Blending combustion carbon reduction system and method after biomass gasification
Through the design of a two-stage fluidized bed gasification furnace, the fluidization and high-temperature blending of biomass are realized, and the pyrolysis gas after biomass is directly treated, which solves the problem of difficult tar treatment and simplifies the process and Improves thermal efficiency.
Patent Information
- Application Number
- CN202411584273.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-07
- Publication Date
- 2024-12-31
AI Technical Summary
In the existing biomass gasification technology, tar is difficult to handle, and traditional rotary furnaces cannot directly treat tar, and it needs to be collected separately and processed in a high-temperature catalytic cracking device. The process is complex and energy consumption is high.
Using a two-stage fluidized bed gasification furnace, including the combustion lower section and the gasification section, the fluidized gasification of biomass is realized through the design of louver-type gas-solid separation plate and partition plate, and the gasified pyrolysis gas is directly used. It is fed into a high-temperature furnace for mixed combustion, avoiding catalytic cracking of tar.
The tar treatment process is simplified, energy consumption and operating costs are reduced, thermal efficiency is improved, and the problem of difficult tar treatment is solved.
Smart Images
Figure CN119220304A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of application of chemical equipment to power system engineering, and in particular relates to a system and method for reducing carbon by blending and burning biomass after gasification. Background Art
[0002] Biomass energy is a kind of solar energy stored in biological matter, which exists in the form of chemical energy. Biomass energy ultimately comes from the photosynthesis of green plants and can be converted into solid, liquid or gaseous fuels that we commonly see. Biomass energy has the characteristics of regeneration and is a sustainable energy source. Nowadays, the research and development of biomass energy technology has become one of the important issues that have attracted much attention worldwide. Therefore, how to efficiently utilize biomass energy, conduct in-depth research on its conversion technology, and develop new biomass energy processing and conversion equipment has become particularly important and urgent.
[0003] Biomass gasification technology is the core process in the process of biomass energy conversion. At present, there are many types of biomass gasification devices, including rotary kiln type and fluidized bed gasifier, among which the rotary kiln type gasifier is mainly composed of a drum, a kiln head and a kiln tail. In the process of biomass gasification, tar will inevitably be generated, and the existence of these tars brings a series of problems: first, tar occupies 5% to 10% of the energy in the combustible gas, and it is difficult to use it together with the combustible gas at a lower temperature, resulting in a large waste of energy; secondly, in the process of purifying the gas, the tar-containing wastewater will cause serious pollution to the environment; thirdly, tar will condense into a viscous liquid at low temperature, which is easy to mix with water, carbon particles and other dust, causing pipeline blockage, valve and fan rotor jamming and other problems, and will also cause corrosion to the equipment; in addition, gas-using equipment such as internal combustion engines has strict requirements on the tar content in the gas, which makes the equipment for removing tar in the gas purification process more complicated. In order to reduce the tar content in biomass pyrolysis gas, one of the most effective means is to catalytically crack it. If direct co-firing for power generation is chosen, the tar does not need special treatment and can be directly transported to the high-temperature furnace for combustion, thereby achieving the goal of reducing carbon emissions.
[0004] In biomass gasification technology, how to effectively remove tar from combustible gas is the biggest challenge facing this field. At present, traditional rotary furnaces can only complete the pyrolysis and gasification process of biomass, but cannot directly process the tar produced. These tars need to be collected separately and further processed in a specially designed catalytic cracking unit. However, this process has high requirements for catalytic temperature, and generally needs to be carried out under high temperature conditions of 750 to 900 degrees Celsius, which not only increases the difficulty of treatment, but also increases operating costs and energy consumption. After the pyrolysis gas comes out of the rotary furnace, the temperature drops to 300-600°C. When it enters the tar catalytic cracking equipment, it needs to be heated again. At the same time, the catalyst has a short life problem, and the catalyst regeneration process is complicated, which cannot simply and effectively reduce the tar content in the biomass pyrolysis gas. The outlet temperature of the fluidized gasifier can usually reach 700-800°C. The tar has not reached the state of low-temperature condensation. A simple pipeline system can be arranged and sent to the high-temperature furnace for mixed combustion treatment, solving the technical bottleneck of tar treatment. Summary of the invention
[0005] In order to solve the problems existing in the prior art, the present invention provides a biomass gasification device, which can realize the fluidized gasification of biomass in an integrated manner, and send it into a high-temperature furnace for carbon reduction and co-combustion without the need for power equipment after gasification, thereby completely solving the problem of difficult treatment of tar in gasification.
[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a biomass gasification post-combustion carbon reduction system, which is a two-stage fluidized bed gasifier, including a lower combustion section and a gasification section, an air distribution plate and an air inlet chamber are arranged at the lower part of the lower combustion section, and the air inlet chamber is connected to the fluidizing fan through an air inlet duct; the gasification section is arranged above the lower combustion section, and a partition is arranged between the gasification section and the lower combustion section, and a louvered gas-solid separation sheet is arranged on the partition, and the lower combustion section and the gasification section are respectively connected to a feeding device; a gasification gas outlet pipe is arranged on the top of the gasification section; a plurality of partition holes are arranged on the partition, and each partition hole is arranged with two layers of louvered gas-solid separation sheets; the bottom of the lower combustion section is connected to a drum slag cooler.
[0007] Furthermore, a gas inlet is opened on the cylinder wall of the gas phase zone of the gasification section, and a gas distribution pipe is arranged in the solid phase zone of the gasification section, the gas distribution pipe is connected with the gas inlet, a plurality of gas outlet holes are opened on the tube wall of the gas distribution pipe along its axis, the gas outlet holes of the gas distribution pipe located in the solid phase zone face the inner wall of the gasification section, and protective plates perpendicular to the radial section of the gas distribution pipe are also arranged on both sides of the gas outlet holes of the gas distribution pipe located in the solid phase zone.
[0008] Furthermore, an air distribution plate is arranged on the top of the air inlet chamber, a plurality of small holes for air distribution pipes are arranged on the air distribution plate, a mushroom head-shaped wind cap is arranged on each small hole for air distribution pipes, and a variable frequency motor is used to control the fluidizing fan and control the amount of the lower combustion section and sealing air.
[0009] Furthermore, a heater is provided on the feeding device, a control signal input end of the heater is connected to a control signal output end of the gasification gas control device, and the heater is a combination of one or more of an electromagnetic heater, a microwave heater, an electric heating wire heater, and a plasma heater.
[0010] Furthermore, the lower combustion section, gasification section and gasification gas outlet are all provided with temperature sensors, and the temperature sensors are connected to the input end of the gasification gas control device; the lower combustion section and gasification section are provided with pressure sensors, and the pressure sensors are connected to the frequency conversion control device of the feeding device.
[0011] Furthermore, a steam inlet is provided on the cylinder wall of the lower combustion section and / or the gasification section, and the steam inlet is connected to the steam outlet of the superheater through a movable duct assembly; the steam inlet is used to introduce superheated steam, and a temperature sensor is provided on the movable duct assembly of the steam inlet.
[0012] Furthermore, a gas inlet is arranged on the wall of the gas phase zone of the gasification section, the gas inlet is connected to a gas distribution pipe, and a plurality of gas outlet holes are opened on the wall of the gas distribution pipe along its axis; the refluidizing and cooling medium is gas, and the cooling medium outlet is connected to the gas inlet on the wall of the gasification section; a valve is arranged at the gas inlet, and the valve is a manual valve and / or an automatic valve, and the opening of the automatic valve is controlled by the detection and control device.
[0013] Furthermore, a feeding device is arranged outside the lower combustion section and the gasification section, and the feeding device adopts a sealed conveying channel, and the sealed conveying channel is also connected to a fluidizing fan, and a variable frequency motor is used to control the action of the fluidizing fan to control the lower combustion section and the sealing air consumption.
[0014] The present invention also provides a biomass gasification method, comprising the following steps: The materials are dried and partially burned in sequence, and part of the materials undergo oxidation reaction with oxygen-containing gas, releasing a large amount of heat, so that the reaction temperature rises to 600-900°C, and part of the materials undergo gasification reaction at 600-900°C to generate biochar and fuel gas, and most of the biomass oil undergoes cracking reaction at this temperature to generate fuel gas; the unreacted biomass continues to undergo pyrolysis reaction to obtain pyrolysis gas, which contains biomass oil, water vapor and fuel gas, and the material temperature rises to 400-500°C; Most of the biomass oil in the pyrolysis gas does not need catalytic cracking and directly enters the high-temperature furnace for full combustion; The biochar is separated from the pyrolysis gas.
[0015] Furthermore, the biochar separated by the partition is continuously burned by an oxygen-containing gaseous medium to release heat, and the oxygen-containing gaseous medium is heated by the biochar and participates in the oxidation reaction of the material in the lower part of the combustion; the reaction temperature of the material is detected, and according to the real-time monitored temperature, the amount of oxygen-containing gas that undergoes oxidation reaction with the material is adjusted to control the gasification reaction temperature.
[0016] Compared with the prior art, the present invention has at least the following beneficial effects: in the biomass gasification equipment provided by the present invention, a fluidized gasifier is adopted, the feed end of the fluidized gasifier is in the lower combustion section, the discharge end is located at the lower part of the air distribution plate, and is connected to the drum-type slag cooler by a slag discharge pipe. The fluidized gasifier comprises a wind chamber, an air distribution plate, a lower combustion section, a gas-solid separation section, a gasification section, and a gas outlet section from the feed end to the gas outlet. An air distribution plate is arranged between the lower combustion section and the wind chamber, and a partition is arranged between the lower combustion section and the gasification section. A square hole is provided at the bottom of the partition. During operation, after the material enters the gasifier, it passes through the lower combustion section, the partition, the gasification section, and the gas outlet section in sequence along the fluidization trajectory from bottom to top under the action of the fluidizing wind. The biomass gasification heat source and the pyrolysis and gasification of the material can be completed in the gasifier at one go. There is no need to discharge the pyrolysis gas outside the equipment for treatment by a dedicated tar catalytic cracking equipment. Therefore, there is no need for complicated secondary heating, thereby simply and effectively solving the problem of tar content in the biomass pyrolysis gas.
[0017] Since a fluidized gasifier which was not available before is adopted, it is possible to directly set a temperature sensor and an electric heater on the gasifier and connect them with a control device through a wire to complete the detection and control of the temperature in the gasifier, which is more conducive to the reaction control of each process in the gasifier, thereby completing multiple processes such as material drying, partial combustion and pyrolysis gasification in one device; in the biomass gasification method provided by the present invention, biomass pyrolysis can be completed continuously, the process is simplified, the heat of the pyrolysis gas and biochar in the process can be utilized, and the thermal efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.
[0019] Figure 1 A schematic structural diagram of a biomass gasification device provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a gas distribution pipe of a gasifier provided in an embodiment of the present invention; Figure 3A schematic structural diagram of a partition plate of a gasifier provided in an embodiment of the present invention; In the attached drawings, 1 is a fluidizing fan, 2 is an air chamber, 3 is an air distribution plate and a hood, 4 is a lower combustion section, 5 is a partition, 6 is a gasification section, 7 is a gasification gas outlet pipe, 8 is a gasification section feeding device, and 9 is a lower combustion section feeding device. DETAILED DESCRIPTION
[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0021] refer to Figure 1 A biomass gasification post-combustion carbon reduction system is a two-stage fluidized bed gasifier, including a combustion lower section 4 and a gasification section 6. The combustion lower section 4 is provided with an air inlet chamber 2. In order to achieve the gasification temperature required by the equipment, the theoretically required fluidizing air volume and combustion air volume are calculated, and the air distribution plate and air chamber area of the combustion lower section are designed accordingly. The air chamber and the combustion lower section adopt a cylindrical structure, and the air hood 33 is arranged on the air distribution plate 32. The air hood adopts a mushroom head form. The height of the combustion lower section 4 is set according to the corresponding proportion of biomass burnout and heat release. The section includes an air inlet duct, an air inlet chamber 2, a feed port, a combustion section and a gas-solid separation section. The gas-solid separation section is provided with a partition 5, and the partition 5 is located at the upper part close to the combustion lower section. The gasification section 6 is located above the partition 5; a gasification gas outlet pipe 7 is provided above the gas phase area of the gas-solid separation section; the gasification section 6 is provided at the upper part of the combustion lower section 4, and a gasification material inlet is provided in the gasification section 6 for biomass gasification. The gasification heat energy is provided by the combustion lower section 4. After gasification, no gas-solid separation device is provided, and the kinetic energy after gasification is directly used to transport the gasification gas into the furnace for gasification gas mixing and combustion; The feeding device is arranged outside the lower combustion section and the gasification section, and is used for sealed conveying of biomass. In addition to the use of an auger feeder, due to the insufficient density of the material, sealed air is used for sealed conveying to ensure that the material will not leak into the environment during the conveying process, and at the same time, it also prevents external air or moisture from entering the conveying system; the feeding device has a variable frequency regulation function; the variable frequency regulation allows the conveying amount of the feeding device to be precisely controlled. It is necessary to select a motor with a variable frequency speed regulation function and equip it with a corresponding control system. By changing the speed of the motor, the conveying amount of biomass can be precisely controlled, thereby meeting the precise requirements for the material amount during the gasification or combustion process.
[0022] The gasification gas control device is connected to the air inlet chamber 2 through an air duct, and is used to control the action of the fluidizing fan through a variable frequency motor, control the amount of the lower combustion stage and the sealing air, and adjust the gasification gas outlet volume according to the feedback of the feeding device.
[0023] Temperature sensors are provided in the lower combustion section 4, the gasification section 6 and the conveying section of the gasification gas outlet pipe 7. The temperature sensors are connected to the input end of the gasification gas control device. The temperature sensors monitor the temperature of each key area in the gasification process in real time. By obtaining accurate temperature data, the thermal state of the gasification process can be understood, and then the gasification gas control device can be accurately adjusted to ensure the stability and efficiency of the gasification process; the temperature sensor is provided in the lower combustion section to monitor the progress of the combustion reaction and ensure the stability and sufficiency of the combustion process; the gasification section is a key area for the conversion of biomass into gasification gas. The temperature sensor is provided to monitor the temperature of the gasification reaction in real time, providing an accurate adjustment basis for the control device; the temperature sensor is provided in the conveying section of the gasification gas outlet pipe 7 to monitor the outlet temperature of the gasification gas, which is helpful to monitor and ensure the quality and stability of the gasification gas.
[0024] The feeding device is provided with an electric heater, and a control signal input end of the electric heater is connected to a control signal output end of the gasification gas control device; the electric heater can be an electric heating wire heater, an electromagnetic heater, a plasma heater or a microwave heater, or a combination of two or more of these heaters. Those skilled in the art know how to set the electric heater.
[0025] refer to Figure 3 , Figure 3 In the figure, a is a schematic diagram of a top view of a partition hole 51, b is a schematic diagram of a longitudinal section of the partition hole 51, and c is a schematic diagram of a top view of the partition 5. A plurality of partition holes 51 are arranged on the partition 5 of the gas-solid separation section, and each partition hole 51 is arranged with two layers of louvered gas-solid separation plates. The separated solids and combustion waste slag are discharged from the lower combustion section through the slag discharge device; the slag discharge device is arranged at the bottom of the lower combustion section, and a drum slag cooler is arranged to be connected to the lower combustion section to discharge the waste slag from the combustion and gas-solid separation from the lower combustion section, and the drum slag cooler adjusts the speed through the frequency conversion speed regulation device to adjust the system output.
[0026] The device described in the present application also includes a gas inlet arranged on the wall of the gas phase zone of the gasification section 6 and a gas distribution pipe arranged in the solid phase zone of the gasification section 6. The gas inlet is used to introduce air into the gasification section 6. The gas distribution pipe is connected to the gas inlet. A plurality of gas outlet holes are opened on the wall of the gas distribution pipe along its axis. The gas outlet holes of the gas distribution pipe located in the solid phase zone face the inner wall of the gasification section. The gas outlet holes of the gas distribution pipe located in the solid phase zone are also provided with guard plates perpendicular to the radial section of the gas distribution pipe on both sides. The guard plates are used to prevent the material from entering the gas outlet holes, release the gasifying agent through the gas outlet holes, and allow the gasifying agent to penetrate into the interior of the material and fully contact with the material, thereby accelerating the gasification reaction. The design of the guard plate can also guide the flow direction of the gasifying agent so that it is more evenly distributed in the material. A valve is arranged at the gas inlet. The valve is a manual valve and / or an automatic valve, and the opening of the automatic valve is controlled by the detection and control device.
[0027] A steam inlet is also provided on the cylinder wall of the lower combustion section and / or the gasification section, and the steam inlet is connected to the steam outlet of the superheater through a movable conduit assembly; the steam inlet is located on the cylinder wall of the lower combustion section and / or the gasification section, and is used to introduce superheated steam. Superheated steam has the characteristics of high temperature and high energy, and can play a variety of roles in the gasification process, such as providing additional heat, promoting the pyrolysis and gasification of materials, and increasing the output and quality of gasified gas; the movable conduit assembly connects the steam inlet and the steam outlet of the superheater to ensure that the superheated steam can be stably and efficiently transported to the gasification section; the superheated steam has a high temperature, which can provide additional heat for the gasification process and promote the pyrolysis and gasification reaction of the material; the presence of steam can reduce the pyrolysis temperature of the material, accelerate the pyrolysis process, and make the material easier to convert into gasified gas; the steam can react with the carbon in the material to produce more hydrogen and carbon monoxide and other combustible gases, thereby increasing the output and quality of the gasified gas; it can also help adjust the temperature and pressure of the gasification process, making the gasification process more stable and controllable.
[0028] The refluidizing and cooling medium is gas, and the cooling medium outlet is communicated with the gas inlet on the wall of the gasification section.
[0029] An insulating layer and a heating jacket are arranged outside the lower combustion section and the gasification section. A pyrolysis gas inlet is arranged on the outer wall of the heating jacket near the gasification section, and a pyrolysis gas outlet is arranged on the outer wall of the heating jacket near the feed end. The insulating layer is used to reduce the heat exchange between the lower combustion section and the gasification section and the external environment, maintain the high temperature environment required for the gasification process, help improve the gasification efficiency, reduce energy waste, and protect the external structure from high temperature; the heating jacket is located outside the insulating layer, and is used to provide additional heat to the gasification process. The heating function can be achieved by circulating a heat medium (such as steam, heat transfer oil) to ensure that the gasification section and the lower combustion section maintain a suitable operating temperature.
[0030] In the above-mentioned biomass gasification equipment, a fluidizing fan is also provided, and the outlet of the fluidizing fan is communicated with the inlet of the wind chamber of the lower combustion section.
[0031] A tar inspection port is provided on the cylinder wall of the lower combustion section and / or gasification section; samples can be taken regularly or irregularly to detect the tar content, so as to timely understand the status of the gasification or combustion process. According to the tar detection results, the process parameters of the gasification or combustion, such as temperature, pressure, gasification agent, etc., can be adjusted to optimize the process efficiency and product quality. Excessive accumulation of tar in the system may cause safety hazards such as pipeline blockage and equipment damage; by regularly checking the tar content, potential blockage or damage risks can be discovered and dealt with in time to ensure the safe and stable operation of the system; the tar inspection port should be opened on the cylinder wall of the lower combustion section or the gasification section to facilitate sampling and detection.
[0032] The partition is arranged between the lower combustion section and the gasification section.
[0033] It also includes a pressure sensor arranged on the fluidized gasification furnace, the pressure sensor is connected to the input end of the feeding device controller, and the feeding device controller adopts a frequency converter.
[0034] A temperature sensor is arranged at the gasification gas outlet or connected to the steam pipeline to detect the temperature of the gas passing through the gasification gas outlet; the temperature sensor is arranged on the gasification gas outlet and the steam pipeline, which can not only improve the efficiency and safety of the gasification process, but also provide strong data support for the automatic control of the gasification system. By monitoring the temperature of the gas in real time, the gasification conditions, such as temperature, pressure, gasifying agent, etc., can be adjusted in time to optimize the gasification effect, assist in improving the quality and output of gas production, and can timely discover and deal with potential overheating risks to ensure the safe and stable progress of the gasification process.
[0035] Based on the above embodiment, a regulating valve is provided on the steam pipeline or at the inlet of the fluidizing fan, and the regulating valve is used to regulate the gas flow passing through the steam outlet and the fluidizing fan outlet, and the induced draft fan is a variable frequency induced draft fan, which is used to regulate the gas flow passing through the steam outlet. The regulating valve is used to regulate the gas flow through the steam pipeline or the inlet of the fluidizing fan. By adjusting the opening of the valve, the gas flow and pressure can be accurately controlled to meet the gas flow requirements of the gasification process or subsequent processes; in the gasification process, the regulating valve makes the gasification process more flexible and controllable; the variable frequency induced draft fan is mainly used to regulate the gas flow passing through the steam outlet, and by changing the speed of the induced draft fan, the gas flow can be accurately controlled, thereby optimizing the efficiency, energy consumption and safety of the gasification process.
[0036] The present invention also provides a biomass gasification method, comprising the following steps: The materials are dried and partially burned in sequence, and part of the materials undergo oxidation reaction with oxygen-containing gas, releasing a large amount of heat, so that the reaction temperature rises to 600-900°C, and part of the materials undergo gasification reaction at this temperature to generate biochar and fuel gas, and most of the biomass oil undergoes cracking reaction at this temperature to generate fuel gas; the unreacted biomass enters the gasification section to continue to undergo pyrolysis reaction to obtain pyrolysis gas, which contains biomass oil, water vapor and fuel gas, and the material temperature rises to 400-500°C; Most of the biomass oil in the pyrolysis gas does not need catalytic cracking and directly enters the high-temperature furnace for full combustion; The biochar is separated from the pyrolysis gas.
[0037] The above-mentioned biomass gasification method also includes continuing to burn the biochar separated by the partition through an oxygen-containing gas medium to release heat, and the oxygen-containing gas medium is heated by the biochar and participates in the oxidation reaction of the lower combustion part of the material.
[0038] In the above-mentioned biomass gasification method, the reaction temperature of the material is detected, and according to the real-time monitored temperature, the amount of oxygen-containing gas that undergoes oxidation reaction with the material is regulated to control the gasification reaction temperature.
[0039] In the above-mentioned biomass gasification method, when the material temperature in the drying and partial combustion steps is too low and the biomass is difficult to react with the oxygen-containing gas, the material is heated by electric heating. When the material is heated to the biomass auto-ignition temperature and undergoes an oxidation reaction with the oxygen-containing gas and the temperature is further increased, the electric heating is stopped.
[0040] refer to Figure 2 , Figure 2In the figure a is a schematic diagram of the longitudinal section of the air distribution plate and the air hood, and b is a schematic diagram of the structure of the air distribution plate and the air hood from a top view. In the present embodiment, the air distribution plate and the air hood 3 are used for uniform air distribution. Specifically, the air distribution plate and the air hood 3 include an air hood 31 and an air distribution plate 32 with small holes and air distribution pipe small holes 33 provided on the air distribution plate, wherein the air distribution pipe small holes 33 are evenly distributed, that is, the lateral spacing and the longitudinal spacing are equal, or the difference between the two is within ±20 mm, and the air hood 31 is arranged on the air distribution pipe small holes 33.
[0041] As a possible preferred embodiment, an intermediate partition 5 is provided between the lower combustion section and the gasification section. The specific structure of the intermediate partition 5 includes a partition hole 51 and a partition 52. A louver plate 53 is arranged in the partition hole for gas-solid separation in the lower combustion section and to provide resistance for the gasification section. The designed resistance range is between 300-1000Pa. The louver plates are arranged at a certain inclination, preferably 45°, and the blade width range is 10-50mm.
[0042] The above contents are only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.
Claims
1. A biomass gasification and post-combustion carbon reduction system, characterized in that: A two-stage fluidized bed gasifier is used, comprising a combustion lower section (4) and a gasification section (6); an air distribution plate and an air inlet chamber (2) are arranged at the lower part of the combustion lower section (4); the air inlet chamber (2) is connected to a fluidizing fan (1) through an air inlet duct; the gasification section (6) is arranged above the combustion lower section (4); a partition (5) is arranged between the gasification section (6) and the combustion lower section (4); a shutter-type gas-solid separation sheet is arranged on the partition (5); the combustion lower section (4) and the gasification section (6) are respectively connected to a feeding device; a gasification gas outlet pipe (7) is arranged at the top of the gasification section (6); a plurality of partition holes (51) are arranged on the partition (5), and two layers of shutter-type gas-solid separation sheets are arranged on each partition hole (51); and the bottom of the combustion lower section is connected to a drum slag cooler.
2. The biomass gasification and post-combustion carbon reduction system according to claim 1, characterized in that: A gas inlet is provided on the wall of the gas phase zone of the gasification section (6), and a gas distribution pipe is provided in the solid phase zone of the gasification section (6). The gas distribution pipe is connected to the gas inlet, and a plurality of gas outlet holes are provided on the wall of the gas distribution pipe along its axis. The gas outlet holes of the gas distribution pipe in the solid phase zone face the inner wall of the gasification section, and guard plates perpendicular to the radial section of the gas distribution pipe are provided on both sides of the gas outlet holes of the gas distribution pipe in the solid phase zone.
3. The biomass gasification and post-combustion carbon reduction system according to claim 1, characterized in that: An air distribution plate (32) is arranged at the top of the air inlet chamber (2), a plurality of air distribution duct holes (33) are arranged on the air distribution plate (32), a mushroom head-shaped wind cap (31) is arranged on each air distribution duct hole (33), and a variable frequency motor is used to control the fluidizing fan (1), control the combustion lower section (4) and the sealing air consumption.
4. The biomass gasification and post-combustion carbon reduction system according to claim 1, characterized in that: The feeding device is provided with a heater, a control signal input end of the heater is connected to a control signal output end of the gasification gas control device, and the heater is a combination of one or more of an electromagnetic heater, a microwave heater, an electric heating wire heater, and a plasma heater.
5. The biomass gasification and post-combustion carbon reduction system according to claim 1, characterized in that: The lower combustion section (4), the gasification section (6) and the gasification gas outlet are all provided with temperature sensors, and the temperature sensors are connected to the input end of the gasification gas control device; the lower combustion section (4) and the gasification section (6) are provided with pressure sensors, and the pressure sensors are connected to the frequency conversion control device of the feeding device.
6. The biomass gasification and post-combustion carbon reduction system according to claim 1, characterized in that: A steam inlet is also provided on the cylinder wall of the lower combustion section (4) and / or the gasification section (6), and the steam inlet is connected to the steam outlet of the superheater through a movable conduit assembly; the steam inlet is used to introduce superheated steam, and a temperature sensor is provided on the movable conduit assembly of the steam inlet.
7. The biomass gasification and post-combustion carbon reduction system according to claim 1, characterized in that: A gas inlet is arranged on the wall of the gas phase zone of the gasification section (6), the gas inlet is connected to a gas distribution pipe, and a plurality of gas outlet holes are opened on the wall of the gas distribution pipe along its axis; the refluidizing and cooling medium is gas, and the cooling medium outlet is connected to the gas inlet on the wall of the gasification section; a valve is arranged at the gas inlet, and the valve is a manual valve and / or an automatic valve, and the opening of the automatic valve is controlled by the detection control device.
8. The biomass gasification and post-combustion carbon reduction system according to claim 1, characterized in that: The feeding device is arranged outside the lower combustion section (4) and the gasification section (6), and the feeding device adopts a sealed conveying channel, and the sealed conveying channel is also connected to the fluidizing fan (1), and the variable frequency motor is used to control the operation of the fluidizing fan, thereby controlling the amount of the lower combustion section and the sealing air.
9. A biomass gasification method, characterized in that: The following steps are involved: The materials are dried and partially burned in sequence, and part of the materials undergo oxidation reaction with oxygen-containing gas, releasing a large amount of heat, so that the reaction temperature rises to 600-900°C, and part of the materials undergo gasification reaction at 600-900°C to generate biochar and fuel gas, and most of the biomass oil undergoes cracking reaction at this temperature to generate fuel gas; the unreacted biomass continues to undergo pyrolysis reaction to obtain pyrolysis gas, which contains biomass oil, water vapor and fuel gas, and the material temperature rises to 400-500°C; Most of the biomass oil in the pyrolysis gas does not need catalytic cracking and directly enters the high-temperature furnace for full combustion; The biochar is separated from the pyrolysis gas.
10. The biomass gasification method according to claim 9, characterized in that: The biochar separated by the partition is continuously burned by an oxygen-containing gaseous medium to release heat. The oxygen-containing gaseous medium is heated by the biochar and participates in the oxidation reaction of the material in the lower section of the combustion. The reaction temperature of the material is detected, and the amount of the oxygen-containing gas that undergoes oxidation reaction with the material is adjusted according to the real-time monitored temperature to control the gasification reaction temperature.