CN117757496A - Catalytic pyrolysis device and method for low-rank coal of coal gas heat carrier - Google Patents
Catalytic pyrolysis device and method for low-rank coal of coal gas heat carrier Download PDFInfo
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Abstract
The invention discloses a catalytic pyrolysis device for low-rank coal of a coal gas heat carrier, which comprises a heat accumulating type coal gas heating furnace, a catalyst moving bed, a catalytic pyrolysis device, a mixing chamber, a dust remover and a coal gas condensing device, wherein the catalytic pyrolysis device comprises a drying section, a catalytic pyrolysis section and a cooling section, flue gas after passing through the cooling section sequentially passes through the dust remover, the mixing chamber enters the drying section to serve as a drying heat source of raw coal, and raw coal gas generated by the catalytic pyrolysis section passes through the coal gas condensing device to obtain product coal gas. The invention adopts the combination of the heat accumulating type gas heating furnace, the catalyst moving bed and the internal heating type pyrolysis furnace to carry out catalytic pyrolysis on raw coal, and compared with the traditional pyrolysis mode, the invention improves the tar yield and the gas quality.
Description
Technical Field
The invention relates to a catalytic pyrolysis device and method, in particular to a catalytic pyrolysis device and method for low-rank coal by using a coal gas heat carrier.
Background
Coal pyrolysis refers to a thermal processing technology that coal is placed in an air-insulated or inert gas environment, and after being continuously heated to a certain temperature, a series of physical changes and chemical changes occur, so that coal gas (gas state), coal tar (liquid state) and semicoke (solid) are obtained. Pyrolysis is an important link in the coal thermal processing process, and is widely focused due to the advantages of low processing temperature, simple process and operation, and the like. The method is characterized in that the method is used for carrying out differential processing according to the property and structural difference of pyrolysis products, so that an industrial chain is extended, various chemical raw materials and various fine chemicals can be produced, and clean and efficient utilization of coal is realized.
The chemical reaction in the pyrolysis of coal is a very complex parallel radical reaction, mainly comprising two types of reactions, cracking and polycondensation. The macromolecular structure of coal is decomposed after being heated, the structure with poor thermal stability such as molecular side chains, bridging bonds, functional groups and the like is broken and falls off to form free radicals, decomposition and combination reaction are carried out in a certain pyrolysis atmosphere to finally form coal gas and tar, and the core structure of coal is combined with each other to generate dehydrogenation polycondensation or crosslinking reaction to form semicoke.
The factors influencing the pyrolysis of coal are many, and the distribution of pyrolysis products can be regulated and controlled by controlling parameters such as pyrolysis temperature, heating rate, pyrolysis pressure and the like or optimizing pyrolysis atmosphere. H in pyrolysis atmosphere 2 、CO、CO 2 And CH (CH) 4 The content and the mutual proportion thereof have certain promotion or inhibition effect on the generation of tar. Under the action of catalyst, the components of high-temperature gas heat carrier reform to raise H 2 Content of CO is controlled 2 And CH (CH) 4 In such a proportion that part of CH in the gas 4 The formation of free radicals can promote the production of hydrocarbon gas and the stable progress of micromolecular side chains and free radicals generated by pyrolysis reaction, and greatly improve the tar yield. To realize pyrolysis industry deviceThe device is stable and reliable to operate, improves the product quality, and a plurality of units search in the aspects of process routes, pyrolysis devices and the like, but can not obtain coal gas with higher heat value and higher tar yield at the same time, most of the processes can not realize accurate temperature control, and a means for adjusting the product quality is lacked.
Patent CN201010276076.9 discloses a method and device for preparing coal tar by catalytic pyrolysis of pulverized coal, wherein an outlet at the upper end of a catalytic pyrolysis reactor is communicated with an inlet of a raw gas purifying device, an outlet at the middle part of the catalytic pyrolysis reactor is communicated with an inlet at the lower end of a heating riser and is communicated with an inlet at the middle part of a high-temperature semicoke heat exchanger, a heating furnace is communicated with an inlet of the heating riser, an outlet at the middle part of the heating riser is communicated with the semicoke inlet of the catalytic pyrolysis reactor, an outlet at the upper end of the heating riser is communicated with a flue gas inlet of the high-temperature gas heat exchanger, an outlet of the raw gas purifying device is communicated with a gas input end of the high-temperature gas heat exchanger through a circulating gas blower, a lower outlet of the raw gas purifying device is communicated with the inlet of the high-temperature semicoke heat exchanger through a gas blower, an outlet of the high-temperature gas heat exchanger is communicated with the catalytic pyrolysis reactor, another outlet of the high-temperature semicoke heat exchanger is communicated with an inlet of the catalytic pyrolysis reactor through a flue gas induced draft fan. The method comprises the steps of cyclic semicoke powder heating, pulverized coal catalytic pyrolysis reaction, coal tar recovery and waste heat utilization. The method takes pulverized coal as a treatment object, has a complex process route, and has the core that part of semi-coke powder is combusted to obtain high-temperature flue gas, the flue gas exchanges heat with coal gas to obtain high-temperature coal gas, and the high-temperature coal gas and the semi-coke powder after passing through a catalyst carry out pyrolysis reaction in a pyrolysis reactor. The catalytic pyrolysis mode provided by the method reduces the quality of semicoke, the fluidized pyrolysis process is difficult to control, the gas-solid high-temperature separation difficulty is high, and industrial application cannot be realized. In addition, the temperature of the reacted high-temperature gas outlet is about 500 ℃, the heat is not completely used, and the system has low heat efficiency.
The patent CN 109321264A discloses a coal pyrolysis oil-increasing device and a process, wherein the disclosed coal pyrolysis oil-increasing device comprises a coal slurry preparation unit, a buffer tank, a tubular heating furnace, a coking tower, a fractionating tower, a tar collecting unit and a coke collecting unit. The invention starts from the pyrolysis process mechanism of coal, takes the primary pyrolysis affecting the coal as a core, and realizes the pyrolysis and oil increase of the coal by strengthening the generation of free radicals and the escape of the free radicals in the pyrolysis process of the coal. Solves the problem of high hydrogen consumption of the prior hydropyrolysis. The pyrolysis process adopts a kerosene slurry feeding mode, although pyrolysis does not generate dust phenomenon in a pyrolysis furnace, low-metamorphic coal and coal tar or fractions thereof are mixed for pulping, certain requirements are met on the pulping property of raw coal, and the coal tar is heated to separate out additional heat, so that the tar is cracked or carbon precipitation reacted after heating pyrolysis, and the quality of the tar is not improved. The components of the heat carrier are regulated through the catalytic reaction, so that the generation and stability of pyrolysis free radicals are promoted, and the tar yield is improved more simply and practically.
Patent CN200510045853.8 discloses a method to increase tar yield during pyrolysis and coking of coal. Methane is taken as reaction gas, a proper oxidant is added, the mixture of methane and the oxidant enters a pyrolysis reactor, the pyrolysis reactor is divided into an upper layer and a lower layer, the middle is separated by a gas distribution plate, and the methane enters a coal bed after being activated by a catalyst to carry out pyrolysis and coking on coal. According to the method, methane is used as the hydropyrolysis reaction gas, the yield of tar in the product is higher than that of the hydropyrolysis tar under the same condition, and the catalyst and the coal are not directly mixed, so that the catalyst is easy to recycle. However, this method does not mention how the heat source for the pyrolysis reaction, i.e., the mixed heat carrier of methane and oxidant, is heated to a high temperature. The catalyst and coal are placed in a reactor, and coal dust can enter the catalyst layer through the middle gas distribution plate, so that the replacement and regeneration of the catalyst are adversely affected. In addition, it is not economically viable to formulate a specific ratio of hybrid heat carrier alone to increase tar yield.
Patent CN101942313a discloses a process and apparatus for fractional retorting of oil shale in a fully circulated state using gas as a heat carrier. The oil shale is divided into three different specifications of large, medium and small after being crushed and sieved, and the oil shale is dried and heated to more than 50 ℃ and less than 150 ℃ by waste flue gas discharged from a gas heating furnace and then enters into a carbonization furnace for carbonization with different specifications. The inside of the carbonization furnace is provided with a distributing device and a gas distributing structure which are matched with the particle size of the oil shale. The thermal cycle gas is heated to more than 700 ℃ in a heating furnace and is evenly and continuously fed into the middle part of the carbonization furnace. Cold circulation gas enters from the lower part of the carbonization furnace, the carbonized semicoke is cooled to 250 ℃, and then is discharged into a semicoke tank of a water seal after being cooled by cooling water, is cooled to 80 ℃ and is discharged out of the furnace by a scraping plate. Part of the semicoke is sent to a heating furnace to be mixed with gas for combustion, and the other part is sent to a power plant to be used as fuel. After oil-water separation, a part of the gas is used as a heat carrier for recycling. Part of the fuel is used as heating furnace fuel, and the other part is used as fuel gas for generating electricity. The method uses the gas heat storage furnace in the pyrolysis process, but the gas is not subjected to catalytic reforming after being heated, and the gas in the carbonization furnace is only used as a heat transfer medium and has no chemical promotion effect on the pyrolysis reaction.
The patent CN 109679673A discloses a low-rank coal pyrolysis furnace and a grading utilization process thereof, and particularly comprises a furnace body and a plate type material conveying mechanism arranged along the length direction of the furnace body, wherein the furnace body is of a closed heat-preserving structure, the upper part of one end is provided with a low-rank coal feeding bin, the lower part is provided with a coal ash discharging pipe, a drying section, a preheating temperature-rising section, a carbonization section and a cooling section are arranged in the furnace body, heat-insulating walls are arranged between the sections, a material channel is reserved between the heat-insulating walls and the plate type material conveying mechanism, a hot carrier gas inlet pipe, a cold gas inlet pipe, a drying gas collecting pipe and a preheating gas collecting pipe are also arranged on the furnace body, the hot carrier gas inlet pipe is communicated with the cooling section, the drying gas collecting pipe is communicated with the drying section, and the preheating gas collecting pipe is communicated with the heating temperature-rising section. The method also uses high-temperature coal gas as a pyrolysis heat carrier, does not involve catalytic reforming of coal gas components, only has the advantage of high quality of coal gas products, but does not remarkably improve tar yield compared with a flue gas heat carrier or an indirect heating mode.
The patent CN 106398732A relates to a low-quality coal poly-generation quality-improving process and device, and is characterized in that the low-quality coal is continuously fed into a carbonization furnace through a material receiving device and a material receiving metering device for heating and carbonization, coal gas (comprising coal tar and water) is separated, and the remaining solid materials are cooled by a dry quenching device to obtain clean coal with lower volatile components and are continuously fed out, and the carbonization furnace is provided with a plurality of carbonization chambers, combustion chambers and regenerator burners. The invention adopts an indirect heating method to ensure higher gas quality and combines the regenerative burner to improve the energy efficiency of the system. Compared with direct heat exchange, the device for gas-solid indirect heat exchange has lower processing capacity, obvious temperature gradient in the furnace, incomplete reaction of large-particle coal and difficult quality control.
Patent CN 107267178A relates to a system and a method for producing medium-low order powdered coal catalytic pyrolysis coupling calcium carbide, and provides a system and a method for producing medium-low order powdered coal catalytic pyrolysis coupling calcium carbide. The system comprises a stirring tank, a pyrolysis device and an entrained flow bed; the stirring tank is used for mixing pulverized coal with the catalyst; the pyrolysis device is used for generating high-temperature coal gas and high-temperature semicoke through the reaction of the mixture; the entrained flow bed is used for calcium carbide production. The method mixes the pulverized coal with the catalyst solution and then sprays the mixture into the pyrolysis device by using a nozzle to react, thereby improving the yield of tar. However, the pulverized coal has high surface tension, is generally hydrophobic, is difficult to uniformly distribute the catalyst solution on the surface of particles, has a mixing effect related to the structural form and operation parameters of the stirring tank, has a limited promotion effect on the pyrolysis reaction, and moreover, the catalyst cannot be recovered and regenerated by the method.
In summary, the existing low-rank coal pyrolysis device can be divided into external heating type and internal heating type according to the heating mode, and can be divided into a moving bed, a fluidized bed, a rotary furnace and the like according to the device type, wherein the internal heating type moving bed pyrolysis device has high heat transfer efficiency, large equipment treatment and stable operation, and is most mature in industry and more in application. However, when the combustion flue gas is used as a heat carrier, the quality of the byproduct gas is low, and when the gas is used as the heat carrier, the gas is only used as a heat transfer medium, so that the method has no promotion effect on complex chemical reactions involved in the pyrolysis process. The related research units introduce a catalyst or a hydropyrolysis atmosphere in the pyrolysis process to promote tar generation, but the problems of complex process, unreasonable reactor, incapability of recycling the catalyst, difficult flexible control of the reaction process and the like generally exist.
Disclosure of Invention
The invention aims to: the invention aims to provide a coal gas heat carrier low-rank coal catalytic pyrolysis device with recoverable catalyst and high tar yield; the invention further aims to provide a coal gas heat carrier low-rank coal catalytic pyrolysis method with simple process.
The technical scheme is as follows: the invention discloses a catalytic pyrolysis device for low-rank coal of a coal gas heat carrier, which comprises a heat accumulating type coal gas heating furnace, a catalyst moving bed, a catalytic pyrolysis device, a mixing chamber, a dust remover and a coal gas condensing device, wherein the catalytic pyrolysis device comprises a drying section, a catalytic pyrolysis section and a cooling section, flue gas after passing through the cooling section sequentially passes through the dust remover, the mixing chamber enters the drying section to serve as a drying heat source of raw coal, and raw coal gas generated by the catalytic pyrolysis section passes through the coal gas condensing device to obtain product coal gas.
The heat accumulating heating furnace has the functions of cracking partial hydrocarbon gas produced by coal pyrolysis into small molecular components such as methane, hydrogen and the like at high temperature (more than or equal to 1000 ℃), so that the subsequent catalytic efficiency is improved, and the catalyst has the functions of endowing more active sites of the methane and the hydrogen in the gas, providing free radicals for the pyrolysis process, enabling light volatile matters produced by the pyrolysis to form tar macromolecules, inhibiting the thermal polycondensation process and further improving the tar yield. According to the invention, the catalyst material bed is coupled with the moving bed pyrolysis process, the catalyst can be replaced on line under the high temperature effect, and the industrial system and the device for catalytic pyrolysis of coal are more stable and feasible.
Further, the catalytic pyrolysis section is provided with a multi-layer gas distribution structure, and the multi-layer gas distribution structure comprises a gas inlet, a gas distribution umbrella, a mixing chamber and a coal bed.
Further, an air distribution umbrella frame for fixing is arranged between the air distribution umbrella.
The method for carrying out catalytic pyrolysis on the coal gas heat carrier low-rank coal based on the device comprises the following steps:
the raw materials enter a heat accumulating type gas heating furnace, after passing through a catalyst moving bed, heat exchange is carried out between the raw materials and hot flue gas in a drying section of a catalytic pyrolysis device, then under the action of gravity, the raw materials enter the catalytic pyrolysis section, heat exchange is carried out between the raw materials and the catalytic reformed gas, the materials after the carbonization reaction continue to flow down to a cooling section, high-temperature flue gas is dedusted by a deduster, the raw materials enter the drying section through a mixing chamber and serve as a drying heat source of raw coal, and raw coal gas generated by the catalytic pyrolysis section is subjected to a gas condensing device to obtain tar products.
Further, 20-30% of the gas in the gas product is used as product gas, and the rest part of the gas enters a heat accumulating type gas heating furnace to be used as circulating gas.
Further, after the residual gas enters a heat accumulating gas heating furnace to be heated, reforming is carried out at a high temperature, then the gas component is activated under the action of a catalyst, and free radicals generated by the pyrolysis reaction of the coal are fast and stable under the atmosphere, so that the tar yield is improved.
Further, the gas is produced by a pyrolysis process, including CO, H 2 And C m H n 。
Further, the raw coal is dried in advance.
Further, when the materials go down to the cooling section, the temperature of the hot semicoke is reduced to below 100 ℃ after heat exchange with the circulating low-temperature flue gas, and the temperature of the flue gas is increased to above 300 ℃.
Further, the tar yield reaches 200% of the yield of the grid Jin Jiaoyou, and the proportion of the effective components of the coal gas is more than 85%.
The invention adopts the combination of the heat accumulating type gas heating furnace, the catalyst moving bed and the internal heating type pyrolysis furnace to carry out catalytic pyrolysis on raw coal, and compared with the traditional pyrolysis mode, the invention improves the tar yield and the gas quality. The catalytic pyrolysis process disclosed by the invention has wide applicability, and is especially suitable for the quality-dividing comprehensive utilization of low-rank coal or oil shale such as lignite, long flame coal and the like. Compared with other processes, the coal gas obtained by pyrolysis of the technology has high quality, high tar yield, mature and reliable process, high heat utilization efficiency and good economic benefit.
The beneficial effects are that: compared with the prior art, the invention has the following remarkable advantages:
(1) Compared with a catalytic pyrolysis integrated device, the catalytic pyrolysis device is an independent moving bed, coal dust and a catalyst are not mixed, the catalytic and pyrolysis processes are relatively independent, the problem of catalyst loss is avoided, the catalytic process is continuously operated, and the catalyst can be replaced on line;
(2) Compared with hydrogenation catalysis and methane/oxidant cooperation, the heat carrier of the technology is obtained by catalyzing on the basis of high-temperature recombination of self-produced pyrolysis gas in a regenerative heating furnace, and the heat carrier is not required to be prepared independently, has lower cost and is easier to realize industrially;
(3) Compared with the pyrolysis process of the gas heat carrier, the effect of the self-produced gas in the pyrolysis process is that the self-produced gas not only provides heat, but also is used as the raw material gas for high-temperature recombination and catalyst activation, and the raw material gas is participated in the pyrolysis reaction to promote the generation of tar, the yield of the tar reaches 200 percent of the yield of Jin Jiaoyou, and the proportion of the effective components of the gas is more than 85 percent;
(4) According to the invention, the self-produced coal gas in the pyrolysis process is heated by a regenerative heating furnace to complete high-temperature reforming to enable the self-produced coal gas to have catalytic activity, and then the self-produced coal gas is used as a heat carrier after being modified by a catalytic moving bed, so that the tar yield and the content of useful components in a coal gas product are greatly improved, the problems of low tar yield, high heavy tar occupancy rate, poor coal gas quality and low heat value during direct pyrolysis of coal are solved, and the economic benefit of a system is also remarkably improved;
(5) Compared with the indirect heating or the heating mode of burning part of semicoke for heating in the pyrolysis process, the heat exchange efficiency is higher, the temperature gradient can not occur in the furnace, and the semicoke yield and quality are more stable and uniform;
(6) The pyrolysis equipment is through multilayer net cloth gas structure to strengthen gas-solid heat transfer, make the throughput of single pyrolysis equipment show the improvement, area is little, and whole technology heat utilization efficiency is high, and running cost is low.
Drawings
FIG. 1 is an overall device diagram of the present invention;
FIG. 2 is a schematic diagram of a gas distribution structure of a catalytic pyrolysis section in a three-dimensional structure;
FIG. 3 is a cross-sectional view of a catalytic pyrolysis section gas distribution structure;
FIG. 4 is a schematic diagram of a catalyst moving bed structure.
Detailed Description
The technical scheme of the invention is further described below with reference to the accompanying drawings.
The reference numerals in fig. 1-3 are: 1-a drying section; 2-a mixing chamber; 3-discharging flue gas; 4-low-temperature flue gas; 5-high temperature flue gas; 6-a dust remover; 7-a catalytic pyrolysis section; 8-a cooling section; 9-a moving bed of catalyst; 10-a heat accumulating type gas heating furnace; 11-circulating coal gas; 12-product tar; 13-a gas condensing device; 14-product gas; 15-air inlets, 16-gas distribution umbrellas, 17-mixing chambers and 18-coal beds.
As shown in fig. 1, the catalytic pyrolysis device for the coal gas heat carrier low-rank coal comprises a heat accumulating type coal gas heating furnace 10, a catalyst moving bed 9, a catalytic pyrolysis device, a mixing chamber 2, a dust remover 6 and a coal gas condensing device 13, wherein the catalytic pyrolysis device comprises a drying section 1, a catalytic pyrolysis section 7 and a cooling section 8, flue gas passing through the cooling section 8 sequentially passes through the dust remover 6, the mixing chamber 2 enters the drying section 1 to serve as a drying heat source of raw coal, and raw coal gas generated by the catalytic pyrolysis section 7 passes through the coal gas condensing device 13 to obtain product coal gas.
As shown in fig. 2 and 3, the catalytic pyrolysis section 7 is provided with a multi-layer gas distribution structure, which comprises a gas inlet 15, a gas distribution umbrella 16, a mixing chamber 17 and a coal seam 18. The high-temperature heat carrier enters the catalytic pyrolysis section through the mixing chamber 17 in a layered manner, exchanges heat with coal, and fully meets the requirements of different heating stages on the temperature of the heat carrier.
A schematic of the structure of the moving bed 9 of catalyst is shown in fig. 4.
Taking long flame coal pyrolysis as an example, raw materials can be directly fed into a furnace through a conveying belt, heat exchange is carried out between a drying section 1 and high-temperature flue gas 5 from a cooling section after passing through a catalyst moving bed 9, external water is completely removed, the temperature of materials is increased to about 200 ℃, low-temperature flue gas 4 after heat exchange is separated out from the drying section 1, 90% of the low-temperature flue gas enters the cooling section 8, and the rest is discharged flue gas 3. Under the action of gravity, the materials enter a catalytic pyrolysis section 7 and exchange heat with the catalytic reformed coal gas at 850 ℃. In order to reduce the resistance of gas passing through materials and increase the gas residence time, high-temperature gas is led into the furnace in a layered manner through a multi-layer gas inlet structure, the temperature of the materials is gradually increased to 600 ℃ and is subject to pyrolysis reaction, volatile matters are separated out in a gas form, and then are led out of the furnace after being gathered through multi-layer gas collecting channels in the furnace, and the gas outlet temperature is about 300 ℃.
The materials after the carbonization reaction continue to go down to the cooling section, the temperature is reduced to below 100 ℃ after the heat exchange of the hot semicoke and the circulating cold flue gas, the temperature of the flue gas is increased to 300 ℃, and the materials enter the drying section through the mixing chamber after dust removal to serve as a drying heat source of raw coal. The heat load of the carbonization section can be reduced by pre-drying raw coal, most of the drying heat source is from sensible heat of materials in the cooling section, and if the raw coal has higher moisture, part of hot flue gas can be supplemented through the combustion system.
Raw gas generated in the catalytic pyrolysis section 7 is subjected to dust removal, cooling by a gas condensing device 13 and oil-water separation to obtain a product tar 12, 20-30% of gas is used as a product gas 14, the gas is completely generated in the pyrolysis process, and most of the gas comprises CO and H 2 、CH 4 、C m H n Etc., the effective component ratio is high, and can be used as synthesis gas or for preparing LNG. The rest part enters a regenerative gas heating furnace 10 as circulating gas 11 and is heated to 1000 ℃ and H at high temperature 2 、CH 4 、C m H n The equal gases are cracked and recombined, the reaction activity is obviously enhanced, and CH in the gas 4 With CO/CO 2 The ratio of the catalyst to the catalyst is more favorable for gas catalysis, a catalyst moving bed 9 is arranged at the rear part of the heating furnace, and CH is caused to be reacted under the action of the catalyst 4 The gas temperature is reduced to about 850 ℃ and then is led into a catalytic pyrolysis section 7 of the catalytic pyrolysis device through a multi-layer gas distribution structure, and under the atmosphere, the gas not only serves as a heat transfer medium, but also has a promoting effect on the pyrolysis reaction process and tar generation, so that the tar yield is improved. The yield of tar reaches 200% of the yield of the grid Jin Jiaoyou, and the proportion of the effective components of the gas is more than 85%.
Claims (10)
1. The utility model provides a coal gas heat carrier low order coal catalytic pyrolysis device, its characterized in that, the device includes heat accumulation formula coal gas heating furnace (10), catalyst moving bed (9), catalytic pyrolysis device, mixing chamber (2), dust remover (6) and coal gas condensing equipment (13), catalytic pyrolysis device includes dry section (1), catalytic pyrolysis section (7) and cooling section (8), and flue gas after cooling section (8) passes through dust remover (6) in proper order, and mixing chamber (2) get into dry section (1) and regard as the dry heat source of raw coal, and the raw gas that catalytic pyrolysis section (7) produced obtains product gas after coal gas condensing equipment (13).
2. The catalytic pyrolysis device for coal gas heat carrier low-rank coal according to claim 1, characterized in that the catalytic pyrolysis section (7) is provided with a multi-layer gas distribution structure comprising a gas inlet (15), a gas distribution umbrella (16), a mixing chamber (17) and a coal seam (18).
3. The catalytic pyrolysis device for coal gas heat carrier low rank coal according to claim 1, characterized in that a gas distribution umbrella frame for fixing is arranged between the gas distribution umbrellas (16).
4. A method for catalytic pyrolysis of coal gas heat carrier low rank coal based on the device of any one of claims 1-3, characterized by comprising the steps of:
raw materials enter a heat accumulating type gas heating furnace (10), after passing through a catalyst moving bed (9), heat exchange is carried out between a drying section (1) of a catalytic pyrolysis device and hot flue gas, then under the action of gravity, the raw materials enter a catalytic pyrolysis section (7), heat exchange is carried out between the raw materials and the gas subjected to catalytic reforming, the materials after the carbonization reaction continue to descend to a cooling section (8), high-temperature flue gas is dedusted through a deduster (6), the raw materials enter the drying section (1) through a mixing chamber (2) to serve as a drying heat source of raw coal, and raw coal gas generated by the catalytic pyrolysis section (7) is subjected to a gas condensing device (13) to obtain tar products.
5. The method for catalytic pyrolysis of coal gas heat carrier low-rank coal according to claim 4, wherein 20-30% of the condensed coal gas is used as product coal gas, and the rest part enters a regenerative coal gas heating furnace (10) as circulating coal gas.
6. The method for catalytic pyrolysis of low-rank coal by using a gas heat carrier according to claim 5, wherein the rest part of the gas enters a regenerative gas heating furnace (10) to be heated, reformed at a high temperature, and then gas components are activated under the action of a catalyst, and free radicals generated by the pyrolysis reaction of the coal are rapidly stabilized in the atmosphere, so that the tar yield is improved.
7. The method for catalytic pyrolysis of coal gas heat carrier low rank coal according to claim 4 wherein the coal gas is produced by a pyrolysis process comprising CO, H 2 And C m H n 。
8. The method for catalytic pyrolysis of coal gas heat carrier low rank coal according to claim 4 wherein the raw coal is previously dried.
9. The method for catalytic pyrolysis of coal gas heat carrier low-rank coal according to claim 4, wherein when the materials go down to the cooling section, the temperature is reduced to below 100 ℃ after heat exchange between the hot semicoke and circulating low-temperature flue gas, and the temperature of the flue gas is increased to above 300 ℃.
10. The method for catalytic pyrolysis of coal gas heat carrier low rank coal according to claim 4 wherein the tar yield reaches 200% of the yield of grid Jin Jiaoyou and the proportion of the effective components of the coal gas is more than 85%.
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