Apparatus and method for co-production of syngas and hydrogen-rich gas

Abstract

The application discloses a device and method for co-production of synthesis gas and hydrogen-rich gas, which comprises a microwave moving bed for heating by microwave during the process of biomass screw feeding, with a heating temperature of 400-500 DEG C; after heating, synthesis gas and coke particles are generated, and the synthesis gas is directly discharged; a double fluidized bed comprising a combustion chamber and a hydrogen production chamber; oxygen is introduced into the combustion chamber, coke particles are received and react with high-valence iron-based oxygen carriers as bed materials, and a bubbling fluidization state is presented during the reaction process, generating carbon dioxide, low-valence iron-based oxygen carriers or iron element; the hydrogen production chamber receives the low-valence iron-based oxygen carriers or iron element and reacts with the introduced water vapor to generate hydrogen and high-valence iron-based oxygen carriers; the high-valence iron-based oxygen carriers are transported back to the combustion chamber to complete the cyclic regeneration of the oxygen carriers. The application uses biomass as raw material, adopts a chemical chain hydrogen production process, and combines the microwave moving bed and the double fluidized bed, so that synthesis gas, high-purity hydrogen and carbon dioxide can be co-produced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen production from biomass, and particularly relates to a device and method for co-production of syngas and hydrogen-rich gas. BACKGROUND

[0002] As a kind of efficient clean energy, hydrogen energy is developing at the right moment. Among various technical routes for hydrogen production from biomass, the use of fluidized bed reactor for efficient thermal conversion to produce hydrogen-rich gas has a promising prospect.

[0003] The combustion and gasification processes of the traditional fluidized bed reactor are carried out in the same reactor, which leads to partial combustion of syngas and low yield. There are applications of double fluidized bed in the prior art. The double fluidized bed reactor has the following advantages: it decouples combustion and gasification, indirect heating, and high hydrogen production rate; there is only efficient exchange of solids and heat between the combustion chamber and the gasification chamber, which can achieve high heat flux and high processing capacity with small volume; the tar content is lower than that of the conventional route, which is convenient for subsequent tar removal treatment. When using water vapor as an external hydrogen source, 40% to 60% of hydrogen can be produced. Combined with the AER technology for in-situ absorption of carbon dioxide, the hydrogen concentration can reach 78%. However, due to the production of methane, hydrocarbons, carbon monoxide, and carbon dioxide, etc. from biomass, there is an upper limit to the increase of hydrogen concentration.

[0004] Chinese patent application CN109704278A discloses a device and method for preparing hydrogen from biomass pyrolysis and gasification by double fluidized bed. The double fluidized bed includes a fluidized bed pyrolysis furnace and a fluidized bed combustion furnace. The fluidized bed pyrolysis furnace includes a pyrolysis furnace riser pipe, and the rear end of the pyrolysis furnace riser pipe is connected with a pyrolysis furnace cyclone separator. The upper part of the pyrolysis furnace cyclone separator is connected with a shift reactor, and the lower part is connected with a pyrolysis furnace return valve. The other outlet of the pyrolysis furnace return valve is connected with the fluidized bed combustion furnace. The fluidized bed combustion furnace includes a combustion furnace riser pipe. The other outlet of the pyrolysis furnace return valve is connected with the bottom of the combustion furnace riser pipe. The middle part of the combustion furnace riser pipe is provided with an oxygen carrier cyclone separator, and the top part is provided with a CO2absorbing agent cyclone separator. In the preparation process of the scheme, pure oxygen is not needed as a gasification agent. The system only needs to supplement air as a gasification agent to meet the production demand, and the production cost is low. The pyrolysis furnace does not use air for fluidization, and the content of effective components in the biomass gas is high.

[0005] Microwave moving bed is favored in recent years because microwaves can penetrate materials, uniformly vibrate polar molecules to achieve uniform heating, and many studies have shown that microwave non-thermal effects can improve the speed of chemical reactions. However, the temperature of biomass gasification by moving bed in a microwave field needs to reach 900℃, which consumes a lot of electricity, but the concentration of hydrogen produced is low, about 30% to 50%, and the tar content is high.

[0006] Chemical looping hydrogen production is an emerging green hydrogen production technology that uses biomass waste to produce negative carbon green hydrogen. The process uses metal-based oxygen carriers as intermediates, and with the help of electron and oxygen lattice migration, the fuel redox reaction is decomposed into three stages: reduction, steam oxidation, and air oxidation. Concentrations of 90% to 99% hydrogen are produced in different stages, but the energy consumption and fuel cost are high, and methane and other fuels are often used.

[0007] Therefore, there is an urgent need for a device and method for co-producing synthesis gas and hydrogen-rich gas that not only produces hydrogen with a purity of 90% to 99% but also effectively addresses the cost issues of chemical looping hydrogen production and biomass microwave hydrogen production.

[0008] The information disclosed in this Background section is only intended to increase an understanding of the general context in which the present application can be practiced. It should not be taken as an acknowledgement or any form of suggestion that this information forms prior art that is already known to those skilled in the art. SUMMARY

[0009] The purpose of the present application is to provide a device and method for co-producing synthesis gas and hydrogen-rich gas. By using biomass as a raw material and adopting a chemical looping hydrogen production process, and by combining a microwave moving bed with a dual fluidized bed, synthesis gas, high-purity hydrogen, and carbon dioxide can be co-produced.

[0010] To achieve the above-mentioned purpose, according to the first aspect of the present application, the present application provides a device for co-producing synthesis gas and hydrogen-rich gas, comprising: a microwave moving bed that heats biomass during the process of screw feeding by microwaves, with a heating temperature of 400-500℃; after heating, synthesis gas and coke particles are produced, and the synthesis gas is directly discharged; a dual fluidized bed comprising a combustion chamber and a hydrogen production chamber; the combustion chamber is connected to oxygen and receives coke particles and reacts with high-valence iron-based oxygen carriers as bed material, and presents a bubbling fluidization state during the reaction process, generating carbon dioxide, low-valence iron-based oxygen carriers, or elemental iron; the hydrogen production chamber receives low-valence iron-based oxygen carriers or elemental iron and reacts with the water vapor introduced to produce hydrogen and high-valence iron-based oxygen carriers; the high-valence iron-based oxygen carriers are transported back to the combustion chamber to complete the cyclic regeneration of the oxygen carriers.

[0011] Further, in the above technical solution, the microwave moving bed can include: a pushing screw mechanism including a pushing screw and a wave-transparent tube, the pushing screw being arranged in the microwave moving bed enclosed by the wave-transparent tube, for screw feeding the biomass raw material from the feeding port into the combustion chamber of the dual fluidized bed; a microwave source, the number of which is multiple and fixed on the microwave cavity shell, for microwave heating of the biomass raw material during screw feeding; a heat preservation lining is filled between the wave-transparent tube and the microwave cavity shell.

[0012] Further, in the above technical solution, the microwave source can adopt a magnetron with a microwave frequency of 915MHz.

[0013] Further, in the technical solution, the pushing screw and the microwave cavity shell can be made of metal; the wave-transparent tube can be made of quartz; and the heat-insulating lining can be made of ceramic fiber.

[0014] Further, in the technical solution, the microwave sources can be uniformly arranged on the microwave cavity shell in a staggered or side-by-side manner.

[0015] Further, in the technical solution, a cutoff waveguide tube is arranged at the end of the pushing screw, which can prevent the microwave from entering the combustion chamber of the double fluidized bed and contacting the oxygen to cause combustion and explosion.

[0016] Further, in the technical solution, the double fluidized bed further comprises: a lower return feeder provided with a loosening chamber and a return chamber; the loosening chamber receives the low-grade iron-based oxygen carrier or iron single substance and ash particles from the lower discharge port of the combustion chamber, and forms a preliminary stratification of the particles by the bottom loosening air while generating a material seal; the return chamber carries the particles from the loosening chamber to the inertial separator by the bottom return air.

[0017] Further, in the technical solution, the double fluidized bed further comprises: a cyclone separator in communication with the top of the hydrogen production chamber, used for separating the hydrogen and high-grade iron-based oxygen carrier generated in the hydrogen production chamber; an upper return feeder provided with a loosening chamber and a return chamber; the loosening chamber receives the high-grade iron-based oxygen carrier separated from the cyclone separator and forms a material seal; and the return chamber carries the high-grade iron-based oxygen carrier to the upper inlet of the combustion chamber by the return air at the bottom of the return chamber.

[0018] Further, in the technical solution, the combustion chamber is provided with a carbon dioxide exhaust port at the top, which is used for recycling and storing the carbon dioxide or using the carbon dioxide gas as the loosening air of the lower return feeder.

[0019] To achieve the above-mentioned purpose, according to the second aspect of the present application, the present application provides a method for co-producing synthesis gas and hydrogen-rich gas, comprising the following steps: A, heating by microwave in the process of biomass screw feeding, the heating temperature is 400-500℃; after heating, synthesis gas and coke particles are generated, and the synthesis gas is directly discharged; B, oxygen is introduced into the combustion chamber, and the coke particles react with the high-grade iron-based oxygen carrier as the bed material in the combustion chamber, and the reaction process presents a bubbling fluidization state, generating carbon dioxide, low-grade iron-based oxygen carrier or iron single substance; steam is introduced into the hydrogen production chamber, and the low-grade iron-based oxygen carrier or iron single substance reacts with the steam to produce hydrogen and high-grade iron-based oxygen carrier; and the high-grade iron-based oxygen carrier is carried back to the combustion chamber to complete the cyclic regeneration of the oxygen carrier.

[0020] Further, in the above technical solution, in step B, the step of returning the material to the lower part and separating the low-valence iron-based oxygen carrier or iron single substance from the ash particles can be further performed between the combustion chamber and the hydrogen production chamber.

[0021] Further, in the above technical solution, in step B, the step of separating the hydrogen from the high-valence iron-based oxygen carrier and returning the material to the upper part can be further performed between the hydrogen production chamber and the combustion chamber.

[0022] Further, in the above technical solution, the carbon dioxide generated in the combustion chamber can be directly discharged as a product or stored, and / or can be used as the loosening air for the material returning to the lower part.

[0023] Further, in the above technical solution, the purity of the hydrogen can reach 90% to 99%.

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

[0025] 1) The present application combines the advantages of the microwave moving bed and the double fluidized bed reactors, and can co-produce synthesis gas, high-purity hydrogen and carbon dioxide.

[0026] 2) The present application uses low-cost biomass fuel, and the microwave only performs preliminary pyrolysis on the biomass, which can effectively improve the economy of the entire process while providing the required heat for the chemical chain hydrogen production, and solves the cost problem of the chemical chain hydrogen production and the microwave hydrogen production of biomass.

[0027] 3) The present application uses the chemical chain hydrogen production process, and the carbon elements after the microwave pyrolysis of the biomass only burn in the combustion chamber to produce high-purity carbon dioxide, which can facilitate the storage of carbon dioxide in the later stage, change the entire process from zero-carbon technology to negative-carbon technology, and improve the environmental protection.

[0028] 4) The hydrogen elements in the water vapor only produce hydrogen in the hydrogen production chamber, and only the heat and oxygen elements are transmitted through the metal oxygen carrier in the chemical chain hydrogen production between the combustion chamber and the hydrogen production chamber, so that hydrogen with a purity of 90% to 99% can be produced.

[0029] 5) The present application uses the loosening air and the returning air with different flow rates in the returning material device, the higher flow rate of the loosening air can fully fluidize and stratify the oxygen carrier particles and the ash particles, so as to preliminarily separate the oxygen carrier particles and the ash particles; by using the inertial separator, the ash particles can be further screened out on the basis of the preliminary separation, so as to realize that the solid particles entering the hydrogen production chamber are basically oxygen carrier particles, and the carbon elements can be excluded from the hydrogen production chamber to the maximum extent, thereby maximizing the purity of the prepared hydrogen.

[0030] The above description is only a summary of the technical solutions of the present application. In order to make the technical means of the present application more clearly understood and implemented according to the content of the description, and to make the above and other purposes, technical features and advantages of the present application more easily understood, one or more preferred embodiments are listed below and are described in detail as follows with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a structural schematic diagram of the device for co-production of synthesis gas and hydrogen-rich gas according to the present application.

[0032] Figure 2 is a sectional view of the microwave moving bed in the device according to the present application.

[0033] Figure 3 is a structural schematic diagram of the upper return feeder of the double fluidized bed in the device according to the present application.

[0034] MAIN REFERENCE NUMERALS EXPLANATION:

[0035] 1-microwave moving bed, 10-biomass raw material feeding port, 11-feeding screw, 12-wave-penetrating tube, 13-microwave cavity outer shell, 14-heat-insulating lining, 15-microwave source, 16-wave-penetrating sealing material, 2-double fluidized bed, 21-combustion chamber, 22-hydrogen production chamber, 23-lower return feeder, 231-lower return feeder loosening chamber, 232-lower return feeder return chamber, 24-inertial separator, 241-baffle, 25-cyclone separator, 26-upper return feeder, 260-bottom plate, 2601-air cap, 261-upper return feeder loosening chamber, 262-upper return feeder return chamber, 263-air distribution wind cavity. DETAILED DESCRIPTION

[0036] The specific embodiments of the present application are described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present application is not limited by the specific embodiments.

[0037] Unless otherwise explicitly stated, throughout the specification and claims, the term "comprise" or its variants such as "comprises" or "comprising" will be understood to encompass the stated element or components, but not to exclude other elements or components.

[0038] For the purposes of this description, spatially relative terms, such as "beneath", "below", "lower", "above", "upper", and the like, can be used to describe a relationship of one element or feature to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device is inverted or rotated by 90 degrees, an element described as "below" or "beneath" another element or feature would then be oriented "above" or "over" the other element or feature. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative terms used herein interpreted accordingly.

[0039] In this document, the terms "first", "second", etc. are used to distinguish between two different elements or portions, and are not used to define a particular position or relative relationship. In other words, in some embodiments, the terms "first", "second", etc. can also be interchanged with each other.

[0040] The inventors have found that in the technical route of hydrogen production from biomass, the biomass in the microwave field is gasified by a moving bed, which requires a high temperature, consumes a large amount of electricity, and is prone to damage the equipment, and the hydrogen concentration is low. The biomass is gasified by combustion of carbon in the biomass using a double fluidized bed reactor, which is low in cost and good in hydrogen production effect, but due to the production of methane, hydrocarbons, carbon monoxide and carbon dioxide and other gases from biomass, there is an upper limit to the increase of hydrogen concentration. The present application combines the advantages of microwave moving bed and double fluidized bed reactors, and can co-produce synthesis gas, high-purity hydrogen and carbon dioxide. Using low-cost biomass fuel, the microwave only performs preliminary pyrolysis on the biomass, provides the required heat for chemical chain hydrogen production, and produces crude synthesis gas for Fischer-Tropsch synthesis or combustion heat, improving the economy of the entire process and solving the cost problem of chemical chain hydrogen production and microwave hydrogen production from biomass. The present application uses the process of chemical chain hydrogen production to decouple the reaction of biomass and steam in the gasification chamber in the double fluidized bed hydrogen production route, i.e. the carbon elements after microwave pyrolysis of biomass only burn in the combustion chamber to produce high-purity carbon dioxide, which is convenient for carbon dioxide sequestration in the later stage, changes the entire process from zero-carbon technology to negative-carbon technology, and improves environmental protection; the hydrogen elements in the steam only produce hydrogen in the hydrogen production chamber, and only the heat and oxygen elements are transferred between the two chambers through the metal oxygen carrier of the chemical chain hydrogen production, which can produce hydrogen with a purity of 90% to 99% through experimental verification.

[0041] As Figure 1As shown, the device for co-production of synthesis gas and hydrogen-rich gas of the present application comprises a microwave moving bed 1 and a double fluidized bed 2. The microwave moving bed 1 is heated by microwave during the process of biomass screw feeding, and the heating temperature is 400-500℃; after heating, synthesis gas and coke particles are generated, and the synthesis gas is directly discharged without entering the double fluidized bed 2. The double fluidized bed 2 comprises a combustion chamber 21 and a hydrogen production chamber 22. Oxygen is introduced from the bottom of the combustion chamber 21, coke particles from the microwave moving bed are received, and react with high-valence iron-based oxygen carrier (Fe3O4) as the bed material of the double fluidized bed, and oxygen is used as fluidizing wind, and the combustion reaction process presents a bubbling fluidization state. After the combustion reaction, carbon dioxide, low-valence iron-based oxygen carrier (FeO) or iron single substance (Fe) are generated. The hydrogen production chamber 22 receives the low-valence iron-based oxygen carrier (FeO) or iron single substance (Fe) generated by the reaction of the combustion chamber, and reacts with steam introduced from the bottom to generate hydrogen and high-valence iron-based oxygen carrier (Fe3O4). The high-valence iron-based oxygen carrier (Fe3O4) is transported back to the combustion chamber 21, and the oxygen carrier is regenerated in a cycle.

[0042] The present application first pyrolyzes the biomass by microwave, and only heats to a lower temperature, which provides the required heat for the chemical chain hydrogen production, and the generated crude synthesis gas is directly discharged at this stage for other use; by using the chemical chain hydrogen production process in the double fluidized bed, the cost problem of chemical chain hydrogen production and biomass microwave hydrogen production is solved.

[0043] Further as shown in Figure 1 , 2 The microwave moving bed 1 comprises a pushing screw mechanism and a microwave source 15. The pushing screw mechanism comprises a pushing screw 11 and a wave-transparent tube 12, and the pushing screw 11 is arranged in the microwave moving bed enclosed by the wave-transparent tube 12, and is used for screw feeding the biomass raw material from the feeding port 10 to the combustion chamber 21 of the double fluidized bed 2. Specifically, the main body of the microwave moving bed 1 is arranged transversely, and the microwave moving bed is tubular (i.e. the wall surface is the wave-transparent tube 12), the wave-transparent tube 12 can be made of quartz material, and the microwave can penetrate the tubular wall surface and heat the biomass raw material in the wall surface. The pushing screw 11 is made of metal material, and is arranged in the wave-transparent tube 12 and can be driven to rotate by a driving mechanism such as a motor, so as to continuously send the biomass raw material entering from the left side in Figure 2 to the outlet on the right side. Since the screw feeding mode can make the biomass stay in the wave-transparent tube 12 for a long time, and the tubular moving bed is a small cavity, which is beneficial to uniformly heat the biomass.

[0044] Further as shown in Figure 1 , 2As shown, multiple microwave sources 15 are fixed to the outer shell 13 of the microwave cavity, and can microwave heat the biomass raw materials during the spiral feeding process. Furthermore, an insulating lining 14, preferably made of ceramic fiber, is filled between the waveguide 12 and the outer shell 13 to prevent microwave heat loss. The microwave sources 15 preferably use magnetrons with a microwave frequency of 915MHz. Multiple microwave sources 15 can be arranged in two ways: staggered or side-by-side. The figure shows a staggered arrangement, which effectively avoids interference between microwave sources. In this invention, the microwave sources 15 are fixed to the outside of the outer shell 13 of the microwave cavity. The corresponding chambers are bolted to the outer shell, and the microwave sources are installed within these chambers for easy replacement. Simultaneously, holes are made in the outer shell 13 of the microwave cavity to allow the microwave sources to emit microwaves inward. The space between the outer shell 13 and the microwave sources 15 is sealed with a wave-transparent hole and a wave-transparent sealing material 16.

[0045] Furthermore, a cutoff waveguide (not shown in the figure) is provided at the end of the pusher screw 11 to prevent microwaves from entering the combustion chamber 21 of the dual fluidized bed 2 and coming into contact with oxygen in the combustion chamber, causing combustion and explosion.

[0046] Further as Figure 1 As shown, the dual fluidized bed 2 of the present invention, in addition to the aforementioned combustion chamber 21 and hydrogen production chamber 22, also includes a lower return feeder 23, an inertial separator 24, a cyclone separator 25, and an upper return feeder 26. For the specific structure of the upper return feeder 26, please refer to the attached diagram. Figure 3 As shown, the upper return feeder 26 includes a loosening chamber 261 and a return chamber 262. The loosening chamber 261 is connected to the cyclone separator 25 via a material leg. The diameter of the loosening chamber 261 can be the same as the diameter of the material leg. The bottom plate 260 of the loosening chamber 261 and the return chamber 262 has openings or is equipped with air caps. The lower part of the bottom plate 260 is an air distribution chamber 263. The loosening air and the return air introduced into the upper return feeder 26 of this invention are the same, therefore only one air inlet pipe is needed to introduce the upper return air. The solid particles entering the loosening chamber are fluidized under the action of the upper return air and can achieve material sealing. The solid particles entering the return chamber are transported to the discharge port under the action of the upper return air and then enter the combustion chamber 21 of the dual fluidized bed of this invention.

[0047] Further as Figure 1As shown, the main structure and components of the down feeder 23 of the present application are similar to the up feeder 26, and will not be described in detail here, and different from the up feeder 26 is that, due to the process requirements of the present application, the down feeder 23 of the present application is different from the up feeder 26 in the loosening air and the return air, and therefore the air distribution air chamber of the down feeder 23 of the present application is divided into two parts, and the down loosening air and the down return air with different flow rates and flow rates can be respectively introduced. Specifically, the loosening chamber 231 of the down feeder 23 receives the low-grade iron-based oxygen carrier or iron single substance and ash particles from the lower discharge port of the combustion chamber 21, and forms a preliminary stratification of particles by the bottom loosening air while forming a material seal. Due to the high flow rate of the loosening air of the down feeder 23 of the present application, the ash particles can be preliminarily separated by fluidization, which facilitates further separation in the inertial separator 24. The return air chamber 232 can transport the particles from the loosening chamber 231 to the inertial separator 24 by the bottom return air (with a lower flow rate).

[0048] Further as Figure 1 shown, the inertial separator 24 is a chamber structure and vertically arranged in the middle part is a baffle 241 composed of a porous material, which is used to screen out ash particles, and the low-grade iron-based oxygen carrier or iron single substance passes through the baffle 241 under the action of inertia and enters the hydrogen production chamber 22. Through the screening effect of the baffle, the low-grade iron-based oxygen carrier or iron single substance with smaller particle size can pass through, while the ash particles with larger particle size cannot pass through and will fall into the collection tank below the inertial separator 24. The inertial separator 24 of the present application can filter out the ash particles from the combustion chamber to the maximum extent, so that the carbon element will not enter the hydrogen production chamber 22, thereby preparing for the preparation of high-purity hydrogen. The low-grade iron-based oxygen carrier or iron single substance entering the hydrogen production chamber 22 reacts with the water vapor entering from the bottom to generate high-purity hydrogen and high-grade iron-based oxygen carrier.

[0049] Further as Figure 1 shown, the hydrogen production chamber 22 is communicated with the cyclone separator 25 at the top, and the cyclone separator 25 can realize effective separation of gas and solid according to the design of the oxygen carrier and the gas amount, and the separated high-purity hydrogen is discharged from the top of the cyclone separator 25 for recycling, and the high-grade iron-based oxygen carrier particles enter the loosening chamber 261 of the up feeder 26 from the bottom of the cyclone separator 25, and the loosening chamber 261 receives the separated high-grade iron-based oxygen carrier and forms a material seal; the high-grade iron-based oxygen carrier is transported to the feed inlet of the upper part of the combustion chamber by the return air of the bottom of the return air chamber 262, and then returns to the combustion chamber 21 to complete the circulation of the oxygen carrier.

[0050] It should be noted that: the combustion chamber 21 in the double fluidized bed 2 is provided with a carbon dioxide exhaust port at the top, which is used for recycling and sealing carbon dioxide, and the part of the carbon dioxide gas can be used as the loosening air of the lower return feeder 23. High-purity carbon dioxide gas can be obtained in the combustion chamber, which is convenient for the sealing of carbon dioxide in the later stage, changes the whole process from zero carbon technology to negative carbon technology, and can effectively improve the environmental protection.

[0051] The application also provides a method for co-production of synthesis gas and hydrogen-rich gas, which comprises the following steps:

[0052] In step S101, the biomass is heated by microwave during the process of screw feeding, and the heating temperature is 400-500 DEG C; after heating, synthesis gas and coke particles are generated, the synthesis gas is directly discharged, and the coke particles enter the combustion chamber of the double fluidized bed.

[0053] In step S102, oxygen is introduced into the combustion chamber 21, the coke particles react with the high-valence iron-based oxygen carrier as the bed material in the combustion chamber, and the reaction process presents a bubbling fluidization state, generating carbon dioxide, low-valence iron-based oxygen carrier or iron single element, ash particles and the like; the carbon dioxide is directly discharged from the top of the combustion chamber, and the solid particles enter the lower return feeder 23, and the oxygen carrier and the ash particles are preliminarily layered while the material is sealed, and the low-valence iron-based oxygen carrier or iron single element and the ash particles are further separated by the inertial separator 24, and the separated low-valence iron-based oxygen carrier or iron single element enters the hydrogen production chamber 22; water vapor is introduced into the hydrogen production chamber, and the low-valence iron-based oxygen carrier or iron single element reacts with the water vapor to generate hydrogen and high-valence iron-based oxygen carrier; the hydrogen and the high-valence iron-based oxygen carrier are separated by the cyclone separator 25, and then the high-valence iron-based oxygen carrier is transported back to the combustion chamber 21 by the upper return feeder 26, so that the circulation and regeneration of the oxygen carrier are completed.

[0054] Through the microwave and double fluidization process involved in the above steps and the chemical chain hydrogen production process, the purity of the obtained hydrogen can reach 90% to 99%.

[0055] The method of the application will be described in detail below with one specific embodiment:

[0056] Example 1

[0057] The biomass raw material enters the microwave moving bed from the hopper through the feeding screw, and is heated to about 500 DEG C by the microwave generated by the microwave source when slowly passing through, and pyrolysis occurs to a certain extent to produce synthesis gas and coke particles, the synthesis gas is discharged from the spiral gas outlet of the microwave moving bed, and the coke particles enter the double fluidized bed combustion chamber along the spiral;

[0058] The hot coke particles enter the double fluidized bed combustion chamber, the combustion chamber uses a small amount of oxygen (or a mixture of oxygen and carbon dioxide generated by combustion in the combustion chamber) as fluidizing gas, the coke particles react with the high-valence iron-based oxygen carrier (Fe3O4) entering the combustion chamber, and the high-valence iron-based oxygen carrier is reduced to Fe single element or low-valence iron-based oxygen carrier (FeO), the two particles are in a bubbling fluidized state in the double fluidized bed combustion chamber, the bed temperature is 850°C, the generated low-valence iron-based oxygen carrier or iron single element and ash particles enter the lower return feeder, the combustion generated carbon dioxide can be used as a product or sealed, thereby improving the environmental protection of the whole process and reducing carbon emissions;

[0059] The generated low-valence iron-based oxygen carrier or iron single element and ash particles are affected by the small amount of loose air (which can use the carbon dioxide generated by combustion in the combustion chamber) in the lower return feeder, and stratification occurs in the lower return feeder loose chamber, a part of the ash particles is discharged through the ash pipe in the lower return feeder, and the other part of the ash particles that are not separated mix with the low-valence iron-based oxygen carrier or iron single element and enter the return chamber of the lower return feeder, and are carried to the inertial separator under the action of high-speed return air, and are further separated under the action of the inertial separator, the ash particles fall into the slag discharge device, and are conveniently recycled;

[0060] The low-valence iron-based oxygen carrier or iron single element separated by the inertial separator enters the double fluidized bed hydrogen production chamber, and reacts with the water vapor introduced from the bottom of the hydrogen production chamber to produce hydrogen and high-valence iron-based oxygen carrier (Fe3O4). After the two are separated by the cyclone separator, high-purity hydrogen is discharged from the top as product gas, and the high-valence iron-based oxygen carrier falls into the upper return feeder below the cyclone separator and is carried to the double fluidized bed combustion chamber by the upper return air (water vapor) for reduction and heating, thereby completing the cyclic regeneration of the oxygen carrier.

[0061] The foregoing description of specific exemplary embodiments of the application is intended for purposes of illustration and example only. These descriptions are not intended to limit the application in any way and it is clear that many modifications and changes to the specific embodiments described can be made by persons of ordinary skill in the art having the benefit of this disclosure, which is intended to be broadly applicable to all equivalent structures and processes. The purpose of the foregoing description is to explain the principles of the application and its practical application to enable others skilled in the art to best utilize it in various embodiments and various modifications as are suited to the particular use contemplated. Any simple modification, equivalent replacement, and modification of the foregoing exemplary embodiments should fall within the scope of the application.

Claims

1. An apparatus for co-producing syngas and hydrogen-rich gas, characterized in that, include: The microwave moving bed is heated by microwaves during the biomass screw feeding process, with a heating temperature of 400-500℃; after heating, syngas and coke particles are produced, and the syngas is directly discharged. A dual fluidized bed includes a combustion chamber and a hydrogen production chamber. The combustion chamber is purged with oxygen, receives coke particles, and reacts with a high-valent iron-based oxygen carrier used as bed material. During the reaction, a bubbling fluidized state is observed, generating carbon dioxide, a low-valent iron-based oxygen carrier, or elemental iron. The hydrogen production chamber receives the low-valent iron-based oxygen carrier or elemental iron and reacts with purged water vapor to produce hydrogen and the high-valent iron-based oxygen carrier. The high-valent iron-based oxygen carrier is then transported back to the combustion chamber, completing the recycling and regeneration of the oxygen carrier.

2. The apparatus for co-producing syngas and hydrogen-rich gas according to claim 1, characterized in that, The microwave moving bed includes: The feeding screw mechanism includes a feeding screw and a wave tube. The feeding screw is disposed in the microwave moving bed enclosed by the wave tube and is used to feed biomass feedstock from the feed inlet into the combustion chamber of the dual fluidized bed. Multiple microwave sources are fixed on the outer shell of the microwave cavity and microwave heating is performed on the biomass raw material during the spiral feeding process; the space between the wave tube and the outer shell of the microwave cavity is filled with a heat-insulating lining.

3. The apparatus for co-producing syngas and hydrogen-rich gas according to claim 2, characterized in that, The microwave source uses a magnetron with a microwave frequency of 915MHz.

4. The apparatus for co-producing syngas and hydrogen-rich gas according to claim 2, characterized in that, The feeding spiral and microwave cavity shell are made of metal; the wave tube is made of quartz; and the thermal insulation lining is made of ceramic fiber.

5. The apparatus for co-producing syngas and hydrogen-rich gas according to claim 2, characterized in that, The microwave sources are evenly distributed on the outer shell of the microwave cavity, and the arrangement is either staggered or side by side.

6. The apparatus for co-producing syngas and hydrogen-rich gas according to claim 2, characterized in that, The end of the pusher screw is equipped with a cutoff waveguide to prevent microwaves from entering the combustion chamber of the dual fluidized bed and coming into contact with oxygen, thus preventing combustion and explosion.

7. The apparatus for co-producing syngas and hydrogen-rich gas according to claim 1, characterized in that, The dual fluidized bed also includes: The lower return feeder is equipped with a loosening chamber and a return chamber. The loosening chamber receives low-valence iron-based oxygen carrier or elemental iron and ash particles from the lower outlet of the combustion chamber, and forms preliminary stratification of particles through bottom loosening air while generating a material seal. The return chamber transports the particles from the loosening chamber to the inertial separator through bottom return air. An inertial separator has a chamber structure with a baffle made of porous material vertically arranged in the middle to screen out the ash particles. The low-valence iron-based oxygen carrier or elemental iron passes through the baffle under inertial action and enters the hydrogen production chamber.

8. The apparatus for co-producing syngas and hydrogen-rich gas according to claim 7, characterized in that, The dual fluidized bed also includes: A cyclone separator, which is connected to the top of the hydrogen production chamber, is used to separate the hydrogen produced in the hydrogen production chamber from the high-valence iron-based oxygen carrier. The upper return feeder is provided with a loosening chamber and a return chamber; the loosening chamber receives the high-valence iron-based oxygen carrier separated from the cyclone separator and forms a material seal; the high-valence iron-based oxygen carrier is transported to the feed inlet at the top of the combustion chamber by the return air at the bottom of the return chamber.

9. The apparatus for co-producing syngas and hydrogen-rich gas according to claim 7, characterized in that, The combustion chamber is equipped with a carbon dioxide exhaust port at the top, which is used to recover and store carbon dioxide or to use carbon dioxide gas as loosening air for the lower return feeder.

10. A method for co-producing syngas and hydrogen-rich gas, characterized in that, Includes the following steps: A. During the biomass screw feed process, heating is performed by microwave at a temperature of 400-500℃; after heating, syngas and coke particles are generated, and the syngas is directly discharged. B. Oxygen is introduced into the combustion chamber, where coke particles react with the high-valent iron-based oxygen carrier used as bed material. The reaction is carried out in a bubbling fluidized state, generating carbon dioxide, low-valent iron-based oxygen carrier, or elemental iron. Water vapor is introduced into the hydrogen production chamber, where the low-valent iron-based oxygen carrier or elemental iron reacts with water vapor to produce hydrogen and the high-valent iron-based oxygen carrier. The high-valent iron-based oxygen carrier is then transported back to the combustion chamber to complete the recycling and regeneration of the oxygen carrier.

11. The method for co-producing syngas and hydrogen-rich gas according to claim 10, characterized in that, In step B, a process is also performed between the combustion chamber and the hydrogen production chamber to seal the return material and separate the low-valent iron-based oxygen carrier or elemental iron from the ash particles.

12. The method for co-producing syngas and hydrogen-rich gas according to claim 10, characterized in that, In step B, a further step is performed between the hydrogen production chamber and the combustion chamber to separate the hydrogen from the high-valence iron-based oxygen carrier and to seal the return material.

13. The method for co-producing syngas and hydrogen-rich gas according to claim 11, characterized in that, The carbon dioxide generated in the combustion chamber can be discharged or stored as a product, and / or used as loosening air for the bottom return material seal.

14. The method for co-producing syngas and hydrogen-rich gas according to claim 10, characterized in that, The hydrogen gas has a purity of 90% to 99%.

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