Device and method for fluidized catalytic gasification of pulverized coal

Abstract

The present invention discloses a device for fluidized catalytic gasification of pulverized coal, comprising: a feeder; a fast bed pyrolysis furnace connected to the feeder through a feed inclined pipe; a fluidized bed gasifier connected to the fast bed pyrolysis furnace; a fast bed gasifier, the lower inlet of which is connected to the upper outlet of the fluidized bed gasifier; a fluidized bed combustion chamber, the upper inlet of which is connected to the lower outlet of the fluidized bed gasifier; a fine powder settler / stripper connected to the fast bed pyrolysis furnace through a gasification inclined pipe. The present invention also discloses a method for fluidized catalytic gasification of pulverized coal. The present invention has the characteristics of high carbon conversion rate, high gasification intensity, high utilization rate of pulverized coal, wide adaptability of gasified coal types, reasonable energy utilization, and stable and efficient operation of the device.

Description

Technical Field

[0001] The present invention belongs to the field of coal gasification, and relates to an apparatus and method for fluidized catalytic gasification of pulverized coal. Background Art

[0002] Coal, petroleum, and natural gas are the world's three major primary energy sources. Among them, coal accounts for approximately 79% of the world's energy reserves. Coal is one of the main fuel resources for generating power, heat, coal coking, and by-product tar. China is a country with a mainly coal-based energy structure, which will not change in the long term. According to statistics, in China's primary energy consumption structure in 2015, coal accounted for 63.7%. With the increasing shortage of petroleum resources, the effective utilization of coal resources has become a strategy for the sustainable development of China's energy. China's low-rank coal reserves account for more than 55% of the total coal resources. However, it has a high moisture content and a low degree of coalification, resulting in low direct combustion efficiency, wasting resources and polluting the environment, causing emissions of acid rain, PM2.5, and greenhouse gases such as SOx and NOx. Coal gasification technology is the key technology for the clean, efficient, and comprehensive utilization of coal, an important way for coal conversion, and also one of the key technologies for synthesizing chemicals, combined cycle power generation, and coal-based substitute natural gas. Achieving the efficient and clean utilization of coal is the key to China's sustainable energy development and an effective way to solve the global energy and environmental problems.

[0003] China is the world's largest application market for coal gasification technology. At present, a variety of coal gasification technologies have been successfully industrialized. Currently, the more widely used one belongs to the entrained flow gasification technology, which improves the carbon conversion rate at the cost of high temperature and high pressure, bringing problems such as high energy consumption, difficult gas purification, and strict requirements for equipment. At the same time, the excessively high operating temperature of the entrained flow slag gasification technology increases the investment, maintenance, and operating costs of the entrained flow bed. The research report of the Electric Power Research Institute (EPRI) of the United States points out that existing industrial entrained flow gasifiers are not suitable for the gasification of high-ash and high-ash fusion point coals, and the world needs industrialized fluidized bed gasification technology. The fluidized bed technology, whether for combustion or gasification, has the nature of adapting to high-ash fusion point and high-ash coal types. The successful combustion of coal gangue in a circulating fluidized bed boiler is evidence of this.

[0004] Natural gas is a high-quality fuel and an important chemical raw material. It is safe, reliable, green and environmentally friendly. With the rapid development of my country's economy and the acceleration of urbanization, the demand for natural gas is increasing. my country's own natural gas production cannot meet the demand for natural gas, and the contradiction between supply and demand is becoming increasingly prominent. The supply gap can only be made up by imports, which greatly affects my country's energy security. The existing coal-to-gas technology can be divided into two types: two-step method and one-step method. The two-step coal-to-gas technology is a relatively traditional technology. It is a method of first converting coal into synthesis gas (CO+H2) and then methanating it to obtain SNG. It needs to go through the following steps: gasification, shift cooling, purification, methane synthesis, etc. The one-step coal-to-gas technology directly synthesizes methane from coal as raw material, and realizes the gasification, shift and methanation reaction process through a catalyst in the gasifier to obtain a methane-rich synthesis gas. The two-step coal-to-gas technology needs to be implemented in different reactors, which causes the temperature and pressure of each reaction process to be mismatched, and there is a lot of heat loss when circulating inside the system, which reduces the energy conversion efficiency of the system. The one-step coal-to-natural gas technology effectively solves the above-mentioned problems, realizes the coupling of logistics and heat, and has high economy and feasibility, thus becoming an important research direction in the field of coal-to-natural gas.

[0005] US Patent No. 4077778 proposes a one-step coal-to-methane process, which uses alkali metal carbonate or alkali metal hydroxide as a catalyst, controls the reaction temperature in the furnace at about 700°C through superheated steam, and reacts with coal powder under the action of the catalyst to directly obtain methane-rich gas. This process requires superheated steam to be heated to about 850°C, which has high energy consumption and low carbon conversion rate. It is difficult to maintain the reaction temperature without external heating, and the technology is still in the research and development stage.

[0006] Chinese patent CN102021037B proposes a one-step method for producing methane by catalytic gasification of coal, which divides the gasifier into a synthesis gas generation section, a coal methanation section and a synthesis gas methanation section, so that combustion, gasification, methanation reaction and pyrolysis reaction are carried out in stages. However, a multi-layer air distribution plate and an overflow channel need to be set in the gasifier, the structure in the furnace is complex, the gasification efficiency and methane yield are low, and the introduction of oxygen at the bottom of the fluidized bed easily causes the ash to melt and agglomerate, forming large pieces of molten slag, blocking the outlet of the gasifier and the gas distributor, thereby affecting the operating stability of the device and there is no industrial device for this technology.

[0007] In summary, although the existing coal catalytic gasification technologies have, to a certain extent, solved the shortcomings of traditional fixed-bed and entrained-flow bed gasification for producing rich-methane synthesis gas, they are all in the R & D or scale-up stage and have not yet been industrially applied. Due to the limitations of fluidized bed technology and catalytic process conditions, the carbon conversion rate and gasification intensity are low. Therefore, how to effectively improve the carbon conversion rate and gasification intensity, effectively utilize the heat cascades of combustion, gasification, and pyrolysis, reasonably couple the reaction processes of combustion, gasification, pyrolysis, shift, and methanation, and achieve the efficient and clean utilization of pulverized coal with true pyrolysis-gasification integration in terms of quality and grading is the key to the development of coal gasification technology. Summary of the Invention

[0008] The object of the present invention is to provide a pulverized coal fluidized catalytic gasification device and method that couple pulverized coal pyrolysis, combustion, and gasification, aiming at the problems existing in the prior art, such as low carbon conversion rate, low gasification intensity, low methane yield, low pulverized coal utilization rate, and difficulty in utilizing low-rank coal. The present invention is characterized by high carbon conversion rate, high gasification intensity, high methane yield, high pulverized coal utilization rate, wide adaptability to gasification coal types, reasonable energy utilization, and stable and efficient operation of the device.

[0009] According to one aspect of the present invention, there is provided a device for pulverized coal fluidized catalytic gasification, comprising:

[0010] A feeder;

[0011] A fast bed pyrolysis furnace, which is connected to the feeder through a feed inclined pipe;

[0012] A fluidized bed gasification furnace, which is connected to the fast bed pyrolysis furnace;

[0013] A fast bed gasification furnace, the lower inlet of which is connected to the upper outlet of the fluidized bed gasification furnace;

[0014] A fluidized bed combustion chamber, the upper inlet of which is connected to the lower outlet of the fluidized bed gasification furnace;

[0015] A fine powder settling / stripper, which is connected to the fast bed pyrolysis furnace through a gasification inclined pipe.

[0016] According to some embodiments of the present invention, the lower part of the side wall of the fast bed pyrolysis furnace is respectively provided with a pulverized coal inlet and a gasified semicoke inlet. The pulverized coal inlet is connected to the feeder through a feed inclined pipe; the gasified semicoke inlet is connected to the fine powder settling / stripper through a gasification inclined pipe; the upper part of the fast bed pyrolysis furnace is provided with a pyrolysis product outlet, which is connected to the fluidized bed gasification furnace.

[0017] According to a preferred embodiment of the present invention, a pyrolysis fluidizing gas inlet is provided at the bottom of the fast bed pyrolysis furnace for receiving pyrolysis fluidizing gas.

[0018] According to a preferred embodiment of the present invention, the fluidized bed gasifier and the fast bed pyrolyzer are arranged side by side.

[0019] According to some embodiments of the present invention, a pyrolysis product inlet is provided in the upper part of the side wall of the fluidized bed gasifier, which is connected to the fast bed pyrolyzer.

[0020] According to a preferred embodiment of the present invention, a gasifying agent inlet is provided in the lower part of the side wall of the fluidized bed gasifier, and the gasifying agent inlet is used to receive the gasifying agent.

[0021] According to a preferred embodiment of the present invention, the lower outlet of the fluidized bed gasifier is connected to the upper inlet of the fluidized bed combustor.

[0022] According to some embodiments of the present invention, a gas distribution plate is provided below the interior of the fluidized bed combustor; a slag discharge outlet is provided at the bottom of the fluidized bed combustor, and the slag discharge outlet is connected to a slag tank.

[0023] According to a preferred embodiment of the present invention, the upper outlet of the fluidized bed gasifier is reduced in diameter and then connected to the lower inlet of the fast bed gasifier.

[0024] According to a preferred embodiment of the present invention, the fast bed gasifier includes a fast bed gasification / cracking zone, a fast bed steam reforming zone, and a fast bed methanation zone from bottom to top; preferably, a steam inlet is provided on the side wall of the fast bed steam reforming zone, and a syngas recycle port is provided on the side wall of the fast bed methanation zone.

[0025] According to some embodiments of the present invention, the fine powder settling / stripper includes a stripping section, a fine powder settling section, and a fine powder settling / stripper cyclone separator; a stripping gas inlet for receiving the stripping gas is provided in the lower part of the side wall of the fine powder settling / stripper; a semi-coke outlet is provided in the lower part of the side wall of the fine powder settling / stripper, which is connected to the fast bed pyrolyzer through a gasification inclined pipe; a syngas outlet is provided at the top of the fine powder settling / stripper, which is connected to the gas outlet of the fine powder settling / stripper cyclone separator for discharging the separated syngas.

[0026] According to a preferred embodiment of the present invention, a fast bed cyclone separator is provided inside the fine powder settling / stripper, which is connected to the upper outlet of the fast bed gasifier.

[0027] According to some embodiments of the present invention, the device further includes a post-treatment system, which includes:

[0028] A gas-solid fast separator, which is connected to the syngas outlet of the fine powder settling / stripper;

[0029] A gas separation device, which is connected to the gas-solid fast separator.

[0030] According to a preferred embodiment of the present invention, the gas-solid fast separator is provided with a syngas inlet, a fly ash outlet, and a gas-solid fast separator gas outlet. The syngas inlet is connected to the syngas outlet of the fine powder settling / stripper, and the gas-solid fast separator gas outlet is connected to a gas separation device.

[0031] According to a preferred embodiment of the present invention, the gas separation device is provided with a gas inlet, a recycle gas outlet, and a syngas outlet. The gas inlet is connected to the gas-solid fast separator gas outlet, and the recycle gas outlet is connected to the syngas return port of the fast bed methanation zone.

[0032] According to some embodiments of the present invention, the device further includes a catalyst system, which includes a catalyst recovery device and a catalyst loading device; the upstream of the catalyst recovery device is connected to the ash tank, and the downstream is connected to the catalyst loading device; the upstream of the catalyst loading device is connected to the catalyst recovery device, and the downstream is connected to the feeder.

[0033] According to a preferred embodiment of the present invention, the catalyst recovery device is provided with an inlet, an ash outlet, and a catalyst outlet. The inlet is connected to the ash tank, and the catalyst outlet is connected to the catalyst loading device.

[0034] According to a preferred embodiment of the present invention, the catalyst loading device is provided with a first catalyst inlet, a second catalyst inlet, a carrier inlet, and a catalyst outlet. The first catalyst inlet is connected to the catalyst outlet of the catalyst recovery device, the second catalyst inlet is used to supplement the catalyst, the carrier inlet is used to add the carrier, and the catalyst outlet is connected to the feeder.

[0035] According to a preferred embodiment of the present invention, a gasification semicoke return valve is provided on the gasification inclined pipe, which is a non-mechanical return valve, preferably a U valve, a J valve, an L valve or an M valve. Loosening gas is introduced into the gasification semicoke return valve, and the circulation amount of the gasification semicoke, or the liquid level of the fine powder settling / stripper, or the temperature of the fast bed pyrolysis furnace is controlled by adjusting the air volume of the loosening gas.

[0036] According to another aspect of the present invention, a method for pulverized coal fluidized catalytic gasification is provided, which uses the above-mentioned device and includes the following steps:

[0037] (a) The pulverized coal raw material is fed into the fast bed pyrolysis furnace by the feeder, and is heated by mixing with high-temperature gasification semicoke in the fast bed pyrolysis furnace. The pulverized coal undergoes a pyrolysis reaction to generate a pyrolysis product containing pyrolysis semicoke and pyrolysis gas;

[0038] (b) The pyrolysis products enter the fluidized bed gasifier and contact with the gasifying agent, and gasification reactions and tar cracking reactions occur in the fluidized bed gasifier and the fast bed gasifier to generate syngas and carbonaceous gasified semicoke;

[0039] (c) The syngas enters the fine powder settler / stripper to separate out the high-temperature gasified semicoke, and the high-temperature gasified semicoke enters the fast bed pyrolysis furnace via the gasification inclined pipe;

[0040] (d) The carbonaceous gasified semicoke enters the fluidized bed combustion chamber downward from the fluidized bed gasifier, and a combustion reaction occurs to produce ash and high-temperature gas; the high-temperature gas enters the fluidized bed gasifier upward as the gasifying agent.

[0041] According to some embodiments of the present invention, the pulverized coal raw material includes pulverized coal and at least one of a catalyst and biomass; preferably, the catalyst includes at least one of an alkali metal, an alkaline earth metal, and a transition metal.

[0042] According to a preferred embodiment of the present invention, the catalyst is loaded on the pulverized coal by means of impregnation, dry mixing, ion exchange, etc., and the loading amount of the catalyst accounts for 0.1-30% of the mass of the pulverized coal.

[0043] According to a preferred embodiment of the present invention, the pyrolysis pressure of the fast bed pyrolysis furnace is 0-6.5 MPa, and the pyrolysis temperature is 400-800 °C; and / or, the average density of the pulverized coal in the dense phase region of the fast bed pyrolysis furnace is 200-550 kg / m 3 , and the superficial gas velocity is 0.1-1.0 m / s.

[0044] According to a preferred embodiment of the present invention, pyrolysis fluidizing gas is introduced into the fast bed pyrolysis furnace through the pyrolysis fluidizing gas inlet at the bottom thereof; the pyrolysis fluidizing gas includes at least one of water vapor, CO2, CO, and an inert gas.

[0045] According to some embodiments of the present invention, the pyrolysis products enter the upper part of the fluidized bed gasifier and contact with the gasifying agent, and gasification reactions and tar cracking reactions occur in the fluidized bed gasifier and the fast bed gasifier to generate syngas and carbonaceous gasified semicoke. While the gasification reaction occurs in the fast bed gasifier, water vapor is introduced into the fast bed water gas shift zone to carry out a water gas reaction (CO + H2O = CO2 + H2) to adjust the H2 / CO ratio; recycled syngas is introduced into the fast bed methanation zone to carry out a methanation reaction (CO + 3H2 = CH4 + H2O) to increase the methane yield in the product.

[0046] According to a preferred embodiment of the present invention, the gasifying agent is the high-temperature gas from the fluidized bed combustion chamber or the gasifying agent from the outside introduced through the gasifying agent inlet; the gasifying agent includes water vapor and / or CO2.

[0047] According to a preferred embodiment of the present invention, the gasification pressure of the fluidized bed gasifier is 0 - 6.5 MPa, the gasification temperature is 700 - 1200 °C, and the average density of pulverized coal is 200 - 450 kg / m 3 , and the average superficial velocity is 0.2 - 1.2 m / s.

[0048] According to a preferred embodiment of the present invention, the gasification pressure of the fast bed gasification / pyrolysis zone is 0 - 6.5 MPa, and the gasification temperature is 700 - 1200 °C; and / or, the gasification pressure of the fast bed water gas shift zone is 0 - 6.5 MPa, and the gasification temperature is 700 - 1000 °C; and / or, the gasification pressure of the fast bed methanation zone is 0 - 6.5 MPa, and the gasification temperature is 700 - 900 °C; and / or, the average density of pulverized coal in the fast bed gasifier is 50 - 150 kg / m 3 , and the average superficial velocity is 1.0 - 3.0 m / s.

[0049] According to some embodiments of the present invention, the syngas coming out of the fast bed gasifier carries unvaporized semicoke fines, and first enters the fast bed cyclone separator for preliminary gas-solid separation. The solid falls into the stripping section of the fines settling / stripper, and the gas enters the settling section of the fines settling / stripper.

[0050] According to a preferred embodiment of the present invention, the gas coming out of the fast bed cyclone separator enters the settling section of the fines settling / stripper and the fines settling / stripper cyclone separator to further separate the solid. The solid falls into the stripping section of the fines settling / stripper, and the gas leaves the fines settling / stripper and enters the gas-solid fast separator to remove fly ash, and then enters the gas separation device; the gas separation device separates methane from the syngas and divides it into recycle gas (methane-lean gas) and methane-rich syngas; a part of the gas coming out of the gas separation device is recycled back to the fast bed methanation zone, and the other part is discharged as methane-rich syngas.

[0051] According to a preferred embodiment of the present invention, stripping gas is introduced into the stripping section of the fines settling / stripper through the stripping gas inlet to strip the solid in the stripping section and remove the fly ash entrained in the solid to obtain high-temperature gasified semicoke, and the high-temperature gasified semicoke enters the fast bed pyrolysis furnace through the gasification dip tube.

[0052] According to a preferred embodiment of the present invention, the stripping gas includes at least one of water vapor, CO2, CO, and inert gas.

[0053] According to a preferred embodiment of the present invention, loosening gas is introduced into the gasified semicoke return valve, and the circulation amount of the gasified semicoke, or the level of the fines settling / stripper, or the temperature of the fast bed pyrolysis furnace is controlled by adjusting the air volume of the loosening gas.

[0054] According to a preferred embodiment of the present invention, the loose gas includes at least one of water vapor, CO2, CO, air, oxygen, and inert gas.

[0055] According to a preferred embodiment of the present invention, the pressure of the fine powder sedimentation / stripper is 0 - 6.5 MPa, the temperature is 700 - 1200 °C, and the average density of pulverized coal is 350 - 550 kg / m 3 , and the average superficial gas velocity is 0.1 - 0.5 m / s.

[0056] According to some embodiments of the present invention, the carbon-containing gasified semicoke enters the fluidized bed combustion chamber downward from the fluidized bed gasifier, contacts with the oxidant, undergoes a combustion reaction to produce ash and high-temperature gas; the high-temperature gas enters the fluidized bed gasifier upward as a gasifying agent and provides heat for the gasification reaction; the ash is discharged to the ash tank through the ash discharge port, then enters the catalyst recovery device to separate the catalyst and the ash, the ash is discharged externally, and the recovered catalyst enters the catalyst loading device, is loaded onto the carrier and then is transported to the feeder as a raw material.

[0057] According to a preferred embodiment of the present invention, the oxidant includes air and / or oxygen.

[0058] According to a preferred embodiment of the present invention, the carrier includes pulverized coal, coke, and other carbon-containing substances.

[0059] According to a preferred embodiment of the present invention, the catalyst and / or biomass can also be supplemented into the catalyst loading device through the second catalyst inlet.

[0060] According to a preferred embodiment of the present invention, the combustion pressure of the fluidized bed combustion chamber is 0 - 6.5 MPa, the combustion temperature is 800 - 1500 °C, and the average density of pulverized coal is 300 - 450 kg / m 3 , and the average superficial gas velocity is 0.2 - 0.6 m / s.

[0061] The technical solution of the present invention pyrolyzes pulverized coal raw materials in a pyrolysis furnace to obtain pyrolysis gas (including coal tar) and gasification raw materials - pyrolysis semicoke. By obtaining gasification raw materials through pyrolysis, the applicable range of coal types is expanded. In the gasification furnace, gasification reactions of pyrolysis semicoke particles and cracking reactions of coal tar occur to produce syngas. Moreover, most of the high-temperature gasified semicoke particles that are not completely gasified serve as heat carriers and circulate into the pyrolysis furnace as the heat source for pyrolysis, reducing energy consumption and also saving the cost of externally loaded heat carriers in traditional processes. A small part of the gasified semicoke particles that are not completely gasified enter the combustion chamber to react with oxygen to convert the semicoke into ash, improving the carbon conversion rate and the utilization rate of residual carbon. The heat generated by the combustion reaction is used to supply the heat consumption and heat loss in the gasification reaction and provides the necessary gasifying agent for the gasification reaction. The present invention specifically provides a fine powder settling / stripper, the purpose of which is to remove the fly ash entrained in the high-temperature gasified semicoke entering the pyrolysis furnace, thereby reducing the fly ash entrained in the pyrolysis gas and avoiding the blockage of related equipment by fly ash.

[0062] The present invention couples processes such as pyrolysis and gasification, gasification and combustion, gasification and shift, methanation, and methanation, etc. It realizes the partition coupling of gasification, shift, methanation, and tar cracking in one gasification furnace, effectively improving the methane yield of the single-pass reaction; the separated syngas is recycled back to the methanation zone of the gasification furnace for further methanation reaction, which can produce methane-rich syngas and by-product coal tar, realizing the separate and graded utilization of low-rank coal. It can carry out direct gasification of pulverized coal or catalytic gasification of pulverized coal. The catalyst is recycled after separation and recovery, realizing the efficient, clean, and reasonable comprehensive utilization of coal.

[0063] Adopting the technical solution of the present invention, compared with the prior art, the carbon conversion rate at the gasification outlet in the reactor is increased to 98%, the methane content in the syngas is increased to 25%, and the tar production is increased by 10%. It has the characteristics of high carbon conversion rate, high methane production rate, increased tar production, and high utilization rate of pulverized coal, achieving good technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a schematic diagram of the device for fluidized catalytic gasification of pulverized coal of the present invention:

[0065] Figure 1Among them, 1 is a feeder; 2 is a feed inclined pipe; 3 is a fast bed pyrolysis furnace; 4 is a fluidized bed combustion chamber; 5 is a fluidized bed gasifier; 6 is a fast bed gasifier; 7 is a fast bed gasification / pyrolysis zone; 8 is a fast bed steam reforming zone; 9 is a fast bed methanation zone; 10 is a fine powder settling / stripper; 11 is a fast bed gasifier cyclone separator; 12 is a stripping section; 13 is a fine powder settling section; 14 is a fine powder settling / stripper cyclone separator; 15 is a gas distribution plate; 16 is a slag discharge port; 17 is a slag tank; 18 is a gasification inclined pipe; 19 is a gasification semi-coke return valve; 20 is a gas-solid fast separator; 21 is a gas separation device; 22 is a catalyst recovery device; 23 is a pulverized coal catalyst loading device; A is a pulverized coal raw material; B is a pyrolysis fluidizing gas; C is an oxidant; D is a gasifying agent; E is steam; F is a stripping gas; G and H are fluidizing gases; I is fly ash; J is a methane-rich syngas; K is slag; M is a carrier; N is a catalyst and / or biomass. Specific Embodiments

[0066] The present invention will be further described below by way of examples, but is not limited to these examples.

[0067] In the following examples, the evaluation and testing methods involved are as follows:

[0068] The carbon conversion rate is calculated based on the residual carbon in the slag. The specific formula is:

[0069] CC = (1 - C ash / C raw ) × 100%, where CC is the carbon conversion rate, C ash is the carbon content in the slag, and C raw is the carbon content in the pulverized coal raw material;

[0070] The gas components are measured by the external standard method of an on-line gas chromatograph to obtain the methane content in the syngas;

[0071] The tar yield is calculated by the mass balance of gas-liquid-solid products. The specific formula is: Y tar = (M raw - M gas - M ash ) / M raw × 100%, where Y tar is the tar yield, M raw is the mass flow rate of the pulverized coal raw material, M gas is the mass flow rate of the product gas, and M ash is the mass flow rate of the slag.

[0072]

Example 1

[0073] The reaction process is as follows: The raw materials are fed into the fast bed pyrolysis furnace (3) by a feeder (1), mixed with the high-temperature gasified semicoke / ash from the gasifier, heated, and undergo pyrolysis reactions. The pyrolysis gas and pyrolysis semicoke enter the fluidized bed gasifier (5). Among them, the pyrolysis semicoke contacts with the gasifying agent D, and gasification reactions and tar cracking reactions occur in the fluidized bed gasifier (5) and the fast bed gasifier (6) to generate syngas. While the gasification reaction occurs in the fast bed gasifier (6), steam E is introduced into the fast bed steam reforming zone (8) to carry out steam reforming reactions to adjust the H2 / CO ratio. Recirculated syngas is introduced into the fast bed methanation zone (9) to carry out methanation reactions to increase the methane yield in the product. The syngas separated from the syngas entraining semicoke fines enters the subsequent gas-solid fast separator (20) to remove fly ash I. Then, part of the syngas is recycled back to the fast bed methanation zone (9) as recycle gas to further carry out methanation reactions and increase the methane yield. The fines recovered by the fines settling / stripping cyclone separator (14) fall into the stripping section (12) through the dipleg. The stripping section (12) uses stripping gas F to strip the unreacted carbon-containing semicoke and ash. After stripping, the carbon-containing semicoke and ash compounds enter the fast bed pyrolysis furnace (3) after controlling the recycle amount, mix with fresh pulverized coal, and heat the newly introduced pulverized coal for pyrolysis. The carbon-containing gasified semicoke and ash fall from the bottom of the fluidized bed gasifier (5) into the fluidized bed combustor (4), contact and mix with the oxidant C, and undergo combustion reactions. The ash is discharged from the device regularly or continuously. The high-temperature gas generated by combustion rises into the fluidized bed gasifier (5) as the gasifying agent and provides heat for the gasification medium. The catalyst-containing ash discharged from the ash hopper (17) is heat-exchanged and then enters the catalyst recovery device (22) to recover the catalyst and then be discharged. The recovered catalyst enters the catalyst loading device (23) for recycling.

[0074] Lignite is used as the raw material in the reaction process. The pyrolysis pressure of the fast bed pyrolysis furnace (3) is 0, and the pyrolysis temperature is 400 °C. The average density of the pulverized coal in the fast bed pyrolysis furnace (3) is 200 kg / m 3 , and the superficial velocity in the empty tower of the fast bed pyrolysis furnace (3) is 1.0 m / s; the gasification pressure of the fluidized bed gasifier (5) is 0, the gasification temperature is 700 °C, and the average density of the pulverized coal is 200 kg / m 3 , and the average superficial velocity in the empty tower of the fluidized bed gasifier (8) is 1.2 m / s; the gasification pressure of the fast bed gasification / pyrolysis zone (7) is 0, and the gasification temperature is 700 °C; the gasification pressure of the fast bed steam reforming zone (8) is 0, and the gasification temperature is 700 °C; the gasification pressure of the fast bed methanation zone (9) is 0, and the gasification temperature is 700 °C; the average density of the pulverized coal in the fast bed gasifier (6) is 50 kg / m 3 , and the average superficial velocity in the empty tower is 3.0 m / s; the combustion pressure of the fluidized bed combustor (4) is 0, the combustion temperature is 800 °C, and the average density of the pulverized coal is 300 kg / m 3, the average superficial gas velocity in the fluidized bed combustion chamber (4) is 0.6 m / s; the pressure in the fine powder settling / stripper (10) is 0, the temperature is 700 °C, and the average density of pulverized coal is 350 kg / m 3 , the average superficial gas velocity in the fine powder settling / stripper (10) is 0.5 m / s. Among them, the pyrolysis fluidizing gas B uses an inert gas, and the gasifying agent D uses steam. Through the above scheme, the carbon conversion rate at the gasification outlet in the reactor is 93%, the methane content in the syngas is increased to 16.7%, and the tar yield is 8.2%. The detailed results are shown in Table 1.

[0075]

Example 2

[0076] The reaction process is the same as that in Example 1. Lignite is used as the raw material in the reaction process. The pyrolysis pressure in the fast bed pyrolyzer (3) is 0, the pyrolysis temperature is 400 °C, and the average density of pulverized coal in the fast bed pyrolyzer (3) is 200 kg / m 3 , the superficial gas velocity in the fast bed pyrolyzer (3) is 1.0 m / s; the gasification pressure in the fluidized bed gasifier (5) is 0, the gasification temperature is 700 °C, and the average density of pulverized coal is 200 kg / m 3 , the average superficial gas velocity in the fluidized bed gasifier (8) is 1.2 m / s; the gasification pressure in the fast bed gasification / pyrolysis zone (7) is 0, the gasification temperature is 700 °C; the gasification pressure in the fast bed steam reforming zone (8) is 0, the gasification temperature is 700 °C; the gasification pressure in the fast bed methanation zone (9) is 0, the gasification temperature is 700 °C; the average density of pulverized coal in the fast bed gasifier (6) is 50 kg / m 3 , the average superficial gas velocity is 3.0 m / s; the combustion pressure in the fluidized bed combustion chamber (4) is 0, the combustion temperature is 800 °C, and the average density of pulverized coal is 300 kg / m 3 , the average superficial gas velocity in the fluidized bed combustion chamber (4) is 0.6 m / s; the pressure in the fine powder settling / stripper (10) is 0, the temperature is 700 °C, and the average density of pulverized coal is 350 kg / m 3 , the average superficial gas velocity in the fine powder settling / stripper (10) is 0.5 m / s. Among them, the pyrolysis fluidizing gas B uses an inert gas, and the gasifying agent D uses steam. Through the above scheme, the carbon conversion rate at the gasification outlet in the reactor is 93%, the methane content in the syngas is increased to 17.3%, and the tar yield is 7.8%. The detailed results are shown in Table 1.

[0077]

Example 3

[0078] The reaction process is the same as that in Example 1. Lignite is used as the raw material in the reaction process. The pyrolysis pressure in the fast bed pyrolyzer (3) is 0, the pyrolysis temperature is 800 °C, and the average density of pulverized coal in the fast bed pyrolyzer (3) is 200 kg / m 3 , the superficial gas velocity in the fast bed pyrolyzer (3) is 1.0 m / s; the gasification pressure in the fluidized bed gasifier (5) is 0, the gasification temperature is 1200 °C, and the average density of pulverized coal is 200 kg / m3 , the average superficial velocity in the fluidized bed gasifier (8) is 1.2 m / s; the gasification pressure in the fast bed gasification / pyrolysis zone (7) is 0, and the gasification temperature is 1200 °C; the gasification pressure in the fast bed steam reforming zone (8) is 0, and the gasification temperature is 1000 °C; the gasification pressure in the fast bed methanation zone (9) is 0, and the gasification temperature is 900 °C; the average density of pulverized coal in the fast bed gasifier (6) is 50 kg / m 3 , the average superficial velocity is 3.0 m / s; the combustion pressure in the fluidized bed combustor (4) is 0, and the combustion temperature is 1500 °C, and the average density of pulverized coal is 300 kg / m 3 , the average superficial velocity in the fluidized bed combustor (4) is 0.6 m / s; the pressure in the fine powder settling / stripper (10) is 0, and the temperature is 1200 °C, and the average density of pulverized coal is 350 kg / m 3 , the average superficial velocity in the fine powder settling / stripper (10) is 0.5 m / s. Among them, the pyrolysis fluidized gas B uses an inert gas, and the gasifying agent D uses steam. Through the above scheme, the carbon conversion rate at the gasification outlet in the reactor is 96%, the methane content in the syngas is increased to 20.8%, and the tar yield is 5.8%. The detailed results are shown in Table 1.

[0079]

Example 4

[0080] The reaction process is the same as that in Example 1. Lignite is used as the raw material in the reaction process. The pyrolysis pressure in the fast bed pyrolyzer (3) is 0, and the pyrolysis temperature is 800 °C. The average density of pulverized coal in the fast bed pyrolyzer (3) is 200 kg / m 3 , the superficial velocity in the fast bed pyrolyzer (3) is 1.0 m / s; the gasification pressure in the fluidized bed gasifier (5) is 6.5 MPa, and the gasification temperature is 1200 °C. The average density of pulverized coal is 200 kg / m 3 , the average superficial velocity in the fluidized bed gasifier (8) is 1.2 m / s; the gasification pressure in the fast bed gasification / pyrolysis zone (7) is 6.5 MPa, and the gasification temperature is 1200 °C; the gasification pressure in the fast bed steam reforming zone (8) is 6.5 MPa, and the gasification temperature is 1000 °C; the gasification pressure in the fast bed methanation zone (9) is 6.5 MPa, and the gasification temperature is 900 °C; the average density of pulverized coal in the fast bed gasifier (6) is 50 kg / m 3 , the average superficial velocity is 3.0 m / s; the combustion pressure in the fluidized bed combustor (4) is 6.5 MPa, and the combustion temperature is 1500 °C. The average density of pulverized coal is 300 kg / m 3 , the average superficial velocity in the fluidized bed combustor (4) is 0.6 m / s; the pressure in the fine powder settling / stripper (10) is 6.5 MPa, and the temperature is 1200 °C. The average density of pulverized coal is 350 kg / m 3, the average superficial velocity in the fine powder settling / stripper (10) is 0.5 m / s. Among them, the pyrolysis fluidizing gas B is an inert gas, and the gasifying agent D is steam. Through the above solution, the carbon conversion rate at the gasification outlet in the reactor is 96%, the methane content in the syngas is increased to 22.3%, and the tar yield is 5.3%. The detailed results are shown in Table 1.

[0081]

Example 5

[0082] The reaction process is the same as that in Example 1. Lignite is used as the raw material in the reaction process. The pyrolysis pressure of the fast bed pyrolyzer (3) is 0, the pyrolysis temperature is 800 °C, and the average density of pulverized coal in the fast bed pyrolyzer (3) is 550 kg / m 3 , the superficial velocity in the fast bed pyrolyzer (3) is 0.1 m / s; the gasification pressure of the fluidized bed gasifier (5) is 6.5 MPa, the gasification temperature is 1200 °C, and the average density of pulverized coal is 450 kg / m 3 , the average superficial velocity in the fluidized bed gasifier (8) is 0.2 m / s; the gasification pressure of the fast bed gasification / pyrolysis zone (7) is 6.5 MPa, the gasification temperature is 1200 °C; the gasification pressure of the fast bed steam reforming zone (8) is 6.5 MPa, the gasification temperature is 1000 °C; the gasification pressure of the fast bed methanation zone (9) is 6.5 MPa, the gasification temperature is 900 °C; the average density of pulverized coal in the fast bed gasifier (6) is 150 kg / m 3 , the average superficial velocity is 1.0 m / s; the combustion pressure of the fluidized bed combustor (4) is 6.5 MPa, the combustion temperature is 1500 °C, and the average density of pulverized coal is 500 kg / m 3 , the average superficial velocity in the fluidized bed combustor (4) is 0.2 m / s; the pressure of the fine powder settling / stripper (10) is 6.5 MPa, the temperature is 1200 °C, and the average density of pulverized coal is 550 kg / m 3 , the average superficial velocity in the fine powder settling / stripper (10) is 0.1 m / s. Among them, the pyrolysis fluidizing gas B is an inert gas, and the gasifying agent D is steam. Through the above solution, the carbon conversion rate at the gasification outlet in the reactor is 96%, the methane content in the syngas is increased to 22.9%, and the tar production is increased by 5.2%. The detailed results are shown in Table 1.

[0083]

Example 6

[0084] The reaction process is the same as that in Example 1. Lignite is used as the raw material in the reaction process. The pyrolysis pressure of the fast bed pyrolyzer (3) is 0, the pyrolysis temperature is 600 °C, and the average density of pulverized coal in the fast bed pyrolyzer (3) is 550 kg / m 3 , the superficial velocity in the fast bed pyrolyzer (3) is 0.1 m / s; the gasification pressure of the fluidized bed gasifier (5) is 6.5 MPa, the gasification temperature is 900 °C, and the average density of pulverized coal is 450 kg / m 3, the average superficial velocity in the fluidized bed gasifier (8) is 0.2 m / s; the gasification pressure in the fast bed gasification / pyrolysis zone (7) is 6.5 MPa and the gasification temperature is 900 °C; the gasification pressure in the fast bed steam conversion zone (8) is 6.5 MPa and the gasification temperature is 850 °C; the gasification pressure in the fast bed methanation zone (9) is 6.5 MPa and the gasification temperature is 800 °C; the average density of pulverized coal in the fast bed gasifier (6) is 150 kg / m 3 , the average superficial velocity is 1.0 m / s; the combustion pressure in the fluidized bed combustor (4) is 6.5 MPa, the combustion temperature is 1100 °C, and the average density of pulverized coal is 500 kg / m 3 , the average superficial velocity in the fluidized bed combustor (4) is 0.2 m / s; the pressure in the fine powder settling / stripper (10) is 6.5 MPa, the temperature is 900 °C, and the average density of pulverized coal is 550 kg / m 3 , the average superficial velocity in the fine powder settling / stripper (10) is 0.1 m / s. Among them, the pyrolysis fluidized gas B uses an inert gas, and the gasifying agent D uses steam. Through the above scheme, the carbon conversion rate at the gasification outlet in the reactor is 95%, the methane content in the syngas is increased to 23.6%, and the tar production is increased by 9.9%. The detailed results are shown in Table 1.

[0085]

Example 7

[0086] The reaction process is the same as that in Example 1. The raw materials used in the reaction process are lignite + 5% K2CO3. The pyrolysis pressure in the fast bed pyrolyzer (3) is 0, the pyrolysis temperature is 600 °C, and the average density of pulverized coal in the fast bed pyrolyzer (3) is 550 kg / m 3 , the superficial velocity in the fast bed pyrolyzer (3) is 0.1 m / s; the gasification pressure in the fluidized bed gasifier (5) is 6.5 MPa, the gasification temperature is 900 °C, and the average density of pulverized coal is 450 kg / m 3 , the average superficial velocity in the fluidized bed gasifier (8) is 0.2 m / s; the gasification pressure in the fast bed gasification / pyrolysis zone (7) is 6.5 MPa and the gasification temperature is 900 °C; the gasification pressure in the fast bed steam conversion zone (8) is 6.5 MPa and the gasification temperature is 850 °C; the gasification pressure in the fast bed methanation zone (9) is 6.5 MPa and the gasification temperature is 800 °C; the average density of pulverized coal in the fast bed gasifier (6) is 150 kg / m 3 , the average superficial velocity is 1.0 m / s; the combustion pressure in the fluidized bed combustor (4) is 6.5 MPa, the combustion temperature is 1100 °C, and the average density of pulverized coal is 500 kg / m 3 , the average superficial velocity in the fluidized bed combustor (4) is 0.2 m / s; the pressure in the fine powder settling / stripper (10) is 6.5 MPa, the temperature is 900 °C, and the average density of pulverized coal is 550 kg / m 3, the average superficial velocity in the fine powder sedimentation / stripper (10) is 0.1 m / s. Among them, the pyrolysis fluidizing gas B is an inert gas, and the gasifying agent D is steam. Through the above scheme, the carbon conversion rate at the gasification outlet in the reactor is 98%, the methane content in the syngas is increased to 24.8%, and the tar production is increased by 8.7%. The detailed results are shown in Table 1.

[0087]

Example 8

[0088] The reaction process is the same as that in Example 1. In the reaction process, the raw material is lignite + 5% K2CO3. The pyrolysis pressure of the fast bed pyrolyzer (3) is 0, the pyrolysis temperature is 600 °C, and the average density of pulverized coal in the fast bed pyrolyzer (3) is 550 kg / m 3 , the superficial velocity in the fast bed pyrolyzer (3) is 0.1 m / s; the gasification pressure of the fluidized bed gasifier (5) is 6.5 MPa, the gasification temperature is 900 °C, and the average density of pulverized coal is 450 kg / m 3 , the average superficial velocity in the fluidized bed gasifier (8) is 0.2 m / s; the gasification pressure of the fast bed gasification / pyrolysis zone (7) is 6.5 MPa, the gasification temperature is 900 °C; the gasification pressure of the fast bed steam reforming zone (8) is 6.5 MPa, the gasification temperature is 850 °C; the gasification pressure of the fast bed methanation zone (9) is 6.5 MPa, the gasification temperature is 800 °C; the average density of pulverized coal in the fast bed gasifier (6) is 150 kg / m 3 , the average superficial velocity is 1.0 m / s; the combustion pressure of the fluidized bed combustor (4) is 6.5 MPa, the combustion temperature is 1100 °C, and the average density of pulverized coal is 500 kg / m 3 , the average superficial velocity in the fluidized bed combustor (4) is 0.2 m / s; the pressure of the fine powder sedimentation / stripper (10) is 6.5 MPa, the temperature is 900 °C, and the average density of pulverized coal is 550 kg / m 3 , the average superficial velocity in the fine powder sedimentation / stripper (10) is 0.1 m / s. Among them, the pyrolysis fluidizing gas B is hydrogen, and the gasifying agent D is steam. Through the above scheme, the carbon conversion rate at the gasification outlet in the reactor is 98%, the methane content in the syngas is increased to 25.0%, and the tar production is increased by 8.1%. The detailed results are shown in Table 1.

[0089]

Example 9

[0090] The reaction process is the same as that in Example 1. In the reaction process, the raw material is lignite + 5% K2CO3. The pyrolysis pressure of the fast bed pyrolyzer (3) is 0, the pyrolysis temperature is 600 °C, and the average density of pulverized coal in the fast bed pyrolyzer (3) is 550 kg / m 3 , the superficial velocity in the fast bed pyrolyzer (3) is 0.1 m / s; the gasification pressure of the fluidized bed gasifier (5) is 6.5 MPa, the gasification temperature is 900 °C, and the average density of pulverized coal is 450 kg / m 3, the average superficial velocity in the fluidized bed gasifier (8) is 0.2 m / s; the gasification pressure in the fast bed gasification / pyrolysis zone (7) is 6.5 MPa and the gasification temperature is 900 °C; the gasification pressure in the fast bed steam conversion zone (8) is 6.5 MPa and the gasification temperature is 850 °C; the gasification pressure in the fast bed methanation zone (9) is 6.5 MPa and the gasification temperature is 800 °C; the average density of pulverized coal in the fast bed gasifier (6) is 150 kg / m 3 , the average superficial velocity is 1.0 m / s; the combustion pressure in the fluidized bed combustor (4) is 6.5 MPa, the combustion temperature is 1100 °C, and the average density of pulverized coal is 500 kg / m 3 , the average superficial velocity in the fluidized bed combustor (4) is 0.2 m / s; the pressure in the fine powder settling / stripper (10) is 6.5 MPa, the temperature is 900 °C, and the average density of pulverized coal is 550 kg / m 3 , the average superficial velocity in the fine powder settling / stripper (10) is 0.1 m / s. Among them, the pyrolysis fluidizing gas B adopts an inert atmosphere, and the gasifying agent D adopts CO2. Through the above scheme, the carbon conversion rate at the gasification outlet in the reactor is 98%, the methane content in the syngas is increased to 24.7%, and the tar production is increased by 8.7%. The detailed results are shown in Table 1.

[0091]

Comparative Example 1

[0092] The reaction process is the same as that in Example 1. In the reaction process, the raw material uses lignite + 5% K2CO3. The pyrolysis pressure in the fast bed pyrolyzer (3) is 0, the pyrolysis temperature is 600 °C, and the average density of pulverized coal in the fast bed pyrolyzer (3) is 550 kg / m 3 , the superficial velocity in the fast bed pyrolyzer (3) is 0.1 m / s; the gasification pressure in the fluidized bed gasifier (5) is 6.5 MPa, the gasification temperature is 900 °C, and the average density of pulverized coal is 450 kg / m 3 , the average superficial velocity in the fluidized bed gasifier (8) is 0.2 m / s; the gasification pressure in the fast bed gasification / pyrolysis zone (7) is 6.5 MPa and the gasification temperature is 900 °C; the gasification pressure in the fast bed steam conversion zone (8) is 6.5 MPa and the gasification temperature is 850 °C; the gasification pressure in the fast bed methanation zone (9) is 6.5 MPa and the gasification temperature is 800 °C; the average density of pulverized coal in the fast bed gasifier (6) is 150 kg / m 3 , the average superficial velocity is 1.0 m / s; the combustion pressure in the fluidized bed combustor (4) is 6.5 MPa, the combustion temperature is 1100 °C, and the average density of pulverized coal is 500 kg / m 3, the average superficial velocity in the fluidized bed combustor (4) is 0.2 m / s; the fine powder settling / stripper (10) is not provided, and only the cyclone separator is used to replace the fine powder settling / stripper. The pyrolysis fluidizing gas B adopts an inert atmosphere; the gasifying agent D adopts steam. Through the above scheme, the carbon conversion rate at the gasification outlet in the reactor is 90%, the methane content in the syngas is increased to 19.5%, and the tar yield is 7.9%. The detailed results are shown in Table 1.

[0093]

Comparative Example 2

[0094] The new Aoyuan Group PDU gasification reaction device in the prior art is adopted (see Bi Jicheng, Development Progress of Catalytic Gasification (One-step Method) Coal to SNG Technology [C]. The Fourth Symposium on Technology and Economy of Coal to SNG, 2013, Urumqi). The raw material is lignite, and 10% potassium carbonate is added as a catalyst. The linear velocity is <10 m / s, the operating temperature is 800 °C, the methane content in the outlet gas components obtained by gasification is 14%, but its carbon conversion rate is 90%, and no tar product is generated. The results are shown in detail in Table 1.

[0095]

Comparative Example 3

[0096] The traditional Lurgi pressurized fixed bed gasification device in the prior art is adopted (see Wang Peng et al., Development and Application of Lurgi Coal Gasification Technology [J]. Clean Coal Technology, 2009, 15(5): 48-51). The raw material is lignite, the gasification temperature is 850 °C, the methane content in the outlet gas components is 8.3%, the tar yield is 9%, and the carbon conversion rate is only 90%. The results are shown in detail in Table 1.

[0097] Table 1

[0098]

[0099]

[0100] For any numerical value mentioned in the present invention, if there is only a two-unit interval between any minimum value and any maximum value, all values increasing by one unit from the minimum value to the maximum value are included. For example, if the amount of a component is stated, or the value of a process variable such as temperature, pressure, time, etc. is 50-90, it means in this specification that the specific values of 51-89, 52-88... as well as 69-71 and 70-71, etc. are specifically listed. For non-integer values, it is appropriate to consider 0.1, 0.01, 0.001 or 0.0001 as one unit. These are only some specifically indicated examples. In this application, in a similar manner, all possible combinations of the numerical values between the listed minimum value and the maximum value are considered to have been disclosed.

[0101] It should be noted that the above-described embodiments are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described by reference to exemplary embodiments, but it should be understood that the words used therein are descriptive and explanatory words rather than limiting words. Modifications can be made to the present invention within the scope of the claims of the present invention as provided, and the present invention can be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein. On the contrary, the present invention can be extended to all other methods and applications having the same functions.

Claims

1. An apparatus for fluidized catalytic gasification of pulverized coal, comprising: A feeder; A fast bed pyrolysis furnace, which is connected to the feeder through a feed inclined pipe; A fluidized bed gasifier, which is connected to the fast bed pyrolysis furnace; A fast bed gasifier, the lower inlet of which is connected to the upper outlet of the fluidized bed gasifier; A fluidized bed combustion chamber, the upper inlet of which is connected to the lower outlet of the fluidized bed gasifier; A fine powder sedimentation / stripper, which is connected to the fast bed pyrolysis furnace through a gasification inclined pipe; The fast bed gasifier includes, from bottom to top, a fast bed gasification / cracking zone, a fast bed steam reforming zone, and a fast bed methanation zone; A steam inlet is provided on the side wall of the fast bed steam reforming zone, and a syngas return port is provided on the side wall of the fast bed methanation zone; The side wall of the fast bed pyrolysis furnace is respectively provided with a pulverized coal inlet and a gasified semi-coke inlet at the lower part. The pulverized coal inlet is connected to the feeder through a feed inclined pipe; the gasified semi-coke inlet is connected to the fine powder sedimentation / stripper through a gasification inclined pipe; an outlet is provided at the upper part of the fast bed pyrolysis furnace, which is connected to the fluidized bed gasifier; A pyrolysis product inlet is provided at the upper part of the side wall of the fluidized bed gasifier, which is connected to the outlet of the fast bed pyrolysis furnace; The fine powder sedimentation / stripper includes a stripping section, a fine powder sedimentation section, and a fine powder sedimentation / stripper cyclone separator; a stripping gas inlet is provided at the lower part of the side wall of the fine powder sedimentation / stripper for receiving stripping gas; a semi-coke outlet is provided at the lower part of the side wall of the fine powder sedimentation / stripper, which is connected to the fast bed pyrolysis furnace through a gasification inclined pipe; a syngas outlet is provided at the top of the fine powder sedimentation / stripper, which is connected to the gas outlet of the fine powder sedimentation / stripper cyclone separator for discharging syngas.

2. The device according to claim 1, characterized in that, A pyrolysis fluidizing gas inlet is provided at the bottom of the fast bed pyrolysis furnace for receiving pyrolysis fluidizing gas.

3. The device according to claim 1 or 2, characterized in that An air gasifying agent inlet is provided at the lower part of the side wall of the fluidized bed gasifier, and the air gasifying agent inlet is used to receive air gasifying agent; and / or, a slag discharge outlet is provided at the bottom of the fluidized bed combustion chamber, and the slag discharge outlet is connected to a slag tank.

4. The device according to claim 1 or 2, characterized in that, A fast bed cyclone separator is provided inside the fine powder sedimentation / stripper, which is connected to the upper outlet of the fast bed gasifier.

5. The device according to claim 1 or 2, characterized in that, The apparatus further includes a post-treatment system, which includes: A gas-solid fast separator, which is connected to the syngas outlet of the fine powder sedimentation / stripper; A gas separation device, which is connected to the gas-solid fast separator.

6. The device according to claim 3, characterized in that, The apparatus further includes a catalyst system, which includes a catalyst recovery device and a catalyst loading device; the upstream of the catalyst recovery device is connected to the slag tank, and the downstream is connected to the catalyst loading device; the upstream of the catalyst loading device is connected to the catalyst recovery device, and the downstream is connected to the feeder.

7. A method for fluidized catalytic gasification of pulverized coal, which uses the apparatus according to any one of claims 1-6, comprising the following steps: (a) Pulverized coal raw material is fed into the fast bed pyrolysis furnace by the feeder, and is heated by mixing with high-temperature gasified semi-coke in the fast bed pyrolysis furnace. The pulverized coal undergoes a pyrolysis reaction to generate a pyrolysis product containing pyrolyzed semi-coke and pyrolysis gas; (b)The pyrolysis products enter the fluidized bed gasifier, contact with the gasifying agent, and gasification reactions and tar cracking reactions occur in the fluidized bed gasifier and the fast bed gasifier to generate syngas and carbonaceous gasified semicoke; while the gasification reaction occurs in the fast bed gasifier, steam is introduced into the steam reforming zone of the fast bed to carry out the steam reaction; recycled syngas is introduced into the methanation zone of the fast bed to carry out the methanation reaction. (c)The syngas enters the fine powder settler / stripper to separate out the high-temperature gasified semicoke, and the high-temperature gasified semicoke enters the fast bed pyrolysis furnace via the gasification inclined pipe. (d)The carbonaceous gasified semicoke enters the fluidized bed combustor downward from the fluidized bed gasifier, and a combustion reaction occurs to produce ash and high-temperature gas; the high-temperature gas enters the fluidized bed gasifier upward as the gasifying agent.

8. The method according to claim 7, wherein The pulverized coal raw material includes pulverized coal and at least one of a catalyst and biomass.

9. The method according to claim 8, characterized in that, The catalyst includes at least one of an alkali metal, an alkaline earth metal, and a transition metal.

10. The method according to any one of claims 7-9, characterized in that, The pyrolysis pressure of the fast bed pyrolysis furnace is 0 - 6.5 MPa, and the pyrolysis temperature is 400 - 800 °C; and / or, the average density of the pulverized coal in the fast bed pyrolysis furnace is 200 - 550 kg / m 3 , and the superficial velocity is 0.1 - 1.0 m / s.

11. The method according to any one of claims 7-9, characterized in that The gasification pressure of the fluidized bed gasifier is 0 - 6.5 MPa, the gasification temperature is 700 - 1200 °C, and the average density of pulverized coal is 200 - 450 kg / m 3 , and the average superficial velocity is 0.2 - 1.2 m / s; and / or, the gasification pressure of the fast bed gasification / pyrolysis zone is 0 - 6.5 MPa, and the gasification temperature is 700 - 1200 °C; and / or, the gasification pressure of the fast bed water gas shift zone is 0 - 6.5 MPa, and the gasification temperature is 700 - 1000 °C; and / or, the gasification pressure of the fast bed methanation zone is 0 - 6.5 MPa, and the gasification temperature is 700 - 900 °C; and / or, the average density of pulverized coal in the fast bed gasifier is 50 - 150 kg / m 3 , and the average superficial velocity is 1.0 - 3.0 m / s.

12. The method according to any one of claims 7-9, characterized in that, The syngas coming out of the fast bed gasifier carries ungasified semicoke fines. First, it enters the fast bed cyclone separator for gas-solid separation. The solid falls into the stripping section of the fine powder settler / stripper, and the gas enters the settling section of the fine powder settler / stripper; and / or, the gas coming out of the fast bed cyclone separator enters the settling section of the fine powder settler / stripper and the cyclone separator of the fine powder settler / stripper to further separate out the solid. The solid falls into the stripping section of the fine powder settler / stripper, and the gas leaves the fine powder settler / stripper and enters the gas-solid fast separator to remove fly ash, and then enters the gas separation device; a part of the gas coming out of the gas separation device is recycled back to the methanation zone of the fast bed.

13. The method according to any one of claims 7-9, characterized in that, Stripping gas is introduced into the stripping section of the fine powder settler / stripper to strip the solid in the stripping section to obtain high-temperature gasified semicoke, and the high-temperature gasified semicoke enters the fast bed pyrolysis furnace via the gasification inclined pipe.

14. The method according to any one of claims 7-9, characterized in that The carbonaceous gasified semicoke enters the fluidized bed combustor downward from the fluidized bed gasifier, contacts with the oxidant, and a combustion reaction occurs to produce ash and high-temperature gas; the high-temperature gas enters the fluidized bed gasifier upward as the gasifying agent; the ash is discharged out.

15. The method according to any one of claims 7-9, characterized in that, The pressure of the fine powder settler / stripper is 0 - 6.5 MPa, the temperature is 700 - 1200 °C, and the average density of pulverized coal is 350 - 550 kg / m 3 , and the average superficial velocity is 0.1 - 0.5 m / s; and / or, the combustion pressure of the fluidized bed combustor is 0 - 6.5 MPa, the combustion temperature is 800 - 1500 °C, the average density of pulverized coal is 300 - 450 kg / m 3 , and the average superficial velocity is 0.2 - 0.6 m / s.

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