through the upper outlet of the second cyclone separator, thus achieving in-situ capture of CO2. The magnetic separator separates iron-based OC from Ca-based bed material, allowing OC oxidation and CaCO3 calcination to occur in their respective reactors, while simultaneously controlling the OC / CaO ratio, thereby regulating the system's self-heating balance and hydrogen production. Combined with the splitter, the sensible heat of the high-temperature tail gas is recovered and utilized, improving energy utilization efficiency.

[0063] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0064] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed, and is not intended to limit the scope of the claimed invention, but merely to illustrate preferred embodiments of the invention. Those skilled in the art should understand that the scope of the invention is not limited to the specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A system for adsorption-enhanced biomass gasification hydrogen production based on a magnetic separator, characterized in that, The system includes a fuel reactor (2), a calcination reactor (3), an air reactor (4), a first cyclone separator (5), a second cyclone separator (6), a third cyclone separator (7), a magnetic separator (8), a diverter (16), and a steam generator (17); wherein, The outlet of the fuel reactor (2) is connected to the first cyclone separator (5); the first gas outlet of the first cyclone separator (5) is connected to the steam generator (17), and the lower outlet is connected to the magnetic separator (8); The magnetic branch of the magnetic separator (8) is connected to the air reactor (4), and the non-magnetic branch is connected to the calcination reactor (3). The outlet of the calcination reactor (3) is connected to the second cyclone separator (6); the second gas outlet of the second cyclone separator (6) is connected to the steam generator (17), and the lower outlet is connected to the fuel reactor (2); the outlet of the air reactor (4) is connected to the third cyclone separator (7); the third gas outlet of the third cyclone separator (7) is connected to the steam generator (17), and the lower outlet is connected to the distributor (16); The splitter (16) includes three branches: the first branch is connected to the calcination reactor (3), the second branch is connected to the fuel reactor (2), and the third branch serves as the magnetic oxygen carrier OC outlet (19).

2. The system according to claim 1, characterized in that, The steam generator (17) is provided with a second water inlet (18), and the steam outlet is connected to the steam inlet of the fuel reactor (2). High-temperature H2, CO2 and N2 flow through the steam generator (17) through three channels from the first to the third gas outlet, respectively, and exchange heat with the low-temperature water entering through the second water inlet (18) to form steam.

3. The system according to claim 1, characterized in that, The magnetic branch of the magnetic separator (8) is used to transport the separated reduced magnetic OC; the non-magnetic branch is used to transport the calcium-based adsorbent CaCO3 formed after adsorbing CO2.

4. The system according to claim 3, characterized in that, The calcium-based adsorbent includes limestone and / or dolomite; the calcium-based adsorbent is granular with a particle size of 20~500μm.

5. The system according to claim 4, characterized in that, The magnetic OC includes both reduced and oxidized states, and is achieved using iron-based oxygen carrier Fe-OC particles; the iron-based oxygen carrier is an iron-containing mineral, including magnetite, ilmenite and / or manganese iron ore; the Fe-OC particles have a particle size of 20~500μm.

6. The system according to claim 1, characterized in that, The fuel reactor (2), calcination reactor (3), and air reactor (4) are respectively provided with a first fluid inlet (9), a second fluid inlet (10), and a third fluid inlet (11); wherein, the first fluid inlet (9) introduces water vapor into the fuel reactor (2); the second fluid inlet (10) introduces CO2 into the calcination reactor (3); and the third fluid inlet (11) introduces air into the air reactor (4).

7. A hydrogen production method employing the adsorption-enhanced biomass gasification hydrogen production system based on a magnetic separator as described in any one of claims 1-6, characterized in that, The method includes: A predetermined amount of calcium-based adsorbent and oxidized magnetic OC are introduced through the feed inlet and fed into a three-bed circulation system; after stabilization, a predetermined amount of crushed biomass is introduced into the fuel reactor. A calcium-based adsorbent, or a combination of calcium-based adsorbent and oxidized magnetic OC, circulating between the calcination reactors is introduced into the fuel reactor. Oxidized magnetic OC circulating between the air reactors is also introduced, along with steam. Under fluidization, biomass and steam mix and undergo adsorption-enhanced chemical looping gasification under the influence of the oxidized magnetic OC, generating CO2 and hydrogen-rich syngas. CO2 is adsorbed by the calcium-based adsorbent to form CaCO3, and the oxidized magnetic OC is reduced to a reduced magnetic OC. The hydrogen-rich gas, the CaCO3-containing calcium-based adsorbent, and the reduced magnetic OC then enter the first cyclone separator. Hydrogen-rich gas, calcium-based adsorbent containing CaCO3, and reduced magnetic OC are separated into gas and solid in the first cyclone separator. The hydrogen-rich gas is introduced into the steam generator through the first gas outlet, and the solid bed material enters the magnetic separator through the lower outlet of the first cyclone separator. In the magnetic separator, reduced magnetic OC and non-magnetic calcium-based adsorbent containing CaCO3 are screened and separated. The calcium-based adsorbent containing CaCO3 is fed into the calcination reactor through the non-magnetic branch, while the reduced magnetic OC is fed into the air reactor through the magnetic branch. In the calcination reactor, the CaO and CO2 generated by calcining CaCO3 in the calcium-based adsorbent are separated into gas and solid by the second cyclone separator. The CO2 is fed into the steam generator, and the calcium-based adsorbent is returned to the fuel reactor. Air is introduced into the air reactor, and the reduced magnetic OC is oxidized to the oxidized magnetic OC, which carries heat into the splitter. The diverter directs the high-temperature oxidized magnetic OC to the calcination reactor, fuel reactor, or outside the system, supplementing the calcination reactor with heat and achieving self-heating balance, while simultaneously regulating the magnetic OC and calcium-based adsorbent in the fuel reactor.

8. The method according to claim 7, characterized in that, The splitter divides the high-temperature oxidized magnetic OC flowing out of the air reactor into three streams. The first stream is diverted to the calcination reactor to balance the heat load required in the calcination reactor. After heat exchange, it is mixed with the decomposed calcium-based adsorbent and then enters the fuel reactor. The second stream is diverted to the fuel reactor to achieve self-heating balance in the fuel reactor. The third stream is diverted to the magnetic OC outlet to achieve controllable discharge of magnetic OC, thereby realizing the ratio regulation of magnetic OC and calcium-based adsorbent.

9. The method according to claim 7, characterized in that, The fuel reactor is also equipped with a first fluid inlet; steam is introduced through the fluid inlet, which together with the steam generated in the steam generator provides steam for the water-gas reaction.

10. The method according to claim 7, characterized in that, The diverter sends the oxidized magnetic OC to the calcination reactor, where it mixes with the decomposed calcium-based adsorbent before entering the fuel reactor.

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