阅读说明：本技术 循环流化床粉煤热解-气化装置及粉煤热解-气化方法 (Circulating fluidized bed pulverized coal pyrolysis-gasification device and pulverized coal pyrolysis-gasification method ) 是由 钟思青 徐俊 霍威 金渭龙 于 2019-09-24 设计创作，主要内容包括：本发明公开了一种循环流化床粉煤热解-气化装置,包括：给料机；流化床热解炉,其通过进料斜管与给料机相连；流化床气化炉,其通过热解斜管与流化床热解炉相连；快速床气化炉,其下部入口与流化床气化炉的上部出口相连；流化床燃烧室,其上部入口与流化床气化炉的下部出口相连；细粉沉降/汽提器,其设置于快速床气化炉的外部,并通过气化斜管与流化床热解炉相连。本发明还公开了一种采用该装置进行粉煤热解-气化的方法。本发明具有碳转化率高、气化强度高、粉煤利用率高、气化煤种适应性广、能量利用合理以及装置运行稳定、高效的特点。(The invention discloses a circulating fluidized bed pulverized coal pyrolysis-gasification device, which comprises: a feeder; the fluidized bed pyrolysis furnace is connected with the feeding machine through a feeding inclined pipe; the fluidized bed gasification furnace is connected with the fluidized bed pyrolysis furnace through a pyrolysis inclined pipe; the lower inlet of the fast bed gasification furnace is connected with the upper outlet of the fluidized bed gasification furnace; the upper inlet of the fluidized bed combustion chamber is connected with the lower outlet of the fluidized bed gasification furnace; and the fine powder settling/stripping device is arranged outside the fast bed gasification furnace and is connected with the fluidized bed pyrolysis furnace through a gasification inclined pipe. The invention also discloses a method for pyrolyzing and gasifying pulverized coal by adopting the device. The invention has the characteristics of high carbon conversion rate, high gasification strength, high pulverized coal utilization rate, wide gasified coal type adaptability, reasonable energy utilization, stable and efficient device operation.)

1. A circulating fluidized bed pulverized coal pyrolysis-gasification apparatus comprising:

a feeder;

the fluidized bed pyrolysis furnace is connected with the feeding machine through a feeding inclined pipe;

the fluidized bed gasification furnace is connected with the fluidized bed pyrolysis furnace through a pyrolysis inclined pipe;

the lower inlet of the fast bed gasification furnace is connected with the upper outlet of the fluidized bed gasification furnace;

the upper inlet of the fluidized bed combustion chamber is connected with the lower outlet of the fluidized bed gasification furnace;

and the fine powder settling/stripping device is arranged outside the fast bed gasification furnace and is connected with the fluidized bed pyrolysis furnace through a gasification inclined pipe.

2. The apparatus of claim 1, wherein the fluidized bed pyrolysis furnace comprises a dense phase zone and a olefinic phase zone; preferably, the lower part of the side wall of the dense-phase area is respectively provided with a pulverized coal inlet and a gasified semicoke inlet, and the pulverized coal inlet is connected with the feeder through a feeding inclined pipe; the gasification semicoke inlet is connected with the fine powder settling/stripping device through a gasification inclined pipe; the side wall of the dense-phase area is provided with a pyrolysis semicoke outlet which is connected with the fluidized bed gasification furnace through a pyrolysis inclined pipe; preferably, a fluidized bed pyrolysis furnace cyclone separator is arranged in the olefin phase zone.

3. The apparatus according to claim 1 or 2, wherein a pyrolysis fluidization gas inlet is provided at a bottom of the fluidized bed pyrolysis furnace for receiving pyrolysis fluidization gas; and/or a pyrolysis gas outlet is arranged at the top of the fluidized bed pyrolysis furnace and is connected with a gas outlet of a cyclone separator of the fluidized bed pyrolysis furnace for discharging pyrolysis gas.

4. The apparatus according to any one of claims 1 to 3, wherein a pyrolysis semicoke inlet is provided at a lower portion of a sidewall of the fluidized-bed gasification furnace, and is connected to the fluidized-bed pyrolysis furnace through a pyrolysis inclined tube; preferably, a gasifying agent inlet is formed at a lower portion of a sidewall of the fluidized-bed gasification furnace, and the gasifying agent inlet is configured to receive a gasifying agent.

5. An apparatus according to any one of claims 1-4, characterized in that the bottom of the fluidized bed combustion chamber is provided with a ash discharge opening, which is connected to an ash tank.

6. The apparatus of any one of claims 1 to 5, further comprising a fast bed cyclone connected to an upper outlet of the fast bed gasifier.

7. The apparatus of any one of claims 1-6, wherein the fines settler/stripper comprises a stripping section, a fines settler section, and a fines settler/stripper cyclone; a stripping gas inlet is formed in the lower part of the side wall of the fine powder settling/stripping device and used for receiving stripping gas; a semicoke outlet is arranged at the lower part of the side wall of the fine powder settling/stripping device and is connected with the fluidized bed pyrolysis furnace through a gasification inclined pipe; the top of the fine powder settling/stripping device is provided with a synthesis gas outlet which is connected with a gas outlet of the cyclone separator of the fine powder settling/stripping device and used for discharging synthesis gas.

8. A pulverized coal pyrolysis-gasification method using the apparatus of any one of claims 1 to 7, comprising the steps of:

(a) feeding the pulverized coal raw material into a fluidized bed pyrolysis furnace by a feeder, mixing the pulverized coal raw material with high-temperature gasification semicoke in the fluidized bed pyrolysis furnace and heating, and carrying out pyrolysis reaction on the pulverized coal to generate pyrolysis semicoke and pyrolysis gas;

(b) the pyrolysis semicoke enters the fluidized bed gasification furnace through the pyrolysis inclined tube, contacts with a gasification agent, and generates gasification reaction in the fluidized bed gasification furnace and the fast bed gasification furnace to generate synthesis gas and carbon-containing gasification semicoke;

(c) the synthesis gas enters a fine powder settling/stripping device, high-temperature gasification semi-coke is separated, and the high-temperature gasification semi-coke enters a fluidized bed pyrolysis furnace through a gasification inclined pipe;

(d) the carbon-containing gasified semicoke enters the fluidized bed combustion chamber from the fluidized bed gasification furnace downwards to generate combustion reaction to produce ash and high-temperature gas; the high-temperature gas upwards enters the fluidized bed gasification furnace as a gasification agent.

9. The method of claim 8, wherein the pulverized coal feed comprises pulverized coal and at least one of a catalyst and biomass; preferably, the catalyst comprises at least one of an alkali metal, an alkaline earth metal, and a transition metal.

10. The method according to claim 8 or 9, characterized in that the pulverized coal raw material is fed into a dense-phase zone of the fluidized bed pyrolysis furnace by a feeding machine, and is mixed with high-temperature gasification semi-coke in the dense-phase zone to be heated, and the pulverized coal is subjected to pyrolysis reaction to generate pyrolysis semi-coke and pyrolysis gas; the pyrolysis semicoke enters a fluidized bed gasification furnace through a pyrolysis inclined pipe; the pyrolysis gas carries fine coal powder, the fine coal powder upwards enters the alkene phase region and is subjected to gas-solid separation through a cyclone separator of the fluidized bed pyrolysis furnace, the solid returns to the dense phase region, and the gas leaves the fluidized bed pyrolysis furnace.

11. The method as claimed in any one of claims 8 to 10, wherein the pyrolysis pressure of the fluidized bed pyrolysis furnace is 0 to 6.5MPa, and the pyrolysis temperature is 400-800 ℃; and/or the pulverized coal in the dense-phase zone of the fluidized bed pyrolysis furnace has the average density of 200-³The linear speed of the empty tower is 0.1-1.0 m/s.

12. The method as claimed in any one of claims 8 to 11, wherein the fluidized-bed gasification furnace has a gasification pressure of 0 to 6.5MPa, a gasification temperature of 700-³The average superficial linear velocity is 0.2-1.2 m/s; and/or the gasification pressure of the fast bed gasification furnace is 0-6.5MPa, the gasification temperature is 700-1200 ℃, and the average density of the pulverized coal is 50-150kg/m³The average superficial linear velocity is 1.0-3.0 m/s.

13. The method as claimed in any one of claims 8 to 12, wherein the synthesis gas from the fast bed gasifier, which carries the semi-coke fines that are not gasified, is first subjected to gas-solid separation in a fast bed cyclone separator, the solids fall into the stripping section of a fines settler/stripper, and the gas enters the settling section of the fines settler/stripper.

14. The process of any one of claims 8 to 13, wherein the gas from the fast bed cyclone enters the fines settling/stripper settling section and fines settling/stripper cyclone to further separate out solids, the solids falling into the fines settling/stripper stripping section, and the gas leaving the fines settling/stripper.

15. The method according to any one of claims 8 to 14, characterized in that stripping gas is introduced into the stripping section of the fines settler/stripper to strip the solids in the stripping section and obtain high temperature gasification semicoke, which enters the fluidized bed pyrolysis furnace via gasification inclined tubes.

16. The method according to any one of claims 8 to 15, wherein the carbon-containing gasification semicoke enters the fluidized bed combustion chamber from the fluidized bed gasification furnace downwards, is contacted with the oxidant, and undergoes a combustion reaction to produce ash and high-temperature gas; the high-temperature gas upwards enters a fluidized bed gasification furnace to be used as a gasification agent; and discharging ash slag.

17. The method as claimed in any one of claims 8 to 16, wherein the pressure of the fine powder sedimentation/stripping device is 0 to 6.5MPa, the temperature is 700 ℃ and 1200 ℃, and the average density of the fine coal is 350 ℃ and 550kg/m³The average superficial linear velocity is 0.1-0.5 m/s; and/or the combustion pressure of the fluidized bed combustion chamber is 0-6.5MPa, the combustion temperature is 800-1500 ℃, and the average density of the pulverized coal is 300-450kg/m³The average superficial linear velocity is 0.2-0.6 m/s.

Technical Field

The invention belongs to the field of coal gasification, and relates to a circulating fluidized bed pulverized coal pyrolysis-gasification device and a method for performing pulverized coal pyrolysis-gasification by using the same.

Background

Coal, petroleum and natural gas are three major primary energy sources in the world, wherein coal accounts for about 79% of the world energy reserves, and coal is one of the main fuel resources for generating power, heat, coal tar processing and by-product asphalt. China is a country with coal as a main energy structure, and the coal cannot be changed for a long time in the future, and according to statistics, the coal reaches 63.7% in a primary energy consumption structure of China in 2015. With the increasing shortage of petroleum resources, the effective utilization of coal resources has become a strategy for sustainable development of energy in China. The reserve of low-rank coal in China accounts for more than 55% of the total amount of coal resources, but the low-rank coal has high water content, low coalification degree and low direct combustion efficiency, thereby not only wasting resources, but also polluting the environment and causing the emission of acid rain, PM2.5, SOx, NOx and other greenhouse gases. The coal gasification technology is a key technology for realizing clean, efficient and comprehensive utilization of coal, is an important way for coal conversion, and is also one of key technologies for synthesizing chemicals, combined cycle power generation and preparing substitute natural gas from coal. The method is a key for realizing sustainable energy development in China and is an effective way for solving the global energy and environment problems.

China is the largest coal gasification technology application market in the world, and at present, various coal gasification technologies have been successfully applied in industrialization. The prior art widely belongs to an entrained flow gasification technology, and the carbon conversion rate is improved at the cost of high temperature and high pressure, so that the problems of high energy consumption, difficult gas purification, strict requirements on equipment and the like are caused. At the same time, the excessive operating temperatures of entrained flow slag gasification technology increase the investment, maintenance and operating costs of the entrained flow. Research reports of the American Electric Power Research Institute (EPRI) indicate that the existing industrial entrained-flow gasifier is not suitable for the gasification of high-ash and high-ash fusion-point coal, and the world needs an industrialized fluidized bed gasification technology. The fluidized bed technology has the nature of adapting to high ash melting point and high ash coal types no matter combustion or gasification, and the evidence proves that the circulating fluidized bed boiler successfully combusts coal gangue.

Patent CN102212399B discloses a pyrolysis and gasification combined method and device, which proposes that fuel is pyrolyzed in a low-speed bed pyrolysis furnace, semicoke is sent into a circulating fluidized bed gasification furnace through a material returning device for gasification, and coal gas generated by the gasification furnace carries solid particles to enter a cyclone separator; the solid particles collected by the cyclone separator are sent above a dense-phase area of the pyrolysis furnace to provide heat for fuel pyrolysis. The device adopts a circulating fluidized bed as a gasification furnace, or the gasification furnace has large volume and high energy consumption; or high carbon conversion rate cannot be ensured, and gasification strength is low.

Patent CN102504842A discloses a three fluidized bed solid heat carrier coal pyrolysis gasification combustion cascade utilization method. The method takes high-temperature circulating ash as a solid heat carrier, coal is mixed with the high-temperature circulating ash in a fluidized bed pyrolysis furnace, volatile matters are separated out by heat generation, the volatile matters are cooled and separated to obtain tar and pyrolysis coal gas, pyrolysis semicoke generated by coal pyrolysis is sent to a fluidized bed gasification furnace, gasification reaction is carried out by taking steam and O2 as gasification agents to prepare synthesis gas, the semicoke which is not completely gasified in the gasification furnace is sent to a circulating fluidized bed combustion furnace, air is blown in for conventional combustion, or O2/CO2 is blown in for oxygen-enriched combustion, the solid heat carrier circulating ash is heated, and high-temperature flue gas generated by combustion is used for producing gasification agent steam required by the gasification furnace. The invention has the advantages that the coal pyrolysis gasification combustion cascade utilization realizes the joint production of tar, pyrolysis coal gas and synthesis gas, but the heat cascade utilization sequence of the combustion, pyrolysis and gasification is unreasonable, and further improvement and optimization space exists for the reasonable utilization of energy.

In summary, although the existing pyrolysis-gasification coupled staged utilization technology solves the disadvantages of the traditional gasification technology for preparing synthesis gas and pyrolysis oil to a certain extent, the carbon conversion rate and gasification intensity are low due to the adoption of fluidized bed technology and process condition limitations. Therefore, how to further improve the carbon conversion rate and gasification strength, reasonably utilize the heat gradient utilization of combustion, gasification and pyrolysis and realize the true quality-grading, high-efficiency and clean utilization of the pyrolysis-gasification integrated pulverized coal is the key for the development of the coal gasification technology.

Disclosure of Invention

The invention aims to provide a novel circulating fluidized bed pulverized coal pyrolysis-gasification device and a method for pyrolyzing-gasifying pulverized coal by adopting the same, aiming at the problems of low carbon conversion rate and gasification strength, low pulverized coal utilization rate and difficult utilization of low-rank coal in the prior art. The invention has the characteristics of high carbon conversion rate, high gasification strength, high pulverized coal utilization rate, wide gasified coal type adaptability, reasonable energy utilization, stable and efficient device operation.

According to an aspect of the present invention, there is provided a circulating fluidized bed pulverized coal pyrolysis-gasification apparatus including:

a feeder;

the fluidized bed pyrolysis furnace is connected with the feeding machine through a feeding inclined pipe;

the fluidized bed gasification furnace is connected with the fluidized bed pyrolysis furnace through a pyrolysis inclined pipe;

the lower inlet of the fast bed gasification furnace is connected with the upper outlet of the fluidized bed gasification furnace;

the upper inlet of the fluidized bed combustion chamber is connected with the lower outlet of the fluidized bed gasification furnace;

and the fine powder settling/stripping device is arranged outside the fast bed gasification furnace and is connected with the fluidized bed pyrolysis furnace through a gasification inclined pipe.

According to some embodiments of the invention, the fluidized bed pyrolysis furnace comprises, from bottom to top, a dense phase zone and a olefinic phase zone.

According to the preferred embodiment of the invention, the lower part of the side wall of the dense-phase zone is respectively provided with a pulverized coal inlet and a gasification semicoke inlet, and the pulverized coal inlet is connected with the feeder through a feeding inclined pipe; the gasification semicoke inlet is connected with the fine powder settling/stripping device through a gasification inclined pipe; the middle part of the side wall of the dense-phase area is provided with a pyrolysis semicoke outlet which is connected with the fluidized bed gasification furnace through a pyrolysis inclined pipe.

According to a preferred embodiment of the present invention, a fluidized bed pyrolysis furnace cyclone is disposed within the olefinic phase zone for separating gases produced in the dense phase zone.

According to a preferred embodiment of the present invention, a pyrolysis fluidization gas inlet is provided at the bottom of the fluidized bed pyrolysis furnace for receiving pyrolysis fluidization gas.

According to a preferred embodiment of the invention, a pyrolysis gas outlet is provided at the top of the fluidized bed pyrolysis furnace, which is connected to the gas outlet of the cyclone separator of the fluidized bed pyrolysis furnace for discharging separated pyrolysis gas.

According to a preferred embodiment of the present invention, the fluidized-bed gasification furnace is arranged in parallel with the fluidized-bed pyrolysis furnace.

According to some embodiments of the present invention, the fluidized-bed gasification furnace is provided at a lower portion of a sidewall thereof with a pyrolysis semicoke inlet connected to the fluidized-bed pyrolysis furnace through a pyrolysis chute.

According to a preferred embodiment of the present invention, a gasifying agent inlet is provided at a lower portion of a sidewall of the fluidized-bed gasification furnace, and the gasifying agent inlet is configured to receive a gasifying agent.

According to a preferred embodiment of the present invention, a lower outlet of the fluidized-bed gasification furnace is connected to an upper inlet of the fluidized-bed combustion chamber.

According to some embodiments of the invention, a gas distribution plate is disposed below an interior of the fluidized bed combustor; and an ash residue discharge port is arranged at the bottom of the fluidized bed combustion chamber and is connected with an ash residue tank.

According to a preferred embodiment of the present invention, the upper outlet of the fluidized-bed gasification furnace is reduced in diameter and then connected to the lower inlet of the fast-bed gasification furnace.

According to a preferred embodiment of the present invention, the apparatus further comprises a fast bed cyclone connected to an upper outlet of the fast bed gasification furnace.

According to a preferred embodiment of the present invention, the fast bed gasifier extends axially into the fines sedimentation/stripper from the bottom center thereof, and the two are connected by the fast bed gasifier cyclone.

According to some embodiments of the invention, the fines settling/stripper comprises a stripping section, a fines settling section, and a fines settling/stripper cyclone; a stripping gas inlet is formed in the lower part of the side wall of the fine powder settling/stripping device and used for receiving stripping gas; a semicoke outlet is arranged at the lower part of the side wall of the fine powder settling/stripping device and is connected with the fluidized bed pyrolysis furnace through a gasification inclined pipe; the top of the fine powder settling/stripping device is provided with a synthesis gas outlet which is connected with a gas outlet of the cyclone separator of the fine powder settling/stripping device and used for discharging the separated synthesis gas.

According to a preferred embodiment of the invention, a pyrolysis semicoke return valve is arranged on the pyrolysis inclined tube, and is a non-mechanical return valve, preferably a U valve, a J valve, an L valve or an M valve. And (3) introducing loose air into the pyrolysis semi-coke valve, and controlling the circulation quantity of the pyrolysis semi-coke, or the bed layer density of the fluidized bed gasification furnace, or the material level of the fluidized bed pyrolysis furnace by adjusting the air quantity of the loose air.

According to a preferred embodiment of the invention, a gasification semicoke return valve is arranged on the gasification inclined tube, and is a non-mechanical return valve, preferably a U valve, a J valve, an L valve or an M valve. And (3) introducing loosening gas into the gasification semi-coke valve, and controlling the circulation quantity of the gasification semi-coke, or the material level of the fine powder sedimentation/stripping device, or the temperature of the fluidized bed pyrolysis furnace by adjusting the air quantity of the loosening gas.

According to another aspect of the present invention, there is provided a pulverized coal pyrolysis-gasification method using the above apparatus, comprising the steps of:

(a) feeding the pulverized coal raw material into a fluidized bed pyrolysis furnace by a feeder, mixing the pulverized coal raw material with high-temperature gasification semicoke in the fluidized bed pyrolysis furnace and heating, and carrying out pyrolysis reaction on the pulverized coal to generate pyrolysis semicoke and pyrolysis gas;

(b) the pyrolysis semicoke enters the fluidized bed gasification furnace through the pyrolysis inclined tube, contacts with a gasification agent, and generates gasification reaction in the fluidized bed gasification furnace and the fast bed gasification furnace to generate synthesis gas and carbon-containing gasification semicoke;

(c) the synthesis gas enters a fine powder settling/stripping device, high-temperature gasification semi-coke is separated, and the high-temperature gasification semi-coke enters a fluidized bed pyrolysis furnace through a gasification inclined pipe;

(d) the carbon-containing gasified semicoke enters the fluidized bed combustion chamber from the fluidized bed gasification furnace downwards to generate combustion reaction to produce ash and high-temperature gas; the high-temperature gas upwards enters the fluidized bed gasification furnace as a gasification agent.

According to some embodiments of the invention, the pulverized coal feedstock comprises pulverized coal and at least one of a catalyst and biomass; preferably, the catalyst comprises at least one of an alkali metal, an alkaline earth metal, and a transition metal.

According to the preferred embodiment of the invention, the catalyst is loaded on the pulverized coal by an impregnation method, a dry mixing method, an ion exchange method or the like, and the loading amount of the catalyst accounts for 0.1-30% of the mass of the pulverized coal.

According to some embodiments of the invention, the pulverized coal raw material is fed into a dense-phase region of the fluidized bed pyrolysis furnace by a feeding machine, and is mixed with high-temperature gasification semi-coke in the dense-phase region to be heated, and the pulverized coal undergoes pyrolysis reaction to generate pyrolysis semi-coke and pyrolysis gas; the pyrolysis semicoke enters a fluidized bed gasification furnace through a pyrolysis inclined pipe; the pyrolysis gas carries fine coal powder, the fine coal powder upwards enters the alkene phase region and is subjected to gas-solid separation through a cyclone separator of the fluidized bed pyrolysis furnace, the solid (fine coal powder) returns to the dense phase region, and the gas leaves the fluidized bed pyrolysis furnace.

According to the preferred embodiment of the invention, the pyrolysis pressure of the fluidized bed pyrolysis furnace is 0-6.5MPa, and the pyrolysis temperature is 400-800 ℃; and/or the pulverized coal in the dense-phase zone of the fluidized bed pyrolysis furnace has the average density of 200-³The linear speed of the empty tower is 0.1-1.0 m/s.

According to a preferred embodiment of the present invention, the pyrolysis fluidization gas is introduced into the fluidized bed pyrolysis furnace through a pyrolysis fluidization gas inlet at the bottom thereof; the pyrolysis fluidizing gas comprises water vapor and CO₂At least one of CO, hydrogen and an inert gas.

According to some embodiments of the present invention, the pyrolysis semicoke enters the lower part of the fluidized-bed gasification furnace through the pyrolysis inclined tube, contacts with the gasification agent, and undergoes gasification reaction in the fluidized-bed gasification furnace and the fast-bed gasification furnace to generate synthesis gas and carbon-containing gasification semicoke.

According to the preferred embodiment of the invention, the loosening gas is introduced into the pyrolysis semi-coke valve, and the circulation quantity of the pyrolysis semi-coke, or the bed layer density of the fluidized bed gasification furnace, or the material level of the fluidized bed pyrolysis furnace is controlled by adjusting the air quantity of the loosening gas.

According to a preferred embodiment of the invention, the loosening gas comprises water vapour, CO₂At least one of CO, air, oxygen, and an inert gas.

According to the preferred embodiment of the invention, the gasifying agent is high-temperature gas from a fluidized bed combustion chamber or externally introduced gasifying agent through a gasifying agent inlet; the gasifying agent comprises steam and/or CO₂。

According to the preferred embodiment of the present invention, the gasification pressure of the fluidized bed gasification furnace is 0-6.5MPa, the gasification temperature is 700-1200 ℃, and the average density of the pulverized coal is 200-450kg/m³The average superficial linear velocity is 0.2-1.2 m/s.

According to the preferred embodiment of the invention, the gasification pressure of the fast bed gasification furnace is 0-6.5MPa, the gasification temperature is 700-1200 ℃, and the average density of the pulverized coal is 50-150kg/m³The average superficial linear velocity is 1.0-3.0 m/s.

According to some embodiments of the invention, the synthesis gas from the fast bed gasifier, which carries the non-gasified fine semi-coke powder, first enters the fast bed cyclone separator for preliminary gas-solid separation, the solid falls into the stripping section of the fine powder settling/stripping device, and the gas enters the settling section of the fine powder settling/stripping device.

According to a preferred embodiment of the invention, the gas from the fast bed cyclone enters the settling section of the fines settler/stripper and the fines settler/stripper cyclone to further separate out solids, the solids fall into the stripping section of the fines settler/stripper and the gas leaves the fines settler/stripper.

According to the preferred embodiment of the invention, stripping gas is introduced into the stripping section of the fine powder settling/stripping device through a stripping gas inlet, the solids in the stripping section are stripped, fly ash entrained in the solids is removed, and high-temperature gasification semicoke is obtained and enters the fluidized bed pyrolysis furnace through the gasification inclined tube.

According to the preferred embodiment of the invention, the loosening gas is introduced into the gasification semi-coke valve, and the circulation quantity of the gasification semi-coke, or the material level of the fine powder sedimentation/stripper, or the temperature of the fluidized bed pyrolysis furnace is controlled by adjusting the air quantity of the loosening gas.

According to a preferred embodiment of the invention, the loosening gas comprises water vapour, CO₂At least one of CO, air, oxygen, and an inert gas.

According to a preferred embodiment of the invention, the stripping gas comprises steam, CO₂At least one of CO and an inert gas.

According to the preferred embodiment of the invention, the pressure of the fine powder settling/stripping device is 0-6.5MPa, the temperature is 700-1200 ℃, and the average density of the fine powder is 350-550kg/m³The average superficial linear velocity is 0.1-0.5 m/s.

According to some embodiments of the invention, the carbon-containing gasification semicoke enters the fluidized bed combustion chamber from the fluidized bed gasification furnace downwards, and is contacted with the oxidant to perform a combustion reaction to produce ash and high-temperature gas; the high-temperature gas upwards enters the fluidized bed gasification furnace to be used as a gasification agent and provides heat for gasification reaction; the ash slag is discharged to the ash slag tank through the ash slag discharge port and then discharged.

According to a preferred embodiment of the invention, the oxidant comprises air and/or oxygen.

According to the preferred embodiment of the invention, the combustion pressure of the fluidized bed combustion chamber is 0-6.5MPa, the combustion temperature is 800-1500 ℃, and the average density of the pulverized coal is 300-450kg/m³The average superficial linear velocity is 0.2-0.6 m/s.

The technical scheme of the invention is that the pyrolysis of the pulverized coal raw material is carried out in the pyrolysis furnace to obtain pyrolysis gas (containing coal tar) and gasification raw material-pyrolysis semicoke, and the gasification raw material is obtained through pyrolysis, thereby expanding the application range of coal types. And carrying out gasification reaction of the pyrolysis semicoke particles in the gasification furnace to generate synthesis gas. And most of the high-temperature gasified semicoke particles which are not gasified are used as heat carriers and circularly enter the pyrolysis furnace to be used as a heat source for pyrolysis, so that the energy consumption is reduced, and the cost of the heat carriers added in the traditional process is saved. A small part of gasified semicoke particles which are not gasified enter the combustion chamber to be subjected to combustion reaction with oxygen, and semicoke is converted into ash, so that the carbon conversion rate and the utilization rate of carbon residue are improved. The heat generated by the combustion reaction is used to provide heat consumption and heat rejection in the gasification reaction and to provide the necessary gasification agent for the gasification reaction. The invention is specially provided with a fine powder sedimentation/stripping device, and aims to remove fly ash entrained in high-temperature gasification semicoke entering a pyrolysis furnace, thereby reducing the fly ash entrained in pyrolysis gas, avoiding the blockage of related equipment by the fly ash and reducing the difficulty of liquid-solid separation.

The invention couples pyrolysis with gasification, gasification and combustion together, can produce synthesis gas and coal tar, realize the hierarchical utilization of quality classification of the low rank coal. The pulverized coal can be directly gasified or catalytically gasified, and the high-efficiency, clean and reasonable comprehensive utilization of the coal is realized.

Compared with the prior art, the method has the advantages that the carbon conversion rate of the gasification outlet in the reactor is improved to 98%, the methane content in the synthesis gas is improved to 15%, the yield of the tar is increased by 10%, the method has the characteristics of high carbon conversion rate, high methane yield, high yield of the tar and high utilization rate of the pulverized coal, and a good technical effect is achieved.

Drawings

FIG. 1 is a schematic view of a circulating fluidized bed pyrolysis-gasification apparatus of the present invention:

in fig. 1, 1 is a feeder; 2 is a fluidized bed pyrolysis furnace; 3 is a dense-phase zone of the fluidized bed pyrolysis furnace; 4 is a dilute phase zone of the fluidized bed pyrolysis furnace; 5 is a fluidized bed pyrolysis furnace cyclone separator; 6 is a pyrolysis semicoke returning valve; 7 is a fluidized bed combustion chamber; 8, a fluidized bed gasification furnace; 9 is a fine powder settling/stripping device; 10 is a stripping section; 11 is a fine powder settling section; 12 is a fine powder settling/stripper cyclone separator; 13 is a fast bed gasification furnace; 14 is a cyclone separator of the fast bed gasification furnace; 15 is a gas distribution plate; 16 is a clinker outlet; 17 is a slag tank; 18 is a gasification semicoke return valve; 19 is a feeding inclined tube; 20 is a pyrolysis inclined tube; 21 is a gasification inclined tube. A is a pulverized coal raw material; b is pyrolysis fluidization gas; c is an oxidant; d is a gasifying agent; e is stripping gas; F. g, H, I is loosening air; k is pyrolysis gas; l is ash.

Detailed Description

The present invention will be further illustrated by the following examples, but is not limited to these examples.

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

the carbon conversion rate is calculated based on the carbon residue in the ash, and the specific formula is as follows:

CC＝(1-C_ash/C_raw) X 100%, where CC is carbon conversion, C_ashIs the carbon content in the ash, C_rawIs the carbon content in the powdered coal raw material;

measuring gas components by an external standard method of an online gas chromatograph, and measuring the content of methane in the synthesis gas;

the yield of tar is calculated by the mass balance of gas, liquid and solid products, and the specific formula is as follows:

Y_tar＝(M_raw-M_gas-M_ash)/M_rawx 100% where Y_tarFor tar yield, M_rawIs the mass flow of the powdered coal raw material, M_gasIs the product gas mass flow, M_ashIs the ash mass flow.

[ example 1 ]

The reaction process is as follows: the pulverized coal raw material is sent into a dense-phase zone (3) by a feeder (1), is mixed with high-temperature gasification semi-coke and is heated to generate pyrolysis reaction, fine coal powder recovered after gas-solid separation of pyrolysis gas carrying fine coal powder returns to the dense-phase zone (3), and pyrolysis semi-coke enters the lower part of a fluidized bed gasification furnace (8) after the circulation quantity of the pyrolysis semi-coke is controlled by a pyrolysis semi-coke return valve (6). The pyrolysis semicoke is contacted with a gasifying agent D, gasification reaction is carried out on the fluidized bed gasification furnace (8) and the fast bed gasification furnace (13) to generate synthesis gas, the gasified semicoke which is not gasified is separated by the cyclone separator (14) of the fast bed gasification furnace and then enters the settling section (11) at the upper part of the fine powder settling/stripping device (9), and the gasified semicoke which is not gasified falls into the stripping section (10) at the lower part of the fine powder settling/stripping device (9). The carbon-containing gasification semicoke falls into a fluidized bed combustion chamber (7) from the bottom of the fluidized bed gasification furnace (8) and is contacted and mixed with an oxidant C to generate combustion reaction to convert the carbon-containing semicoke into ash. High-temperature gas generated by combustion enters a fluidized bed gasification furnace (8) upwards to be used as a gasification agent and provides heat for a gasification medium. The synthesis gas coming out of the top of the cyclone separator (14) of the fast bed gasification furnace is separated from the gasification device and enters a subsequent separation and purification device after being recovered by a fine powder settling section (11) and a fine powder settling/stripping cyclone separator (12), and the fine powder recovered by the fine powder settling/stripping cyclone separator (12) falls into a stripping section (10) through a dipleg. The stripping section (10) adopts stripping gas E to strip unreacted carbon-containing semicoke and ash, fly ash carried in the unreacted carbon-containing semicoke and ash is reduced, the stripped carbon-containing semicoke and ash compound enters a gasification inclined pipe (21), the circulating amount of the carbon-containing semicoke and ash compound is controlled by a gasification semicoke return valve (18), and then the carbon-containing semicoke and ash compound enters the lower part of a dense-phase area (3) of the fluidized bed pyrolysis furnace (2) to be mixed with fresh pulverized coal, and the newly-fed pulverized coal is heated for pyrolysis.

The pulverized coal raw material in the reaction process adopts brown coal, the pyrolysis pressure of the fluidized bed pyrolysis furnace (2) is 0MPa, the pyrolysis temperature is 400 ℃, and the average density of the pulverized coal in the dense-phase area (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 200kg/m³The superficial linear velocity in the dense-phase zone (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 1.0 m/s; the gasification pressure of the fluidized bed gasification furnace (8) is 0MPa, the gasification temperature is 700 ℃, and the average density of the pulverized coal is 200kg/m³The linear speed of an average empty tower in the fluidized bed gasification furnace (8) is 1.2 m/s; the gasification pressure of the fast bed gasification furnace (13) is 0MPa, the gasification temperature is 700 ℃, and the average density of the pulverized coal is 50kg/m³The linear speed of an average empty tower in a fast bed gasification furnace (13) is 3.0m/s, the combustion pressure of a fluidized bed combustion chamber (7) is 0MPa, the combustion temperature is 800 ℃, and the average density of pulverized coal is 300kg/m³The linear speed of an average empty tower in the fluidized bed combustion chamber (7) is 0.6 m/s; the pressure of the fine powder sedimentation/stripping device (9) is 0MPa, the temperature is 700 ℃, and the average density of the fine powder is 350kg/m³The mean superficial velocity in the fine powder settler/stripper (9) was 0.5 m/s. Inert gas is adopted as the pyrolysis fluidization gas B; the gasifying agent D adopts steam. Through the scheme, the conversion rate of carbon at the gasification outlet in the reactor is 95%, the content of methane in the synthesis gas is improved to 9.2%, and the yield of tar is 8.1%. The detailed results are shown in Table 1.

[ example 2 ]

The reaction scheme is the same as in example 1. The pulverized coal raw material in the reaction process adopts brown coal, the pyrolysis pressure of the fluidized bed pyrolysis furnace (2) is 6.5MPa, the pyrolysis temperature is 400 ℃, and the average density of the pulverized coal in the dense-phase area (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 200kg/m³The superficial linear velocity in the dense-phase zone (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 1.0 m/s; the gasification pressure of the fluidized bed gasification furnace (8) is 0MPa, the gasification temperature is 700 ℃, and the average density of the pulverized coal is 200kg/m³The linear speed of an average empty tower in the fluidized bed gasification furnace (8) is 1.2 m/s; the gasification pressure of the fast bed gasification furnace (13) is 0MPa, the gasification temperature is 700 ℃, and the average density of the pulverized coal is 50kg/m³(ii) a The linear speed of an average empty tower in the fast bed gasification furnace (13) is 3.0m/s, the combustion pressure of a fluidized bed combustion chamber (7) is 0MPa, the combustion temperature is 800 ℃, and the average density of pulverized coal is 300kg/m³The linear speed of an average empty tower in the fluidized bed combustion chamber (7) is 0.6 m/s; the pressure of the fine powder sedimentation/stripping device (9) is 0MPa, the temperature is 700 ℃, and the average density of the fine powder is 350kg/m³The mean superficial velocity in the fine powder settler/stripper (9) was 0.5 m/s. Inert gas is adopted as the pyrolysis fluidization gas B; the gasifying agent D adopts steam. Through the scheme, the conversion rate of carbon at the gasification outlet in the reactor is 95%, the content of methane in the synthesis gas is improved to 9.6%, and the yield of tar is 7.5%. The detailed results are shown in Table 1.

[ example 3 ]

The reaction scheme is the same as in example 1. The pulverized coal raw material in the reaction process adopts brown coal, the pyrolysis pressure of the fluidized bed pyrolysis furnace (2) is 0, the pyrolysis temperature is 800 ℃, and the average density of the pulverized coal in the dense-phase area (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 200kg/m³The superficial linear velocity in the dense-phase zone (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 1.0 m/s; the gasification pressure of the fluidized bed gasification furnace (8) is 0, the gasification temperature is 1200 ℃, and the average density of the pulverized coal is 200kg/m³The linear speed of an average empty tower in the fluidized bed gasification furnace (8) is 1.2 m/s; the gasification pressure of the fast bed gasification furnace (13) is 0, the gasification temperature is 1200 ℃, and the average density of the pulverized coal is 50kg/m³(ii) a The linear speed of an average empty tower in the fast bed gasification furnace (13) is 3.0m/s, the combustion pressure and the combustion temperature of the fluidized bed combustion chamber (7) are 0 and 1500 ℃, and the average density of the pulverized coal is 300kg/m³The linear speed of an average empty tower in the fluidized bed combustion chamber (7) is 0.6 m/s; the pressure and the temperature of the fine powder sedimentation/stripping device (9) are 0 ℃ and 1200 ℃, and the average density of the fine powder isDegree of 350kg/m³The mean superficial velocity in the fine powder settler/stripper (9) was 0.5 m/s. Inert gas is adopted as the pyrolysis fluidization gas B; the gasifying agent D adopts steam. Through the scheme, the conversion rate of carbon at the gasification outlet in the reactor is 98%, the content of methane in the synthesis gas is increased to 11.6%, and the yield of tar is 5.7%. The detailed results are shown in Table 1.

[ example 4 ]

The reaction scheme is the same as in example 1. The pulverized coal raw material in the reaction process adopts brown coal, the pyrolysis pressure of the fluidized bed pyrolysis furnace (2) is 0, the pyrolysis temperature is 800 ℃, and the average density of the pulverized coal in the dense-phase area (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 200kg/m³The superficial linear velocity in the dense-phase zone (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 1.0 m/s; the gasification pressure of the fluidized bed gasification furnace (8) is 6.5MPa, the gasification temperature is 1200 ℃, and the average density of the pulverized coal is 200kg/m³The linear speed of an average empty tower in the fluidized bed gasification furnace (8) is 1.2 m/s; the gasification pressure of the fast bed gasification furnace (13) is 6.5MPa, the gasification temperature is 1200 ℃, and the average density of the pulverized coal is 50kg/m³(ii) a The linear speed of an average empty tower in the fast bed gasification furnace (13) is 3.0m/s, the combustion pressure of a fluidized bed combustion chamber (7) is 6.5MPa, the combustion temperature is 1500 ℃, and the average density of pulverized coal is 300kg/m³The linear speed of an average empty tower in the fluidized bed combustion chamber (7) is 0.6 m/s; the pressure of the fine powder sedimentation/stripping device (9) is 6.5MPa, the temperature is 1200 ℃, and the average density of the fine powder is 350kg/m³The mean superficial velocity in the fine powder settler/stripper (9) was 0.5 m/s. Inert gas is adopted as the pyrolysis fluidization gas B; the gasifying agent D adopts steam. Through the scheme, the conversion rate of carbon at a gasification outlet in the reactor is 98%, the content of methane in the synthesis gas is increased to 12.9%, and the yield of tar is 5.1%. The detailed results are shown in Table 1.

[ example 5 ]

The reaction scheme is the same as in example 1. The pulverized coal raw material in the reaction process adopts brown coal, the pyrolysis pressure of the fluidized bed pyrolysis furnace (2) is 0, the pyrolysis temperature is 800 ℃, and the average density of the pulverized coal in the dense-phase area (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 550kg/m³The superficial linear velocity in the dense-phase zone (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 0.1 m/s; the gasification pressure of the fluidized bed gasification furnace (8) is 6.5MPa, the gasification temperature is 1200 ℃, and the average density of the pulverized coal is 450kg/m³The fluidized bed gasification furnace (8) is flat and evenThe superficial linear velocity is 0.2 m/s; the gasification pressure of the fast bed gasification furnace (13) is 6.5MPa, the gasification temperature is 1200 ℃, and the average density of the pulverized coal is 150kg/m³(ii) a The linear speed of an average empty tower in the fast bed gasification furnace (13) is 1.0m/s, the combustion pressure of a fluidized bed combustion chamber (7) is 6.5MPa, the combustion temperature is 1500 ℃, and the average density of pulverized coal is 500kg/m³The linear speed of an average empty tower in the fluidized bed combustion chamber (7) is 0.2 m/s; the pressure of the fine powder sedimentation/stripping device (9) is 6.5MPa, the temperature is 1200 ℃, and the average density of the fine powder is 550kg/m³The mean superficial velocity in the fine powder settling/stripping device (9) is 0.1 m/s. Inert gas is adopted as the pyrolysis fluidization gas B; the gasifying agent D adopts steam. Through the scheme, the conversion rate of carbon at the gasification outlet in the reactor is 98%, the content of methane in the synthesis gas is improved to 13.4%, and the yield of tar is 5.0%. The detailed results are shown in Table 1.

[ example 6 ]

The reaction scheme is the same as in example 1. The pulverized coal raw material in the reaction process adopts brown coal, the pyrolysis pressure of the fluidized bed pyrolysis furnace (2) is 0, the pyrolysis temperature is 600 ℃, and the average density of the pulverized coal in the dense-phase area (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 550kg/m³The superficial linear velocity in the dense-phase zone (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 0.1 m/s; the gasification pressure of the fluidized bed gasification furnace (8) is 6.5MPa, the gasification temperature is 900 ℃, and the average density of the pulverized coal is 450kg/m³The linear speed of an average empty tower in the fluidized bed gasification furnace (8) is 0.2 m/s; the gasification pressure of the fast bed gasification furnace (13) is 6.5MPa, the gasification temperature is 900 ℃, and the average density of the pulverized coal is 150kg/m³(ii) a The linear speed of an average empty tower in the fast bed gasification furnace (13) is 1.0m/s, the combustion pressure of a fluidized bed combustion chamber (7) is 6.5MPa, the combustion temperature is 1100 ℃, and the average density of pulverized coal is 500kg/m³The linear speed of an average empty tower in the fluidized bed combustion chamber (7) is 0.2 m/s; the pressure of the fine powder settling/stripping device (9) is 6.5MPa, the temperature is 900 ℃, and the average density of the fine powder is 550kg/m³The mean superficial velocity in the fine powder settling/stripping device (9) is 0.1 m/s. Inert gas is adopted as the pyrolysis fluidization gas B; the gasifying agent D adopts steam. Through the scheme, the conversion rate of carbon at the gasification outlet in the reactor is 97%, the content of methane in the synthesis gas is improved to 13.9%, and the yield of tar is 9.8%. The detailed results are shown in Table 1.

[ example 7 ]

Reaction scheme andthe same applies to example 1. The pulverized coal raw material in the reaction process adopts lignite and 5 percent of K₂CO₃The pyrolysis pressure of the fluidized bed pyrolysis furnace (2) is 0, the pyrolysis temperature is 600 ℃, and the average density of the pulverized coal in the dense-phase area (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 550kg/m³The superficial linear velocity in the dense-phase zone (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 0.1 m/s; the gasification pressure of the fluidized bed gasification furnace (8) is 6.5MPa, the gasification temperature is 900 ℃, and the average density of the pulverized coal is 450kg/m³The linear speed of an average empty tower in the fluidized bed gasification furnace (8) is 0.2 m/s; the gasification pressure of the fast bed gasification furnace (13) is 6.5MPa, the gasification temperature is 900 ℃, and the average density of the pulverized coal is 150kg/m³(ii) a The linear speed of an average empty tower in the fast bed gasification furnace (13) is 1.0m/s, the combustion pressure of a fluidized bed combustion chamber (7) is 6.5MPa, the combustion temperature is 1100 ℃, and the average density of pulverized coal is 500kg/m³The linear speed of an average empty tower in the fluidized bed combustion chamber (7) is 0.2 m/s; the pressure of the fine powder settling/stripping device (9) is 6.5MPa, the temperature is 900 ℃, and the average density of the fine powder is 550kg/m³The mean superficial velocity in the fine powder settling/stripping device (9) is 0.1 m/s. Inert gas is adopted as the pyrolysis fluidization gas B; the gasifying agent D adopts steam. By the scheme, the conversion rate of carbon at the gasification outlet in the reactor is 99%, the content of methane in the synthesis gas is improved to 14.6%, and the yield of tar is 8.8%. The detailed results are shown in Table 1.

[ example 8 ]

The reaction scheme is the same as in example 1. The raw materials in the reaction process adopt brown coal and 5 percent of K₂CO₃The pyrolysis pressure of the fluidized bed pyrolysis furnace (2) is 0, the pyrolysis temperature is 600 ℃, and the average density of the pulverized coal in the dense-phase area (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 550kg/m³The superficial linear velocity in the dense-phase zone (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 0.1 m/s; the gasification pressure of the fluidized bed gasification furnace (8) is 6.5MPa, the gasification temperature is 900 ℃, and the average density of the pulverized coal is 450kg/m³The linear speed of an average empty tower in the fluidized bed gasification furnace (8) is 0.2 m/s; the gasification pressure of the fast bed gasification furnace (13) is 6.5MPa, the gasification temperature is 900 ℃, and the average density of the pulverized coal is 150kg/m³(ii) a The linear speed of an average empty tower in the fast bed gasification furnace (13) is 1.0m/s, the combustion pressure of a fluidized bed combustion chamber (7) is 6.5MPa, the combustion temperature is 1100 ℃, and the average density of pulverized coal is 500kg/m³The linear speed of an average empty tower in the fluidized bed combustion chamber (7) is 0.2 m/s; settling/steaming of fine powderThe pressure of the extractor (9) is 6.5MPa, the temperature is 900 ℃, and the average density of the pulverized coal is 550kg/m³The mean superficial velocity in the fine powder settling/stripping device (9) is 0.1 m/s. The pyrolysis fluidization gas B adopts hydrogen; the gasifying agent D adopts steam. By the scheme, the conversion rate of carbon at the gasification outlet in the reactor is 99%, the content of methane in the synthesis gas is improved to 14.8%, and the yield of tar is 8.1%. The detailed results are shown in Table 1.

[ example 9 ]

The reaction scheme is the same as in example 1. The raw materials in the reaction process adopt brown coal and 5 percent of K₂CO₃The pyrolysis pressure of the fluidized bed pyrolysis furnace (2) is 0, the pyrolysis temperature is 600 ℃, and the average density of the pulverized coal in the dense-phase area (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 550kg/m³The superficial linear velocity in the dense-phase zone (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 0.1 m/s; the gasification pressure of the fluidized bed gasification furnace (8) is 6.5MPa, the gasification temperature is 900 ℃, and the average density of the pulverized coal is 450kg/m³The linear speed of an average empty tower in the fluidized bed gasification furnace (8) is 0.2 m/s; the gasification pressure of the fast bed gasification furnace (13) is 6.5MPa, the gasification temperature is 900 ℃, and the average density of the pulverized coal is 150kg/m³(ii) a The linear speed of an average empty tower in the fast bed gasification furnace (13) is 1.0m/s, the combustion pressure of a fluidized bed combustion chamber (7) is 6.5MPa, the combustion temperature is 1100 ℃, and the average density of pulverized coal is 500kg/m³The linear speed of an average empty tower in the fluidized bed combustion chamber (7) is 0.2 m/s; the pressure of the fine powder settling/stripping device (9) is 6.5MPa, the temperature is 900 ℃, and the average density of the fine powder is 550kg/m³The mean superficial velocity in the fine powder settling/stripping device (9) is 0.1 m/s. The pyrolysis fluidization gas B adopts inert atmosphere; the gasifying agent D adopts CO₂. Through the scheme, the conversion rate of carbon at the gasification outlet in the reactor is 99%, the content of methane in the synthesis gas is improved to 14.7%, and the yield of tar is 8.8%. The detailed results are shown in Table 1.

[ COMPARATIVE EXAMPLE 1 ]

The reaction scheme is the same as in example 1. The raw materials in the reaction process adopt brown coal and 5 percent of K₂CO₃The pyrolysis pressure of the fluidized bed pyrolysis furnace (2) is 0, the pyrolysis temperature is 600 ℃, and the average density of the pulverized coal in the dense-phase area (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 550kg/m³The superficial linear velocity in the dense-phase zone (3) of the reactor of the fluidized bed pyrolysis furnace (2) is 0.1 m/s; gasification pressure of fluidized bed gasification furnace (8)The force is 6.5MPa, the gasification temperature is 900 ℃, and the average density of the pulverized coal is 450kg/m³The linear speed of an average empty tower in the fluidized bed gasification furnace (8) is 0.2 m/s; the gasification pressure of the fast bed gasification furnace (13) is 6.5MPa, the gasification temperature is 900 ℃, and the average density of the pulverized coal is 150kg/m³(ii) a The linear speed of an average empty tower in the fast bed gasification furnace (13) is 1.0m/s, the combustion pressure of a fluidized bed combustion chamber (7) is 6.5MPa, the combustion temperature is 1100 ℃, and the average density of pulverized coal is 500kg/m³The linear speed of an average empty tower in the fluidized bed combustion chamber (7) is 0.2 m/s; the fines settler/stripper (9) was not provided and was replaced by a cyclone separator only. The pyrolysis fluidization gas B adopts inert atmosphere; the gasifying agent D adopts steam. Through the scheme, the conversion rate of carbon at a gasification outlet in the reactor is 90%, the content of methane in the synthesis gas is 13.5%, and the yield of tar is 8.0%. The detailed results are shown in Table 1.

[ COMPARATIVE EXAMPLE 2 ]

The method adopts a traditional Lurgi furnace pressurization fixed bed gasification device in the prior art (see Roc and the like, development and application of Lurgi coal gasification technology [ J ]. clean coal technology, 2009,15 (5): 48-51), anthracite with the particle size of 5-30mm is adopted as a raw material, the gasification temperature is 850 ℃, the linear speed is less than 0.3m/s, the methane content in an outlet gas component is 4.7%, the yield of tar products is only less than 2%, the carbon conversion rate is far lower than 90%, and the result is detailed in Table 1.

[ COMPARATIVE EXAMPLE 3 ]

Adopts a new Aureot group PDU gasification reaction device in the prior art (refer to Bishencheng, catalytic gasification (one-step method) coal-to-natural gas technology development progress [ C ]. fourth coal-to-synthetic natural gas technology economic workshop,

2013, wulu wood qi), the raw material is lignite, 10% potassium carbonate is added as a catalyst, the linear speed is less than 10m/s, the operation temperature is 800 ℃, the methane content in the outlet gas component obtained by gasification is 14%, but the carbon conversion rate is 90%, no tar product is generated, and the result is detailed in table 1.

TABLE 1

Any numerical value mentioned in this specification, if there is only a two unit interval between any lowest value and any highest value, includes all values from the lowest value to the highest value incremented by one unit at a time. For example, if it is stated that the amount of a component, or a value of a process variable such as temperature, pressure, time, etc., is 50 to 90, it is meant in this specification that values of 51 to 89, 52 to 88 … …, and 69 to 71, and 70 to 71, etc., are specifically enumerated. For non-integer values, units of 0.1, 0.01, 0.001, or 0.0001 may be considered as appropriate. These are only some specifically named examples. In a similar manner, all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be disclosed in this application.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.