CN112048343B

CN112048343B - Biomass gasification processor and biomass gasification method

Info

Publication number: CN112048343B
Application number: CN201910491716.9A
Authority: CN
Inventors: 赵丽萍; 宋永一; 王鑫; 张彪; 吴斯侃; 刘继华; 张长安
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2019-06-06
Filing date: 2019-06-06
Publication date: 2021-10-08
Anticipated expiration: 2039-06-06
Also published as: CN112048343A

Abstract

The invention discloses a biomass gasification processor and a biomass gasification method, wherein the biomass gasification processor comprises a shell, the shell comprises a reaction area and an ash storage area, the reaction area is divided into a biomass pyrolysis area and a tar conversion area through a partition board, the biomass pyrolysis area and the tar conversion area are communicated through the ash storage area, the top of the biomass pyrolysis area is provided with a gas inlet, and the top of the tar conversion area is provided with a gas outlet. According to the biomass gasification method, biomass raw materials enter a gasification processor, react in a biomass pyrolysis zone, and high-temperature flue gas and biological semicoke are obtained after the reaction; the high-temperature flue gas enters the tar conversion area after passing through the ash storage area and contacts with the filler filled in the tar conversion area to react. The biomass gasification processor and the biomass gasification method can reduce the tar and dust content of fuel gas and improve the gasification efficiency of raw materials.

Description

Biomass gasification processor and biomass gasification method

Technical Field

The invention belongs to the technical field of biomass treatment, and particularly relates to biomass gasification equipment and a biomass treatment method.

Background

The biomass gasification process needs to be completed in a gasification reactor, and as a core component of a gasification system, the selection of the gasification reactor is very important. The energy conversion efficiency of the gasification reactor is the key point of the whole gasification system, so the type of the gasification reactor and the control operation parameters thereof are very important restriction conditions of the gasification system, common reactor types comprise a fixed bed, a bubbling bed, a fluidized bed, a circulating fluidized bed, a spouted bed, an entrained flow bed and the like, wherein the fixed bed reactor has the advantages of simple structure, low manufacturing cost, easy operation and wide application in the field of medium and small-scale biomass gas production.

In the biomass gasification process, tar is an inevitable by-product, and the tar produced in the biomass gasification process contains thousands of compounds with different types and properties, is in a gaseous state at high temperature, can be completely mixed with combustible gas, and is condensed into a liquid state at low temperature (generally lower than 200 ℃), and the presence of tar has very adverse effects on the pyrolysis gasification process and related equipment. Firstly, the gasification efficiency is reduced, the energy of tar generally accounts for 5% -15% of the total energy, and the part of energy is difficult to be utilized together with combustible gas at low temperature and most of energy is wasted. Secondly, tar is present in the gasified product gas, is carried by the gas flow, is gradually condensed in the conveying process in the pipeline to form viscous liquid, and is attached to the inner wall of the pipeline and the wall surface of related equipment, so that the safe operation of the equipment is threatened; the tar can be combined with dust in the airflow and accumulated in the pipeline, and the pipeline is blocked when the tar is serious; the tar condensed into fine droplets is harder to burn out than gas, and easily generates carbon black during combustion, causing pollution and serious damage to gas utilization equipment. Finally, the tar component contains toxic substances which threaten human health. The ash content of the fuel gas is high, so that the fuel gas is difficult to be conveyed to a conveyor belt, the combustion efficiency of the fuel gas is reduced, and the service life of combustion equipment is shortened. At low temperatures (< 200 ℃) tar condenses to a liquid state, which easily combines with water, ash, etc., blocking gas pipelines.

At present, most researches are focused on secondary utilization of biological tar, so that the steps are complex, the problem of secondary pollution is also caused in the secondary utilization process, for example, multi-stage spraying and washing are required to be arranged in a wet tar removal process, so that a large amount of sewage is generated, oxidation media such as air or oxygen are introduced in the gasification process to perform combustion reaction, tar is removed in a high-temperature mode, 1300 ℃ or even higher reaction temperature is required, and the energy consumption is higher. Therefore, reducing or even eliminating tar at the source is the most fundamentally effective method. Patent CN203462012U proposes a gasification furnace capable of thoroughly removing tar, which adopts a method of mixing coke oven gas and air to burn. CN101580739B discloses a fixed bed straw gasification process with tar back-burning, which is characterized in that combustible gas is dedusted, tar in the fuel gas is captured by a method combining inertia and cooling, and the captured tar is refluxed to a high-temperature oxidation zone of a gasification furnace for combustion. While these methods can solve the tar removal problem, the tar is more converted to carbon dioxide and in fact the effective conversion of carbon is very low. CN100543116C serial connection of the oxygen-poor fluidized bed and the downdraft fixed bed is used, the fuel is burnt in the oxygen-poor fluidized bed to generate semicoke and the semicoke-containing gas is conveyed to the downdraft fixed bed gasification furnace at the downstream under the high temperature state to remove the tar, but the heat loss in the gas conveying process under the high temperature state is large, and the serial connection process is complex.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a biomass gasification processor and a biomass gasification method, which reduce the tar and dust carrying amount of fuel gas as far as possible from the source, improve the raw material gasification efficiency, simultaneously reduce the harm of the tar and dust to the minimum, simplify the complicated subsequent purification process of the fuel gas and produce the cleanest combustible gas or synthetic gas product by the shortest process route.

In order to achieve the above object, a first aspect of the present invention provides a biomass gasification processor, which includes a housing, the housing includes a reaction area and an ash storage area, a partition board is disposed in the reaction area, the reaction area is divided into a biomass pyrolysis area and a tar conversion area by the partition board, the biomass pyrolysis area and the tar conversion area are communicated through the ash storage area, a grate is disposed between the bottom of the biomass pyrolysis area and the ash storage area, and a gas distribution plate is disposed between the bottom of the tar conversion area and the ash storage area.

In the biomass gasification processor, the partition plate is arranged perpendicular to the bottom of the processor, the upper end of the partition plate is hermetically connected with the inner wall of the shell, the lower end of the partition plate is arranged flush with the fire grate, and the gas distribution plate and the fire grate are preferably arranged flush.

In the biomass gasification processor, the screening range of the grate is 2-6 mm multiplied by 2-6 mm, the gas-solid separation of the biomass pyrolysis zone is mainly used for roughly separating high-temperature flue gas, biological semicoke and ash content through the separation effect of the grate, the biological semicoke with larger size is timely discharged out of the biomass pyrolysis zone through the slag extractor, and most of small-volume particles such as ash content, biological semicoke crushed slag and the like enter the ash storage zone through the grate.

According to the biomass gasification processor, the gas distribution plate is uniformly provided with a plurality of holes, the diameter of each hole is 2-5 mm, high-temperature flue gas uniformly passes through the tar conversion area from bottom to top through the gas distribution plate, fillers are filled in the tar conversion area, carbonized material crushed slag and ash content carried by the high-temperature flue gas are deposited in the ash storage area due to gravity in the process that the gas flows from bottom to top, a small part of the ash content is carried through the gas holes and then mutually touches the fillers in the tar conversion area, and the ash content falls into the ash storage area from the gas holes again due to smaller particle size ratio after the fillers are intercepted.

In the biomass gasification processor, the volume ratio of the biomass pyrolysis zone to the tar conversion zone is 1: 1-5: 1, and preferably 1: 1-3: 1. The proportion of the biomass pyrolysis zone and the tar conversion zone in the reaction zone can be adjusted by adjusting the transverse position of the partition plate.

In the biomass gasification processor, the biomass gasification processor is divided into a biomass pyrolysis area, a tar conversion area and an ash storage area through the partition plate, the fire grate and the gas distribution plate, and the transverse position of the partition plate is adjusted to adjust the proportion of the biomass pyrolysis area to the tar conversion area.

In the biomass gasification processor, the ash storage area is positioned at the bottom of the gasification processor, in the process that high-temperature flue gas flows out of the biomass pyrolysis area and enters the tar conversion area through the ash storage area, carried solid particles are settled in the ash storage area through gravity, and a small amount of ash carried away by the high-temperature flue gas in the pyrolysis process, the ash in the biomass pyrolysis area (most of the ash generated in the pyrolysis process), the biological semicoke crushed slag and the ash in the tar conversion area are discharged in time by the ash discharger at the bottom of the ash storage area.

In the biomass gasification processor, the biomass pyrolysis area is provided with the first feeder and the first slag extractor, wherein the first feeder is arranged at the upper part of the biomass pyrolysis area, the first slag extractor is arranged above the grate at the bottom of the biomass pyrolysis area, the feeding rate and the slag extraction rate are controlled according to the biomass accumulation condition of the biomass pyrolysis area, and the biomass processing capacity of the whole system is improved while the full reaction of materials is ensured. Further the first feeder is preferably a screw feeder and the first slag extractor is preferably a screw slag extractor.

In the biomass gasification processor, the tar conversion area is provided with a second feeder and a second slag extractor, wherein the second feeder is arranged at the upper part of the tar conversion area, the second slag extractor is arranged above a gas distribution plate at the bottom of the tar conversion area, a catalyst and a carbonized material which are uniformly mixed are added into the tar conversion area through the feeder, and the second slag extractor above the gas distribution plate discharges the mixture after the reaction is finished and is filled with a new catalyst and a new carbonized material. Further the second feeder is preferably a screw feeder and the second slag extractor is preferably a screw slag extractor.

In the biomass gasification processor, the top of the biomass pyrolysis zone is provided with a gas inlet, and the top of the tar conversion zone is provided with a gas outlet. The biomass gasification processor is operated under micro negative pressure, the vacuum degree is 400-600 Pa, when dry distillation gasification is carried out, a gas inlet is opened only before the device is started, air in the gasification processor is replaced by nitrogen, a gas inlet is closed in the reaction process, the vacuum degree in the reactor is kept at a gas outlet through a pump, and the pump can be a water ring vacuum pump. When gasification reaction is carried out by adopting a gasification medium, the gasification medium passes through the biomass pyrolysis zone from top to bottom from the gas inlet, then passes through the tar conversion zone from bottom to top after passing through the ash storage zone and reaches the gas outlet, and the gasification medium can be one or more of air, oxygen, water vapor and hydrogen.

In a second aspect, the present invention provides a biomass gasification method comprising:

(1) the biomass raw material enters a gasification processor, and reacts in a biomass pyrolysis zone to obtain high-temperature flue gas and biological semicoke;

(2) and (2) allowing the high-temperature flue gas in the step (1) to pass through an ash storage area and then enter a tar conversion area, and contacting and reacting with the filler filled in the tar conversion area.

In the biomass gasification method, the biomass raw material in the step (1) is any lignocellulose-containing biomass such as forestry residues or agricultural residues, the raw material can be in any shape including sheets, circles, cylinders, cones, squares, irregular shapes and the like, and the maximum dimension of the raw material in the direction is not more than 30mm, preferably 1-25 mm.

In the biomass gasification method, the reaction temperature of the biomass pyrolysis zone in the step (1) is 300-900 ℃, and preferably 400-800 ℃.

In the biomass gasification method, the medium-high temperature flue gas in the step (1) comprises a gas phase and a solid phase and mainly comprises pyrolysis volatile components in a biomass pyrolysis zone and carried crushed biological coke particles or other particulate matters.

In the biomass gasification method, high-temperature flue gas and biological semicoke are obtained through full pyrolysis in the step (1), wherein the semicoke accounts for 1-30 wt%, the high-temperature flue gas accounts for 70-99 wt%, and the high-temperature flue gas comprises about 5-20 wt% of condensable components and 1-5 wt% of settleable components.

In the biomass gasification method, in the process that the high-temperature flue gas passes through the tar conversion zone from bottom to top in the step (2), the high-temperature flue gas is contacted with the filler filled in the tar conversion zone, along with the flowing of the high-temperature flue gas, the tar carried in the flue gas and the filler are subjected to cracking reaction, reforming reaction and condensation reaction continuously, and the tar carrying amount of the flue gas is greatly reduced. The solid particles carried in the smoke are gradually settled in the continuous collision with the filler and fall into the ash storage area, and the carrying amount of the solid particles in the smoke is greatly reduced.

In the biomass gasification method, the reaction temperature of the tar conversion zone in the step (2) is 500-900 ℃, and preferably 600-900 ℃.

In the biomass gasification method of the invention, the filler in the step (2) may be a single carbonized material, or may be a mixture composed of a carbonized material and a catalyst, preferably a homogeneous mixture of a carbonized material and a catalyst, where the homogeneous mixture refers to that the carbonized material and the catalyst are mixed together in a certain proportion by a physical or chemical method, where the physical method includes any one of grinding, mechanical mixing, and the like, and the chemical method includes any one of dipping, precipitation, and the like. Further, the carbonized material is one or more of biomass semi-coke, petroleum coke, coal pyrolysis coke, activated carbon and other carbon-based materials, and preferably biological semi-coke and/or activated carbon. The catalyst can be one or more of natural ore and metal supported catalyst; the natural ore can be one or more of limestone, dolomite, attapulgite, iron ore, clay ore and olivine; the metal-loaded catalyst takes one or more of biomass semi-coke, alumina, activated carbon, silicon carbide and porous ceramic as a carrier, and the loaded active component can be one or more of the forms of simple metal, metal salt, metal oxide, metal peroxide and the like, and is preferably metal oxide and/or metal salt. The metal can be one or more of alkali metal, alkaline earth metal and transition metal, and the alkali metal and/or the transition metal are preferred. The alkali metal is one or more of lithium, sodium, potassium, rubidium, cesium and francium, preferably one or more of sodium and potassium; the transition metal is one or more of iron, cobalt, nickel, copper and zinc, and preferably one or more of iron and nickel.

In the biomass gasification method of the present invention, the packing in the tar conversion zone in step (2) is preferably packed in layers, and N layers (N =2 to 6, preferably N =2 to 4, and more preferably N = 2) are provided, and the first packing layer, the second packing layer, … …, the N-1 th packing layer, and the nth packing layer are arranged in this order in the flow direction of the gas material. When two layers are arranged, a first filler layer and a second filler layer are sequentially arranged, wherein the first filler layer is filled with a first filler, the second filler layer is filled with a second filler, the first filler is a uniform mixture of a natural ore catalyst and a carbonization material, and the second filler is a metal-supported catalyst and/or a carbonization material, preferably a metal-supported catalyst.

In the biomass gasification method, the ratio of the first filler to the second filler is 50: 1-1: 1.

In the biomass gasification method, when the second filler comprises the carbonized material, the weight ratio of the carbonized material in the first filler to the carbonized material in the second filler in the tar conversion zone is 10: 1-1: 10, preferably 10:1 to 1: 1.

In the biomass gasification method, the bed temperature of the first filler layer is 600-900 ℃, preferably 700-900 ℃; the bed temperature of the second filler layer is 500-800 ℃, preferably 550-700 ℃, further preferably, the bed temperature of the first filler layer is 20-300 ℃ higher than that of the second filler layer, and further preferably, the bed temperature of the first filler layer is 20-150 ℃ higher than that of the second filler layer.

Compared with the prior art, the biomass gasification processor and the biomass gasification method have the following advantages:

1. the biomass gasification processor realizes biomass partition gasification in one processor, biomass pyrolysis reaction and tar conversion reaction are respectively carried out in different reaction areas, the integration level of a reaction system is high, compared with the conventional multistage series process of pyrolysis gasification, tar cracking and flue gas purification, the biomass gasification processor greatly simplifies the process flow, has higher gasification efficiency and effective carbon conversion rate, and effectively avoids the conventional processThe heat dissipation in the high-temperature flue gas transmission process in the series connection process is realized, and the heat integration is facilitated. The high temperature flue gas gets into tar conversion district through ash storage area from the living beings pyrolysis zone, and the transportation process energy dissipation is few, and living beings pyrolysis zone reaction temperature is close with the reaction temperature on first filler layer, and system temperature fluctuation is little, and the required reaction temperature on second filler layer is lower moreover, and the heat that utilizes high temperature flue gas self to carry can satisfy basically that the reaction is required, only needs a small amount of heating to assist. Solves the problem that the particles deposit and block the transmission pipeline in the process of conveying the high-temperature flue gas, eliminates tar at the source, deeply purifies the gas, and can effectively adjust the H of the fuel gas by regulating and controlling the technological parameters of the tar cracking process₂The ratio of/CO is high, and the grade of the fuel gas product is high.

2. According to the biomass gasification method, a filler grading filling scheme is arranged in the tar conversion area, and proper operating conditions are matched in different filler layers, so that the tar is catalytically converted in a grading manner by adopting multi-bed-layer fillers. The tar carried by the high-temperature flue gas is firstly contacted with a first filling material for catalytic conversion, a catalyst which takes natural ores as main active components in the first filling material adsorbs and promotes the conversion of a large amount of tar in the tar conversion process, and the 'soft tar', such as phenols and derivatives thereof, in the tar components is easily damaged, and the conversion rate of the tar carried by the high-temperature flue gas can reach 90-95% under the action of the first filling material. After the treatment of the first filler, the residual tar in the flue gas is hard tar which takes polycyclic aromatic hydrocarbon which is difficult to convert, such as naphthalene, indene and the like as main components, the activity of the catalyst which takes metal elements as active components in the second filler is higher, the removal rate of the residual tar and the carbon conversion rate of raw materials are greatly improved, and the tar content of the fuel gas finally obtained from a gas outlet is reduced to 50mg/Nm³Compared with the traditional cracking process, the complex post-treatment process for performing multi-stage spraying washing, tar removal and dust removal on high-temperature flue gas has obvious advantages.

3. According to the biomass gasification method, the carbonized material used in the filler has a developed gap structure, and the porous structure provides favorable conditions for adsorbing tar, so that the retention time of the tar in a high-temperature area is prolonged to different degrees, and the cracking reaction of the tar is promoted. In addition, the ash content of the biological semicoke is high, and the ash contains a large amount of calcium oxide, magnesium oxide, potassium oxide and other components, so that the biological semicoke also has a catalytic effect on cracking of tar under a proper temperature condition.

Drawings

FIG. 1 is a schematic diagram of a biomass gasification processor according to the present invention.

Detailed Description

The following examples further illustrate specific aspects of the present invention, but are not limited to the following examples.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top", "bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "provided", "disposed", "connected", "mounted", and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The invention provides a biomass gasification processor, which comprises a shell, wherein the shell comprises a reaction area 1 and an ash storage area 2, a partition plate 3 is arranged in the reaction area 1, the reaction area is divided into a biomass pyrolysis area 4 and a tar conversion area 5 by the partition plate 3, the top of the biomass pyrolysis area 4 is provided with a gas inlet 8, and the top of the tar conversion area 5 is provided with a gas outlet 9; the biomass pyrolysis area 4 is communicated with the tar conversion area 5 through the ash storage area 2, a fire grate 6 is arranged between the bottom of the biomass pyrolysis area 4 and the ash storage area 2, and a gas distribution plate 7 is arranged between the bottom of the tar conversion area 5 and the ash storage area 2; the baffle 3 is vertical to the bottom of the processor, the upper end of the baffle 3 is hermetically connected with the inner wall of the shell, the lower end of the baffle 3 is arranged in parallel with the fire grate 6, and the gas distribution plate 7 is arranged in parallel with the fire grate 6; divide into biomass gasification treater biomass pyrolysis district 4, tar conversion district 5, ash storage district 3 triplex through baffle 3, grate 6, gas distribution plate 7 jointly, adjust the baffle 3 lateral position adjustable biomass pyrolysis district 4 and the proportion of tar conversion district 5. The biomass pyrolysis zone 4 is provided with a first feeder 10 and a first slag extractor 11, wherein the first feeder 10 is arranged on the upper part of the biomass pyrolysis zone 4, the first slag extractor 11 is arranged above the grate 6 at the bottom of the biomass pyrolysis zone 4, the feeding rate and the slag extraction rate are controlled according to the biomass accumulation condition of the biomass pyrolysis zone 4, and the biomass treatment capacity of the whole system is improved while the sufficient reaction of materials is ensured. The tar conversion area 5 is provided with a second feeder 12 and a second slag extractor 13, wherein the second feeder 12 is arranged at the upper part of the tar conversion area 5, the second slag extractor 13 is arranged above a gas distribution plate 7 at the bottom of the tar conversion area 5, a catalyst and a carbonized material which are uniformly mixed are added into the tar conversion area 5 through the second feeder 12, and the mixture is discharged by the second slag extractor 13 above the gas distribution plate 7 after the reaction is finished, and is filled with a new catalyst and a new carbonized material.

The biomass gasification process specifically comprises the following steps: biomass feedstock carries out pyrolytic reaction through first feeder 10 propelling movement entering living beings pyrolysis zone 4 and obtains high temperature flue gas and biological semicoke, and high temperature flue gas top-down realizes the coarse separation of high temperature flue gas and biological semicoke, ash content through grate 6, has the biological semicoke of bigger size and leaves in grate 6 top, in time discharges living beings pyrolysis zone 4 through first slagging-off machine 11, and small volume granule such as most ash content and biological semicoke disintegrating slag then get into ash storage area 2 through grate 6. In the process that high-temperature flue gas flows out of the biomass pyrolysis zone 4 and enters the tar conversion zone 5 through the ash storage zone 2, carried solid particles are settled and dropped in the ash storage zone 2 through gravity. The high-temperature flue gas passes through the tar conversion zone 5 from bottom to top uniformly through the gas distribution plate 7, the tar conversion zone 5 is filled with fillers, the high-temperature flue gas uniformly distributed through the gas distribution plate sequentially contacts with the fillers in the tar conversion zone 5 according to the contact sequence to react, and the reacted gas is led out from the outlet 9 of the reactor. Ash content carried by carbonized material slag and high-temperature flue gas is left in the ash storage area 2 due to gravity sedimentation in the process that the gas flows from bottom to top, a small part of ash content is carried to pass through the air holes and then to be mutually touched with fillers in the tar conversion area 5, and the ash content falls into the ash storage area 2 from the air holes again due to smaller particle size ratio after the fillers are intercepted. The ash storage area 2 is located the biomass gasification treater bottom, and the ash content that is carried away by high temperature gas that produces in the pyrolysis process, the ash content in biomass pyrolysis area (the most ash content that produces in the pyrolysis process) and biological semicoke disintegrating slag and the carbonization material disintegrating slag and the ash content in tar conversion area are in time discharged by the ash exhauster 14 in ash storage area 2 bottom. The screw feeder 12 is used for filling the filler in the tar conversion area, the screw slag extractor 13 is used for discharging the filler in the tar conversion area, and the screw feeder and the screw slag extractor are matched with each other to replace the filler in the tar conversion area when the activity of the catalyst is obviously reduced.

Before the biomass gasification processor is used, nitrogen is required to be used for replacement, the specific operation steps are that under the condition that the air tightness of the biomass gasification processor is good, nitrogen is firstly introduced from a gas inlet 8, air in the biomass gasification processor is replaced and discharged from a gas outlet 9, the replacement time is 3-5 min, then the gas inlet is closed, the biomass gasification processor is operated by micro negative pressure, the vacuum degree is kept between 400 Pa and 600Pa, and the vacuum degree in the reactor is kept at the gas outlet through a pump. When gasification reaction is carried out by adopting a gasification medium, the gasification medium passes through the biomass pyrolysis zone from top to bottom from the gas inlet, then passes through the tar conversion zone from bottom to top after passing through the ash storage zone and reaches the gas outlet, and the gasification medium can be one or more of air, oxygen, water vapor and hydrogen.

The definition of the gasification efficiency and the carbon conversion rate in the examples of the present invention and the comparative examples:

gasification efficiency: the ratio of the amount of heat given off when a unit weight of biomass raw material is converted into a gas fuel and completely burned to the amount of heat of the unit weight of biomass raw material. It is the main index for measuring the gasification process. The specific calculation formula is as follows: gasification efficiency (%) = [ cold gas calorific value (kJ/m)³) Dry cold gas rate (m)³/kg）]Raw material calorific value (kJ/kg)

Carbon conversion rate: the carbon in the biomass fuel is converted into the carbon content in the gas fuel, i.e. the ratio of the carbon content in the gas to the carbon content in the feedstock.

Example 1

By adopting the biomass gasification processor, the forestry residue fir is selected as a raw material, the device feeding is a granular material formed and processed by the fir crushed material, the granular material is columnar granules, the length is 20mm, the section diameter is 10mm, the water content is 4wt%, and the heat value is 18.67 MJ/kg. The fir granules are pushed by the screw feeder to be filled in the biomass pyrolysis area, and the reacted solid product biological semi-coke is filled in the tar conversion area by the screw feeder as a filler of the tar conversion area. And under the condition of good gas tightness of the reactor, nitrogen enters from the gas inlet, the displaced air in the reactor is discharged from the gas outlet, and the gas inlet is closed after 3-5 min of displacement. And micro negative pressure operation is adopted in the reaction process, and the vacuum degree in the reactor is maintained between 400 and 600 Pa. The reaction temperature of the biomass pyrolysis zone is kept at 750 ℃, the reaction temperature of the tar conversion zone is 700 ℃, and the carrying amount of fuel gas tar at the outlet of the reactor is 100mg/Nm³Dust carrying amount of 86mg/Nm³The gasification efficiency of biomass in the whole process reaches 56%, and the carbon conversion rate reaches 74%.

Example 2

By adopting the biomass gasification processor, forestry residues larch are selected as raw materials, the device is fed with granules formed and processed by the larch crushed materials, the granules are columnar granules, the length of the granules is 30mm, the section diameter of the granules is 10mm, the water content of the granules is 10wt%, and the heat value of the granules is 18.63 MJ/kg. The larch granules are pushed by a screw feeder to be filled in a biomass pyrolysis zone, and a filler bag is arranged in a tar conversion zoneComprises two layers, wherein biomass semicoke is taken as a first filling layer, and biological semicoke with 10wt% of potassium carbonate loading is taken as a second filling layer. And under the condition of good gas tightness of the reactor, nitrogen enters from the gas inlet, the displaced air in the reactor is discharged from the gas outlet, and the gas inlet is closed after 3-5 min of displacement. And micro negative pressure operation is adopted in the reaction process, and the vacuum degree in the reactor is maintained between 400 and 600 Pa. The reaction temperature of the biomass pyrolysis zone is maintained at 900 ℃, the reaction temperature of the first packed layer is 850 ℃, and the reaction temperature of the second packed layer is 700 ℃. The carrying amount of gas tar at the outlet of the reactor is 43mg/Nm³Dust carrying amount of 83 mg/Nm³The gasification efficiency of biomass in the whole process reaches 79 percent, and the carbon conversion rate reaches 81 percent.

Example 3

By adopting the biomass gasification processor, the forestry remainder pinus sylvestris is selected as a raw material, the device feeding material is a granular material formed and processed by pinus sylvestris crushed materials, the granular material is columnar granules, the length of the granular material is 15mm, the section diameter of the granular material is 12mm, the water content of the granular material is 6wt%, and the heat value of the granular material is 18.42 MJ/kg. The pinus sylvestris granules are pushed by a screw feeder and filled in a biomass pyrolysis zone, biomass semicoke and dolomite are mechanically mixed according to the mass ratio of 10:1 to serve as a first filling layer, and biological semicoke with the nickel oxide loading capacity of 5wt% serves as a second filling layer. And under the condition of good gas tightness of the reactor, nitrogen enters from the gas inlet, the displaced air in the reactor is discharged from the gas outlet, and the gas inlet is closed after 3-5 min of displacement. And micro negative pressure operation is adopted in the reaction process, and the vacuum degree in the reactor is maintained between 400 and 600 Pa. The reaction temperature of the biomass pyrolysis zone is kept at 700 ℃, the reaction temperature of the first filling layer of the tar conversion zone is 700 ℃, and the reaction temperature of the second filling layer is 680 ℃. The carrying amount of the gas tar at the outlet of the reactor is 27mg/Nm³Dust carrying amount of 80mg/Nm³The gasification efficiency of biomass in the whole process reaches 84%, and the carbon conversion rate reaches 85%.

Comparative example 1

Selecting forestry remainder larch as raw material, wherein the device is fed with granular material formed and processed from larch crushed material, the granular material is columnar granules, the length of the columnar granules is 30mm, and the diameter of the section of the columnar granules is10mm, 10wt% water content and 18.63MJ/kg heat value. Respectively carrying out biomass pyrolysis reaction and tar conversion reaction on two vertical fixed bed reactors connected in series, wherein the temperature of the pyrolysis fixed bed is 850 ℃, the tar conversion catalyst adopts biological semicoke with 5wt% of nickel oxide loading as the catalyst, the temperature of the tar conversion fixed bed is 680 ℃, and the carrying amount of gas tar at the outlet of the reactor is 162mg/Nm³The dust carrying amount is 294 mg/Nm³The biomass gasification efficiency was 52% and the carbon conversion was 67%.

Claims

1. A biomass gasification processor comprises a shell, wherein the shell comprises a reaction area and an ash storage area, a partition board is arranged in the reaction area, the reaction area is divided into a biomass pyrolysis area and a tar conversion area by the partition board, the biomass pyrolysis area and the tar conversion area are communicated through the ash storage area, a grate is arranged between the bottom of the biomass pyrolysis area and the ash storage area, a gas distribution plate is arranged between the bottom of the tar conversion area and the ash storage area, a gas inlet is formed in the top of the biomass pyrolysis area, and a gas outlet is formed in the top of the tar conversion area;

the filling materials in the tar conversion area are arranged in two layers, a first filling material layer and a second filling material layer are sequentially arranged, the first filling material layer is filled with the first filling materials, the second filling material layer is filled with the second filling materials, the first filling materials are uniform mixtures of natural ore catalysts and carbonization materials, and the second filling materials are metal-loaded catalysts or metal-loaded catalysts and carbonization materials.

2. The biomass gasification processor of claim 1, wherein: the baffle sets up perpendicular to treater bottom, baffle upper end and shells inner wall sealing connection, and the baffle lower extreme sets up with grate position parallel and level, gas distribution board sets up with the grate parallel and level.

3. The biomass gasification processor of claim 1, wherein: a plurality of holes are uniformly formed in the gas distribution plate, and the diameter of each hole is 2-5 mm.

4. The biomass gasification processor of claim 1, wherein: the volume ratio of the biomass pyrolysis zone to the tar conversion zone is 1: 1-5: 1.

5. The biomass gasification processor of claim 4, wherein: the volume ratio of the biomass pyrolysis zone to the tar conversion zone is 1: 1-3: 1.

6. The biomass gasification processor of claim 1, wherein: divide into biomass pyrolysis district, tar conversion district, ash storage district triplex with biomass gasification treater through baffle, fire grate, gas distribution board jointly, the adjustable biomass pyrolysis district of adjusting the baffle lateral position is with the proportion in tar conversion district.

7. The biomass gasification processor of claim 1, wherein: the biomass pyrolysis zone is provided with a first feeder and a first slag extractor, wherein the first feeder is arranged at the upper part of the biomass pyrolysis zone, the first slag extractor is arranged above a grate at the bottom of the biomass pyrolysis zone, the first feeder is a spiral feeder, and the first slag extractor is a spiral slag extractor.

8. The biomass gasification processor of claim 1, wherein: the tar conversion area is provided with a second feeder and a second slag extractor, wherein the second feeder is arranged at the upper part of the tar conversion area, the second slag extractor is arranged above the gas distribution plate at the bottom of the tar conversion area, the second feeder is a spiral feeder, and the second slag extractor is a spiral slag extractor.

9. The biomass gasification processor of claim 1, wherein: the biomass gasification processor is operated under micro negative pressure, the vacuum degree is 400-600 Pa, when dry distillation gasification is carried out, a gas inlet is opened only before the device is started, air in the gasification processor is replaced by nitrogen, a gas inlet is closed in the reaction process, and the vacuum degree in the reactor is maintained at a gas outlet through a pump.

10. A biomass gasification process comprising:

(2) the high-temperature flue gas in the step (1) enters a tar conversion area after passing through an ash storage area, and contacts with a filler filled in the tar conversion area to react; wherein the gasification processor adopts the biomass gasification processor of any one of claims 1 to 9;

the device comprises a tar conversion area, a tar storage area and a tar storage area, wherein the tar conversion area is provided with two layers of fillers, a first filler layer and a second filler layer are sequentially arranged, the first filler layer is filled with a first filler, the second filler layer is filled with a second filler, the first filler is a uniform mixture of a natural ore catalyst and a carbonization material, and the second filler is a metal-loaded catalyst or a metal-loaded catalyst and a carbonization material; the bed temperature of the first filler layer is 600-900 ℃; the bed temperature of the second filler layer is 500-800 ℃, and the bed temperature of the first filler layer is 20-300 ℃ higher than that of the second filler layer.

11. The biomass gasification process of claim 10, wherein: the biomass raw material in the step (1) is any biomass containing lignocellulose.

12. The biomass gasification process of claim 10, wherein: the reaction temperature of the biomass pyrolysis zone in the step (1) is 300-900 ℃.

13. The biomass gasification process of claim 12, wherein: the reaction temperature of the biomass pyrolysis zone in the step (1) is 400-800 ℃.

14. The biomass gasification process of claim 10, wherein: the carbonized material is one or more of biomass semi-coke, raw oil coke, coal pyrolysis coke and active carbon.

15. The biomass gasification process of claim 10, wherein: the natural ore is one or more of limestone, dolomite, attapulgite, iron ore, clay ore and olivine; the metal-loaded catalyst takes one or more of biomass semi-coke, alumina, activated carbon, silicon carbide and porous ceramic as a carrier, and the loaded active component is one or more of the forms of a metal simple substance, a metal salt, a metal oxide and a metal peroxide; the metal is one or more of alkali metal, alkaline earth metal and transition metal.

16. The biomass gasification process of claim 15, wherein: the alkali metal is one or more of lithium, sodium, potassium, rubidium, cesium and francium; the transition metal is one or more of iron, cobalt, nickel, copper and zinc.

17. The biomass gasification process of claim 10, wherein: the ratio of the first filler to the second filler is 50: 1-1: 1.

18. The biomass gasification process of claim 17, wherein: when the second filler comprises the carbonized material, the weight ratio of the carbonized material in the first filler to the carbonized material in the second filler in the tar conversion zone is 10: 1-1: 10.

19. the biomass gasification process of claim 18, wherein: the weight ratio of the carbonized material in the first filler to the carbonized material in the second filler in the tar conversion zone is 10: 1-1: 1.

20. The biomass gasification process of claim 10, wherein: the bed temperature of the first filler layer is 700-900 ℃; the bed temperature of the second filler layer is 550-700 ℃.