Biomass fluidized bed partial gasification and biochar synthesis gas tar co-production device

Abstract

A device for co-producing biochar syngas tar by partial gasification of a biomass fluidized bed is characterized in that agricultural and forestry wastes in an agricultural and forestry waste biomass feeding device are gasified in a low-temperature fluidized bed partial gasification furnace and then are subjected to solid-gas separation in a first cyclone separator and a second cyclone separator, and produced biochar is collected by a charcoal cooling device; the methanol passes through a high-temperature gasification chamber, a waste heat recovery device and a high-temperature dust remover, is finally separated from tar by a tar condensing device and an electrical tar precipitator, and is finally conveyed to an external methanol synthesis unit by a synthesis gas fan; according to the device, various kinds of agricultural and forestry waste biomass with complex and changeable characteristics can be used, co-production of charcoal, high-quality synthesis gas and tar is achieved, the agricultural and forestry waste biomass is efficiently utilized in a resource mode, and the economical efficiency of resource utilization of the agricultural and forestry waste biomass is improved.

Description

Technical Field

[0001] This utility model belongs to the field of chemical production, specifically relating to a biomass fluidized bed partial gasification and co-production of biochar synthesis gas and tar device. Background Technology

[0002] Biomass gasification technology based on agricultural and forestry waste is a mature and widely applied high-efficiency resource utilization technology. Conceptually, it is a thermochemical process that converts agricultural and forestry waste biomass into valuable syngas, tar, and biochar under high-temperature (>500℃) and oxygen-deficient conditions. Depending on the gasification device, biomass gasification technology based on agricultural and forestry waste can be divided into fixed-bed gasification, fluidized-bed gasification, and entrained gasification. Among these, fluidized-bed gasification is a highly flexible method for utilizing agricultural and forestry waste biomass. Due to its wide fuel adaptability and suitability for large-scale application, it is receiving increasing attention. Currently, converting agricultural and forestry waste biomass into high-quality syngas through fluidized-bed gasification for the production of chemicals originally derived from fossil fuels is an important development direction for expanding the utilization of agricultural and forestry waste biomass resources.

[0003] However, traditional fluidized bed gasification of agricultural and forestry waste-based biomass aims to convert as much low-quality agricultural and forestry waste-based biomass as possible into valuable syngas, pursuing high conversion rates and efficiency, while paying little attention to the biochar byproduct of the gasification process. In recent years, biochar has been widely used as an adsorbent, gasification feedstock, and catalyst, and has been applied in electrochemistry and soil improvement, enabling its value-added utilization. Furthermore, agricultural and forestry waste-based biomass gasification technology achieves high tar yields even at relatively low gasification operating temperatures. Therefore, removing tar from the syngas as a product output, or decomposing the tar contained in the gasified syngas into syngas components such as CO, H2, and CH4 at high temperatures, is a way to improve the safety and economy of agricultural and forestry waste-based biomass gasification technology. This method can eliminate the adverse effects of tar on subsequent syngas utilization and also generate revenue. Summary of the Invention

[0004] To address the aforementioned problems, this utility model proposes a biomass fluidized bed partial gasification co-production device for biochar, syngas, and tar. This device can utilize various complex and variable agricultural and forestry waste biomass to achieve the co-production of biochar, high-quality syngas, and tar, thereby efficiently utilizing agricultural and forestry waste biomass and improving the economic efficiency of its resource utilization.

[0005] A biomass fluidized bed partial gasification and co-production of biochar synthesis gas and tar apparatus includes a biomass feeding device (1), a low-temperature fluidized bed partial gasifier (2), a primary cyclone separator (3), a secondary cyclone separator (4), a waste heat recovery device (7), a high-temperature dust collector (8), a tar condenser (9) for removing tar mist and water mist, an electrostatic precipitator (10), a synthesis gas blower (11), and a tar pool (12) connected at the bottom of the tar condenser (9) and the electrostatic precipitator (10). The biomass feeding device (1) The feed inlet of the low-temperature fluidized bed partial gasifier (2) is connected to the feed port in the middle and lower part of the low-temperature fluidized bed partial gasifier (2); the bottom of the low-temperature fluidized bed partial gasifier (2) is also provided with a gasifying agent inlet that can be introduced into the gasifying agent composed of two gases, O2 and CO2; the top of the low-temperature fluidized bed partial gasifier (2) is provided with a syngas outlet connected in sequence to a cyclone separator 3 and a cyclone separator 4; the top of the cyclone separator (4) is provided with an outlet connected to the waste heat recovery device (7); the electrostatic precipitator 10 draws the syngas into the external syngas processing unit through the syngas blower 11.

[0006] Preferably, the bottom outlets of the single-swirl separator (3) and the double-swirl separator (4) are equipped with a cold char device (5) for collecting coarser biochar particles.

[0007] Preferably, the connecting pipe between the two-cyclone separator (4) and the waste heat recovery device (7) is equipped with a high-temperature gasification chamber (6).

[0008] As a preferred option, the operating temperature range of the low-temperature fluidized bed partial gasifier (2) is 550℃-750℃; the volume ratio of O2:CO2 in the gasifying agent mixture is 0.5-0.8.

[0009] Preferably, the operating temperature inside the high-temperature gasification chamber (6) is 750℃~900℃.

[0010] Preferably, the waste heat recovery device (7) can cool the high-temperature syngas generated by the low-temperature fluidized bed partial gasifier (2) to 300°C to 400°C, so as to prevent the tar gas components contained in the high-temperature syngas from condensing into liquid components and depositing on the heated surface during the cooling process.

[0011] As a preferred option, the low-temperature fluidized bed partial gasifier (2) operates at atmospheric pressure.

[0012] Preferably, the cooling medium input to the waste heat recovery device (7) is water vapor, and the input temperature is 250℃~350℃.

[0013] The beneficial effects of this utility model are as follows:

[0014] 1. This utility model adopts a fluidized bed partial gasification process for biomass from agricultural and forestry waste with good fuel adaptability, thus greatly relaxing the control over specific agricultural and forestry waste biomass and significantly reducing raw material costs.

[0015] 2. The composition of the gasifying agent in this invention is adjustable. By optimizing the composition of the gasifying agent and the gasification operation parameters, the gasification reaction characteristics can be optimized, and the composition of the syngas and the energy consumption of the gasifier can be controlled within a certain range.

[0016] 3. This utility model utilizes partially gasified agricultural and forestry waste biomass rich in volatile components to produce biochar, tar, and high-quality syngas rich in components such as CO, H2, and CH4. The produced syngas and tar can be used to produce clean natural gas, liquid fuels, or high-value chemicals. The produced biochar can be used as an adsorbent, gasification feedstock, and catalyst, and can be used in the electrochemical field and soil improvement, thereby improving the utilization value and efficiency of agricultural and forestry waste biomass and realizing the efficient and clean resource utilization of agricultural and forestry waste biomass rich in volatile components. Attached Figure Description

[0017] Figure 1 This is a structural diagram of a biomass fluidized bed partial gasification and co-production of biochar synthesis gas and tar device according to this utility model.

[0018] Figure 2 This is a diagram of the device used in Embodiment 3 of this utility model. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments described below are intended to facilitate the understanding of the present invention and are not intended to limit it.

[0020] Example 1

[0021] like Figure 1 As shown, a fluidized bed partial gasification device for agricultural and forestry waste biomass, co-producing biochar and syngas tar, includes an agricultural and forestry waste biomass feeding device 1, a low-temperature fluidized bed partial gasifier 2, a primary cyclone separator 3, a secondary cyclone separator 4, a char cooling device 5, a high-temperature gasification chamber 6, a waste heat recovery device 7, a high-temperature dust collector 8, a tar condenser 9, an electrostatic precipitator for tar 10, a syngas blower 11, and a tar pool 12.

[0022] The following section uses sawdust as an example of agricultural and forestry waste biomass to introduce the fluidized bed partial gasification and co-production of biochar syngas tar process of this utility model, which includes the following steps:

[0023] A1. Agricultural and forestry waste biomass is fed from the agricultural and forestry waste biomass feeding device 1 into the low-temperature fluidized bed partial gasifier 2 at a feed rate of 8 t / h. 4680 Nm³ of gasifying agent is introduced into the gasifying agent inlet at the bottom of the low-temperature fluidized bed partial gasifier 2. 3 / h of O2-CO2 mixed gasifying agent (the volume ratio of O2:CO2 in the gasifying agent mixture is 0.67), agricultural and forestry waste biomass undergoes pyrolysis, combustion and partial gasification reaction with the gasifying agent in the low-temperature fluidized bed partial gasifier 2 to produce gasified syngas and biochar particles; the low-temperature fluidized bed partial gasifier 2 operates at atmospheric pressure and the operating temperature is controlled at 690℃.

[0024] A2. The syngas produced in the low-temperature fluidized bed gasifier 2 carries biochar particles and sequentially enters the first-stage cyclone separator 3 and the second-stage cyclone separator 4 for gas-solid separation. The coarser biochar particles separated are discharged into the cold char unit 5, with a biochar production rate of 0.58 t / h. After cooling, they are sent out as biochar products.

[0025] A3. The separated gasified syngas enters the high-temperature gasification chamber 6, and oxygen is simultaneously introduced into the high-temperature gasification chamber 6. The gasified syngas undergoes combustion and gasification reactions in the high-temperature gasification chamber 6, further raising the temperature of the high-temperature gasification chamber 6 to about 800℃, causing the tar contained therein to decompose. The tar decomposition products become syngas components. The gasified syngas produced by the high-temperature gasification chamber 6 then enters the waste heat recovery device 7 for temperature control and cooling to about 350℃. After being cooled, the gasified syngas enters the high-temperature dust collector 8 for dust removal, and then enters the tar condensation device 9 to condense and precipitate the tar that has not yet been decomposed at high temperature. The condensed tar and liquid water are discharged to the tar pool 12. The tar after oil-water separation is sent out as a product.

[0026] A4. The syngas produced by the tar condenser 9 enters the electrostatic precipitator 10 for further removal of tar mist and water mist. The collected tar and water are discharged to the tar pool 12, where, after oil-water separation, 0.19 t / h of tar product is produced. The purified syngas produced by the electrostatic precipitator 10 is rich in components such as CO, H2, and CH4. The syngas yield is approximately 11944 Nm³. 3 The syngas has a volume fraction of 37.59% CO, 4.76% CH4, 24.08% H2, and 33.67% CO2 per hour. The syngas is then transported to the methanol synthesis unit via syngas blower 11.

[0027] Example 2

[0028] The following section uses corn stalks as an example of agricultural and forestry waste biomass to introduce the fluidized bed partial gasification and co-generation of biochar synthesis gas tar process of this utility model, which includes the following steps:

[0029] A1. Agricultural and forestry waste biomass is fed from the agricultural and forestry waste biomass feeding device 1 into the low-temperature fluidized bed partial gasifier 2 at a feed rate of 8 t / h. 2340 Nm³ of gasifying agent is introduced into the gasifying agent inlet at the bottom of the low-temperature fluidized bed partial gasifier 2. 3 / h of O2-CO2 mixed gasifying agent (the volume ratio of O2:CO2 in the gasifying agent mixture is 0.77), agricultural and forestry waste biomass undergoes pyrolysis, combustion and partial gasification reaction with the gasifying agent in the low-temperature fluidized bed partial gasifier 2 to produce gasified syngas and biochar particles; the low-temperature fluidized bed partial gasifier 2 operates at atmospheric pressure and the operating temperature is controlled at 700℃.

[0030] A2. The syngas produced in the low-temperature fluidized bed gasifier 2 carries biochar particles and sequentially enters the first-stage cyclone separator 3 and the second-stage cyclone separator 4 for gas-solid separation. The coarser biochar particles separated are discharged into the cold char unit 5, with a biochar production rate of 1.51 t / h. After cooling, they are sent out as biochar products.

[0031] A3. The separated gasified syngas enters the high-temperature gasification chamber 6, and oxygen is simultaneously introduced into the high-temperature gasification chamber 6. The gasified syngas undergoes combustion and gasification reactions in the high-temperature gasification chamber 6, further raising the temperature of the high-temperature gasification chamber 6 to about 800℃, causing the contained tar to decompose. The tar decomposition products become syngas components. The gasified syngas produced by the high-temperature gasification chamber 6 then enters the waste heat recovery device 7 for temperature control and cooling to about 350℃. After being cooled, the gasified syngas enters the high-temperature dust collector 8 for dust removal, and then enters the tar condensation device 9 to condense and precipitate the tar that has not yet been decomposed at high temperature. The condensed tar and liquid water are discharged to the tar pool 12, and after oil-water separation, 0.08t / h of tar product is produced.

[0032] A4. The syngas produced by the tar condenser 9 enters the electrostatic precipitator 10 for further removal of tar mist and water mist. The collected tar and water are discharged to the tar pool 12. The tar after oil-water separation is sent out as a product. The purified syngas produced by the electrostatic precipitator 10 is rich in components such as CO, H2, and CH4. The syngas yield is approximately 11237 Nm³. 3 The syngas has a volume fraction of 34.14% CO, 4.27% CH4, 22.75% H2, and 38.84% CO2 per hour. The syngas is then transported to the methanol synthesis unit via syngas blower 11.

[0033] Example 3

[0034] like Figure 2As shown, a fluidized bed partial gasification device for agricultural and forestry waste biomass, co-producing biochar syngas tar, includes an agricultural and forestry waste biomass feeding device 1, a low-temperature fluidized bed partial gasifier 2, a primary cyclone separator 3, a secondary cyclone separator 4, a char cooling device 5, a waste heat recovery device 7, a high-temperature dust collector 8, a tar condenser 9, an electrostatic precipitator 10, a syngas blower 11, and a tar pool 12.

[0035] The following section uses sawdust as an example of agricultural and forestry waste biomass to introduce the fluidized bed partial gasification and co-production of biochar syngas tar process of this utility model, which includes the following steps:

[0036] A1. Agricultural and forestry waste biomass is fed from the agricultural and forestry waste biomass feeding device 1 into the low-temperature fluidized bed partial gasifier 2 at a feed rate of 8 t / h. 2610 Nm³ of gasifying agent is introduced into the gasifying agent inlet at the bottom of the low-temperature fluidized bed partial gasifier 2. 3 / hO2-CO2 mixed gasifying agent, the volume ratio of O2:CO2 in the mixed gasifying agent is 0.55; agricultural and forestry waste biomass undergoes pyrolysis, combustion and partial gasification reaction with the gasifying agent in the low-temperature fluidized bed partial gasifier 2 to produce gasified syngas and biochar particles; the low-temperature fluidized bed partial gasifier 2 operates at atmospheric pressure and the operating temperature is controlled at 690℃.

[0037] A2. The syngas produced in the low-temperature fluidized bed gasifier 2 carries biochar particles and sequentially enters the first-stage cyclone separator 3 and the second-stage cyclone separator 4 for gas-solid separation. The coarser biochar particles separated are discharged into the cold char unit 5, with a biochar production rate of 0.58 t / h. After cooling, they are sent out as biochar products.

[0038] A3. The separated gasified syngas is directly fed into the waste heat recovery device 7 to be cooled to about 300°C; the cooled gasified syngas enters the high temperature dust collector 8 for dust removal, and then enters the tar condensation device 9 for cooling. The condensed tar and liquid water are discharged to the tar pool 12. After oil-water separation, 1.61t / h of tar products are produced. This tar can be further processed to synthesize gasoline, diesel or other chemical products.

[0039] A4. The syngas produced by the tar condenser 9 enters the electrostatic precipitator 10 for further removal of tar mist and water mist. The collected tar and water are discharged to the tar pool 12, and the tar after oil-water separation is sent out as a product; at this time, the syngas production is 8552 Nm³. 3 The volume fractions of the main components of the syngas per hour are: 33.67% CO, 10.76% CH4, 10.58% H2, and 7.32% C. n H m And 37.67% CO2. The syngas is transported to the external methanol synthesis unit via syngas blower 11.

[0040] The embodiments described above provide a detailed explanation of the technical solution and beneficial effects of this utility model. It should be understood that the above descriptions are only specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, additions, and equivalent substitutions made within the scope of the principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A biomass fluidized bed partial gasification and co-production of biochar synthesis gas and tar apparatus, characterized in that: The system includes a biomass feeding device (1), a low-temperature fluidized bed partial gasifier (2), a single-cyclone separator (3), a double-cyclone separator (4), a waste heat recovery device (7), a high-temperature dust collector (8), a tar condenser (9) for removing tar mist and water mist, an electrostatic precipitator (10), a syngas blower (11), and a tar pool (12) connected at the bottom to the tar condenser (9) and the electrostatic precipitator (10). The biomass feeding device (1) is connected to the low-temperature fluidized bed partial gasifier (2) in the middle and lower part of the system. The feed inlet of the part is connected; the bottom of the low-temperature fluidized bed partial gasifier (2) is also provided with a gasifying agent inlet that can be introduced into the gasifying agent mixture composed of O2 and CO2; the top of the low-temperature fluidized bed partial gasifier (2) is provided with a syngas outlet connected in sequence to a cyclone separator (3) and a cyclone separator (4); the top of the cyclone separator (4) is provided with an outlet connected to the waste heat recovery device (7); the electrostatic precipitator (10) draws the syngas into the external syngas processing unit through the syngas blower (11).

2. A biomass fluidized bed partial gasification co-production biochar synthesis gas tar device according to claim 1, characterized in that: The bottom outlets of the single-swirl separator (3) and the double-swirl separator (4) are equipped with a cold carbon device (5) for collecting coarser biochar particles.

3. A biomass fluidized bed partial gasification co-production biochar synthesis gas tar device according to claim 1, characterized in that: The connecting pipe between the two-cyclone separator (4) and the waste heat recovery device (7) is equipped with a high-temperature gasification chamber (6).

4. The biomass fluidized bed partial gasification co-production biochar synthesis gas tar device according to claim 1, characterized in that: The operating temperature range of the low-temperature fluidized bed gasifier (2) is 550℃-750℃; the volume ratio of O2:CO2 in the gasifying agent mixture is 0.5-0.

8.

5. The biomass fluidized bed partial gasification co-production biochar synthesis gas tar device according to claim 3, characterized in that: The operating temperature inside the high-temperature gasification chamber (6) is 750℃~900℃.

6. The biomass fluidized bed partial gasification co-production biochar synthesis gas tar device according to claim 1, characterized in that: The waste heat recovery device (7) can cool the high-temperature syngas generated by the low-temperature fluidized bed partial gasifier (2) to 300℃~400℃, so as to prevent the tar gas components contained in the high-temperature syngas from condensing into liquid phase components and depositing on the heated surface during the cooling process.

7. The biomass fluidized bed partial gasification co-production biochar synthesis gas tar device according to claim 1, characterized in that: The low-temperature fluidized bed gasifier (2) operates at atmospheric pressure.

8. The biomass fluidized bed partial gasification co-production biochar synthesis gas tar device according to claim 1, characterized in that: The cooling medium input to the waste heat recovery device (7) is water vapor, and the input temperature is 250℃~350℃.

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