Biomass gasification hydrogen production device and method based on porous medium moving bed

Abstract

The invention relates to a biomass gasification hydrogen production device and method based on a porous medium moving bed, and aims to solve the problem of how to improve the hydrogen yield by utilizing chemical reaction equilibrium on the premise of ensuring the reaction temperature and the relatively high energy utilization rate, the biomass gasification hydrogen production device comprises a combustion cracking gasification reaction furnace and a rotary discharge box, the bottom of the combustion cracking gasification reaction furnace is connected with the upper part of the rotary discharging box, the combustion cracking gasification reaction furnace comprises a furnace body, a plurality of thermocouple interfaces, an oxidant gas inlet and a water vapor inlet, the plurality of thermocouple interfaces are arranged on the outer wall of the furnace body, and an oxidant interface and a water vapor interface are respectively arranged on the lower part of the furnace body. By arranging an oxidizing agent and water vapor inlet, after an oxidizing agent and water vapor enter the furnace, the water vapor participates in a pyrolysis gasification reaction to generate hydrogen and carbon monoxide synthesis gas, meanwhile, the combustion temperature is reduced, and the purpose of controlling the combustion temperature is achieved. The invention belongs to the field of biomass gasification hydrogen production.

Description

Technical Field

[0001] The present invention relates to a hydrogen production device and method, and in particular to a biomass gasification hydrogen production device and method based on a porous medium moving bed. The present invention belongs to the technical field of biomass gasification hydrogen production. Background Art

[0002] With the development of economy, energy depletion and environmental pollution have become important problems faced by countries around the world. All countries are actively implementing energy strategic transformation and upgrading, and vigorously developing renewable energy and clean energy. Therefore, renewable, high calorific value, pollution-free hydrogen energy has attracted widespread attention from countries around the world. The global demand for hydrogen, especially low-carbon hydrogen, continues to grow. BP predicts that the global demand for low-carbon hydrogen will reach 280-450 million tons per year in 2050.

[0003] In the 1970s, the oil crisis prompted countries to begin to pay attention to the research of alternative energy sources, and biomass hydrogen production technology gradually attracted attention. Since the 1970s, the U.S. Department of Energy (DOE) has begun to fund research on biomass conversion and hydrogen production technology, exploring how to convert biomass into synthesis gas through high-temperature gasification, and then produce hydrogen through the water-gas shift reaction, and developing high-efficiency catalysts to improve the efficiency of gasification and hydrogen production processes. In the early 1980s, institutions such as the Fraunhofer Society and the German Aerospace Center (DLR) promoted the research on biomass hydrogen production technology, focusing on the thermochemical conversion and system integration of biomass. In the 1990s, Japan began to intensively study the application of different types of biomass (such as rice husks, wood chips, crop straw, etc.) in gasification hydrogen production and the process optimization of biomass hydrogen production technology. The Institute of Chemical Physics of the Russian Academy of Sciences has conducted a series of studies on biomass superadiabatic gasification technology, mainly focusing on the fuel applicability of superadiabatic combustion gasification technology. The research results show that superadiabatic combustion gasification can process biomass, solid urban waste, sewage sludge, high-ash coal and coal gangue, peat, oil shale, tires, as well as low calorific value fuels such as polymers and chemical waste, waste oil and oil slurry, and achieve a relatively high gasification rate (up to 95%).

[0004] Biomass hydrogen production technology can be divided into chemical and biological methods. Biomass hydrogen production mainly includes biological and thermochemical conversion methods. From the application perspective, biological hydrogen production technology is far from mature, has a low reaction rate, and is not easy to scale up. Thermochemical hydrogen production is easier to achieve large-scale production and application, so it has attracted more attention. Through fuzzy set theory, a fuzzy comprehensive evaluation of various hydrogen production technologies shows that from the perspective of contribution to environmental quality improvement, environmental benefits obtained through the production of clean energy, and energy-economy-environmental comprehensiveness, biomass gasification hydrogen production is the preferred biomass hydrogen production technology that should be considered in the short and medium term. However, how to ensure the gasification temperature at a high energy utilization rate is a technical difficulty in the economic efficiency of the gasification process. Although the gasification temperature can be increased by energy input or increasing the amount of biomass combustion, it is bound to reduce the energy efficiency of the system. How to use chemical reaction balance to increase the H2 yield under the premise of ensuring the reaction temperature and high energy utilization is the key to biomass gasification technology. Summary of the invention

[0005] The present invention aims to solve the problem of how to improve the hydrogen yield by utilizing chemical reaction balance under the premise of ensuring the reaction temperature and high energy utilization rate, and further proposes a biomass gasification hydrogen production device and method based on a porous medium moving bed.

[0006] The technical solution adopted by the present invention to solve the above problems is:

[0007] The biomass gasification hydrogen production device based on a porous medium moving bed described in the present invention includes a combustion cracking gasification reactor and a rotary discharge box. The bottom of the combustion cracking gasification reactor is connected to the upper part of the rotary discharge box. The combustion cracking gasification reactor includes a furnace body, multiple thermocouple interfaces, an oxidant air inlet and a water vapor air inlet. The furnace body and the outer wall are provided with multiple thermocouple interfaces, and the lower part of the furnace body is respectively provided with an oxidant interface and a water vapor interface.

[0008] Furthermore, the rotary discharging box includes a rotary discharging box shell, a rotating platform, a 90° steering gear, a transmission shaft and a motor. The rotary discharging box shell is installed at the bottom of the furnace body, and the motor is installed on the right side of the rotary discharging box shell. The output end of the motor is fixedly connected to the 90° steering gear through the transmission shaft. The rotating platform is located above the 90° steering gear, and the bottom of the rotating platform is connected to the 90° steering gear through a connecting shaft.

[0009] Furthermore, the transmission ratio of the 90° steering gear is 1:1-1:100.

[0010] A method for producing hydrogen by biomass gasification based on a porous medium moving bed comprises the following steps:

[0011] Step 1: Add inert porous medium particles to the material inlet at the top of the combustion cracking gasification reactor, and stop feeding after the porous medium fills 1 / 6 of the space inside the furnace body;

[0012] Step 2: Open the oxidant air inlet and introduce a mixture of air and natural gas to bake the furnace; keep the flame between the porous medium particles rather than above the porous medium particles, and after the temperature of all the inert porous medium particles reaches 700° C., close the oxidant air inlet and stop the introduction of air and natural gas;

[0013] Step 3: Add a mixture of biomass and inert porous medium particles through the material inlet at the top of the furnace body. After filling the furnace body, stop feeding, open the oxidant air inlet, and only let in air to start combustion. The flame propagates upward from the bottom of the combustion cracking gasification reactor. After the flame surface reaches the middle area of ​​the combustion cracking gasification reactor, open the water vapor supply port and adjust the flow rates of the oxidant air inlet and the water vapor air inlet.

[0014] Step 4: Turn on the motor and adjust the motor speed so that the particle mixture produced by the combustion is discharged at a speed of 1-3 mm / s. The porous medium moving bed combustion pyrolysis gasification furnace is fed at a certain frequency to ensure that the inside of the furnace is always filled; stabilize the combustion flame in the middle area of ​​the combustion pyrolysis gasification reactor, and after passing through the combustion area, the waste after biomass combustion pyrolysis and the inert porous medium particles are discharged from the bottom of the combustion pyrolysis gasification reactor to the rotating discharge box;

[0015] Step 5: As the material is discharged from the discharge port, heat is transferred to the air and water vapor mixture in the feed pipe, and the air and water vapor mixture is preheated to make the combustion temperature higher than the adiabatic flame temperature to achieve a super-adiabatic combustion state. The higher combustion temperature can replace the role of the catalyst, accelerate the cracking of organic matter in the biomass, and with the participation of water vapor, crack and gasify into clean combustible gases such as hydrogen, carbon monoxide, methane, and ethane.

[0016] Furthermore, the material of the inert porous medium particles is an inert material such as refractory brick, Al2O3, zirconium oxide, and yttrium oxide that will not participate in the combustion reaction.

[0017] Furthermore, the ratio of the diameter of the inert porous medium particles to the inner diameter of the furnace body is between 0.06 and 0.1.

[0018] Furthermore, in step 4, the mass proportion of biomass is between 40-80%.

[0019] Furthermore, in step 4, the flow rates of the oxidant air inlet and the water vapor air inlet are adjusted so that the ratio of water vapor to air is between 0.8-1.2.

[0020] The beneficial effects of the present invention are:

[0021] 1. By setting the oxidant and water vapor inlet, after the oxidant and water vapor enter the furnace, the water vapor participates in the cracking and gasification reaction to produce hydrogen and carbon monoxide synthesis gas, while reducing the combustion temperature, thereby achieving the purpose of controlling the combustion temperature.

[0022] 2. The combustion area of ​​the present invention is in the middle area of ​​the furnace body. The high-temperature flue gas generated preheats and dries the mixture of biomass and porous medium particles on the top of the combustion cracking gasification reactor. At the same time, the radiation and convection heat transfer of the flame transfer heat to the inert porous medium, and transfer the heat to the oxidant and water vapor mixture in the feed pipe along with the discharge of the discharge port, so as to preheat the oxidant and steam mixture, so that the combustion temperature is higher than the adiabatic flame temperature, and a super-adiabatic combustion state is achieved. The higher combustion temperature can replace the role of the catalyst and accelerate the cracking of organic matter in the biomass;

[0023] 3. The combustion temperature of the present invention is between 700-900°C, which can largely avoid the generation of NOx, and with the participation of water vapor, the biomass is cracked and gasified into clean combustible gases such as hydrogen, carbon monoxide, methane, and ethane. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0025] In the figure: 1-furnace body, 2-thermocouple interface, 3-oxidant air inlet, 4-steam air inlet, 5-combustion cracking gasification reactor, 6-rotating discharge box, 7-rotating discharge box shell, 8-rotating platform 8, 9-90° steering gear, 10-transmission shaft 10, 11-motor. DETAILED DESCRIPTION

[0026] Specific implementation method 1: Combination Figure 1This embodiment is described. A biomass gasification hydrogen production device based on a porous medium moving bed described in this embodiment includes a combustion cracking gasification reactor 5 and a rotary discharge box 6. The bottom of the combustion cracking gasification reactor 5 is connected to the upper part of the rotary discharge box 6, which plays the role of receiving the combustion cracking gasification of materials. The rotary discharge box 6 is located at the bottom of the entire furnace body. The combustion cracking gasification reactor 5 includes a furnace body 1, a plurality of thermocouple interfaces 2, an oxidant air inlet 3 and a water vapor air inlet 4. The furnace body 1 and the outer wall are provided with a plurality of thermocouple interfaces 2, and the plurality of thermocouple interfaces 2 play the role of online monitoring of the combustion temperature; the lower part of the furnace body 1 is respectively provided with an oxidant interface 3 and a water vapor interface 4. The oxidant interface 3 and the water vapor interface 4 are located in the bottom area of ​​the combustion cracking gasification reactor 5, extending to the inside of the furnace body, and play the role of supplying oxidant and water vapor, wherein the oxidant is to maintain combustion, and the water vapor is a gasifying agent that causes the combustion cracking gasification reactor to produce gasification. The oxidant is a mixture of air and O2 in a certain proportion, the water vapor temperature is between 150-180°C, and the molar ratio of water vapor to O2 is between 0.8-1.2. A certain proportion of water vapor will participate in the biomass combustion process at high temperature to produce a gasification reaction, which can not only reduce the combustion temperature, that is, play the purpose of controlling the combustion temperature, but also participate in the gasification reaction to generate clean combustible gases such as hydrogen, carbon monoxide, methane, and ethane.

[0027] The thermocouple interfaces are arranged in multiple rows and evenly distributed on the outer wall of the furnace body along the circumferential direction. The multiple thermocouple interfaces 2 in each row of thermocouple interfaces are arranged from top to bottom along the height direction of the furnace body.

[0028] The rotary discharge box 6 includes a rotary discharge box housing 7, a rotary platform 8, a 90° steering gear 9, a transmission shaft 10 and a motor 11. The rotary discharge box housing 7 is installed at the bottom of the furnace body 1, and the motor 11 is installed on the right side of the rotary discharge box housing 7. The output end of the motor 11 is fixedly connected to the 90° steering gear 9 through the transmission shaft 10. The rotary platform 8 is located above the 90° steering gear 9, and the bottom of the rotary platform 8 is connected to the 90° steering gear 9 through a connecting shaft. The 90° steering gear 9 is composed of two mutually perpendicular shafts and two bevel gears. The transmission ratio of the 90° steering gear 9 is 1:1-1:100.

[0029] The motor 11 rotates while driving the transmission shaft 10 to rotate. The transmission shaft 10 transmits power to the rotating platform 8 through the 90° steering gear 9. The transmission ratio is 1:1-1:100. The friction between the rotating platform and the combustion products causes the combustion products to fall from the rotating platform 8 to the inside of the rotating discharge box 6 and then be collected. By adjusting the power of the motor 11, the rotation speed of the rotating platform 8 is controlled, and the vertical movement speed of the material in the combustion cracking gasification reactor is controlled to be about 1-3mm / s, so that the combustion flame is stabilized in the middle area of ​​the combustion cracking gasification reactor.

[0030] Specific implementation method 2: A biomass gasification hydrogen production method based on a porous medium moving bed described in this implementation method includes the following steps:

[0031] Step 1: Add inert porous medium particles to the material inlet at the top of the combustion cracking gasification reactor 5, and stop feeding after the porous medium fills 1 / 6 of the space inside the furnace body;

[0032] Step 2: Open the oxidant air inlet 3, and introduce a mixture of air and natural gas to bake the furnace; keep the flame between the porous medium particles instead of above the porous medium particles, and after the temperature of all the inert porous medium particles reaches 700° C., close the oxidant air inlet 3 and stop introducing air and natural gas;

[0033] Step 3: Add a mixture of biomass and inert porous medium particles through the material inlet at the top of the furnace body 1, wherein the mass proportion of biomass is between 40-80%. After filling the furnace body, stop feeding, open the oxidant air inlet 3, and only let in air to start combustion. The flame propagates upward from the bottom of the combustion cracking gasification reactor. After the flame surface reaches the middle area of ​​the combustion cracking gasification reactor, open the water vapor supply port 4, adjust the flow rate of the oxidant air inlet and the water vapor air inlet, and ensure that the ratio of water vapor to air is between 0.8-1.2.

[0034] Step 4: Turn on the motor 11, adjust the speed of the motor 11, so that the particle mixture produced by the combustion is discharged at a speed of 1-3 mm / s, and the porous medium moving bed combustion pyrolysis gasification furnace is fed at a certain frequency to ensure that the inside of the furnace is always filled; stabilize the combustion flame in the middle area of ​​the combustion pyrolysis gasification reactor, and after passing through the combustion area, the waste after biomass combustion pyrolysis and the inert porous medium particles are discharged from the bottom of the combustion pyrolysis gasification reactor to the rotating discharge box 6;

[0035] Step 5: As the material is discharged from the discharge port, heat is transferred to the air and water vapor mixture in the feed pipe, and the air and water vapor mixture is preheated to make the combustion temperature higher than the adiabatic flame temperature to achieve a super-adiabatic combustion state. The higher combustion temperature can replace the role of the catalyst, accelerate the cracking of organic matter in the biomass, and with the participation of water vapor, crack and gasify into clean combustible gases such as hydrogen, carbon monoxide, methane, and ethane.

[0036] Preferably, the discharge temperature of the particle mixture at the discharge port is between 200-300°C.

[0037] Preferably, the material of the inert porous medium particles is an inert material that does not participate in the combustion reaction, such as refractory bricks, Al2O3, zirconium oxide, yttrium oxide, etc.;

[0038] Preferably, the ratio of the diameter of the inert porous medium particles to the inner diameter of the furnace body 1 is between 0.06 and 0.1.

[0039] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A biomass gasification hydrogen production device based on a porous medium moving bed, characterized in that: The device comprises a combustion cracking gasification reaction furnace (5) and a rotating discharge box (6); the bottom of the combustion cracking gasification reaction furnace (5) is connected to the upper part of the rotating discharge box (6); the combustion cracking gasification reaction furnace (5) comprises a furnace body (1), a plurality of thermocouple interfaces (2), an oxidant air inlet (3) and a water vapor air inlet (4); the furnace body (1) and the outer wall are provided with a plurality of thermocouple interfaces (2); the lower part of the furnace body (1) is provided with an oxidant interface (3) and a water vapor interface (4), respectively.

2. The biomass gasification hydrogen production device based on porous media moving bed according to claim 1 is characterized in that: The rotary discharge box (6) comprises a rotary discharge box housing (7), a rotary platform (8), a 90° steering gear (9), a transmission shaft (10) and a motor (11); the rotary discharge box housing (7) is mounted at the bottom of the furnace body (1); the motor (11) is mounted on the right side of the rotary discharge box housing (7); the output end of the motor (11) is fixedly connected to the 90° steering gear (9) via the transmission shaft (10); the rotary platform (8) is located above the 90° steering gear (9); and the bottom of the rotary platform (8) is connected to the 90° steering gear (9) via a connecting shaft.

3. The biomass gasification hydrogen production device based on porous media moving bed according to claim 1 is characterized in that: The transmission ratio of the 90° steering gear (9) is 1:1-1:

100.

4. A method for producing hydrogen by biomass gasification based on a porous medium moving bed, characterized in that: The hydrogen production device according to any one of claims 1 to 3 is used to produce hydrogen, and the hydrogen production method comprises the following steps: Step 1: Add inert porous medium particles to the material inlet at the top of the combustion cracking gasification reactor (5), and stop feeding after the porous medium fills 1 / 6 of the space inside the furnace body; Step 2: Open the oxidant air inlet (3) and introduce a mixture of air and natural gas to bake the furnace; keep the flame between the porous medium particles rather than above the porous medium particles, and after the temperature of all the inert porous medium particles reaches 700° C., close the oxidant air inlet (3) and stop introducing air and natural gas; Step 3: Add a mixture of biomass and inert porous medium particles through the material inlet at the top of the furnace body (1). After the furnace body is filled, stop feeding, open the oxidant air inlet (3), and only let in air to start combustion. The flame propagates upward from the bottom of the combustion cracking gasification reactor. After the flame surface reaches the middle area of ​​the combustion cracking gasification reactor, open the water vapor supply port (4) and adjust the flow rates of the oxidant air inlet and the water vapor air inlet. Step 4: Turn on the motor (11), adjust the speed of the motor (11), so that the particle mixture generated by the combustion is discharged at a speed of 1-3 mm / s, and the porous medium moving bed combustion cracking gasification furnace is fed at a certain frequency to ensure that the inside of the furnace is always filled; stabilize the combustion flame in the middle area of ​​the combustion cracking gasification reactor, and after passing through the combustion area, the waste after biomass combustion cracking and the inert porous medium particles are discharged from the bottom of the combustion cracking gasification reactor to the rotating discharge box (6); Step 5: As the material is discharged from the discharge port, heat is transferred to the air and water vapor mixture in the feed pipe, and the air and water vapor mixture is preheated to make the combustion temperature higher than the adiabatic flame temperature to achieve a super-adiabatic combustion state. The higher combustion temperature can replace the role of the catalyst, accelerate the cracking of organic matter in the biomass, and with the participation of water vapor, crack and gasify into clean combustible gases such as hydrogen, carbon monoxide, methane, and ethane.

5. The method for producing hydrogen by biomass gasification based on a porous medium moving bed according to claim 4, characterized in that: The materials of the inert porous medium particles are refractory bricks, Al2O3, zirconium oxide, and yttrium oxide, which are inert materials that will not participate in the combustion reaction.

6. The method for producing hydrogen by biomass gasification based on a porous medium moving bed according to claim 4, characterized in that: The ratio of the diameter of the inert porous medium particles to the inner diameter of the furnace body (1) is between 0.06 and 0.

1.

7. The method for producing hydrogen by biomass gasification based on a porous medium moving bed according to claim 4, characterized in that: In step 4, the mass proportion of biomass is between 40-80%.

8. The method for producing hydrogen by biomass gasification based on a porous medium moving bed according to claim 4, characterized in that: In step 4, the flow rates of the oxidant air inlet (3) and the water vapor air inlet (4) are adjusted so that the ratio of water vapor to air is between 0.8 and 1.2.

Images