An integrated reaction device for hydrogen production by biomass pyrolysis and tar reforming

Abstract

The utility model discloses a kind of integrated reaction device for biomass pyrolysis and tar reforming hydrogen production, belong to biomass energy conversion equipment technical field.The system includes the preparation unit of aluminium smelting waste residue base catalyst, biomass pyrolysis unit, tar in situ reforming unit and product separation and purification unit by pipeline sequentially in series.The core of the tar in situ reforming unit is a kind of coupling reactor, the reactor adopts the upper and lower intercommunication structure of vertical arrangement, the buffer section on its upper portion is connected with the reaction section on lower portion through the communication hole on horizontal partition, and the radial cross-sectional area of buffer section is greater than reaction section.Between biomass pyrolysis unit and coupling reactor, connect through heat preservation pipeline.The utility model passes through optimizing system overall structure and core reactor structure, effectively realizes the buffer flow equalization and dust pre-separation of pyrolysis gas, guarantees the stable and efficient of subsequent catalytic reforming reaction, system structure is compact, suitable for industrial application.

Description

Technical Field

[0001] This utility model relates to the field of biomass energy conversion and industrial solid waste resource utilization technology, specifically an integrated reaction device for biomass pyrolysis and tar reforming to produce hydrogen. Background Technology

[0002] With the advancement of the "dual carbon" goal, hydrogen energy, as a clean and efficient renewable energy source, has become one of the important directions for energy transformation. Biomass thermochemical hydrogen production has attracted much attention due to its wide availability of raw materials and high energy conversion efficiency. However, the biomass pyrolysis process generates a large amount of tar (mainly composed of polycyclic aromatic hydrocarbons). This tar not only easily leads to condensation and blockage of system pipelines and equipment corrosion, reducing hydrogen yield and fuel quality, but also causes environmental pollution through exhaust emissions, severely restricting the industrial application of biomass hydrogen production technology.

[0003] Currently, the mainstream technologies for solving the tar problem mostly adopt a "pyrolysis-reforming" separate process, which involves first pyrolyzing biomass and then transporting the pyrolysis gas containing tar to a separate reforming reactor for further processing. This process suffers from problems such as high heat loss and easy condensation and blockage of tar during transport. In addition, traditional tar reforming catalysts often use precious metals or molecular sieve supports, which are costly, prone to carbon buildup and deactivation, and difficult to meet the needs of large-scale industrial applications.

[0004] On the other hand, aluminum smelting waste contains metal oxides such as Al2O3 and SiO2, which have the potential to serve as catalyst carriers. However, currently, these are mostly disposed of through stockpiling, which not only occupies land resources but also poses the risk of heavy metal leaching and contaminating soil and groundwater. Therefore, developing an integrated system that combines aluminum smelting waste resource utilization, biomass pyrolysis, in-situ tar reforming, and hydrogen production is of great significance for solving problems such as high heat loss, high catalyst costs, and solid waste pollution in traditional technologies, and for promoting the industrialization of clean biomass hydrogen production. Utility Model Content

[0005] This invention aims to provide an integrated reaction device for biomass pyrolysis and tar reforming to produce hydrogen, which balances environmental protection and economy, and provides key technical support for the industrial application of clean hydrogen production from biomass.

[0006] To solve the above technical problems, the specific solution adopted by this utility model is: an integrated reaction device for biomass pyrolysis and tar reforming to produce hydrogen, comprising: The unit comprises an aluminum smelting waste residue-based catalyst preparation unit, a biomass pyrolysis unit, an in-situ tar reforming unit, and a product separation and purification unit. in, The aluminum smelting waste slag-based catalyst preparation unit, biomass pyrolysis unit, tar in-situ reforming unit, and product separation and purification unit are connected in series via pipelines to form a continuous physical system. The tar in-situ reforming unit includes a coupled reactor having a buffer section and a reaction section arranged vertically and connected vertically. The buffer section is located above the reaction section, and the two are connected by a connecting hole provided on a transverse partition. The internal space of the reaction section is used to fill aluminum smelting waste slag-based catalyst. The biomass pyrolysis unit is connected to the inlet of the buffer section of the coupled reactor via an insulated pipe.

[0007] Preferably, the buffer section and the reaction section are disposed together in a quartz reaction tube, and the outside of the quartz reaction tube is covered with a heat insulation layer.

[0008] Preferably, the tar in-situ reforming unit further includes a supply system for supplying reaction media to the coupled reactor. The supply system includes a steam generator and a carbon dioxide cylinder, which are connected to the reaction section of the coupled reactor via pipes with valves.

[0009] Preferably, the aluminum smelting waste slag-based catalyst preparation unit includes a pretreatment device, a hydrothermal activation reactor, and an impregnation modification tank arranged in sequence. The pretreatment device is used to crush the aluminum smelting waste slag, the hydrothermal activation reactor is used to carry out the hydrothermal activation reaction, and the impregnation modification tank is used to carry out impregnation modification.

[0010] Preferably, the biomass pyrolysis unit includes a biomass crushing device and an airflow pyrolysis furnace connected in sequence. The biomass crushing device is used to crush biomass, and the airflow pyrolysis furnace is used to carry out the pyrolysis reaction.

[0011] Preferably, the product separation and purification unit includes a gas cooler and a gas separator connected in sequence, with the inlet of the gas cooler connected to the outlet of the coupled reactor.

[0012] Preferably, the system further includes a central control module, which is electrically connected to the fluidized bed pyrolysis furnace, the coupled reactor, the steam generator, and the carbon dioxide cylinder.

[0013] Preferably, the radial cross-sectional area of ​​the buffer section is greater than the radial cross-sectional area of ​​the reaction section.

[0014] Beneficial effects Compared with the prior art, the hydrogen production system provided by this utility model has the following significant advantages: The system boasts high integration and a compact structure: This invention connects the aluminum smelting waste-based catalyst preparation unit, biomass pyrolysis unit, tar in-situ reforming unit, and product separation and purification unit in series via pipelines, forming an integrated physical structure. This modular design reduces redundancy in connections between devices, lowers system volume and footprint, and facilitates industrial deployment.

[0015] The coupled reactor boasts a unique structure, ensuring stable and efficient operation: The core coupled reactor employs a vertically arranged, interconnected buffer and reaction section. This physical structure utilizes the principles of gravity and airflow dynamics, allowing the pyrolysis gas to naturally reduce its velocity, homogenize its flow, and pre-settle solid dust within the buffer section. This structure physically prevents the pyrolysis gas from directly impacting the catalyst bed, effectively preventing channeling and localized overheating, and ensuring stable reaction operation.

[0016] Insulated pipe connection effectively prevents blockage: Insulated pipes are used for physical connection between the biomass pyrolysis unit and the tar in-situ reforming unit. This structure maintains the pipes within a specific temperature range, physically preventing the possibility of tar condensing and adhering to the pipe wall due to temperature drop. This fundamentally solves the long-standing technical problem of pipe blockage and improves the reliability of continuous system operation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an integrated reaction device for biomass pyrolysis and tar reforming to produce hydrogen, according to this utility model. Figure 2 This is a schematic diagram of the coupled reactor in this utility model; The markings in the diagram are: 1. Buffer section, 2. Insulation layer, 3. Connecting hole, 4. Reaction section, 5. Quartz reaction tube. Detailed Implementation

[0018] The technical solution of this utility model will be further described in three parts below. The first part is an integrated reaction device for hydrogen production from biomass pyrolysis and tar reforming according to this utility model. The second part is a hydrogen production method based on aluminum smelting waste slag-based catalyst for catalytic biomass pyrolysis coupled with tar reforming according to this utility model. The third part is five specific embodiments based on the first part and using the second part for hydrogen production.

[0019] Part One like Figure 1The hydrogen production system based on catalytic biomass pyrolysis coupled with tar reforming, provided by this utility model, mainly includes an aluminum smelting waste slag-based catalyst preparation unit, a biomass pyrolysis unit, an in-situ tar reforming unit, a product separation and purification unit, a catalyst regeneration unit, and a central control module. Each unit is sequentially connected via pipelines equipped with valves, forming a closed-loop operating system.

[0020] Aluminum smelting waste slag-based catalyst preparation unit: This unit is used to convert industrial solid waste aluminum smelting waste slag into a highly active catalyst, specifically including: Pretreatment device: Equipped with an 80-200 mesh sieve assembly for crushing and sieving aluminum smelting waste residue; also includes a hydrochloric acid soaking tank with a concentration of 1-3 mol / L for acid washing and impurity removal of the sieved waste residue at 25-35 ℃ for 2-4 h, followed by washing with deionized water until neutral, and drying in a drying oven at 105-110 ℃ for 8-12 h.

[0021] Hydrothermal activation reactor: This reactor has an adjustable temperature between 160-200 ℃ and is equipped with an online pH monitoring and adjustment device. The pH value of the system can be adjusted to 8-10 using ammonia or sodium hydroxide solution. The solid-liquid ratio inside the reactor is controlled between 1:5 and 1:10, and it is equipped with stirring and pressure control components to ensure uniform activation reaction.

[0022] Impregnation Modification Tank: This tank is equipped with an ultrasonic-assisted module with adjustable power from 0-100 W, used for uniform impregnation of hydrothermally activated waste residue carriers. The impregnation solution is a 0.5-1.5 mol / L nickel salt (such as nickel nitrate) solution, with 1%-4% Fe2O3, CeO2, or MgO added as additives. The impregnation temperature is maintained at 25-35 ℃, and the impregnation time is 6-12 h to ensure uniform dispersion of the active components.

[0023] Controllable roasting furnace: This furnace supports segmented programmed heating, typically raising the temperature to 200-300 ℃ at a rate of 5-10 ℃ / min and holding it for 1-2 h, then raising it to 500-700 ℃ at a rate of 3-5 ℃ / min and holding it for 3-5 h. The roasting atmosphere is air, and the final product is an aluminum smelting waste slag-based catalyst.

[0024] Biomass pyrolysis unit: This unit is used to convert biomass feedstock into tar-containing pyrolysis gas, specifically including: Biomass crushing device: used to crush biomass raw materials such as corn stalks and sawdust into particles of 40-80 mesh.

[0025] Fluidized bed pyrolysis furnace: This pyrolysis furnace can precisely control the pyrolysis temperature within the range of 500-700 ℃, with a heating rate controlled at 20-30 ℃ / min. The furnace body is equipped with an N2 carrier gas supply module, with a carrier gas flow rate of 50-100 mL / min, used to carry the generated pyrolysis gas out.

[0026] Tar in-situ reforming unit: This unit is the core of the system, used to efficiently convert tar in pyrolysis gas into hydrogen, specifically including: Coupled reactors: such as Figure 2 As shown, the reactor includes vertically distributed quartz reaction tubes 5, with an external insulation layer 2. A transverse partition in the middle of the inner cavity divides the quartz reaction tubes 5 into two sections: an upper buffer section 1 and a lower reaction section 4. The upper and lower sections are connected by a connecting hole 3 on the transverse partition. The pyrolysis gas first enters the buffer section 1 for gas flow homogenization, buffering, and initial settling of solid dust. The reaction section 4 is filled with 5-10 g of the aluminum smelting waste-based catalyst prepared above.

[0027] The H2O / CO2 co-supply system includes a steam generator for supplying steam to the coupled reactor at a flow rate controlled at 0.5-1.5 mL / min, and a CO2 cylinder for supplying carbon dioxide at a flow rate controlled at 10-60 mL / min. The ratio of steam to carbon dioxide is controlled between 1:1 and 1:2.

[0028] Product separation and purification unit: This unit is used to separate and purify the reformed hydrogen-rich fuel gas and to test its performance, including: Gas cooler: Used to cool high-temperature reforming products to room temperature.

[0029] Gas separator: Employing technologies such as pressure swing adsorption, it is used to separate and purify hydrogen, and to separate CO, CO2, and incompletely cracked tar.

[0030] Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS): GC is used for online detection of the composition of gaseous products and hydrogen yield, while GC-MS is used to analyze the residual components and cracking rate of tar.

[0031] Catalyst regeneration unit: This unit is used to restore the activity of deactivated catalysts. It mainly consists of a high-temperature roasting furnace, which can control the temperature at 500-600 ℃ and is equipped with an air supply module (flow rate 80-120 mL / min). The carbon on the surface of the catalyst is removed by roasting.

[0032] Central control module: It adopts a PLC control system with an integrated touch screen, which can collect parameters such as temperature, pressure and gas flow rate of each unit in real time, and automatically adjust the pyrolysis temperature, reforming reaction temperature and H2O / CO2 supply rate to achieve automated and stable operation of the system.

[0033] The biomass pyrolysis unit and the tar in-situ reforming unit are connected by an insulated pipe. The pipe is kept at a temperature of 300-500 ℃ to prevent tar from condensing and clogging during transportation.

[0034] Part Two This invention discloses a hydrogen production method based on aluminum smelting waste slag-based catalyst-catalyzed biomass pyrolysis coupled with tar reforming. The process method for hydrogen production using the above system includes the following steps: Catalyst preparation: The aluminum smelting waste residue is crushed and sieved (80-200 mesh) using a pretreatment device. It is then soaked in 1-3 mol / L hydrochloric acid at 25-35 ℃ for 2-4 h to remove impurities, followed by washing with deionized water until neutral, and drying at 105-110 ℃ for 8-12 h. The pretreated waste residue is mixed with deionized water at a solid-liquid ratio of 1:5-1:10, and the pH is adjusted to 8-10 with ammonia. The mixture is then transferred to a hydrothermal activation reactor and reacted at 160-200 ℃ for 4-8 h. The hydrothermally activated product is transferred to an impregnation modification tank, and a 0.5-1.5 mol / L nickel salt solution containing 1%-4% Fe2O3 / CeO2 / MgO additives is added. The mixture is impregnated for 10-60 min under ultrasonic assistance (0-100 W power), and then allowed to stand at 25-35 ℃ for 6-12 h. Finally, the impregnated material is transferred to a controlled roasting furnace and roasted in stages in an air atmosphere (first, it is heated to 200-300 ℃ at 5-10 ℃ / min and held for 1-2 h, then heated to 500-700 ℃ at 3-5 ℃ / min and held for 3-5 h). After natural cooling, an aluminum smelting waste slag-based catalyst is obtained.

[0035] Biomass pyrolysis: Biomass raw materials such as corn stalks and sawdust are crushed to 40-80 mesh using a biomass crushing device. The crushed biomass is then fed into an entrained flow pyrolysis furnace, where it undergoes a pyrolysis reaction at a temperature of 500-700 ℃ and a heating rate of 20-30 ℃ / min. Simultaneously, N2 is introduced as a carrier gas at a flow rate of 50-100 mL / min to generate pyrolysis gas containing tar. This pyrolysis gas is then directly transported to the coupled reactor of the tar in-situ reforming unit through a pipeline maintained at a temperature of 300-500 ℃.

[0036] In-situ reforming of tar for hydrogen production: The prepared aluminum smelting waste-based catalyst (5-10 g) was loaded into the lower reaction section 4 of the coupled reactor. The temperature of reaction section 4 of the coupled reactor was controlled at 700-900 ℃. Steam and carbon dioxide were introduced to participate in the synergistic reaction, with the steam flow rate at 0.5-1.5 mL / min and the carbon dioxide flow rate at 10-60 mL / min, and the ratio of the two was controlled at 1:1-1:2. The pyrolysis gas from the pyrolysis unit first entered the upper buffer section 1 of the coupled reactor for buffering and homogenization, and then smoothly entered the lower reaction section 4. Under the action of the catalyst, the tar in it underwent a catalytic reforming reaction to generate hydrogen-rich fuel gas.

[0037] Product separation and detection: The hydrogen-rich fuel gas produced by the reforming reaction is first cooled to room temperature by a gas cooler. The cooled gas then enters a gas separator to separate hydrogen products and other components such as CO and CO2. The purity and yield of hydrogen are detected by gas chromatography (GC), and the residual amount of tar in the gas is analyzed by gas chromatography-mass spectrometry (GC-MS) to assess the tar cracking rate.

[0038] Catalyst regeneration: When the catalyst activity is monitored to drop below 70% of its initial activity, the deactivated catalyst is removed from the coupled reactor and sent to the high-temperature calcination furnace of the catalyst regeneration unit. At 500-600 °C, air is introduced at a flow rate of 80-120 mL / min, and the catalyst is calcined for 2-3 hours to completely burn off the carbon deposits on the catalyst surface, restoring its activity to above 85% of its initial activity, at which point it can be returned to the system for recycling.

[0039] Part Three Example 1: Catalyst preparation: Aluminum smelting waste was crushed and passed through a 150-mesh sieve. It was then soaked in 2 mol / L hydrochloric acid at 30 °C for 3 h. After washing and drying, it was mixed with deionized water at a solid-liquid ratio of 1:8. The pH was adjusted to 9 with ammonia, and the mixture was hydrothermally reacted at 180 °C for 6 h. Subsequently, a 1.0 mol / L nickel nitrate solution (containing 2% CeO2 additive) was added at a solid-liquid ratio of 1:10. The mixture was then impregnated for 30 min under ultrasonic assistance at 50 W and allowed to stand at 30 °C for 8 h. Finally, it was calcined in a muffle furnace at 600 °C for 4 h to obtain catalyst A.

[0040] Hydrogen production process: Corn stalks are crushed to 3 mm and pyrolyzed in an entrained flow pyrolysis furnace at 650 °C with an N2 carrier gas flow rate of 80 mL / min. The pyrolysis gas is introduced into a coupled reactor packed with 6 g of catalyst A, and the temperature of reaction section 4 is controlled at 750 °C. Simultaneously, steam (0.8 mL / min) and CO2 (40 mL / min, H2O:CO2 = 1:1.25) are introduced to carry out a reforming reaction.

[0041] Results: GC detection showed that the hydrogen yield was 66.5%, and GC-MS analysis showed that the tar cracking rate reached 91.2%.

[0042] Example 2: Catalyst preparation: basically the same as in Example 1, but the additive added to the impregnation solution was changed to 3% Fe2O3, and the calcination temperature was changed to 550 ℃, to obtain catalyst B.

[0043] Hydrogen production process: Wood chips are used as raw material, and the pyrolysis temperature is 600℃. The reforming reaction temperature is 700℃, and the steam and CO2 flow rates are 1.0 mL / min and 50 mL / min, respectively (H2O:CO2=1:2).

[0044] Results: Hydrogen yield was 63.8%, and tar cracking rate was 89.5%.

[0045] Example 3: Process Condition Investigation: Using the same catalyst A and corn stalk raw materials as in Example 1, with a fixed pyrolysis temperature of 650℃ and a reforming temperature of 800℃, the effect of the H2O / CO ratio was systematically investigated. The CO2 flow rate was fixed at 45 mL / min, while the water vapor flow rate was varied to 0.5 mL / min (ratio 1:1.8), 0.75 mL / min (ratio 1:1.5), and 1.0 mL / min (ratio 1:1.25).

[0046] Results: The hydrogen yield was highest at a steam flow rate of 0.75 mL / min (H2O:CO2=1:1.5), reaching 68.7%, while the catalyst carbon deposition was lowest.

[0047] Example 4: Catalyst life and regeneration test: Catalyst A was continuously operated for 12 hours under the process conditions of Example 1.

[0048] Results: In the initial stage of operation (0-4 h), the hydrogen yield remained stable above 66%; after 10 h, the yield dropped to approximately 64%; and after 12 h, the yield dropped to 61%. Regeneration was then performed, and after calcination at 550 ℃ in air for 2.5 h, the catalyst activity recovered to 92% of its initial activity. The regenerated catalyst underwent another 12-h test, and its performance remained stable, indicating a good regeneration effect.

[0049] Example 5: Verification of the function of buffer section 1: Comparison of the effect of having or not having buffer section 1 on reaction stability. Using catalyst A and corn straw as raw materials, the pyrolysis conditions remained unchanged. Case 1: Using a complete two-stage coupled reactor (with buffer section 1). Case 2: Using a cylindrical reactor (without buffer section 1, pyrolysis gas directly enters the catalyst bed).

[0050] Results: With the pyrolysis feed rate intentionally set to fluctuate by 10%, in Case 1 (with buffer section 1), the hydrogen yield at the reactor outlet fluctuated by less than ±2%, and the pressure drop in the catalyst bed showed no significant change after 8 hours of operation. In Case 2 (without buffer section 1), the hydrogen yield fluctuated by more than ±8%, and local hot spots appeared in the bed after 4 hours of operation, with a significant increase in pressure drop, indicating channeling and carbon deposition. This example demonstrates the importance of buffer section 1 in maintaining reaction stability and protecting the catalyst.

Claims

1. An integrated reaction apparatus for biomass pyrolysis and tar reforming to produce hydrogen, characterized in that, include: The unit comprises an aluminum smelting waste residue-based catalyst preparation unit, a biomass pyrolysis unit, an in-situ tar reforming unit, and a product separation and purification unit. in, The aluminum smelting waste slag-based catalyst preparation unit, biomass pyrolysis unit, tar in-situ reforming unit, and product separation and purification unit are connected in series via pipelines to form a continuous physical system. The tar in-situ reforming unit includes a coupled reactor with a buffer section (1) and a reaction section (4) arranged vertically and connected vertically. The buffer section (1) is located above the reaction section (4), and the two are connected by a connecting hole (3) on the transverse partition. The internal space of the reaction section (4) is used to fill aluminum smelting waste slag-based catalyst. The biomass pyrolysis unit is connected to the inlet of the buffer section (1) of the coupled reactor via an insulated pipe.

2. The integrated reaction apparatus for biomass pyrolysis and tar reforming to produce hydrogen as described in claim 1, characterized in that: The buffer section (1) and the reaction section (4) are together located in a quartz reaction tube (5), and the outside of the quartz reaction tube (5) is covered with a heat insulation layer (2).

3. The integrated reaction apparatus for biomass pyrolysis and tar reforming to produce hydrogen as described in claim 1, characterized in that: The tar in-situ reforming unit also includes a supply system for supplying reaction media to the coupled reactor. The supply system includes a steam generator and a carbon dioxide cylinder, which are connected to the reaction section (4) of the coupled reactor via pipes with valves.

4. The integrated reaction apparatus for biomass pyrolysis and tar reforming to produce hydrogen as described in claim 1, characterized in that: The aluminum smelting waste slag-based catalyst preparation unit includes a pretreatment device, a hydrothermal activation reactor, and an impregnation modification tank arranged in sequence. The pretreatment device is used to crush the aluminum smelting waste slag, the hydrothermal activation reactor is used to carry out the hydrothermal activation reaction, and the impregnation modification tank is used to carry out impregnation modification.

5. The integrated reaction apparatus for biomass pyrolysis and tar reforming to produce hydrogen as described in claim 1, characterized in that: The biomass pyrolysis unit includes a biomass crushing device and an entrained flow pyrolysis furnace connected in sequence. The biomass crushing device is used to crush biomass, and the entrained flow pyrolysis furnace is used to carry out the pyrolysis reaction.

6. The integrated reaction apparatus for biomass pyrolysis and tar reforming to produce hydrogen as described in claim 1, characterized in that: The product separation and purification unit includes a gas cooler and a gas separator connected in sequence, with the inlet of the gas cooler connected to the outlet of the coupled reactor.

7. The integrated reaction apparatus for biomass pyrolysis and tar reforming to produce hydrogen as described in claim 5, characterized in that: The system also includes a central control module, which is electrically connected to the fluidized bed pyrolysis furnace, the coupled reactor, the steam generator, and the carbon dioxide cylinder.

8. An integrated reaction apparatus for biomass pyrolysis and tar reforming to produce hydrogen as described in claim 2, characterized in that: The radial cross-sectional area of ​​the buffer section (1) is greater than that of the reaction section (4).

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