System and method for comprehensively utilizing biomass

Abstract

The invention discloses a system and a method for comprehensively utilizing biomass. The device belongs to the technical field of biomass comprehensive utilization and comprises a plasma gas pyrolyzing furnace, a gas-liquid separation system, a plasma gas generation system and the like, the plasma gas pyrolyzing furnace is used for pyrolyzing biomass by using high-energy plasma gas as a heat carrier, and long chains of heavy fractions are broken through collision of high-energy particles; in the pyrolysis process, the high-energy plasma gas and pyrolysis gas generated by pyrolysis leave the pyrolysis furnace, one part of the high-energy plasma gas is stored for later use after being purified, and the other part of the high-energy plasma gas enters a plasma gas generation system. One part of the biomass gas entering the plasma gas generation system generates high-voltage direct current through the direct-current gas generator set, and energy is provided for the plasma generator to ionize the biomass gas. According to the invention, a high-energy plasma gas pyrolysis process is adopted, so that the temperature required by biomass pyrolysis is reduced, charcoal production and activation integration is realized, the process route of traditional biological activated carbon production is shortened, and the operation stability of the system is improved.

Description

Technical Field

[0001] The invention belongs to the field of biomass comprehensive utilization and relates to a system and method for biomass comprehensive utilization. Background Art

[0002] In our current life, although biomass resources are abundant, their effective utilization rate is very low due to their diverse types, scattered production areas and high transportation costs. At the same time, the areas where such resources are produced are often in remote areas, and a system that can efficiently utilize such resources and has less dependence on the outside world is needed to solve the problem.

[0003] At present, the comprehensive utilization of biomass pyrolysis is a very promising application direction. Through the biomass pyrolysis comprehensive utilization system, biomass is converted into biochar, biomass gas, high-quality bio-oil and other products. However, the current industrial biomass pyrolysis comprehensive utilization method is still in its infancy. There are problems such as the high temperature and high energy consumption required for the pyrolysis of the original biomass in the pyrolysis process, the low activity of the produced biochar, the need for additional activation equipment, the long process flow and high investment cost, and the tar and other heavy fractions produced during the pyrolysis process, which are prone to cause carbon deposition and blockage, and the system is unstable. This patent proposes a plasma gas heat carrier circulation pyrolysis technology to pyrolyze biomass under completely anaerobic conditions. The convective heat exchange greatly reduces the utilization rate of heat and reduces energy consumption. The impact of high-energy plasma can increase the activity of biochar during the pyrolysis process, eliminating the additional activation process, and reducing the production of heavy fractions. Improve the stability of the system operation.

[0004] In summary, based on the current situation of biomass utilization and the problems existing in the biomass charcoal making process, there is an urgent need for a system and method that is environmentally friendly, efficient, stable in operation, and high-value utilization of biomass. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to address the defects of the prior art and propose a system and method for comprehensive utilization of biomass. The plasma gas circulation pyrolysis technology is used to reduce the temperature required for biomass pyrolysis and reduce energy consumption, and realize the integration of biochar production and activation to improve the quality of biological activated carbon, reduce the generation of heavy fractions, and reduce problems such as carbon deposition in pipelines, which helps to improve the stability of system operation. At the same time, the system is not limited to the recycling of waste wood, but can also be used for the high-value utilization of waste biomass resources such as straw and rice husks in theory.

[0006] The technical solution of the present invention is: a system for comprehensive utilization of biomass according to the present invention comprises a gas cabinet, a plasma gas generation system, an ion gas pyrolysis furnace and a gas-liquid separation system which are interconnected;

[0007] The plasma gas generating system comprises a circulation pipeline and a gas direct current power generation system, a gas delivery regulator and a plasma generator which are interconnected.

[0008] Furthermore, the gas-fired DC power generation system comprises a DC gas-fired generator set and a high-voltage DC power supply;

[0009] Among them, the output power of the DC gas generator set is 50-100kW, and the output voltage of the high-voltage DC power supply is 5-10kV.

[0010] Furthermore, the plasma generator is a DC arc plasma generator, the main material of which is made of high-temperature resistant ceramics, the operating temperature of which is 5000-7500K, and the operating voltage of which is 5-10kV.

[0011] Furthermore, the gas-liquid separation system includes two stages of mutually connected scrubber towers and an intercooler.

[0012] Further, the gas cabinet is connected to the gas delivery regulator of the plasma gas generation system through the main pyrolysis gas pipeline, the gas delivery regulator is connected to the gas direct current power generation system through the power generation fuel pipeline, the gas direct current power generation system is connected to the plasma generator through the pipeline, and the other end of the gas delivery regulator is connected to the plasma generator through the gas heat carrier pipeline;

[0013] The other end of the plasma generator is connected to the ion gas pyrolysis furnace through a pipeline;

[0014] The other end of the ion gas pyrolysis furnace is connected to the two-stage scrubber tower of the gas-liquid separation system through pipelines, the other end of the scrubber tower is connected to the intercooler through pipelines, and the other end of the intercooler is connected to the gas cabinet through pipelines.

[0015] Furthermore, the ion gas pyrolysis furnace and the scrubber tower of the gas-liquid separation system work through pyrolysis gas, the temperature of which is 400°C-450°C;

[0016] The intercooler and the gas holder work through clean pyrolysis gas, the temperature of which is 50°C-70°C.

[0017] Furthermore, the working steps of the system for comprehensive utilization of biomass are as follows:

[0018] Step 1: The biomass fuel obtained from the outside enters the plasma gas generation system through the gas cabinet after being crushed and dried;

[0019] Step 2: After the treated biomass enters the plasma gas generation system, the volatile matter is first separated out, and then it continues to move downward into the ion gas pyrolysis furnace;

[0020] Step 3: The char and heavy fractions encounter the high-energy plasma gas introduced from the bottom of the ion gas pyrolysis furnace. The high-energy plasma breaks the long chains of the heavy fractions through high-speed impact, thereby reducing the production of tar and increasing the yield of activated carbon and pyrolysis gas.

[0021] Step 4: The heavy fraction is fractured and separated to produce a porous structure in the carbonaceous solid residue. Plasma gases with different electrical properties can consolidate this structure to obtain activated carbon.

[0022] Step 5: The gas products produced during the pyrolysis process leave the ion gas pyrolysis furnace and enter the gas-liquid separation system, thereby obtaining pure biomass gas, wood vinegar and high-quality bio-oil;

[0023] Step 6: Part of the pure biomass gas is stored for backup, and part of it enters the plasma gas generation system through the gas cabinet to regenerate the pyrolysis gas, ionize it to produce high-energy plasma heat carrier, and then return to the ion gas pyrolysis furnace to complete the cycle.

[0024] Furthermore, the biomass in the ion gas pyrolysis furnace is countercurrently heated by high-energy plasma gas as a gas heat carrier, and after stable operation, it can work continuously without external energy, and biochar activation is simultaneously achieved during the pyrolysis process.

[0025] Furthermore, the high-energy plasma gas comprises carbon monoxide particles, methane ions, hydrogen ions and electrons, and has a temperature of 450-550° C., a pressure of 0.1-0.15 MPa, and an ion collision frequency of 10 6 -10 7 s -1 .

[0026] Furthermore, the high-quality bio-oil is composed of one of hexane, cyclohexanone, phenol, methylphenol, benzene or xylene.

[0027] The beneficial effects of the present invention are as follows: 1. The present invention utilizes gas heat carriers with higher energy utilization efficiency than traditional external heating. The use of high-energy plasma gas heat carriers reduces the temperature required for biomass pyrolysis, saves 20-30% energy compared to traditional pyrolysis processes, and has a lower degree of dependence on external energy; 2. The present invention shortens the process flow of bioactivated carbon production through plasma gas heat carrier pyrolysis, and the texture of the obtained charcoal is more uniform, and the specific surface area of ​​the activated carbon meets the national high-quality activated carbon standard; 3. The present invention adopts plasma gas heat carrier pyrolysis to decompose wood tar into charcoal and light fractions, and the generation of heavy fractions is reduced by more than 90%. While improving the economic benefits of the product, it reduces problems such as tar blockage, and the system operation is more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1It is a schematic diagram of the workflow of the present invention;

[0029] In the figure, 1 is a gas cabinet, 2 is a plasma gas generating system, 3 is an ion gas pyrolysis furnace, and 4 is a gas-liquid separation system. DETAILED DESCRIPTION

[0030] The specific technical scheme of the present invention is further described in detail below with reference to specific examples.

[0031] As shown in the figure, a system for comprehensive utilization of biomass according to the present invention comprises a gas cabinet 1, a plasma gas generating system 2, an ion gas pyrolysis furnace 3 and a gas-liquid separation system 4. The ion gas pyrolysis furnace 3 utilizes high-energy plasma gas as a heat carrier to pyrolyze biomass, and the collision of high-energy particles causes the long chains of heavy fractions to break, leaving more holes on the activated carbon to improve the activity of the activated carbon.

[0032] During the pyrolysis process, the high-energy plasma gas gradually loses energy, and the ion gas generated by the pyrolysis is purified by the gas-liquid separation system 4, and a part of it is stored for standby use, and a part of it enters the plasma gas generation system 2 through the gas cabinet 1;

[0033] A portion of the biomass gas entering the plasma gas generation system 2 generates high-voltage direct current through the direct current gas power generation system, providing energy for the plasma generator to ionize the biomass gas, generating high-energy plasma gas heat carriers that enter the ion gas pyrolysis furnace 3 to complete the cycle.

[0034] Furthermore, a method for the system of comprehensive utilization of biomass comprises the following steps:

[0035] S1. The biomass fuel obtained from the outside is crushed and dried and then enters the plasma gas generation system 2 through the gas cabinet 1;

[0036] S2. The treated biomass enters the ion gas pyrolysis furnace 3 through the plasma gas generation system 2, and then volatiles are first separated, and then continue to move downward;

[0037] S3. The char and heavy fractions encounter the high-energy plasma gas introduced from the bottom of the ion gas pyrolysis furnace 3. The high-energy plasma breaks the long chains of the heavy fractions through high-speed impact, reduces the production of tar, and increases the yield of activated carbon and pyrolysis gas;

[0038] S4. The fracture and precipitation of heavy fractions produce more porous structures in the carbonaceous solid residues. Plasma gases with different electrical properties can consolidate this structure and directly obtain high-quality activated carbon.

[0039] S5. The gaseous products produced during the pyrolysis process leave the ion gas pyrolysis furnace 3 and enter the gas-liquid separation system 4 to obtain pure biomass gas, wood vinegar and high-quality bio-oil;

[0040] S6. A portion of the pure biomass fuel gas is stored for backup, and a portion of it enters the plasma gas generation system 2 through the gas cabinet 1 again to regenerate the pyrolysis gas ionization to generate high-energy plasma heat carriers and return to the ion gas pyrolysis furnace 3 to complete the cycle.

[0041] Furthermore, the biomass raw material is pretreated. Taking wood as an example, the raw material is graded, crushed and dried. The size of the obtained wood is preferably 50-150 mm, and the moisture content is less than 10%.

[0042] Furthermore, the biomass in the ion gas pyrolysis furnace 3 is countercurrently heated by high-energy plasma gas as a gas heat carrier. After stable operation, it can work continuously without external energy, and biochar activation is simultaneously achieved during the pyrolysis process. Compared with the side wall heat exchange method of the traditional pyrolysis furnace, the temperature required for biomass pyrolysis is reduced by 100 to 150°C, and the thermal efficiency is increased by 20 to 30%.

[0043] Furthermore, during the pyrolysis process of the high-energy plasma gas heat carrier, the generation of heavy fractions is reduced and more pores are generated by high-energy plasma impact, and the specific surface area of ​​the obtained activated carbon reaches 1500m 2 / g or more

[0044] Furthermore, the main components of the high-energy plasma gas are carbon monoxide particles, methane ions, hydrogen ions and electrons, the temperature is preferably 450-550° C., the pressure is preferably 0.1-0.15 MPa, and the ion collision frequency is preferably 10 6 -10 7 s -1 , the plasma potential is preferably 5-10V.

[0045] Furthermore, the plasma gas generating system 2 includes a circulation pipeline, a gas direct current power generation system, a gas delivery regulator and a plasma generator.

[0046] Furthermore, the circulation pipeline includes a total pyrolysis gas pipeline, which is divided into two paths of power generation fuel and gas heat carrier through a gas regulating conveyor. The power generation fuel pipeline is connected to the DC gas generator set, and the gas heat carrier pipeline is connected to the plasma generator. The flow ratio between the two is 4:1. The high-energy plasma gas heat carrier generated in the plasma generator is transported back to the pyrolysis furnace through the plasma gas heat carrier pipeline.

[0047] Furthermore, the pyrolysis gas pipeline, power generation fuel pipeline and gas heat carrier pipeline materials are preferably 304 stainless steel pipelines, and the plasma gas heat carrier pipeline material is preferably alumina ceramic material.

[0048] Furthermore, the gas-fired DC power generation system mainly includes a gas-fired DC generator set and a high-voltage DC power supply, wherein the output power of the gas-fired DC generator set is 50-100kW, and the output voltage of the high-voltage DC power supply is 5-10kV.

[0049] Furthermore, the plasma generator is a DC arc plasma generator, which adopts a pulse working mode, the main material is made of high-temperature resistant ceramics, the electrode material is a tungsten electrode, the operating temperature is preferably 5000-7500K, the ionization voltage is preferably 5-10kV, and the ionization current is preferably 10A; the ionization gas pressure is preferably 0.1-0.15MPa, and the gas flow rate is preferably 50-100slpm.

[0050] Furthermore, the gas-liquid separation system 4 comprises two-stage scrubbing towers, an intercooler and a product collection pool. The temperature of the pyrolysis gas after the two-stage scrubbing towers is preferably below 240°C, and the temperature of the pyrolysis gas after the intercooler is preferably below 70°C.

[0051] Furthermore, the main components of the high-quality bio-oil are light fractions with high calorific value and good combustion performance, such as hexane, cyclohexanone, phenol, methylphenol, benzene, and xylene.

[0052] Example 1

[0053] The discarded lychee wood is sent to the raw material pretreatment system, broken into small pieces of 100 mm, and then dried with hot air generated by biochar cooling to a moisture content of less than 10%, and then sent to the ion gas pyrolysis furnace 3 by the feeder (gas cabinet 1, plasma gas generation system 2).

[0054] The heat carrier pyrolysis gas is introduced into the ion gas pyrolysis furnace 3, and the temperature is controlled at 450°C. After the fruit wood is heated in the ion gas pyrolysis furnace 3, it is decomposed into solid fruit wood charcoal and gaseous pyrolysis gas. The obtained pyrolysis gas enters the gas-liquid separation system 4 through the pipeline above the pyrolysis furnace. The charcoal further reacts with the high-energy plasma gas heat carrier in the lower part of the ion gas pyrolysis furnace 3 to produce more charcoal and pyrolysis gas and complete activation, and then enters the hot charcoal cooling chamber; when the activated carbon is discharged from the pyrolysis furnace, it first enters the intermittent sealed chamber, and is sprayed with inert gas or water mist to make it The temperature is reduced to below 200℃, completing the first stage of cooling to avoid re-ignition; then the activated carbon is sent to the storage and packaging workshop through a wire mesh conveyor or a cooling scraper conveyor. During this transportation stage, the activated carbon can be further cooled to below 40℃ by natural wind or circulating cooling water in the cooling scraper conveyor to meet storage or packaging requirements; the wire mesh conveyor or the cooling scraper conveyor can minimize the breakage loss of activated carbon caused by the transportation process, and the heat collected during the cooling process can be used for raw material drying and combustion support;

[0055] After the pyrolysis gas enters the gas-liquid separation system 4, it passes through a two-stage spray scrubber. The spray water used in the scrubber is taken from the upper layer of the circulating water pool. The main components are circulating water and a small amount of acetic acid, light tar, etc. The dry distillation gas is cooled with the circulating water in the tower, and a small amount of large molecular tar substances condense into droplets and flow to the circulating water pool with the circulating water. Since the large molecular tar substances have a greater specific gravity than water, they gradually precipitate in the circulating water pool and gradually form a tar layer at the bottom. The precipitated tar is regularly extracted from the bottom through a plunger pump; circulating water The top of the pool contains light tar and some circulating water, as well as a small amount of acetic acid, which can be regularly extracted and sent to the vinegar liquid pool; after the pyrolysis gas in the scrubber, the temperature is reduced to below 240°C, and enters the intercooler, where it exchanges heat with the cooling water in the intercooler and is cooled to below 70°C. Since the boiling points of acetic acid and some effective components such as phenol and naphthalene are between 80-180°C, the effective components of this part of the wood vinegar are concentrated in the intercooler to form a liquid through the condensation effect of the intercooler, and flow to the vinegar liquid pool to form crude vinegar liquid. The cooled fuel gas passes through the electric light oil collector to capture the last remaining light oil, and then is sent to gasholder 1 for standby;

[0056] The pyrolysis gas in the gas cabinet has two uses, one part is sold as a commodity, and the other part enters the plasma gas generation system. Part of the biomass gas entering the plasma gas generation system 2 generates high-voltage direct current through the DC gas power generation system, providing energy for the plasma generator to ionize the biomass gas, generate high-energy plasma gas heat carriers, and enter the ion gas pyrolysis furnace 3 to complete the cycle.

[0057] After the operating state is stable, collect the activated carbon, wood vinegar, and pyrolysis gas for later use and record the continuous working time of the system.

[0058] Example 2

[0059] The waste straw is sent to the raw material pretreatment system, broken into small segments of 100 mm, and then dried by hot air generated by biochar cooling until the moisture content is less than 10%, and then sent to the ion gas pyrolysis furnace 3 by the feeder;

[0060] The heat carrier pyrolysis gas is introduced into the ion gas pyrolysis furnace 3, and the temperature is controlled at 450°C. After the straw is heated in the ion gas pyrolysis furnace 3, it is decomposed into solid biomass charcoal and gaseous pyrolysis gas. The obtained pyrolysis gas enters the gas-liquid separation system 4 through the pipeline above the ion gas pyrolysis furnace 3. The biochar further reacts with the high-energy plasma gas heat carrier below the ion gas pyrolysis furnace 3 to produce more charcoal and pyrolysis gas and complete activation, and then enters the hot charcoal cooling bin; when the activated carbon is discharged from the ion gas pyrolysis furnace 3, it first enters the intermittent sealed bin and is cooled by inert gas or water. The spraying of mist cools the activated carbon to below 200℃, completing the first stage of cooling to avoid re-ignition; then the activated carbon is sent to the storage and packaging workshop through a wire mesh conveyor or a cooling scraper conveyor. During this transportation stage, the activated carbon can be further cooled to below 40℃ by natural wind or circulating cooling water in the cooling scraper conveyor to meet storage or packaging requirements; the wire mesh conveyor or the cooling scraper conveyor can minimize the breakage loss of activated carbon caused by the transportation process, and the heat collected during the cooling process can be used for raw material drying and combustion support;

[0061] After the pyrolysis gas enters the gas-liquid separation system 4, it passes through a two-stage spray scrubber. The spray water used in the scrubber is taken from the upper layer of the circulating water pool. The main components are circulating water and a small amount of acetic acid, light tar, etc. The dry distillation gas is cooled with the circulating water in the tower, and a small amount of large molecular tar substances condense into droplets and flow to the circulating water pool with the circulating water. Since the large molecular tar substances have a greater specific gravity than water, they gradually precipitate in the circulating water pool and gradually form a tar layer at the bottom. The precipitated tar is regularly extracted from the bottom through a plunger pump; circulating water The top of the pool contains light tar and some circulating water, as well as a small amount of acetic acid, which can be regularly extracted and sent to the vinegar liquid pool; after the pyrolysis gas in the scrubber, the temperature is reduced to below 240°C, and enters the intercooler, where it exchanges heat with the cooling water in the intercooler and is cooled to below 70°C. Since the boiling points of acetic acid and some effective components such as phenol and naphthalene are between 80-180°C, the effective components of this part of the wood vinegar are concentrated in the intercooler to form a liquid through the condensation effect of the intercooler, and flow to the vinegar liquid pool to form crude vinegar liquid. The cooled fuel gas passes through the electric light oil collector to capture the last remaining light oil, and then is sent to gasholder 1 for standby;

[0062] The pyrolysis gas in the gas cabinet 1 has two uses, one part is sold as a commodity, and the other part enters the plasma gas generation system 2; a part of the biomass gas entering the plasma gas generation system 2 generates high-voltage direct current through the direct current gas power generation system, which provides energy for the plasma generator to ionize the biomass gas, and generates high-energy plasma gas heat carriers to enter the ion gas pyrolysis furnace 3 to complete the cycle;

[0063] After the operating state is stable, collect the activated carbon, wood vinegar, and pyrolysis gas for later use and record the continuous working time of the system.

[0064] Comparative Example 1

[0065] The discarded lychee wood is sent to the raw material pretreatment system, broken into small pieces of 100 mm, and then dried to a moisture content of less than 10% using the hot air generated by the cooling of the biochar, and then sent to the pyrolysis furnace by the feeder.

[0066] The most commonly used pyrolysis furnace in the traditional biomass pyrolysis process is the rotary kiln pyrolysis furnace. After the biomass raw material enters the rotary kiln through the feed port, it moves forward under the rotation of the kiln body. The gas burner generates heat by burning gas, and then provides heat to the biomass by rotating to contact the kiln wall. The required temperature is 500-600℃. During the rotation process, the biomass is gradually decomposed by heat. When the temperature gradually rises to above 300℃, some volatile organic matter in the biomass begins to decompose, releasing a small amount of pyrolysis gas and wood tar. The components of wood tar at this time are mainly some light organic compounds, such as alcohols, phenols, aldehydes, etc., which form pyrolysis gas. As the temperature continues to rise to 500℃, the cellulose, hemicellulose and lignin in the biomass begin to decompose on a large scale, forming a large amount of wood tar, pyrolysis gas and biochar. The output of wood tar is large at this stage, containing a complex mixture of organic compounds. These liquid products can collect wood tar and biochar products after condensation. After the biochar is discharged from the kiln, it needs to enter the activation furnace, and after the temperature is raised to 800-1000℃, activation gases such as water vapor, carbon dioxide, or oxygen are injected into the furnace. These gases react with the carbon in the carbonized material at high temperature to produce CO and CO 2 , and form a large number of micropores and mesopores. After the activation is completed, stop injecting the activation gas and gradually reduce the temperature in the furnace. Usually use cooling gas (such as nitrogen) or natural cooling to avoid sudden cooling that may cause structural damage to the activated carbon. The waste gas (such as CO, CO 2 and other volatile organic compounds) need to be treated by the exhaust gas treatment system to ensure that the emissions meet environmental protection standards.

[0067] After the pyrolysis gas enters the gas-liquid separation system, it passes through a two-stage spray scrubber. The spray water used in the scrubber is taken from the upper layer of the circulating water pool. The main components are circulating water and a small amount of acetic acid, light tar, etc. The dry distillation gas is cooled with the circulating water in the tower, and a small amount of large molecular tar substances condense into droplets and flow to the circulating water pool with the circulating water. Since the specific gravity of large molecular tar substances is greater than that of water, they gradually precipitate in the circulating water pool and gradually form a tar layer at the bottom. The precipitated tar is regularly extracted from the bottom through a plunger pump; circulating water pool The top contains light tar and some circulating water, as well as a small amount of acetic acid, which can be regularly extracted and sent to the vinegar liquid pool; after the pyrolysis gas in the scrubber, the temperature is reduced to below 240°C, and enters the intercooler, where it exchanges heat with the cooling water in the intercooler and is cooled to below 70°C. Since the boiling points of acetic acid and some effective components such as phenol and naphthalene are between 80-180°C, through the condensation of the intercooler, the effective components of this part of the wood vinegar are concentrated in the intercooler to form a liquid, and flow to the vinegar liquid pool to form a crude vinegar liquid. The cooled gas passes through the electric light oil collector, captures the last remaining light oil, and is then sent to the gas holder for standby use.

[0068] After the operating state is stable, collect activated carbon, wood tar, wood tar, and pyrolysis gas for use and record the continuous working time of the system.

[0069] Comparative Example 2

[0070] The straw is fed into the raw material pretreatment system, broken into small pieces of 100 mm, and then dried using the hot air generated by biochar cooling to a moisture content of less than 10%, and then fed into the pyrolysis furnace by a feeder.

[0071] The most commonly used pyrolysis furnace in the traditional biomass pyrolysis process is the rotary kiln pyrolysis furnace. After the biomass raw material enters the rotary kiln through the feed port, it moves forward under the rotation of the kiln body. The gas burner generates heat by burning gas, and then provides heat to the biomass by rotating to contact the kiln wall. The required temperature is 500-600℃. During the rotation process, the biomass is gradually decomposed by heat. When the temperature gradually rises to above 300℃, some volatile organic matter in the biomass begins to decompose, releasing a small amount of pyrolysis gas and wood tar. The components of wood tar at this time are mainly some light organic compounds, such as alcohols, phenols, aldehydes, etc., which form pyrolysis gas. As the temperature continues to rise to 500℃, the cellulose, hemicellulose and lignin in the biomass begin to decompose on a large scale, forming a large amount of wood tar, pyrolysis gas and biochar. The output of wood tar is large at this stage, containing a complex mixture of organic compounds. These liquid products can collect wood tar and biochar products after condensation. After the biochar is discharged from the kiln tail, it needs to enter the activation furnace. After the temperature is raised to 800-1000℃, the activation gas such as water vapor, carbon dioxide, or oxygen is injected into the furnace. These gases react with the carbon in the carbonized material at high temperature to generate CO and CO2, and form a large number of micropores and mesopores. After the activation is completed, the injection of the activation gas is stopped and the temperature in the furnace is gradually reduced. Usually, cooling gas (such as nitrogen) or natural cooling is used for cooling to avoid sudden cooling that may cause structural damage to the activated carbon. The waste gas generated during the activation process (such as CO, CO2 and other volatile organic compounds) needs to be treated by the waste gas treatment system to ensure that the emissions meet environmental standards.

[0072] After the pyrolysis gas enters the gas-liquid separation system, it passes through a two-stage spray scrubber. The spray water used in the scrubber is taken from the upper layer of the circulating water pool. The main components are circulating water and a small amount of acetic acid, light tar, etc. The dry distillation gas is cooled with the circulating water in the tower, and a small amount of large molecular tar substances condense into droplets and flow to the circulating water pool with the circulating water. Since the specific gravity of large molecular tar substances is greater than that of water, they gradually precipitate in the circulating water pool and gradually form a tar layer at the bottom. The precipitated tar is regularly extracted from the bottom through a plunger pump; circulating water pool The top contains light tar and some circulating water, as well as a small amount of acetic acid, which can be regularly extracted and sent to the vinegar liquid pool; after the pyrolysis gas in the scrubber, the temperature is reduced to below 240°C, and enters the intercooler, where it exchanges heat with the cooling water in the intercooler and is cooled to below 70°C. Since the boiling points of acetic acid and some effective components such as phenol and naphthalene are between 80-180°C, through the condensation of the intercooler, the effective components of this part of the wood vinegar are concentrated in the intercooler to form a liquid, and flow to the vinegar liquid pool to form a crude vinegar liquid. The cooled gas passes through the electric light oil collector, captures the last remaining light oil, and is then sent to the gas holder for standby use.

[0073] After the operating state is stable, collect activated carbon, wood tar, wood tar, and pyrolysis gas for use and record the continuous working time of the system.

[0074] Table 1 summarizes the input-output of a biomass comprehensive utilization system and traditional biomass comprehensive utilization methods for different raw materials after the system reaches a steady state

[0075]

Claims

1. A system for comprehensive utilization of biomass, characterized in that: It comprises a gas cabinet (1), a plasma gas generation system (2), an ion gas pyrolysis furnace (3) and a gas-liquid separation system (4) which are interconnected; The plasma gas generation system (2) comprises a circulation pipeline and a gas direct current power generation system, a gas delivery regulator and a plasma generator which are interconnected.

2. A system for comprehensive utilization of biomass according to claim 1, characterized in that: The gas direct current power generation system comprises a direct current gas generator set and a high voltage direct current power supply; Among them, the output power of the DC gas generator set is 50-100kW, and the output voltage of the high-voltage DC power supply is 5-10kV.

3. A system for comprehensive utilization of biomass according to claim 1, characterized in that The plasma generator is a DC arc plasma generator, the main material of which is made of high-temperature resistant ceramics, the operating temperature of which is 5000-7500K, and the operating voltage of which is 5-10kV.

4. A system for comprehensive utilization of biomass according to claim 1, characterized in that The gas-liquid separation system (3) comprises two stages of mutually connected scrubber towers and an intercooler.

5. The system for comprehensive utilization of biomass according to claim 1, characterized in that: The gas cabinet (1) is connected to a gas delivery regulator of a plasma gas generation system (2) through a total pyrolysis gas pipeline, the gas delivery regulator is connected to a gas-fired direct current power generation system through a power generation fuel pipeline, the gas-fired direct current power generation system is connected to a plasma generator through a pipeline, and the other end of the gas delivery regulator is connected to the plasma generator through a gas heat carrier pipeline; The other end of the plasma generator is connected to the ion gas pyrolysis furnace (3) through a pipeline; The other end of the ion gas pyrolysis furnace (3) is successively connected to the two-stage scrubber tower of the gas-liquid separation system (4) through pipelines, the other end of the scrubber tower is connected to the intercooler through pipelines, and the other end of the intercooler is connected to the gas cabinet (1) through pipelines.

6. A system for comprehensive utilization of biomass according to claim 5, characterized in that: The ion gas pyrolysis furnace (3) and the scrubber tower of the gas-liquid separation system (4) work through pyrolysis gas, the temperature of which is 400° C.-450° C.; The intercooler and the gas cabinet (1) work via clean pyrolysis gas, the temperature of which is between 50°C and 70°C.

7. A working method of a system for comprehensive utilization of biomass according to any one of claims 1 to 6, characterized in that: The working steps are as follows: Step 1: The biomass fuel obtained from the outside is crushed and dried and then enters the plasma gas generation system (2) through the gas cabinet (1); Step 2: After the treated biomass enters the plasma gas generation system (2), volatile matter is first precipitated, and then it continues to move downward into the ion gas pyrolysis furnace (3); Step 3: The char and heavy fractions encounter high-energy plasma gas introduced from the bottom of the ion gas pyrolysis furnace (3). The high-energy plasma breaks the long chains of the heavy fractions through high-speed impact, thereby reducing the production of tar and increasing the yield of activated carbon and pyrolysis gas. Step 4: The heavy fraction is fractured and separated to produce a porous structure in the carbonaceous solid residue. Plasma gases with different electrical properties can consolidate this structure to obtain activated carbon. Step 5: The gaseous products produced during the pyrolysis process leave the ion gas pyrolysis furnace (3) and enter the gas-liquid separation system (4), thereby obtaining pure biomass gas, wood vinegar and high-quality bio-oil; Step 6: A portion of the pure biomass gas is stored for standby use, and a portion enters the plasma gas generation system (2) through the gas cabinet (1) to regenerate the pyrolysis gas for ionization to generate high-energy plasma heat carriers that return to the ion gas pyrolysis furnace (3) to complete the cycle.

8. The working method of a system for comprehensive utilization of biomass according to claim 7, characterized in that: The biomass in the ion gas pyrolysis furnace (3) is countercurrently heated by high-energy plasma gas as a gas heat carrier, and after stable operation, it can work continuously without the need for external energy, and biochar activation is simultaneously achieved during the pyrolysis process.

9. The working method of a system for comprehensive utilization of biomass according to claim 7, characterized in that: The high-energy plasma gas is composed of carbon monoxide particles, methane ions, hydrogen ions and electrons, with a temperature of 450-550°C, a pressure of 0.1-0.15 MPa, and an ion collision frequency of 10 6 -10 7 s -1 .

10. The working method of a system for comprehensive utilization of biomass according to claim 7, characterized in that: The high-quality bio-oil comprises one of hexane, cyclohexanone, phenol, methylphenol, benzene or xylene.

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