CN109401792B

CN109401792B - Catalytic gasification combined fluidized bed reaction device and reaction method

Info

Publication number: CN109401792B
Application number: CN201710704545.4A
Authority: CN
Inventors: 徐俊; 钟思青; 高攀; 金渭龙
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2017-08-17
Filing date: 2017-08-17
Publication date: 2020-06-09
Anticipated expiration: 2037-08-17
Also published as: CN109401792A

Abstract

The invention relates to a catalytic gasification combined fluidized bed reaction device and a reaction method, which mainly solve the problems of low carbon conversion rate and gasification intensity, low methane yield and poor operation stability of a gasification furnace in the prior art. The invention better solves the technical problems by adopting the technical scheme that the catalyst is loaded in the carbon-containing raw material, the catalyst, the gasifying agent and the oxidant simultaneously carry out partial combustion and gasification reaction with lower particle concentration in a fine reactor at higher linear speed, and the generated synthetic gas and the carbon-containing particles which do not finish the reaction carry out further gasification reaction in a coarse reactor with higher particle concentration, and the invention can be applied to the industrial production of rich methane by catalytic gasification.

Description

Catalytic gasification combined fluidized bed reaction device and reaction method

Technical Field

The invention relates to a catalytic gasification combined fluidized bed reaction device and a reaction method.

Background

China is a large coal country, has rich coal resources, and with the rapid development of economy in China, the production and consumption of coal are increased in sections, and the coal yield in China in 2014 reaches 38.7 hundred million tons, which is close to one half of the world yield. China has become the largest world-wide coal producing and consuming countries. A large amount of pollutants are released in the direct combustion and utilization of coal, so that the haze is frequent in many areas of China, and the environmental problem is seriously influenced. 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. At present, various coal gasification technologies have been successfully applied to industrialization, and non-catalytic gasification technologies are adopted to increase the carbon conversion rate at the cost of high temperature and high pressure, which brings about the problems of large coal gas cooling strength, difficult gas purification, high energy consumption, strict requirements on equipment and the like. However, the catalytic gasification process of coal not only increases the gasification reaction rate, but also significantly reduces the gasification reaction temperature, enabling a mild gasification process of coal. Meanwhile, a plurality of synthesis processes can be carried out, and chemical raw materials such as methane, methanol, ammonia and the like can be synthesized while gasifying coal under the action of the catalyst, so that the process flow is shortened. Wherein, the method of coal catalytic gasification is used for directly preparing the synthesis gas rich in methane, which is an important research direction of coal catalytic gasification.

Patent US4318712 discloses a process for preparing methane by a coal one-step method, wherein a catalyst and pulverized coal are premixed and then introduced into a reactor, and a gasification agent adopts superheated steam and is also used as a heat source to maintain the reaction temperature in the reactor. The temperature of the superheated steam is 850 ℃, and the gasification reaction temperature is controlled to be about 700 ℃. Coal and superheated steam are subjected to gasification reaction under the action of a catalyst, and CO and H are introduced simultaneously₂The main circulation synthesis gas strengthens methanation reaction in the furnace, and the methane-rich synthesis gas is directly obtained.

Patent CN201010279560.7 discloses a multilayer fluidized bed catalytic gasification methane production process, which divides a gasification furnace into a synthesis gas generation section, a coal methanation section and a synthesis gas methanation section. The combustion, gasification, methanation and pyrolysis reactions are carried out in sections, and the reaction degree and temperature distribution of each section are controlled, so that the methane yield is improved. However, in the pyrolysis section above the gasification furnace, fine pulverized coal escapes from the gasification furnace without reaction, so that the carbon content of the fly ash is high, and the unreacted coal coke is back-mixed to the slag hole at the bottom of the gasification furnace and directly discharged from the gasification furnace, so that the carbon conversion rate in the reaction process is low. When the retention time of the coke particles in the gasification furnace is 2-3 h, the carbon conversion rate is basically maintained within the range of 60-90%.

In summary, in the coal catalytic gasification technology, because methanation reaction needs to be considered, the reaction temperature is low, which results in reduction of reaction rate and carbon conversion rate, leakage of carbon-containing fly ash in the synthesis gas and direct discharge of coarse slag at the bottom of the gasification furnace also affect the increase of carbon conversion rate to a large extent, and from the aspect of energy utilization rate, when the carbon conversion rate is low, the heat value of the carbon residue is not fully utilized. Therefore, it is necessary to develop a catalytic coal gasification method capable of improving the carbon conversion rate and enhancing the gasification intensity, the methane yield, and the operation stability and reliability of the gasification furnace.

Disclosure of Invention

The invention mainly solves the technical problems of low carbon conversion rate and gasification strength, low methane yield and poor operation stability and reliability of a gasification furnace in the prior art, and provides a novel catalytic gasification combined fluidized bed reaction device and a reaction method. The fluidized bed reactor in the method has the characteristics of high carbon conversion rate, high gasification strength, high methane yield and stable operation of the gasification furnace, and ensures high efficiency and stability of the reaction.

The second technical problem to be solved by the present invention is to provide a reaction method corresponding to the first technical problem.

In order to solve one of the above technical problems, the technical scheme adopted by the invention is as follows: a catalytic gasification combined fluidized bed reaction device mainly comprises the following equipment: the device comprises a fine reactor 3, a coarse reactor 4 and a settler 6, wherein the upper end of the fine reactor 3 is expanded and then communicated with the bottom of the coarse reactor 4, the coarse reactor 4 is communicated with the settler 6 through a separation device 7, the bottom of the settler 6 is communicated with the fine reactor 3 through a material returning mechanism 8, and the separation device 7 is positioned in the barrel of the settler 6.

In the technical scheme, the height of the fine reactor 3 is 2-8 times of the height of the coarse reactor 4, the diameter of the coarse reactor 4 is 1.5-6 times of the diameter of the fine reactor 3, the settler 6 is internally provided with separation equipment 7, and the separation equipment 7 is formed by combining 2 groups of cyclone separators and more than 2 groups of cyclone separators.

More preferably, the height of the fine reactor 3 is 3-6 times of the height of the coarse reactor 4, and the diameter of the coarse reactor 4 is 3-4.5 times of the diameter of the fine reactor 3.

In order to solve the second problem, the invention adopts the following technical scheme: the method for preparing the olefin from the methanol with the catalyst mixer adopts the reaction device, and comprises the following steps:

a. the carbon-containing raw material E loaded with the catalyst enters a settler 6 through a feeding pipeline 10, is introduced through a material returning mechanism 8, and simultaneously enters a fine reactor 3 with a gasifying agent A from a gas pipeline 2 to be mixed and gasified, large granular slag after reaction naturally settles and falls into a slag pool 1, and ash G is separated from the slag through a catalyst recovery device 11, and a catalyst F is recovered from the slag pool;

b. the method comprises the following steps that carbon-containing particles reacted in a fine reactor 3 are lifted into a coarse reactor 4 through gas, further gasification reaction is carried out under the action of circulating synthesis gas B from a gas purification and separation system 9, the volume ratio of hydrogen to carbon monoxide in the circulating synthesis gas B is 0.8-4.5, the reacted gas and solids enter a separation device 7, the solids contain fine ash, carbon-containing particles and slag, after separation, the gas, unseparated fine ash and unseparated carbon-containing particles are discharged through cyclone and enter a rapid reactor 5 for rapid gasification reaction, and then a product gas, an outlet fine ash C and a catalyst D recovered from the fine ash are extracted through the gas purification and separation system 9;

c. on the other hand, the carbonaceous particles and the slag separated by the separation device 7 are settled in the settler 6, mixed with the catalyst D recovered from the fine ash from the feed line 10, the catalyst-supporting carbonaceous raw material E, and the slag pool recovered catalyst F, and returned to the fine reactor 3 through the material returning mechanism 8 to continue the gasification reaction.

In the above technical scheme, the carbonaceous raw material comprises coal, petroleum coke, biomass and a mixture thereof, and the gasifying agent comprises oxygen, air, liquid water, steam, carbon dioxide or hydrogen and a mixture thereof. The reaction conditions of the fine reactor 3 are: the reaction pressure is 0-6.5MPa, the reaction temperature is 800-1600 ℃, the gas phase line speed is 2.0-15.0m/s, and the flow state in the fine reactor 3 is fast fluidization; the reaction conditions of the crude reactor 4 are: the reaction pressure is 0-6.5MPa, the reaction temperature is 600-1100 ℃, the gas phase line speed is 0.1-1.0m/s, and the flow state in the crude reactor 4 is turbulent fluidization or bubbling fluidization. The catalyst is selected from at least one of alkali metal, alkaline earth metal and transition metal; the catalyst is loaded on the carbon-containing raw material in an impregnation method, a dry mixing method or an ion exchange method; the loading capacity of the catalyst accounts for 0.1-20% of the mass of the raw coal. The water-carbon ratio in the fine reactor 3 ranges from 0.5 mol/mol to 4mol/mol, and the water-carbon ratio in the coarse reactor 4 ranges from 2mol/mol to 20 mol/mol. The fast reactor 5 is a down-flow fluidized bed reactor, a cyclone reactor, a tubular reactor or a fluidized bed reactor.

In the above technical scheme, the recycle synthesis gas B is CO₂Absorption apparatus for removing CO₂The gas is then passed to the synthesis gas in the crude reactor 4.

In the above technical scheme, the settler 6 is used not only as a container for settling separation of product gas and particles, but also as a feed end for premixing, and the carbonaceous raw material loaded with catalyst is mixed with returned hot carrier particles in the settler after being added into the settler for heat transfer, so that the carbonaceous raw material is ensured to have a certain uniform temperature before entering the gasification reactor 3, and the improvement of reaction rate is facilitated. Meanwhile, the settler 6 has a pressure accumulation function in the whole circulating system, so that particles can smoothly enter the fine reactor 3 for reaction through the material returning mechanism 8.

In the invention, the carbon-containing raw material and the gasifying agent which are loaded with the catalyst enter the fine reactor 3, and the reactor mainly comprises a combustion reaction and a gasification reaction, and also comprises a partial shift reaction and a methanation reaction. The first reactor has high linear speed, high gas-solid ratio, high water-carbon ratio and temperature controlled within 900-1600 deg.c, and is favorable to combustion and gasification reaction. Under the action of catalyst, the gas-solid two-phase flow state in the reactor is fast fluidized, so that the gas content is very high and the gas-solid contact efficiency is also very high, thus leading the combustion reaction rate and the gasification reaction rate to be faster and improving the carbon conversion rate and the utilization rate of carbon residue. The heat generated by the combustion reaction is used to provide heat removal and heat rejection in the gasification reaction zone and to provide the necessary heat and gasification agents for the gasification reaction.

In the present invention, the gasification reaction, shift reaction and methanation reaction are mainly performed in the crude reactor 4. CO and H in the gas component flowing from the fine reactor 3₂、CO₂、H₂O and CH₄Simultaneously present at the bottom of the crude reactor 4The circulating synthesis gas B is introduced to improve the CO and H in the crude reactor 4₂In an amount of diluting CO₂Promoting shift reaction balance to move rightwards, increasing H₂The ratio of the gas phase to the CO is low, the gas-solid flow state is bubbling or turbulent flow, the gas-solid ratio is much lower than that in the fine reactor 3, and the temperature is controlled within the range of 600 plus 1100 ℃, so that the shift of the methanation reaction balance is promoted, and the outlet CH is improved₄Yield.

In the invention, the rapid reactor 5 carries out further gasification reaction aiming at part of fine-grained carbon-containing substances separated by the separation equipment 7, the unreacted carbon residue and gas components with the function of a gasification agent are rapidly gasified and reacted in the rapid reactor 9 under the catalytic action of the catalyst carried in the fine-grained particles, and because the gas components in the reactor have high concentration, the grain diameter of the fine-grained carbon residue particles is smaller and the grain concentration is low, the gasification reaction of the carbon residue can be rapidly realized, thereby further improving the carbon conversion rate and the utilization rate of the carbon residue.

The main reactor and the circulating system device in the invention are mature circulating fluidized bed systems, the internal temperature is easy to control, the gas-solid contact efficiency is high, and the mass transfer and heat transfer are strong. The material returning mechanism is non-mechanical material returning equipment and is not easy to leak and block. The whole structure is simple, the equipment is mature, the abrasion and the leakage are not easy to occur, and the whole frame of the system is much lower than that of the prior art.

Compared with the prior art, the technical scheme of the invention has the advantages that the carbon conversion rate of the gasification outlet in the reactor is improved, the methane content in the outlet synthesis gas is improved by 31 percent, the carbon conversion rate is improved by 97 percent, the characteristics of high carbon conversion rate, high gasification strength, high methane yield and stable operation of the gasification furnace are realized, the high efficiency and stability of the reaction are ensured, and the better technical effect is achieved.

Drawings

FIG. 1 is a schematic flow diagram of the method of the present invention:

in fig. 1, 1 is a slag bath; 2 is a gas inlet pipeline; 3 is a fine reactor; 4 is a coarse reactor; 5 is a rapid reactor; 6 is a settler; 7 is a separation device; 8 is a material returning mechanism; 9 is a gas purification and separation system; 10 is a catalyst and carbon-containing raw material feeding pipeline; 11 is a catalyst recovery device; 12 is a recycle syngas distributor. A is gasifying agent comprising oxygen, air, liquid water, water vapor, carbon dioxide or hydrogen and mixture thereof; b is circulating synthesis gas; c is outlet fine ash; d is a fine ash recovered catalyst; e is a carbon-containing raw material of a supported catalyst; f is a catalyst recovered from the slag pool; g is ash.

The catalyst and the carbonaceous raw material enter a settler 6 through a feeding pipeline 10, are guided into a fine reactor 3 through a material returning mechanism 8, are mixed with water vapor and oxygen air from a gas pipeline 2 and then are subjected to gasification reaction in the fine reactor 3, large granular slag after the reaction falls into a slag pool 1 through natural sedimentation, and is separated from slag through a catalyst recovery device 11 to recover the catalyst. The carbon-containing particles reacted in the fine reactor 3 are lifted by gas to enter the coarse reactor 4 for further gasification reaction. The reacted gas and solid fine ash, carbon-containing particles and slag enter a separation device 7, the gas, part of fine ash and carbon-containing particles are discharged by cyclone after separation and enter a rapid reactor 5 for rapid gasification reaction, and then a gas purification and separation system 9 is used for extracting product gas, fine ash and part of recovered catalyst; on the other hand, the carbonaceous particles and slag separated by the separation device 7 are settled in the settler 6, mixed with fresh catalyst from the catalyst and carbonaceous material feed line, carbonaceous material, fine ash recovery catalyst, slag pool recovery catalyst, and returned to the fine reactor 3 through the material returning mechanism 8 to continue gasification reaction.

The carbon-containing raw material E loaded with the catalyst enters a settler 6 through a feeding pipeline 10, is introduced through a material returning mechanism 8, and simultaneously enters a fine reactor 3 with a gasifying agent A from a gas pipeline 2 to be mixed and gasified, large granular slag after reaction naturally settles and falls into a slag pool 1, and ash G is separated from the slag through a catalyst recovery device 11, and a catalyst F is recovered from the slag pool; the carbon-containing particles reacted in the fine reactor 3 are lifted by the gas into the coarse reactor 4 for further gasification reaction under the action of the recycle synthesis gas B from the gas purification and separation system 9The volume ratio of hydrogen to carbon monoxide in the circulating synthesis gas B is 0.8-4.5, the reacted gas and solid containing fine ash, carbon-containing particles and slag enter a separating device 7, the gas, the unseparated fine ash and unseparated carbon-containing particles are discharged by cyclone after separation and enter a rapid reactor 5 for rapid gasification reaction, and then a product gas is extracted by a gas purification and separation system 9,An outletFine ash C and fine ash recovered catalyst D; on the other hand, the carbonaceous particles and the slag separated by the separation device 7 are settled in the settler 6, mixed with the catalyst D recovered from the fine ash from the feed line 10, the catalyst-supporting carbonaceous raw material E, and the slag pool recovered catalyst F, and returned to the fine reactor 3 through the material returning mechanism 8 to continue the gasification reaction.

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

Detailed Description

[ example 1 ]

The reaction process is as follows: the catalyst and the carbonaceous raw material enter a settler through a feeding pipeline, are guided into a fine reactor through a material returning mechanism, are mixed with water vapor and oxygen from a gas pipeline and then are subjected to gasification reaction in the fine reactor, large granular slag after the reaction falls into a slag pool through natural sedimentation, and is separated from slag through catalyst recovery equipment to recover the catalyst. And the carbon-containing particles reacted in the fine reactor enter the coarse reactor for further gasification reaction through gas lifting. The reacted gas and solid fine ash, carbon-containing particles and slag enter separation equipment, the gas, part of fine ash and carbon-containing particles are discharged by cyclone after separation and enter a rapid reactor for rapid gasification reaction, and then a gas purification and separation system is used for extracting product gas, fine ash and part of recovered catalyst; on the other hand, the carbon-containing particles and the slag separated by the separation equipment are settled in a settler, mixed with fresh catalyst, carbon-containing raw material, fine ash recovery catalyst and slag pool recovery catalyst from the catalyst and carbon-containing raw material feeding pipelines, and returned to the fine reactor through the material returning mechanism to continue gasification reaction.

The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 24.1 percent, and the conversion rate of outlet carbon reaches 96.6 percent.

[ example 2 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 300mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 24.8 percent, and the conversion rate of outlet carbon reaches 97.2 percent.

[ example 3 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 150mm, the height is 1500mm, the reaction temperature is 650 ℃,the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 25 percent, and the conversion rate of outlet carbon reaches 97 percent.

[ example 4 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 225mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 25.4 percent, and the conversion rate of outlet carbon reaches 97.2 percent.

The reaction scheme is the same as in example 1 [ example 5 ]. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 375mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthesis rich in methaneGas, outlet CH in synthesis gas₄The concentration is 23.9 percent, and the conversion rate of outlet carbon reaches 95.5 percent.

[ example 6 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 24.6%, and the conversion rate of outlet carbon reaches 96.9%.

[ example 7 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1000mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 24.2 percent, and the conversion rate of outlet carbon reaches 96.5 percent.

[ example 8 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. Thin and thinThe diameter of the reactor is 50mm, the height is 3000mm, the linear speed is 15m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 30.3 percent, and the conversion rate of outlet carbon reaches 96.3 percent.

[ example 9 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 7m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 26.8 percent, and the conversion rate of outlet carbon reaches 96.9 percent.

[ example 10 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 0.1 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for the synthesis gas at the outlet of the gasification device20% of the total amount, the ratio of hydrogen to carbon monoxide in the recycle synthesis gas being 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 22%, and the outlet carbon conversion rate reaches 94.5%.

[ example 11 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 6.5 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 25.3 percent, and the conversion rate of outlet carbon reaches 97.2 percent.

[ example 12 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 1000 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄Concentration 31.2%, outlet carbon conversionReaching 98.7 percent.

[ example 13 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 20% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 27.5 percent, and the conversion rate of outlet carbon reaches 97.7 percent.

[ example 14 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 1 percent of the mass of the raw coal. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 21.5%, and the conversion rate of outlet carbon reaches 96.5%.

[ example 15 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the thin reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, and the water-carbon ratio4mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 22 percent, and the conversion rate of outlet carbon reaches 98.3 percent.

[ example 16 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 0.2mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 24%, and the conversion rate of outlet carbon reaches 94.2%.

[ example 17 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The gas amount of the circulating synthesis gas accounts for 20 percent of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 4.5. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 29.2 percent, and the conversion rate of outlet carbon reaches 91.9 percent.

[ example 18 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 20% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 2. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 26.6%, and the outlet carbon conversion rate reaches 93.9%.

[ example 19 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 45% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 27.8 percent, and the conversion rate of outlet carbon reaches 93.2 percent.

[ example 20 ]

The reaction scheme is the same as in example 1. The experiment selects inner Mongolia lignite, the inner Mongolia lignite is crushed to be less than 1mm to obtain pulverized coal, and the pulverized coal is mixed with 5% of potassium carbonate catalyst. The diameter of the fine reactor is 50mm, the height is 3000mm, the linear speed is 2m/s, the water-carbon ratio is 1mol/mol, the reaction temperature is 800 ℃, and the reaction pressure is 2 MPa; the diameter of the coarse reactor is 75mm, the height is 1500mm, the reaction temperature is 650 ℃, and the reaction pressure is 2 MPa. The loading of the catalyst accounts for 5% of the raw coal mass. The amount of the circulating synthesis gas accounts for 10% of the total amount of the synthesis gas at the outlet of the gasification device, and the ratio of hydrogen to carbon monoxide in the circulating synthesis gas is 1. The fast reactor was chosen as the tubular reactor, operating at 850 ℃ because of the high separation efficiency and the very low number of particles leaving the separation device. The product gas is a synthetic gas rich in methane, and CH in the synthetic gas is discharged₄The concentration is 23.7 percent, and the conversion rate of outlet carbon reaches 97.4 percent. [ COMPARATIVE EXAMPLE 1 ]

The method adopts a gasification reaction device in the process of preparing the methane-rich gas by catalytic gasification of a multilayer fluidized bed in the prior art, selects inner Mongolia lignite with the grain diameter of less than 1mm, uses 15 percent potassium carbonate as a catalyst, and has the operation pressure of 2MPa, the operation temperature of 700 ℃ and the gas phase line speed of 1.2 m/s. CO + H in outlet gas component obtained by experiment₂The content is 60.2%, the methane content is 7.9%, and the carbon conversion rate is 55%.

[ COMPARATIVE EXAMPLE 2 ]

The method adopts a Lurgi furnace in the prior art as a coal gasification reaction device in the process of preparing methane from coal, selects inner Mongolia lignite with the grain diameter smaller than 1mm, uses 15 percent of potassium carbonate as a catalyst, and has the operation pressure of 2MPa, the operation temperature of 700 ℃ and the gas phase line speed of 1.2 m/s. CO + H in outlet gas component obtained by experiment₂The content of 64 percent, the methane content of 14.1 percent and the carbon conversion rate of 91.7 percent.

TABLE 1

TABLE 1

TABLE 1

Claims

1. A catalytic gasification combined fluidized bed reaction method is characterized by comprising the following steps:

(a) the carbon-containing raw material (E) carrying the catalyst enters a settler (6) through a feeding pipeline (10), is introduced through a material returning mechanism (8), and simultaneously enters a fine reactor (3) with a gasifying agent (A) from a gas pipeline (2) to be mixed and gasified for reaction, large granular slag after the reaction naturally settles and falls into a slag pool (1), and ash (G) is separated through catalyst recovery equipment (11) and the catalyst (F) is recovered from the slag pool;

(b) after reaction, the carbon-containing particles in the fine reactor (3) are lifted by gas and enter a coarse reactor (4) for further gasification reaction under the action of circulating synthesis gas (B) from a gas purification and separation system (9), the volume ratio of hydrogen to carbon monoxide in the circulating synthesis gas (B) is 0.8-4.5, the reacted gas and solid enter a separation device (7), the solid contains fine ash, carbon-containing particles and slag, after separation, the gas, unseparated fine ash and unseparated carbon-containing particles are discharged by cyclone and enter a rapid reactor (5) for rapid gasification reaction, and then product gas, outlet fine ash (C) and a catalyst (D) recovered from the fine ash are extracted by the gas purification and separation system (9);

(c) and on the other hand, the carbon-containing particles and the slag separated by the separation equipment (7) are settled in a settler (6), mixed with the catalyst (D) recovered from the fine ash of the feeding pipeline (10), the carbon-containing raw material (E) carrying the catalyst and the catalyst (F) recovered in a slag pool, and returned to the fine reactor (3) through a material returning mechanism (8) to continue gasification reaction.

2. The catalytic gasification combined fluidized bed reaction method according to claim 1, characterized in that the carbonaceous feedstock is selected from coal, petroleum coke, biomass and mixtures thereof, and the gasifying agent is selected from oxygen, air, liquid water, steam, carbon dioxide or hydrogen and mixtures thereof.

3. A catalytic gasification combined fluidized bed reaction process according to claim 1, characterized in that the reaction conditions of the fine reactor (3) are: the reaction pressure is 0-6.5MPa, the reaction temperature is 800-1600 ℃, the gas phase line speed is 2.0-15.0m/s, and the flow state in the fine reactor (3) is fast fluidization; the reaction conditions of the crude reactor (4) are as follows: the reaction pressure is 0-6.5MPa, the reaction temperature is 600-1100 ℃, the gas phase line velocity is 0.1-1.0m/s, and the flow state in the crude reactor (4) is turbulent fluidization or bubbling fluidization.

4. The catalytic gasification combined fluidized bed reaction method according to claim 1, characterized in that the catalyst is selected from at least one of alkali metals, alkaline earth metals, transition metals; the catalyst is loaded on the carbon-containing raw material in an impregnation method, a dry mixing method or an ion exchange method; the loading capacity of the catalyst accounts for 0.1-20% of the mass of the raw coal.

5. A catalytic gasification combined fluidized bed reaction process according to claim 1, characterized in that the water to carbon ratio in the fine reactor (3) ranges from 0.5 to 4mol/mol and the water to carbon ratio in the coarse reactor (4) ranges from 2 to 20 mol/mol.

6. The catalytic gasification combined fluidized bed reaction method according to claim 1, characterized in that the fast reactor (5) is a cyclone reactor, a tubular reactor or a fluidized bed reactor.

7. A catalytic gasification combined fluidized bed reaction apparatus, characterized in that the catalytic gasification combined fluidized bed reaction method according to any one of claims 1 to 6 is employed, the catalytic gasification combined fluidized bed reaction apparatus comprising: the device comprises a fine reactor (3), a coarse reactor (4) and a settler (6), wherein the upper end of the fine reactor (3) is expanded and then communicated with the bottom of the coarse reactor (4), the coarse reactor (4) is communicated with the settler (6) through a separation device (7), the bottom of the settler (6) is communicated with the fine reactor (3) through a material returning mechanism (8), and the separation device (7) is positioned in the barrel of the settler (6).

8. A catalytic gasification combined fluidized bed reaction apparatus according to claim 7, characterized in that the height of the fine reactor (3) is 2-8 times the height of the coarse reactor (4).

9. A catalytic gasification combined fluidized bed reaction apparatus according to claim 7, characterized in that the diameter of the coarse reactor (4) is 1.5-6 times the diameter of the fine reactor (3).

10. A combined fluidized bed reactor for catalytic gasification according to claim 7, characterized in that the separator (7) is built in the settler (6), and the separator (7) is composed of more than 2 sets of cyclone separators.