Tar self-refluxing biomass gasification device and gasification method

Abstract

This invention relates to the field of biomass treatment technology, and more particularly to a tar self-recirculation biomass gasification device and method. The invention includes a gasifier, a spray-washing radiator, a wood vinegar condenser, and a jet mixer. The gasifier includes a waste heat evaporator and a biomass gasifier, the latter being internally divided into a dry distillation section, a redox section, and a combustion chamber. The spray-washing radiator includes a crude wood vinegar collection tank, an air-cooled radiator, and a demister. The dry distillation section and the redox section are respectively connected to the crude wood vinegar collection tank, the lower end of which is connected to the waste heat evaporator. The wood vinegar vapor outlet and tar outlet on the waste heat evaporator are respectively connected to the jet mixer via pipelines. The wood vinegar vapor outlet is also connected to the condenser via a pipeline, and the jet mixer outlet is connected to the combustion chamber. This biomass gasification device achieves in-situ high-temperature tar disposal and efficient waste heat utilization through tar separation and recirculation, realizing stable system operation and high-value utilization of by-products.

Description

Technical Field

[0001] This invention relates to the field of biomass treatment technology, and in particular to a tar self-recirculation biomass gasification device and gasification method. Background Technology

[0002] Biomass gasification is an important way to realize the resource and energy utilization of agricultural and forestry waste. However, current traditional biomass gasification devices generally face a series of technical challenges: (1) The gasification process produces a large amount of tar, which can easily clog pipelines and corrode equipment. Conventional water washing and discharge can easily cause secondary pollution. Catalytic cracking has high cost and poor stability. (2) The gasifier temperature fluctuates greatly and lacks precise automatic control, which can easily lead to problems such as low-temperature flameout, tar accumulation, and large fluctuations in the calorific value of the gas. (3) The waste heat of high-temperature reducing gas has not been utilized efficiently in stages, resulting in low energy utilization rate; (4) The separation effect of crude wood vinegar and tar is poor, and the by-products are difficult to utilize in a high-value manner.

[0003] Therefore, existing technologies cannot achieve integrated and coordinated operation of tar reflux, high-temperature pyrolysis and reburning, waste heat recovery and wood vinegar co-production, and cannot fundamentally solve common industry problems such as tar pollution, low calorific value and poor system stability. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings in the prior art, the present invention provides a tar self-recirculation biomass gasification device and gasification method. The biomass gasification device achieves in-situ high-temperature tar consumption and efficient utilization of waste heat through tar separation and back injection, thereby realizing stable system operation and high-value by-products.

[0005] The technical solution of the present invention is: a tar self-recirculation biomass gasification device, comprising a gasifier, a spray water washing heat dissipation tower, a wood vinegar condenser, and a jet mixer; The gasifier includes a waste heat evaporator and a biomass gasifier. The biomass gasifier is equipped with a grate inside, and the grate is divided into a dry distillation section, an oxidation-reduction section and a combustion chamber by several longitudinal baffles. The spray water washing heat dissipation tower includes a coarse wood vinegar collection tank, and an air-cooled radiator and a demister are arranged in sequence above the coarse wood vinegar collection tank. The demister is provided with a biomass mixed gas outlet at the upper end, and a spray pump is connected to the upper side wall of the spray water washing heat dissipation tower through a spray inlet. A screw feeder is connected to one side of the dry distillation section in the gasifier. The dry distillation section and the oxidation-reduction section are respectively connected to the coarse wood vinegar collection tank through different pipes. The lower end of the coarse wood vinegar collection tank is connected to the waste heat evaporator through a pipe. The upper part of the waste heat evaporator is provided with a wood vinegar vapor outlet, which is connected to a condenser and a jet mixer through pipes. The lower part of the waste heat evaporator is provided with a tar outlet, which is connected to the jet mixer through a pipe. The outlet of the jet mixer is connected to the combustion chamber.

[0006] Furthermore, the air-cooled radiator is connected to a blower on one side and has an air outlet on the other side. The bottom of the grate in the biomass gasifier is provided with an air inlet, and the air outlet and the air inlet are connected by a pipe.

[0007] Furthermore, the biomass gasifier has a slag outlet at the bottom of the combustion chamber and a temperature detection port at the top of the combustion chamber, with a temperature sensor installed on the temperature detection port.

[0008] Furthermore, the biomass gasifier is provided with a first partition, a second partition, and a third partition from left to right inside; a dry distillation gas outlet is opened on the top plate of the biomass gasifier between the first and second partitions, and the dry distillation gas outlet is connected to the coarse wood vinegar collection tank through a pipe; a high-temperature reducing gas outlet is opened on the top plate of the biomass gasifier between the second and third partitions, and the high-temperature reducing gas outlet is connected to the high-temperature reducing gas inlet on the waste heat evaporator, and the high-temperature reducing gas inlet is connected to the coarse wood vinegar collection tank through a pipe.

[0009] Furthermore, the upper end of the first partition is connected to the left side plate of the biomass gasifier, and the lower end is located above the front end of the grate; the upper end of the second partition is connected to the top plate of the biomass gasifier, and the lower end corresponds to the middle section of the grate; the upper end of the third partition is connected to the top plate of the biomass gasifier, and the lower end corresponds to the rear section of the grate.

[0010] Furthermore, a reflux valve is installed on the pipeline between the coarse wood vinegar collection tank and the waste heat evaporator.

[0011] Furthermore, a wood vinegar vapor ejector valve is installed on the pipe between the wood vinegar vapor outlet and the jet mixer; a tar reflux valve is installed on the pipe between the tar outlet and the jet mixer.

[0012] Furthermore, the wood vinegar condenser has a wood vinegar vapor inlet at the upper end and a distilled wood vinegar outlet at the lower end. The wood vinegar vapor inlet is connected to the wood vinegar vapor outlet on the waste heat evaporator, and the distilled wood vinegar outlet is connected to the refined wood vinegar collection tank.

[0013] A method for tar self-reflux biomass gasification using the aforementioned device includes the following steps: S1. Biomass pellets are fed into the dry distillation section of the biomass gasifier via a screw feeder. Dry distillation produces dry distillation mixed gas and semi-coke. The semi-coke is fed into the oxidation-reduction section by the grate to generate high-temperature reducing gas, and the high-temperature residual carbon is fed into the combustion chamber by the grate. S2, the dry distillation mixed gas and the high-temperature reducing gas both enter the spray water washing radiator. After being sprayed and washed, cooled by the air-cooled radiator and demisted by the demister, the purified gas is discharged from the top biomass mixed gas outlet, and the separated coarse wood vinegar flows downward into the coarse wood vinegar collection tank. S3. The coarse wood vinegar collected in the coarse wood vinegar collection tank enters the waste heat evaporator for waste heat separation. At the same time, the high-temperature reducing gas generated in the oxidation-reduction section passes through the waste heat evaporator as a heat source to heat the coarse wood vinegar, thereby achieving the separation of tar and wood vinegar vapor. S4. When the temperature in the combustion chamber is ≥500℃, the tar return valve and the wood vinegar vapor ejector valve are opened, and the tar and wood vinegar vapor enter the injection mixer. The injection mixer injects them into the combustion chamber for high-temperature pyrolysis and combustion. The combustion products enter the oxidation-reduction section to be reformed into fuel gas. When the temperature inside the combustion chamber is <500℃, the tar return valve and the wood vinegar vapor ejector valve are closed, and the wood vinegar vapor enters the condenser to condense into distilled wood vinegar, which is then collected by the refined wood vinegar collection tank.

[0014] Furthermore, in step S4, the blower sends air into the air-cooled radiator for preheating, and then enters the combustion chamber as combustion air.

[0015] The present invention has the following beneficial effects: By adopting the above scheme, the waste heat of the high-temperature reducing gas generated by the biomass gasifier is used to heat the wood vinegar in the waste heat evaporator, so that the tar is automatically separated and deposited at the bottom of the waste heat evaporator. It then enters the injection mixer through the tar return pipe. At the same time, the crude wood vinegar is converted into wood vinegar vapor. The wood vinegar vapor is used as the power source for the injection mixer to inject the tar and wood vinegar together into the combustion chamber. The high-temperature residual carbon in the combustion chamber is used to ignite the oxygen-enriched combustion, producing carbon dioxide and tar cracking gas that flow counter-currently into the oxidation-reduction zone, thereby improving the calorific value and output of the fuel gas, while also solving the problem of tar pollution. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention.

[0017] In the diagram: 1-Gasifier, 2-Spray water washing heat dissipation tower, 3-Wood vinegar condenser, 4-Jet mixer, 101-Waste heat evaporator, 102-Biomass gasifier, 103-Screw feeder, 104-Slag discharger, 105-Grate, 106-First baffle, 107-Second baffle, 108-Third baffle, 109-Diesel section, 110-Oxidation-reduction section, 111-Combustion chamber, 112-Feed inlet, 113-Diesel gas outlet, 114-High-temperature reducing gas outlet, 115-Slag outlet, 116-Tar return spray pipe, 117-Temperature detection port, 118-Air inlet, 119-High-temperature reducing gas inlet, 120-Reducing gas outlet. 121-Level gauge, 122-Tar outlet, 123-Wood vinegar vapor outlet, 124-Crude wood vinegar inlet, 201-Crude wood vinegar collection tank, 202-Air-cooled radiator, 203-Demister, 204-Dry distillation gas inlet, 205-Reducing gas inlet, 206-Crude wood vinegar outlet, 207-Reflux valve, 208-Spray pump, 209-Blower, 210-Air outlet, 211-Biomass mixed gas outlet, 212-Spray inlet, 301-Wood vinegar vapor inlet, 302-Refined wood vinegar outlet, 303-Refined wood vinegar collection tank, 401-Temperature sensor, 402-Tar reflux valve, 403-Wood vinegar vapor ejector valve. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as "upper," "lower," "left," "right," "inner," "outer," "top," and "bottom" are based on the orientations or positional relationships shown in the accompanying drawings. They are intended only to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the components referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] Depend on Figure 1 As shown, a tar self-recirculation biomass gasification device includes a gasifier 1, a spray water washing heat dissipation tower 2, a wood vinegar condenser 3, and a jet mixer 4.

[0021] The gasifier 1 includes a waste heat evaporator 101, a biomass gasifier 102, a screw feeder 103, and a slag discharger 104. The waste heat evaporator 101 is located above the biomass gasifier 102. The biomass gasifier 102 has a feed inlet 112 on its side wall, and the screw feeder 103 is connected to the feed inlet 112. The slag discharger 104 is located at the bottom of the biomass gasifier 102 and corresponds to the slag discharge port 115 of the biomass gasifier 102.

[0022] The biomass gasifier 102 has a grate 105 at its inner bottom. A drive device is connected to the end of the grate 105, which can drive the grate 105 to swing and transport the material on the grate 105 forward. An air inlet 118 is opened on the bottom plate of the biomass gasifier 102 at the bottom of the grate 105. Air discharged from the spray water washing radiator 2 enters the biomass gasifier 102 through the air inlet 118 for combustion. The grate 105 is divided into a dry distillation section 109, an oxidation-reduction section 110, and a combustion chamber 111 by several longitudinal baffles. The partitions, from left to right, are a first partition 106, a second partition 107, and a third partition 108. The upper end of the first partition 106 is connected to the left side plate of the biomass gasifier 102, and the lower end is located above the front end of the grate 105. The upper end of the second partition 107 is connected to the top plate of the biomass gasifier 102, and the lower end corresponds to the middle section of the grate 105. The upper end of the third partition 108 is connected to the top plate of the biomass gasifier 102, and the lower end corresponds to the rear section of the grate 105.

[0023] A pyrolysis section 109 is formed between the first partition 106 and the second partition 107. A pyrolysis gas outlet 113 is provided on the top plate of the biomass gasifier 102 corresponding to the pyrolysis section 109. The pyrolysis gas outlet 113 is connected to the spray washing heat dissipation tower 2 via a pipe. A redox section 110 is formed between the second partition 107 and the third partition 108. A high-temperature reducing gas outlet 114 is provided on the top plate of the biomass gasifier 102 corresponding to the redox section 110. The high-temperature reducing gas outlet 114 is connected to the high-temperature reducing gas inlet 119 on the waste heat evaporator 101. The high-temperature reducing gas inlet 119 is connected to the spray washing heat dissipation tower 2 via a pipe. The shape and position of the three partitions should ensure that the upper width of the pyrolysis section 109 and the redox section 110 is greater than the lower width, so that the gas in the corresponding sections can rise rapidly. The combustion chamber 111 is located between the third partition 108 and the right side wall of the biomass gasifier 102. The slag outlet 115 is located at the bottom of the combustion chamber 111. A temperature detection port 117 is provided at the upper end of the combustion chamber 111 to monitor the temperature inside the combustion chamber at any time.

[0024] The waste heat evaporator 101 is located above the biomass gasifier 102. The waste heat evaporator 101 includes an inner cavity and an outer cavity. The upper end of the outer cavity has a coarse wood vinegar inlet 124, which is connected to the spray water washing heat dissipation tower 2 via a pipe. A reflux valve 207 is installed on the pipe, allowing the coarse wood vinegar collected by the spray water washing heat dissipation tower 2 to enter the outer cavity of the waste heat evaporator 101 through the coarse wood vinegar inlet 124. The bottom of the inner cavity of the waste heat evaporator 101 has a high-temperature reducing gas inlet 119, and the upper part has a reducing gas outlet 120. The high-temperature reducing gas inlet 119 is connected to the high-temperature reducing gas outlet 114 of the oxidation-reduction section 110. The high-temperature reducing gas can heat the coarse wood vinegar in the outer cavity, achieving the separation of tar and wood vinegar vapor. The reducing gas outlet 120 is connected to the spray water washing heat dissipation tower 2. Meanwhile, a level gauge 121 is installed on the outer wall of the outer cavity. The level gauge 121 is linked to the reflux valve 207 to automatically control the level. That is, when the level in the outer cavity reaches the set upper limit, the reflux valve 207 is closed, and when it drops to the lower limit, the reflux valve 207 is opened to automatically replenish the material, avoid excessive feeding, and reserve steam space.

[0025] The waste heat evaporator 101 also has a wood vinegar vapor outlet 123 and a tar outlet 122 on its outer cavity. The wood vinegar vapor outlet 123 is located at the top of the outer cavity and is connected to the condenser 3 and the jet mixer 4 via pipes. A wood vinegar vapor ejector valve 403 is installed on the pipe between the wood vinegar vapor outlet 123 and the jet mixer 4. The opening or closing of the wood vinegar vapor ejector valve 403 is determined by the temperature inside the combustion chamber 111. The tar outlet 122 is also connected to the jet mixer 4, and a tar return valve 402 is installed on the pipe between the two. Similarly, the opening or closing of the tar return valve 402 is also determined by the temperature inside the combustion chamber 111.

[0026] The spray water washing heat dissipation tower 2 includes a coarse wood vinegar collection tank 201, an air-cooled radiator 202, and a demister 203, wherein the air-cooled radiator 202 is located above the coarse wood vinegar collection tank 201, and the demister 203 is located above the air-cooled radiator 202.

[0027] The coarse wood vinegar collection tank 201 has a dry distillation gas inlet 204 and a reducing gas inlet 205 on its side wall. The dry distillation gas inlet 204 is connected to the dry distillation gas outlet 113 of the dry distillation section 109, and the reducing gas inlet 205 is connected to the reducing gas outlet 120 of the waste heat evaporator 101. That is, both the dry distillation gas and the reducing gas generated by the gasifier 1 enter the coarse wood vinegar collection tank 201. The bottom of the coarse wood vinegar collection tank 201 has a coarse wood vinegar outlet 206, which is connected to the coarse wood vinegar inlet 124 of the waste heat evaporator 101. The coarse wood vinegar enters the outer cavity of the waste heat evaporator 101 for tar and wood vinegar vapor separation.

[0028] The air-cooled radiator 202 is connected to a blower 209 on one side and has an air outlet 210 on the other side. The air outlet 210 is connected to the air inlet 105 at the bottom of the grate 105 via a pipe. The biomass gasifier 102 assists in combustion. A spray inlet 212 is opened on the side wall of the spray water washing radiator 2. The spray inlet 212 is located on the upper part of the air-cooled radiator 202 and is connected to a spray pump 208.

[0029] The demister 203 is equipped with several demisting folding plates, and a biomass mixed gas outlet 211 is opened at the upper end of the demister 203. The dry distillation mixed gas and reducing gas generated by the gasifier 1 enter the crude wood vinegar collection tank 201 from the dry distillation gas inlet 204 and the reducing gas inlet 205, respectively. After being washed by the back spray of the spray pump 208, they flow upward through the air-cooled radiator 202 for cooling, and then pass through the folding plates in the demister 203 for demisting, and finally are discharged from the biomass gas outlet 211 at the top of the demister 203. The separated crude wood vinegar and tar enter the waste heat evaporator 101 through a pipeline from the crude wood vinegar outlet 206 at the bottom.

[0030] The wood vinegar condenser 3 has a wood vinegar vapor inlet 301 at the upper end and a distilled wood vinegar outlet 302 at the lower end. The wood vinegar vapor inlet 301 is connected to the wood vinegar vapor outlet 123 of the waste heat evaporator 101, and the distilled wood vinegar outlet 302 is connected to the refined wood vinegar collection tank 303. When the wood vinegar vapor ejector valve 403 is closed, the wood vinegar vapor enters the wood vinegar condenser 3 for condensation, forming distilled wood vinegar, which is then collected in the refined wood vinegar collection tank 303 through the distilled wood vinegar outlet 302.

[0031] The injection mixer 4 includes a temperature sensor 401, a tar return valve 402, and a wood vinegar vapor ejector valve 403. The temperature sensor 401 is connected to a temperature detection port 117 inside the combustion chamber 111 to continuously monitor the temperature inside the combustion chamber 111. The injection mixer 4 is connected via pipes to the wood vinegar vapor outlet 123 and the tar outlet 122 of the waste heat evaporator 101. The tar return valve 402 and the wood vinegar vapor ejector valve 403 are opened based on the temperature inside the combustion chamber 111. The injection mixer 4 is also connected to a tar return injection pipe 116, the outlet of which is located above the combustion chamber 111. When the tar return valve 402 and the wood vinegar vapor ejector valve 403 are open, the injection mixer 4 can inject the wood vinegar vapor and tar entering it into the combustion chamber 111, enabling secondary combustion and more complete combustion within the combustion chamber 111.

[0032] In this invention, the opening and closing of the tar return valve 402 and the wood vinegar vapor ejector valve 403 are controlled by the temperature inside the combustion chamber 111. When the temperature inside the combustion chamber is ≥500℃, the tar return valve 402 and the wood vinegar vapor ejector valve 403 are opened, and the tar and wood vinegar vapor enter the injection mixer 4. The injection mixer 4 injects the mixture into the combustion chamber 111 for high-temperature pyrolysis and combustion, and the combustion products enter the oxidation-reduction section for reforming into fuel gas. When the temperature inside the combustion chamber 111 is <500℃, the tar return valve 402 and the wood vinegar vapor ejector valve 403 are closed, and the wood vinegar vapor enters the condenser 3 and is condensed into distilled wood vinegar, which is collected by the refined wood vinegar collection tank 303.

[0033] Based on the aforementioned tar self-reflux biomass gasification device, this invention also provides a tar self-reflux biomass gasification method, and the specific process flow of the gasification device is described in detail according to the gasification method. It should be noted that during the reaction in this invention, the following steps may occur simultaneously; the division into steps here is for ease of description only and does not represent the order of the reactions.

[0034] The specific steps of the tar self-reflux biomass gasification method of the present invention are as follows: S1. Biomass pellets are fed into the pyrolysis section 109 of the biomass gasifier 102 via the screw feeder 103. A pyrolysis reaction occurs there, generating a pyrolysis mixture and semi-coke. The pyrolysis mixture mainly consists of pyrolysis gas, water vapor, and light tar. The semi-coke moves with the grate 105 into the oxidation-reduction section 110, where it reacts to generate high-temperature reducing gas. The high-temperature residual carbon generated in the oxidation-reduction section 110 moves with the grate 105 into the combustion chamber 111, where it undergoes oxygen-enriched combustion with the air at the bottom of the grate 105 and the back-injected tar. The resulting carbon dioxide and tar cracking gas flow back into the oxidation-reduction zone and finally exit through the high-temperature reducing gas outlet 114, thereby effectively increasing the calorific value and yield of the biomass gas.

[0035] S2. The dry distillation mixture generated in step S1 enters the coarse wood vinegar collection tank 201 of the spray water washing radiator 2 through dry distillation gas outlet 113 and dry distillation gas inlet 204 in sequence; similarly, the high temperature reducing gas enters the coarse wood vinegar collection tank 201 through high temperature reducing gas outlet 114, high temperature reducing gas inlet 119, reducing gas outlet 120 and reducing gas inlet 205 in sequence.

[0036] The gas entering the coarse wood vinegar collection tank 201 is washed by the spraying action of the spray pump 208, then flows upward through the air-cooled radiator 202 to cool down, and then passes through the folded plate in the demister 203 to remove mist, forming purified gas, which is finally discharged from the top biomass mixed gas outlet 211; the separated coarse wood vinegar enters the coarse wood vinegar collection tank 201 below.

[0037] S3. The coarse wood vinegar collected in the coarse wood vinegar collection tank 201 enters the waste heat evaporator 101 through the coarse wood vinegar outlet 206 and the coarse wood vinegar inlet 124 for waste heat separation. At the same time, the high-temperature reducing gas generated in the oxidation-reduction section 110 passes through the waste heat evaporator 101 as a heat source to heat the coarse wood vinegar, thereby achieving the separation of tar and wood vinegar vapor.

[0038] S4. The tar separated by the waste heat evaporator 101 enters the jet mixer 4 through the tar outlet 122 and is controlled by the tar reflux valve 402. The jet mixer 4 then injects the tar into the calcination chamber 111 for calcination. The wood vinegar vapor separated by the waste heat evaporator 101 flows out of the wood vinegar vapor outlet 123 and has two destinations: one is to enter the jet mixer 4 and be injected into the calcination chamber 111 for calcination; the other is to enter the condenser 3 for condensation to form distilled wood vinegar, which is collected in the refined wood vinegar collection tank 303.

[0039] In this invention, when the temperature inside the combustion chamber 111 is ≥500℃, the tar return valve 402 and the wood vinegar vapor ejector valve 403 are opened, the bottom tar flows by gravity to the injection mixer 4, and the upper wood vinegar vapor is used as a driving force to carry the tar into the combustion chamber, where it is instantly ignited by the high-temperature residual carbon. The furnace body heat is supplemented through oxygen-enriched combustion, and the combustion products enter the oxidation-reduction section 110 to be reformed into fuel gas.

[0040] When the temperature inside the combustion chamber 111 is <500℃, the tar return valve 402 and the wood vinegar vapor ejector valve 403 are closed to stop the back injection, thus avoiding a sudden drop in furnace temperature and tar accumulation due to the inability to ignite at low temperatures. At this time, the remaining wood vinegar vapor in the evaporator 101 is switched to enter the condenser 3 for condensation to obtain high-purity distilled wood vinegar, which is then collected and sold by the refined wood vinegar collection box 303.

[0041] During this process, the blower 209 sends air into the air-cooled radiator 202 for preheating, and then enters the combustion chamber 111 as combustion air through the air outlet 210 and the air inlet 118.

[0042] In this invention, the waste heat of the high-temperature reducing gas generated by the biomass gasifier is used to heat the wood vinegar in the waste heat evaporator. When the temperature reaches 118°C, the tar automatically separates and deposits at the bottom of the waste heat evaporator. It then enters the injection mixer through the tar return pipe. At the same time, the crude wood vinegar is converted into wood vinegar vapor. The wood vinegar vapor is used as the power source for the injection mixer to inject the tar and wood vinegar together into the combustion chamber. The high-temperature residual carbon in the combustion chamber is used to ignite the oxygen-enriched combustion, producing carbon dioxide and tar cracked gas that flow counter-currently into the oxidation-reduction zone, thereby increasing the calorific value and yield of the fuel gas.

[0043] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A tar self-recirculation biomass gasification device, characterized in that: It includes a gasifier (1), a spray water washing heat dissipation tower (2), a wood vinegar condenser (3), and a jet mixer (4). The gasifier (1) includes a waste heat evaporator (101) and a biomass gasifier (102). The biomass gasifier (102) is equipped with a grate (105). Above the grate (105), there are several longitudinal baffles that divide the gasification section (109), the oxidation-reduction section (110), and the combustion chamber (111) in sequence. The spray water washing heat dissipation tower (2) includes a coarse wood vinegar collection tank (201), and an air-cooled radiator (202) and a demister (203) are arranged in sequence above the coarse wood vinegar collection tank (201). The demister (203) is provided with a biomass mixed gas outlet (211) at the upper end, and a spray pump (208) is connected to the upper side wall of the spray water washing heat dissipation tower (2) through a spray inlet (212). The gasifier (1) has a screw feeder (103) connected to one side of the dry distillation section (109). The dry distillation section (109) and the oxidation-reduction section (110) are connected to the coarse wood vinegar collection tank (201) through different pipes. The lower end of the coarse wood vinegar collection tank (201) is connected to the waste heat evaporator (101) through a pipe. The upper part of the waste heat evaporator (101) is provided with a wood vinegar vapor outlet (123). The wood vinegar vapor outlet (123) is connected to the condenser (3) and the jet mixer (4) through pipes. The lower part of the waste heat evaporator (101) is provided with a tar outlet (122). The tar outlet (122) is connected to the jet mixer (4) through a pipe. The outlet of the jet mixer (4) is connected to the combustion chamber (111).

2. The tar self-recirculation biomass gasification device according to claim 1, characterized in that: The air-cooled radiator (202) is connected to a blower (209) on one side and has an air outlet (210) on the other side. The bottom of the grate (105) in the biomass gasifier (102) is provided with an air inlet (118), and the air outlet (210) and the air inlet (118) are connected by a pipe.

3. The tar self-recirculation biomass gasification device according to claim 1, characterized in that: The biomass gasifier (102) has a slag outlet (115) at the bottom of the combustion chamber (111), and a temperature detection port (117) is provided at the upper end of the combustion chamber (111), with a temperature sensor (401) on the temperature detection port (117).

4. The tar self-recirculation biomass gasification device according to claim 1, characterized in that: The biomass gasifier (102) is provided with a first partition (106), a second partition (107) and a third partition (108) from left to right inside; a dry distillation gas outlet (113) is opened on the top plate of the biomass gasifier (102) between the first partition (106) and the second partition (107), and the dry distillation gas outlet (113) is connected to the coarse wood vinegar collection tank (201) through a pipe; a high temperature reducing gas outlet (114) is opened on the top plate of the biomass gasifier (102) between the second partition (107) and the third partition (108), and the high temperature reducing gas outlet (114) is connected to the high temperature reducing gas inlet (119) on the waste heat evaporator (101), and the high temperature reducing gas inlet (119) is connected to the coarse wood vinegar collection tank (201) through a pipe.

5. The tar self-recirculation biomass gasification device according to claim 4, characterized in that: The upper end of the first partition (106) is connected to the left side plate of the biomass gasifier (102), and the lower end is located above the front end of the grate (105); the upper end of the second partition (107) is connected to the top plate of the biomass gasifier (102), and the lower end corresponds to the middle section of the grate (105); the upper end of the third partition (108) is connected to the top plate of the biomass gasifier (102), and the lower end corresponds to the rear section of the grate (105).

6. The tar self-reflux biomass gasification device according to claim 4, characterized in that: A reflux valve (207) is provided on the pipeline between the coarse wood vinegar collection tank (201) and the waste heat evaporator (101).

7. The tar self-recirculation biomass gasification device according to claim 1, characterized in that: A wood vinegar vapor ejector valve (403) is provided on the pipe between the wood vinegar vapor outlet (123) and the jet mixer (4); a tar return valve (402) is provided on the pipe between the tar outlet (122) and the jet mixer (4).

8. The tar self-recirculation biomass gasification device according to claim 1, characterized in that: The wood vinegar condenser (3) has a wood vinegar vapor inlet (301) at the upper end and a distilled wood vinegar outlet (302) at the lower end. The wood vinegar vapor inlet (301) is connected to the wood vinegar vapor outlet (123) on the waste heat evaporator (101), and the distilled wood vinegar outlet (302) is connected to the refined wood vinegar collection tank.

9. A method for tar self-reflux biomass gasification using the apparatus described in any one of claims 1-8, characterized in that... Includes the following steps: S1. Biomass pellets are fed into the dry distillation section (109) of the biomass gasifier (102) via a screw feeder (103) to generate dry distillation mixed gas and semi-coke; the semi-coke is fed into the oxidation-reduction section (110) by the grate (105) to generate high-temperature reducing gas, and the high-temperature residual carbon is fed into the combustion chamber (111) by the grate (105). S2, the dry distillation mixed gas and the high temperature reducing gas both enter the spray water washing radiator (2). After being sprayed and washed, cooled by the air-cooled radiator (202) and demisted by the demister (203), the purified gas is discharged from the top biomass mixed gas outlet (211), and the separated coarse wood vinegar flows downward into the coarse wood vinegar collection tank (201). S3. The coarse wood vinegar collected in the coarse wood vinegar collection tank (201) enters the waste heat evaporator (101) for waste heat separation. At the same time, the high temperature reducing gas generated in the oxidation-reduction section (110) passes through the waste heat evaporator (101) as a heat source to heat the coarse wood vinegar, thereby achieving the separation of tar and wood vinegar vapor. S4. When the temperature inside the combustion chamber (111) is ≥500℃, the tar return valve (402) and the wood vinegar vapor ejector valve (403) are opened. The tar and wood vinegar vapor enter the injection mixer (4) and are injected into the combustion chamber (111) by the injection mixer (4) for high-temperature pyrolysis combustion. The combustion products enter the oxidation-reduction section to be reformed into fuel gas. When the temperature inside the combustion chamber (111) is <500℃, the tar return valve (402) and the wood vinegar vapor ejector valve (403) are closed, and the wood vinegar vapor enters the condenser (3) and is condensed into distilled wood vinegar, which is collected by the refined wood vinegar collection tank (303).

10. The tar self-recirculation biomass gasification method according to claim 9, characterized in that: In step S4, the blower (209) sends air into the air-cooled radiator (202) for preheating, and then enters the combustion chamber (111) as combustion air.

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