Integrated apparatus and method for coproduction of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification

Abstract

An integrated apparatus and method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification are provided. The apparatus includes an integrated reaction system, an internal and external radial energy supply system, and a product separation and collection system. The method includes firstly performing low-temperature pyrolysis on feedstock to greatly improve its absorbing property, and then preparing co-production of a hydrogen-rich gas and a porous carbon product by microwave gasification and online reforming, where the combustion of the pyrolysis gas provides heat for feedstock drying and its low-temperature pyrolysis reaction; performing separation and purification on the hydrogen-rich gas to prepare a high-purity hydrogen product, where the separated gas serving as a gasification agent returns for gasification reaction. By using multi-system collaborative integrated designing, the low-temperature pre-pyrolysis improves microwave product quality and reaction efficiency while greatly reducing high-quality electric energy consumption, and supplying heat by self-made low-quality thermal energy recycling.

What is claimed is: 
     
         1 . An integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification, comprising an integrated reaction system, an internal and external radial energy supply system, and a product separation and collection system;
 wherein the integrated reaction system comprises a drying chamber, a low-temperature pyrolysis chamber, a microwave gasification chamber, and an online reforming reaction chamber, wherein the drying chamber, the low-temperature pyrolysis chamber, and the microwave gasification chamber are sequentially communicated from top down, the online reforming reaction chamber is disposed outside the low-temperature pyrolysis chamber; the drying chamber is configured to load and dry a biomass feedstock; the low-temperature pyrolysis chamber is configured to perform preliminary pyrolysis carbonization on the biomass feedstock to improve an absorbing capability of the biomass feedstock; the microwave gasification chamber is connected with the online reforming reaction chamber via a gas phase outlet to produce a high-quality gas product and a porous carbon product with a high-absorbing material; and the online reforming reaction chamber is connected with the product separation and collection system via a reformed gas outlet to perform online catalytic reforming on the high-quality gas product generated by microwave gasification;   the internal and external radial energy supply system comprises a combustion heat supply chamber, a gasification agent chamber, and a hoop direct-feed microwave generator, wherein the combustion heat supply chamber and the gasification agent chamber are disposed from top down along a central axis of an interior of the integrated reaction system, the hoop direct-feed microwave generator is disposed outside the microwave gasification chamber; the combustion heat supply chamber penetrates through interiors of the drying chamber and the low-temperature pyrolysis chamber, with above-disposed drying tail gas outlets located between the drying chamber and the low-temperature pyrolysis chamber, the drying tail gas outlets release a combustion tail gas of a pyrolysis gas and supply heat for a pyrolysis reaction and material drying, and with below-disposed pyrolysis gas outlets connected with the low-temperature pyrolysis chamber; a blower is connected with the combustion heat supply chamber via a combustion air supply tube; the gasification agent chamber is disposed on an axis of the microwave gasification chamber for a gasification reaction of a material, an upper top of the gasification agent chamber is connected with the microwave gasification chamber via first gasification agent outlets, and a bottom of the gasification agent chamber is connected with a gasification agent inlet; the hoop direct-feed microwave generator is configured to provide a microwave for the microwave gasification chamber;   the product separation and collection system comprises a first-level gas separation device, a second-level purification device, a gas storage cylinder, and a carbon material collection box; the first-level gas separation device is configured to receive and separate a reformed gas and provide a gasification agent for the gasification reaction, wherein a reformed gas inlet, a crude hydrogen outlet, and a second gasification agent outlet are disposed on the first-level gas separation device, the reformed gas inlet is connected with the reformed gas outlet, the crude hydrogen outlet is connected with the gas storage cylinder via the second-level purification device, and the second gasification agent outlet is connected with the gasification agent inlet; the carbon material collection box is connected with a solid outlet at a bottom of the microwave gasification chamber.   
     
     
         2 . The integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 1 , wherein the drying chamber is an inverted-funnel shape with upper large and lower small, wherein a ratio of inner diameters of an upper end and a lower end of the drying chamber is 2:1 to 3:1 and an inclination angle α of an inner wall of the drying chamber is 30°-60°; an upper end of the combustion heat supply chamber is a conical frustum structure, the drying tail gas outlets are disposed on the conical frustum structure, a ratio of a bottom diameter of the conical frustum structure to an inner diameter of the low-temperature pyrolysis chamber is 1:2 to 2:3, a ratio of a top diameter of the conical frustum structure to the bottom diameter is 1:2 to 1:3, a ratio of the top diameter of the conical frustum structure to a height of the conical frustum structure is 1:1 to 1:1.5, and a ratio of the top diameter of the conical frustum structure to an inner diameter of the combustion heat supply chamber is 1:1; a ratio of a height of the microwave gasification chamber to a height of the low-temperature pyrolysis chamber is 2:3, and a ratio of a height of the online reforming reaction chamber to the height of the low-temperature pyrolysis chamber is 4:5 to 1:1. 
     
     
         3 . The integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 1 , wherein a first-level microwave suppression partition plate and a second-level microwave suppression partition plate are disposed sequentially from top down between the low-temperature pyrolysis chamber and the microwave gasification chamber; a first end of the first-level microwave suppression partition plate is connected to a bottom of an inner wall of the low-temperature pyrolysis chamber, and a second end of the first-level microwave suppression partition plate is tilted downward at an inclination angle β of 20° to 45°; a first end of the second-level microwave suppression partition plate is connected to an outer wall of the gasification agent chamber, and a second end of the second-level microwave suppression partition plate is tilted downward at an inclination angle γ of β+15° and has a vertical distance of 0 to 50 mm from an outer end of the first-level microwave suppression partition plate; a ratio of a spacing between an outer end of the second-level microwave suppression partition plate and an outer wall of the microwave gasification chamber to an inner diameter of the microwave gasification chamber is 3:4. 
     
     
         4 . The integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 1 , wherein the pyrolysis gas outlets are symmetrically and circumferentially disposed in 4 to 6 layers, each of which comprises 2 to 4 pyrolysis gas outlets, along an inner wall of the combustion heat supply chamber; and the combustion air supply tube is provided with combustion spray nozzles, wherein the combustion spray nozzles have a diameter of 40 mm and are located between two layers of pyrolysis gas outlets. 
     
     
         5 . The integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 1 , wherein the first gasification agent outlets are symmetrically and circumferentially disposed in 4 to 6 layers each of which comprises 2 to 4 first gasification agent outlets, along an outer wall of the gasification agent chamber. 
     
     
         6 . The integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 1 , wherein a peripheral symmetrical feed port is disposed on an outer wall of the microwave gasification chamber, the hoop direct-feed microwave generator is connected to the peripheral symmetrical feed port via an echo suppressor, a bottom air curtain outlet is disposed at a bottom of the peripheral symmetrical feed port, and the gasification agent chamber is connected with the bottom air curtain outlet. 
     
     
         7 . A method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification by using the integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 1 , comprising the following steps:
 at step S1, the biomass feedstock enters the drying chamber and is heated and dried by the drying tail gas outlets, and then enters the low-temperature pyrolysis chamber for the preliminary pyrolysis carbonization; the pyrolysis gas enters the combustion heat supply chamber via the pyrolysis gas outlets, and a remaining solid material enters the microwave gasification chamber;   at step S2, the remaining solid material goes through the gasification reaction with the gasification agent in the microwave gasification chamber; the high-quality gas product enters the online reforming reaction chamber via the gas phase outlet for the online catalytic reforming and then enters the first-level gas separation device; the porous carbon product enters the carbon material collection box through the solid outlet and is cooled down to below 60° C. in an air-isolated state.   at step S3, the pyrolysis gas in the step S1 is combusted in cooperation with an air in the combustion heat supply chamber to supply heat to the low-temperature pyrolysis chamber; the combustion tail gas is discharged into the drying chamber through the drying tail gas outlets for drying; the reformed gas in the step S2 is separated into crude hydrogen and the gasification agent through the first-level gas separation device; the gasification agent is returned to the microwave gasification chamber through the gasification agent chamber to fully contact with the material for the gasification reaction, and an air curtain is formed on a surface of a peripheral symmetrical feed port by a bottom air curtain outlet so as to protect the peripheral symmetrical feed port.   
     
     
         8 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 7 , wherein in the step S1, a pyrolysis reaction temperature of the low-temperature pyrolysis chamber is 200° C. to 360° C., wherein the pyrolysis reaction temperature is adjusted based on the material and heat supply conditions; in the step S2, a gasification reaction temperature of the microwave gasification chamber is 600° C. to 1200° C.; in the step S3, a combustion temperature in the combustion heat supply chamber is 900° C. to 1300° C., and an excess air coefficient is 1.2 to 1.5. 
     
     
         9 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 7 , wherein in the step S2, the gasification agent is separated carbon dioxide or a gas mixture of the separated carbon dioxide and a small amount of other gases, the gasification agent is introduced in a form of gaseous state, and a mass ratio of the gasification agent to the remaining solid material is 1:2 to 4:1. 
     
     
         10 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 7 , wherein in the step S2, a natural catalyst and a synthetic supported catalyst for catalyzing tar to pyrolyse are placed in the online reforming reaction chamber, the synthetic supported catalyst comprises a nickel-based synthetic supported catalyst with γ-Al 2 O 3  as a carrier and nano nickel oxide as an active component, wherein the nickel-based synthetic supported catalyst is prepared by impregnation, drying, and calcination in air atmosphere at a temperature of 400° C., with nickel nitrate and the γ-Al 2 O 3  as raw materials and urea as a precipitant. 
     
     
         11 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 7 , wherein in the integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification, the drying chamber is an inverted-funnel shape with upper large and lower small, wherein a ratio of inner diameters of an upper end and a lower end of the drying chamber is 2:1 to 3:1 and an inclination angle α of an inner wall of the drying chamber is 30°-60°; an upper end of the combustion heat supply chamber is a conical frustum structure, the drying tail gas outlets are disposed on the conical frustum structure, a ratio of a bottom diameter of the conical frustum structure to an inner diameter of the low-temperature pyrolysis chamber is 1:2 to 2:3, a ratio of a top diameter of the conical frustum structure to the bottom diameter is 1:2 to 1:3, a ratio of the top diameter of the conical frustum structure to a height of the conical frustum structure is 1:1 to 1:1.5, and a ratio of the top diameter of the conical frustum structure to an inner diameter of the combustion heat supply chamber is 1:1; a ratio of a height of the microwave gasification chamber to a height of the low-temperature pyrolysis chamber is 2:3, and a ratio of a height of the online reforming reaction chamber to the height of the low-temperature pyrolysis chamber is 4:5 to 1:1. 
     
     
         12 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 7 , wherein in the integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification, a first-level microwave suppression partition plate and a second-level microwave suppression partition plate are disposed sequentially from top down between the low-temperature pyrolysis chamber and the microwave gasification chamber; a first end of the first-level microwave suppression partition plate is connected to a bottom of an inner wall of the low-temperature pyrolysis chamber, and a second end of the first-level microwave suppression partition plate is tilted downward at an inclination angle β of 20° to 45°; a first end of the second-level microwave suppression partition plate is connected to an outer wall of the gasification agent chamber, and a second end of the second-level microwave suppression partition plate is tilted downward at an inclination angle γ of β+15° and has a vertical distance of 0 to 50 mm from an outer end of the first-level microwave suppression partition plate; a ratio of a spacing between an outer end of the second-level microwave suppression partition plate and an outer wall of the microwave gasification chamber to an inner diameter of the microwave gasification chamber is 3:4. 
     
     
         13 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 7 , wherein in the integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification, the pyrolysis gas outlets are symmetrically and circumferentially disposed in 4 to 6 layers each of which comprises 2 to 4 pyrolysis gas outlets, along an inner wall of the combustion heat supply chamber; and the combustion air supply tube is provided with combustion spray nozzles, wherein the combustion spray nozzles have a diameter of 40 mm and are located between two layers of pyrolysis gas outlets. 
     
     
         14 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 7 , wherein in the integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification, the first gasification agent outlets are symmetrically and circumferentially disposed in 4 to 6 layers each of which comprises 2 to 4 first gasification agent outlets, along an outer wall of the gasification agent chamber. 
     
     
         15 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 7 , wherein in the integrated apparatus for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification, the peripheral symmetrical feed port is disposed on an outer wall of the microwave gasification chamber, the hoop direct-feed microwave generator is connected to the peripheral symmetrical feed port via an echo suppressor, the bottom air curtain outlet is disposed at a bottom of the peripheral symmetrical feed port, and the gasification agent chamber is connected with the bottom air curtain outlet. 
     
     
         16 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 11 , wherein in the step S1, a pyrolysis reaction temperature of the low-temperature pyrolysis chamber is 200° C. to 360° C., wherein the pyrolysis reaction temperature is adjusted based on the material and heat supply conditions; in the step S2, a gasification reaction temperature of the microwave gasification chamber is 600° C. to 1200° C.; in the step S3, a combustion temperature in the combustion heat supply chamber is 900° C. to 1300° C., and an excess air coefficient is 1.2 to 1.5. 
     
     
         17 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 12 , wherein in the step S1, a pyrolysis reaction temperature of the low-temperature pyrolysis chamber is 200° C. to 360° C., wherein the pyrolysis reaction temperature is adjusted based on the material and heat supply conditions; in the step S2, a gasification reaction temperature of the microwave gasification chamber is 600° C. to 1200° C.; in the step S3, a combustion temperature in the combustion heat supply chamber is 900° C. to 1300° C., and an excess air coefficient is 1.2 to 1.5. 
     
     
         18 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 13 , wherein in the step S1, a pyrolysis reaction temperature of the low-temperature pyrolysis chamber is 200° C. to 360° C., wherein the pyrolysis reaction temperature is adjusted based on the material and heat supply conditions; in the step S2, a gasification reaction temperature of the microwave gasification chamber is 600° C. to 1200° C.; in the step S3, a combustion temperature in the combustion heat supply chamber is 900° C. to 1300° C., and an excess air coefficient is 1.2 to 1.5. 
     
     
         19 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 14 , wherein in the step S1, a pyrolysis reaction temperature of the low-temperature pyrolysis chamber is 200° C. to 360° C., wherein the pyrolysis reaction temperature is adjusted based on the material and heat supply conditions; in the step S2, a gasification reaction temperature of the microwave gasification chamber is 600° C. to 1200° C.; in the step S3, a combustion temperature in the combustion heat supply chamber is 900° C. to 1300° C., and an excess air coefficient is 1.2 to 1.5. 
     
     
         20 . The method for co-production of carbon and hydrogen by biomass cascade pyrolysis-microwave gasification according to  claim 15 , wherein in the step S1, a pyrolysis reaction temperature of the low-temperature pyrolysis chamber is 200° C. to 360° C., wherein the pyrolysis reaction temperature is adjusted based on the material and heat supply conditions; in the step S2, a gasification reaction temperature of the microwave gasification chamber is 600° C. to 1200° C.; in the step S3, a combustion temperature in the combustion heat supply chamber is 900° C. to 1300° C., and an excess air coefficient is 1.2 to 1.5.