阅读说明：本技术 加压移动床多层加氢煤制天然气联产燃油、芳烃方法 (Method for co-production of fuel oil and aromatic hydrocarbon by using pressurized moving bed and multi-layer hydrogenation of coal to prepare natural gas ) 是由 李宁 李开建 于 2019-09-20 设计创作，主要内容包括：加压移动床多层加氢煤制天然气联产燃油、芳烃方法,将加压移动床煤气化床自上而下设计为氢煤气段、段间过渡段、水煤气段；在氢煤气段用多层加氢优化气、固逆流和H<Sub>2</Sub>、CH<Sub>4</Sub>分压条件,增加煤焦油产率和C+2H<Sub>2</Sub>→CH<Sub>4</Sub>反应动力；出炉富烃氢煤气再通过净化分离得到煤焦油、甲烷、氢气；煤焦油通过加氢重整分馏制得燃油、芳烃,氢气经循环机升压循环使用；生产CH<Sub>1</Sub>后的残焦经水煤气段气化、CO变换、酸气脱除后,成为煤加氢及煤焦油加氢的补充氢；正常生产用电由自产天然气通过燃机发电提供,动力蒸汽由燃机余热锅炉提供,没有燃煤蒸汽锅炉。本方法可大幅提高产品能效、降低水耗、投资和环境污染。(A method for producing natural gas and co-producing fuel oil and aromatic hydrocarbon by multilayer hydrogenation coal in a pressurized moving bed is characterized in that a pressurized moving bed coal gasification bed is designed into a hydrogen gas section, an intersegmental transition section and a water gas section from top to bottom; multi-layer hydrogenation optimization gas, solid countercurrent and H in hydrogen gas section 2 、CH 4 Partial pressure conditions, increasing coal tar yield and C +2H 2 →CH 4 Reaction power; the coal gas rich in hydrocarbon and hydrogen is taken out of the furnace and is purified and separated to obtain coal tar, methane and hydrogen; coal cokeThe oil is fractionated to prepare fuel oil and aromatic hydrocarbon through hydro-reforming, and the hydrogen is pressurized and recycled through a circulator; production of CH 1 The residual coke after the reaction is gasified in a water gas section, CO converted and removed by acid gas to become supplementary hydrogen for coal hydrogenation and coal tar hydrogenation; the electricity for normal production is provided by the natural gas produced by self through the power generation of the gas turbine, the power steam is provided by the waste heat boiler of the gas turbine, and no coal-fired steam boiler is provided. The method can greatly improve the energy efficiency of the product and reduce water consumption, investment and environmental pollution.)

1. A process for preparing natural gas, fuel oil and arylhydrocarbon from the multi-layer hydrogenated coal in pressurized moving bed includes such steps as pressurizing and gasifying the raw coal by oxygen-enriched steam moving bed, gas washing, afterheat recovery and CO transform₂The system comprises the following systems of proportion adjustment, low-temperature methanol acid washing gas removal, methane catalytic synthesis, a methane dehydration process, a coal-fired boiler for power generation, power steam, process steam and the like, and is characterized in that:

the pressurized moving bed coal gasification bed is designed into a hydrogen gas section (A), an intersegmental transition section (G) and a water gas section (B) from top to bottom:

the hydrogen gas section (A) is designed into a hydrocarbon-rich hydrogen gas drying layer (10), a methane-rich hydrogen gas hydrogenation destructive distillation layer (11), a methane-poor hydrogen gas semicoke hydrogenation gasification layer (13), a semicoke hydrogenation layer (14) and an upper coke hydrogenation gasification layer (15) from top to bottom, and is structurally characterized in that the upper coke hydrogenation layer (16), the lower coke hydrogenation gasification layer (17) and the lower coke hydrogenation layer (17A) are respectively used for injecting hydrogen into the corresponding hydrogenation gasification layers through the semicoke hydrogenation layer (14), the upper coke hydrogenation layer (16) and the lower coke hydrogenation layer (17A) during operation, and the components and the temperature of a hydrogen bed layer are regulated and controlled so as to provide a chemical reaction driving force for methane generation and content increase; a stirrer (12) is arranged in the methane-rich hydrogen gas hydrogenation and dry distillation layer (11);

the intersegment transition section (G) is a section of bed layer in which residual coke after the coke hydrogenation reaction moves from a coke hydrogenation layer (17A) to a water gas section (B), and consists of a residual coke accumulation layer (18A) and a discharging structure (18B); the discharging structure (18B) is preferably a funnel-shaped discharging hopper with a large upper part and a small lower part, residual coke from a coke hydrogenation layer (17A) is loaded in the discharging hopper and discharged to a water gas section (B), a gas gathering area (19) is arranged outside the discharging hopper, and the residual coke in the residual coke gathering layer (18A) and the discharging hopper (18B) is utilized to block mutual gas communication between water gas and hydrogen; the middle part of the discharge hopper is provided with a middle gas collecting box (C) which is used for collecting coal gas in the middle area of the water-coal reaction layer (20), and the middle gas collecting box (C) is communicated with the coal gas gathering area (19) through a pipeline so that the coal gas of the middle gas collecting box (C) enters the coal gas gathering area (19);

the water gas section (B) is designed into a water gas reaction layer (20), an oxygen combustion layer (21) and an ash layer (22) from top to bottom and adopts O₂And water vapor and CO₂Mixed or O₂And CO₂Mixed gasification agent, using residual coke from the intersegmental transition section (18A) as raw material to produce H₂And CO to provide H to the hydrogen gas section (A)₂Raw material gas;

the raw material coal enters a pressurized moving bed through a coal lock (8), and sequentially:

firstly, heating and drying the coal gas rich in hydrocarbon and hydrogen at the temperature of 400 ℃ in a drying layer (10), namely removing water to obtain anhydrous raw material coal;

secondly, pyrolyzing, dry distilling and gasifying the anhydrous raw material coal in a dry distillation layer (11) by methane-rich hydrogen gas at 400-700 ℃, and analyzing coal tar, oxygen, nitrogen and sulfur compounds: CO, CO₂、H₂O、NH₃、H₂S, COS into semicoke;

thirdly, the semicoke moves downwards and is gasified into coke gas by methane-poor hydrogen at 700-800 ℃ in a semicoke hydrogenation gasification layer (13);

the coke moves downwards to penetrate through the semicoke hydrogenation layer (14), and is gasified into shallow residual coke by hydrogen at 800-900 ℃ in the upper coke hydrogenation gasification layer (15);

the shallow residual coke downwards passes through the upper coke hydrogenation layer (16) and is gasified into residual coke by hydrogen at 900-1100 ℃ in the lower coke hydrogenation gasification layer (17);

sixthly, the residual coke moves downwards to pass through a lower coke hydrogenation layer (17A), residual coke accumulation layers (18A) and (18B) in an intersegment transition section G move downwards slowly, and the gas cross-flow between the water gas produced by the water gas section (B) and the hydrogen of the lower coke hydrogenation layer (17A) is prevented by utilizing the resistance of the carbon layer;

seventhly, residual coke discharged by the discharging structure (18B) is coated with H in the water gas reaction layer (20)₂O+CO₂Gasifying the mixture into low-carbon residual coke;

the last low carbon residual coke of the oxygen combustion layer (21) is gasified by O in the steam oxygen gasification agent₂Oxidizing and burning the carbon into slag, namely oxidizing all residual carbon elements into CO₂Providing a heat source for the water gas reaction;

the hydrogen circulator (35A) sends the hydrogen for preparing the hydrogen-rich gas to the hydrogen gas section (A) after passing through a hydrogen heater (35B) and a start-up heating device (36) and respectively passing through a semicoke hydrogenation layer inlet (4) with a regulating valve, an upper coke hydrogenation layer inlet (4A) and a lower coke hydrogenation layer inlet (4B); hydrogen enters a lower coke hydrogenation gasification layer (17) through a lower coke hydrogenation layer (17A), and residual coke which is slowly moved downwards is heated to about 900 ℃ at first, and because the content of methane in the hydrogen is far lower than the equilibrium concentration and the local airspeed is low, the method is very favorable for C +2H₂Generating CH₄And releasing heat to raise the temperature to 1000-1100 ℃ to obtain high-temperature lean methane hydrogen gas; the high-temperature methane-poor hydrogen gas goes upwards to pass through the upper coke hydrogenation layer (16) and is mixed with the low-temperature hydrogen added into the upper coke hydrogenation layer, the temperature is reduced to about 800 ℃, and the high-temperature methane-poor hydrogen gas enters the upper coke hydrogenation gasification layer (15) to be subjected to C +2H₂→CH₄Reacting and releasing heat to raise the temperature to 900-1000 ℃; the methane-depleted hydrogen gas with higher methane content continuously goes upward, passes through the semicoke hydrogenation layer (14) and is mixed with the low-temperature hydrogen added into the semicoke hydrogenation layer, the temperature is reduced to about 700 ℃, and the gas enters the semicoke hydrogenation gasification layer (13) to mainly carry out multi-carbon olefin C_nH_2n+nH₂→nCH₄Alkyne C_nH_2n-2+(n+1)H₂→nCH₄When unsaturated hydrocarbon is hydrogenated to quickly generate methane, the temperature is increased from 700 ℃ to about 800 ℃ to become methane-rich hydrogen gas; the methane-rich hydrogen coal gas ascends into the methane-rich hydrogen coal gas hydrogenation and carbonization layer (11) to provide heat for coal pyrolysis, carbonization and gasification, and the hydrogen and methane partial pressure in the methane-rich hydrogen coal gas is high, so that the generation of hydrogen during the cracking of solid coal and liquid coal tar is effectively prevented, the generation rate of methane is greatly reduced, hydrogen elements in coal are forced to be more combined in the coal tar, and the yield of the coal tar and the utilization rate of the hydrogen elements in the coal are increased; due to the strong diffusion and permeation of hydrogen under the temperature and pressure, the hydrogen also enters the coal particle interior and hydrocarbon C_XH_YReacting to generate more coal tar of the multi-carbon saturated hydrocarbon and release heat, so that the coal tar is heated into gaseous hydrocarbon and enters a gas phase, and the methane-rich hydrogen gas becomes hydrocarbon-rich hydrogen gas at about 600 ℃; the hydrocarbon-rich hydrogen gas continuously goes upwards to enter a raw material coal drying layer (10), the moisture in the coal is dried while the raw material coal is heated, so that the adsorbed water and the crystal water in the raw material coal are converted into water vapor to enter the hydrocarbon-rich hydrogen gas, and the hydrocarbon-rich hydrogen gas is discharged from a hydrocarbon-rich hydrogen gas outlet (5) at the upper part of the furnace wall when the temperature of the hydrocarbon-rich hydrogen gas is reduced to about 400 ℃;

removing tar and dust from the hydrogen-rich gas after discharging through a tar and dust separator (37), reducing the temperature through a heat exchanger (38), cooling to normal temperature through a cooling oil-water separator (39), separating oil and water, entering an acid gas hydrogen separation process (40), and separating H₂S、COS、CO₂The CO acid gas and the hydrogen gas become the coal-made synthetic natural gas (40D) which meets the GB/T33445-2016 standard; most of hydrogen (40A) separated in the acid gas-hydrogen separation process (40) and hydrogen (33B) from the water gas-acid gas removal process (33) enter a hydrogen main pipe (35) together, are subjected to pressure boosting through a hydrogen circulator (35A), and then enter the furnace again to produce hydrogen-rich gas; a small part (40F) of the hydrogen separated in the acid gas-hydrogen separation process (40) and the tar (41A) separated in the cooling oil-water separator (41) are sent to a process (41) for preparing fuel oil aromatic hydrocarbon by hydrogenation of the coal tar to produce fuel oil (42A) and aromatic hydrocarbon(42B)；

After entering the furnace from the furnace bottom inlet (1), a gasifying agent (28A) formed by mixing oxygen and water vapor passes through the grate from bottom to top and passes through the ash layer (22) to absorb heat carried by the ash layer, the temperature is raised to about 600 ℃ and then enters the oxygen gasification combustion layer (21), and the oxygen in the gasifying agent enables carbon elements remained in residual coke to be rapidly combusted and gasified to generate CO₂And a large amount of heat is released, so that the temperature of water vapor and a bed layer in the gasifying agent reaches over 1000 ℃ and is below an ash melting point; containing CO₂The high-temperature water vapor enters a water gas reaction layer (20) from bottom to top, and the heat is transferred to the hydro-gasification residual coke from the hydrogen gas section, and simultaneously, the high-temperature water vapor and carbon element in the residual coke perform endothermic water gas reaction C + H₂O＝CO+H₂Most of carbon elements in the residual coke react with 30-40% of water molecules in the water vapor and are converted into CO and H in the water gas₂The water gas is wet hot water gas with the temperature of about 700 ℃, the water gas ascends to enter a gas collection area (19) and a middle gas collection box (C), and then is discharged from the furnace through a water gas outlet (3) in the middle of the furnace wall;

the water gas discharged from the furnace is heated by a dust removal device (28B), a hydrogen heater (35B) and a steam superheating device (29) and enters the furnace steam, the water gas enters a waste heat steam boiler (30) to produce steam required by partial coal gasification, the steam enters a water gas washing device (31) to remove dust, colloid and miscellaneous salt, the water gas enters a CO conversion process (32), and more than 95 percent of CO is subjected to CO + H by a catalyst₂O＝CO+H₂Carrying out a shift reaction; the converted gas is called converted gas, and the main component of the converted gas is H₂And CO₂(ii) a Converting CO in gas₂Acid gas and small amount of H₂S acid gas is removed by adopting a Pressure Swing Adsorption (PSA) separation process in an acid gas removal process (33): removed H₂S (33C) is sent to a sulfur recovery device (33D) to prepare sulfur, and the heat value of combustible components is more than or equal to 400kJ/Nm³Part of CO above₂And the desorbed gas (33A) is sent to a gas turbine tail gas boiler (45) to produce steam, combustible components in the steam are converted into steam energy for recycling, and hydrogen separated in the acid gas removal process (33) is sent to a hydrogen main pipe (35) as make-up hydrogen (33B).

2. The method for producing the fuel oil and the aromatic hydrocarbon by the coal-to-natural gas co-production through the multi-layer hydrogenation of the pressurized moving bed is characterized in that during normal production, the whole coal-to-natural gas co-production fuel oil production system contains the requirements of processes and equipment such as air separation, oxygen production, coal tar hydrogenation, byproduct recovery, air cooling, circulating water, three-waste treatment and the like: a electricity is provided by a portion (40E) of the self-produced natural gas (40D) via a combustion engine (43) and an electric generator (44); b, the power steam is provided by a gas turbine waste heat boiler (45) for combusting the process tail gas; heating steam for fuel oil and aromatic hydrocarbon fractionation and phenol and ammonia byproduct recovery is provided by steam (46A) after partial power is recovered by a steam turbine (46), and the coal-free steam boiler operates.

3. The method for producing natural gas and CO-producing fuel oil and aromatic hydrocarbon by pressurizing moving bed multi-layer hydrogenation coal is characterized in that during normal production, steam in a steam oxygen gasifying agent fed into a furnace is provided by a water jacket steam drum (23A) connected with a water jacket of a gas furnace, a waste heat boiler (30), CO shift reaction heat and a saturation tower (27A); the oxygen entering the furnace is saturated with water vapor through a saturation tower (27A), then mixed with superheated steam from a dust removal steam superheating device (29) and enters the furnace through a steam oxygen gasifying agent inlet (1); the saturation tower (27A) adopts the structures of mass and heat transfer devices (14), (14A), (14B) and (14C) in the patent ZL2011100943882 and corresponding medium inlets and outlets.

4. The method for CO-production of fuel oil and aromatic hydrocarbon by using the pressurized moving bed multi-layer hydrogenation coal as the raw material according to claim 1, wherein the content of methane, hydrogen and CO + CO in the hydrogen gasifying agent entering the hydrogen gas section (A) is less than or equal to 20%, 80-100% and the content of CO + CO₂+H₂O+N₂≤10％，H₂S≤0.5％，O₂Less than or equal to 0.5 percent; the height-diameter ratio of a gasification bed layer of the hydrogen gas section (A) is 1-8; the number of hydrogenation layers is determined according to the characteristics of coal types, the yield of methane and tar, the number is not limited to 3 layers, and the distance between the hydrogenation layers is determined according to the hydrogenation chemical reaction activity of coal; the height-diameter ratio of the residual coke gasification bed layer of the water gas section (B) is 0.5-3.5; resistance adjusting devices are arranged at the water gas outlet (3) and the hydrocarbon-rich hydrogen gas outlet (5) so as to eliminate the mutual reaction between the hydrogen of the lower coke hydrogenation layer (17A) and the water gas of the water gas section (B)And (4) communicating qi.

5. The method for co-production of fuel oil and aromatic hydrocarbon by using the pressurized moving bed multi-layer hydrogenation coal as the raw material according to claim 1, wherein the temperature of the hydrocarbon-rich hydrogen gas outlet (5) is 300-500 ℃, preferably 400 ℃; the highest temperature of the water gas section (B) is a dry slag gasification mode below the ash melting point temperature or a slag gasification mode above the ash melting point temperature.

6. The method for producing natural gas and co-producing fuel oil and aromatic hydrocarbon by using pressurized moving bed multi-layer hydrogenation coal as claimed in claim 1, wherein the temperature and the flow of hydrogen gas entering the inlet (4) of the semicoke hydrogenation layer, the inlet (4A) of the upper coke hydrogenation layer and the inlet (4B) of the lower coke hydrogenation layer are adjusted to control the temperature of the semicoke hydrogenation gasification layer (13), the upper coke hydrogenation gasification layer (15), the lower coke hydrogenation gasification layer (17), the dry distillation layer (11) and the drying layer (10) in the hydrogen gas section (A), thereby controlling the temperature and the composition of the gas in the hydrocarbon-rich hydrogen gas outlet (5).

7. The method for producing natural gas and co-producing fuel oil and aromatic hydrocarbon by using the pressurized moving bed multi-layer hydrogenation coal as claimed in claim 1, wherein the production ratio of the water gas to the hydrocarbon-rich hydrogen gas is controlled by adjusting the flow ratio of the oxygen-rich water vapor (28A) entering the water gas section (B) to the hydrogen gas (36A) entering the hydrogen gas section (A).

8. The method for producing natural gas and co-producing fuel oil and aromatic hydrocarbon by using pressurized moving bed multi-layer hydrogenation coal as claimed in claim 1, wherein the process pressure of the pressurized coal gasification bed is 1-3 MPa, or 3-6 MPa, or 6-10 MPa; the process pressure for preparing the fuel aromatic hydrocarbon by coal tar hydrogenation is 8-15 MPa.

9. The method for co-producing fuel oil and aromatic hydrocarbon by using the pressurized moving bed multi-stage hydrogenation coal as the coal, according to claim 1, wherein the coal as fired is lignite, bituminous coal or anthracite, or is lignite, bituminous coal or anthracite added with a catalyst; pulverized coal with the granularity of 6-50 mm, or 15-80 mm, or the granularity of less than 6 mm; when the coal as fired is non-caking coal, no stirrer is arranged.

10. The method for producing natural gas, fuel oil and aromatic hydrocarbon through multi-layer hydrogenation of coal by using pressurized moving bed according to claim 1, wherein the hydrogen gas section (A) and the water gas section (B) are respectively provided with a temperature thermocouple and thermocouple insertion ports (D) and (E) so as to detect and regulate the bed temperature.

Technical Field

The invention belongs to the field of energy and chemical engineering, and particularly relates to a technique and equipment for energy regeneration of coal-based natural gas and fuel oil.

Background

The existing two-step method for synthesizing oil and gas after coal gasification or one-step method for producing oil and gas by direct coal hydrogenation has the disadvantages of complex process route and low energy conversion efficiency in the process, namely only 43% of coal oil, 3.4 tons of standard coal/ton of oil, only 55% of coal natural gas and 2.3 tons of standard coal/km³(ii) a High equipment investment, 1600 million yuan per 1000 ten thousand tons of coal-made oil, 280 million yuan per 40 million m of coal-made natural gas³(ii) a High water resource consumption, 7 ton/ton oil consumption water from coal and 7 ton/km natural gas from coal³(ii) a Heavy environmental pollution, high cost of sewage treatment, CO₂High emission, and the like, and cannot be commercialized in a large scale.

The main reason for this is that the coal gasification is CO + H₂Then synthesized into CnH₂n₊₂(n-1 is CH)₄N-8 is gasoline and n-16 is diesel) by a two-step process, chemical reaction nCO +2nH₂+H₂＝CnH₂n₊₂+nH₂Oxygen element in O and CO must be H₂To be taken out and prepare H traditionally₂The energy consumption and the cost are high, so the coal gasification process of the two-step method adopts CH in coal gas₁The gasification of coal by a pressurized moving bed with higher content can bring the problems of high steam consumption, high coal gas wastewater and particularly high environmental protection cost; the coal gasification by the entrained flow bed has little steam consumption and coal gas wastewater, is relatively environment-friendly and easy to pass, but the oxygen consumption reaches 2000Nm³After the advantages and disadvantages of the oil/t are balanced, the newly-built coal-to-oil demonstration production line mostly adopts a process route of re-synthesizing oil by entrained flow coal gasification.

The scheme of 'coal topping' low-rank coal pyrolysis oil preparation proposed in the industry in recent years also forces the process to stay in the demonstration stage due to low tar yield, low selling price and difficult path of semicoke.

The reason that the oil preparation efficiency of the existing one-step method for directly hydrogenating coal is low is that firstly, the carbon element conversion rate is low, the carbon content of the residue is up to 40 percent, and CO can be generated again only by reheating in a special gasification furnace; secondly, the entrained flow bed is adopted for coal gasification to produce hydrogen, and because the hydrogen element in the coal is in the form of hydrocarbon in the gasification process of the entrained flow bed, the hydrogen element is firstly pyrolyzed to be gaseous below 700 DEG CThe hydrocarbon, in turn, with O in the gas stream₂Gas reaction to CO₂And H₂O gives off heat to enable the furnace temperature to reach 1300-1700 ℃, so a great part of the high furnace temperature of the entrained flow bed is contributed by the combustion of hydrogen elements, thereby resulting in low molar fraction of hydrogen in the coal gas, particularly high CO content, and CO can be converted into hydrogen only by conversion, namely, the hydrogen production process is substantially to burn H in the coal firstly₂Then using C element in coal to prepare CO, converting CO into H₂(ii) a Thirdly, the process pressure is up to 20MPa, the equipment investment is large, and fourthly, the quality requirement of the raw material coal is strict, so the CnH is prepared by the existing one-step method of directly hydrogenating the coal₂n₊₂There are also a number of disadvantages.

Disclosure of Invention

The invention aims to directly separate H element in the raw material coal from coal in the form of gaseous multi-carbon hydrocarbon CmHn by pyrolysis and gasification under proper temperature and gas phase medium conditions; secondly, directly reacting carbon element in the coal into gaseous hydrocarbon by using H element, and thirdly, converting the carbon element in residual coke left after the production of the gaseous hydrocarbon into CO and H by adopting oxygen-rich steam at high temperature₂So as to greatly improve the energy conversion efficiency, greatly reduce the water resource consumption and greatly reduce CO₂Discharge and environmental pollution, greatly reduces the investment of the device and reduces the production cost.

The specific invention content is as follows:

1. a process for preparing natural gas, fuel oil and arylhydrocarbon from the multi-layer hydrogenated coal in pressurized moving bed includes such steps as pressurizing and gasifying the raw coal by oxygen-enriched steam moving bed, gas washing, afterheat recovery and CO transform₂The system comprises the following systems of proportion adjustment, low-temperature methanol acid washing gas removal, methane catalytic synthesis, a methane dehydration process, a coal-fired boiler for power generation, power steam, process steam and the like, and is characterized in that:

the pressurized moving bed coal gasification bed is designed into a hydrogen gas section (A), an intersegmental transition section (G) and a water gas section (B) from top to bottom:

the hydrogen gas section (A) is designed into a hydrocarbon-rich hydrogen gas drying layer (10), a methane-rich hydrogen gas hydrogenation destructive distillation layer (11), a methane-poor hydrogen gas semicoke hydrogenation gasification layer (13), a semicoke hydrogenation layer (14) and an upper coke hydrogenation gasification layer (15) from top to bottom, and is structurally characterized in that the upper coke hydrogenation layer (16), the lower coke hydrogenation gasification layer (17) and the lower coke hydrogenation layer (17A) are respectively used for injecting hydrogen into the corresponding hydrogenation gasification layers through the semicoke hydrogenation layer (14), the upper coke hydrogenation layer (16) and the lower coke hydrogenation layer (17A) during operation, and the components and the temperature of a hydrogen bed layer are regulated and controlled so as to provide a chemical reaction driving force for methane generation and content increase; a stirrer (12) is arranged in the methane-rich hydrogen gas hydrogenation and dry distillation layer (11);

the intersegment transition section (G) is a section of bed layer in which residual coke after the coke hydrogenation reaction moves from a coke hydrogenation layer (17A) to a water gas section (B), and consists of a residual coke accumulation layer (18A) and a discharging structure (18B); the discharging structure (18B) is preferably a funnel-shaped discharging hopper with a large upper part and a small lower part, residual coke from a coke hydrogenation layer (17A) is loaded in the discharging hopper and discharged to a water gas section (B), a gas gathering area (19) is arranged outside the discharging hopper, and the residual coke in the residual coke gathering layer (18A) and the discharging hopper (18B) is utilized to block mutual gas communication between water gas and hydrogen; the middle part of the discharge hopper is provided with a middle gas collecting box (C) which is used for collecting coal gas in the middle area of the water-coal reaction layer (20), and the middle gas collecting box (C) is communicated with the coal gas gathering area (19) through a pipeline so that the coal gas of the middle gas collecting box (C) enters the coal gas gathering area (19);

the water gas section (B) is designed into a water gas reaction layer (20), an oxygen combustion layer (21) and an ash layer (22) from top to bottom and adopts O₂And water vapor and CO₂Mixed or O₂And CO₂Mixed gasification agent, using residual coke from the intersegmental transition section (18A) as raw material to produce H₂And CO to provide H to the hydrogen gas section (A)₂Raw material gas;

the raw material coal enters a pressurized moving bed through a coal lock (8), and sequentially:

firstly, heating and drying the coal gas rich in hydrocarbon and hydrogen at the temperature of 400 ℃ in a drying layer (10), namely removing water to obtain anhydrous raw material coal;

secondly, the anhydrous raw material coal is pyrolyzed, dry distilled and gasified by methane-rich hydrogen gas at 400-700 ℃ in a dry distillation layer (11), and coal tar are resolvedOxygen, nitrogen, sulfur compounds: CO, CO₂、H₂O、NH₃、H₂S, COS into semicoke;

thirdly, the semicoke moves downwards and is gasified into coke gas by methane-poor hydrogen at 700-800 ℃ in a semicoke hydrogenation gasification layer (13);

the coke moves downwards to penetrate through the semicoke hydrogenation layer (14), and is gasified into shallow residual coke by hydrogen at 800-900 ℃ in the upper coke hydrogenation gasification layer (15);

the shallow residual coke downwards passes through the upper coke hydrogenation layer (16) and is gasified into residual coke by hydrogen at 900-1100 ℃ in the lower coke hydrogenation gasification layer (17);

sixthly, the residual coke moves downwards to pass through a lower coke hydrogenation layer (17A), residual coke accumulation layers (18A) and (18B) in an intersegment transition section G move downwards slowly, and the gas cross-flow between the water gas produced by the water gas section (B) and the hydrogen of the lower coke hydrogenation layer (17A) is prevented by utilizing the resistance of the carbon layer;

seventhly, residual coke discharged by the discharging structure (18B) is coated with H in the water gas reaction layer (20)₂O+CO₂Gasifying the mixture into low-carbon residual coke;

the last low carbon residual coke of the oxygen combustion layer (21) is gasified by O in the steam oxygen gasification agent₂Oxidizing and burning the carbon into slag, namely oxidizing all residual carbon elements into CO₂Providing a heat source for the water gas reaction;

the hydrogen circulator (35A) sends the hydrogen for preparing the hydrogen-rich gas to the hydrogen gas section (A) after passing through a hydrogen heater (35B) and a start-up heating device (36) and respectively passing through a semicoke hydrogenation layer inlet (4) with a regulating valve, an upper coke hydrogenation layer inlet (4A) and a lower coke hydrogenation layer inlet (4B); hydrogen enters a lower coke hydrogenation gasification layer (17) through a lower coke hydrogenation layer (17A), and residual coke which is slowly moved downwards is heated to about 900 ℃ at first, and because the content of methane in the hydrogen is far lower than the equilibrium concentration and the local airspeed is low, the method is very favorable for C +2H₂Generating CH₄And releasing heat to raise the temperature to 1000-1100 ℃ to obtain high-temperature lean methane hydrogen gas; the high-temperature methane-depleted hydrogen gas goes upwards through the upper coke hydrogenation layer (16) and is mixed with the low-temperature hydrogen gas added into the upper coke hydrogenation layer, the temperature is reduced to about 800 ℃, and the high-temperature methane-depleted hydrogen gas enters the upper coke hydrogenation layerThe hydrogen-forming layer (15) is again subjected to C +2H₂→CH₄Reacting and releasing heat to raise the temperature to 900-1000 ℃; the methane-depleted hydrogen gas with higher methane content continuously goes upward, passes through the semicoke hydrogenation layer (14) and is mixed with the low-temperature hydrogen added into the semicoke hydrogenation layer, the temperature is reduced to about 700 ℃, and the gas enters the semicoke hydrogenation gasification layer (13) to mainly carry out multi-carbon olefin C_nH_2n+nH₂→nCH₄Alkyne C_nH_2n-2+(n+1)H₂→nCH₄When unsaturated hydrocarbon is hydrogenated to quickly generate methane, the temperature is increased from 700 ℃ to about 800 ℃ to become methane-rich hydrogen gas; the methane-rich hydrogen coal gas ascends into the methane-rich hydrogen coal gas hydrogenation and carbonization layer (11) to provide heat for coal pyrolysis, carbonization and gasification, and the hydrogen and methane partial pressure in the methane-rich hydrogen coal gas is high, so that the generation of hydrogen during the cracking of solid coal and liquid coal tar is effectively prevented, the generation rate of methane is greatly reduced, hydrogen elements in coal are forced to be more combined in the coal tar, and the yield of the coal tar and the utilization rate of the hydrogen elements in the coal are increased; due to the strong diffusion and permeation of hydrogen under the temperature and pressure, the hydrogen also enters the coal particle interior and hydrocarbon C_XH_YReacting to generate more coal tar of the multi-carbon saturated hydrocarbon and release heat, so that the coal tar is heated into gaseous hydrocarbon and enters a gas phase, and the methane-rich hydrogen gas becomes hydrocarbon-rich hydrogen gas at about 600 ℃; the hydrocarbon-rich hydrogen gas continuously goes upwards to enter a raw material coal drying layer (10), the moisture in the coal is dried while the raw material coal is heated, so that the adsorbed water and the crystal water in the raw material coal are converted into water vapor to enter the hydrocarbon-rich hydrogen gas, and the hydrocarbon-rich hydrogen gas is discharged from a hydrocarbon-rich hydrogen gas outlet (5) at the upper part of the furnace wall when the temperature of the hydrocarbon-rich hydrogen gas is reduced to about 400 ℃;

removing tar and dust from the hydrogen-rich gas after discharging through a tar and dust separator (37), reducing the temperature through a heat exchanger (38), cooling to normal temperature through a cooling oil-water separator (39), separating oil and water, entering an acid gas hydrogen separation process (40), and separating H₂S、COS、CO₂The CO acid gas and the hydrogen gas become the coal-made synthetic natural gas (40D) which meets the GB/T33445-2016 standard; most of the hydrogen separated in the acid gas-hydrogen separation step (40) ((40A) The hydrogen (33B) from the water gas acid gas removal process (33) enters a hydrogen main pipe (35) together, is subjected to pressure increase by a hydrogen circulator (35A), and then enters the furnace again to produce hydrogen-rich gas; a small part (40F) of the hydrogen separated in the acid gas-hydrogen separation process (40) and tar (41A) separated in the cooling oil-water separator (41) are sent to a process (41) for preparing fuel oil aromatic hydrocarbon by hydrogenation of the coal tar to produce fuel oil (42A) and aromatic hydrocarbon (42B);

after entering the furnace from the furnace bottom inlet (1), a gasifying agent (28A) formed by mixing oxygen and water vapor passes through the grate from bottom to top and passes through the ash layer (22) to absorb heat carried by the ash layer, the temperature is raised to about 600 ℃ and then enters the oxygen gasification combustion layer (21), and the oxygen in the gasifying agent enables carbon elements remained in residual coke to be rapidly combusted and gasified to generate CO₂And a large amount of heat is released, so that the temperature of water vapor and a bed layer in the gasifying agent reaches over 1000 ℃ and is below an ash melting point; containing CO₂The high-temperature water vapor enters a water gas reaction layer (20) from bottom to top, and the heat is transferred to the hydro-gasification residual coke from the hydrogen gas section, and simultaneously, the high-temperature water vapor and carbon element in the residual coke perform endothermic water gas reaction C + H₂O＝CO+H₂Most of carbon elements in the residual coke react with 30-40% of water molecules in the water vapor and are converted into CO and H in the water gas₂The water gas is wet hot water gas with the temperature of about 700 ℃, the water gas ascends to enter a gas collection area (19) and a middle gas collection box (C), and then is discharged from the furnace through a water gas outlet (3) in the middle of the furnace wall;

the water gas discharged from the furnace is heated by a dust removal device (28B), a hydrogen heater (35B) and a steam superheating device (29) and enters the furnace steam, the water gas enters a waste heat steam boiler (30) to produce steam required by partial coal gasification, the steam enters a water gas washing device (31) to remove dust, colloid and miscellaneous salt, the water gas enters a CO conversion process (32), and more than 95 percent of CO is subjected to CO + H by a catalyst₂O＝CO+H₂Carrying out a shift reaction; the converted gas is called converted gas, and the main component of the converted gas is H₂And CO₂(ii) a Converting CO in gas₂Acid gas and small amount of H₂S acid gas is removed by adopting a Pressure Swing Adsorption (PSA) separation process in an acid gas removal process (33): removed H₂S (33C) is sent to a sulfur recovery device (33D) to prepare sulfur, and the combustible component heatThe value is more than or equal to 400kJ/Nm³Part of CO above₂The desorbed gas (33A) is sent into a gas turbine tail gas boiler (45) to produce steam, combustible components in the steam are converted into steam energy for recycling, and hydrogen separated in the acid gas removal process (33) is sent into a hydrogen main pipe (35) as supplemented hydrogen (33B);

2. the method for producing the fuel oil and the aromatic hydrocarbon by the coal-to-natural gas co-production through the multi-layer hydrogenation of the pressurized moving bed is characterized in that during normal production, the whole coal-to-natural gas co-production fuel oil production system contains the requirements of processes and equipment such as air separation, oxygen production, coal tar hydrogenation, byproduct recovery, air cooling, circulating water, three-waste treatment and the like: a electricity is provided by a portion (40E) of the self-produced natural gas (40D) via a combustion engine (43) and an electric generator (44); b, the power steam is provided by a gas turbine waste heat boiler (45) for combusting the process tail gas; heating steam for fuel oil and aromatic hydrocarbon fractionation and phenol and ammonia byproduct recovery is provided by steam (46A) after partial power is recovered by a steam turbine (46), and the coal-free steam boiler operates.

3. The method for producing natural gas and CO-producing fuel oil and aromatic hydrocarbon by pressurizing moving bed multi-layer hydrogenation coal is characterized in that during normal production, steam in a steam oxygen gasifying agent fed into a furnace is provided by a water jacket steam drum (23A) connected with a water jacket of a gas furnace, a waste heat boiler (30), CO shift reaction heat and a saturation tower (27A); the oxygen entering the furnace is saturated with water vapor through a saturation tower (27A), then mixed with superheated steam from a dust removal steam superheating device (29) and enters the furnace through a steam oxygen gasifying agent inlet (1); the saturation tower (27A) adopts the structures of mass and heat transfer devices (14), (14A), (14B) and (14C) in the patent ZL2011100943882 and corresponding medium inlets and outlets.

4. According to the scheme, the method for producing natural gas and CO-producing fuel oil and aromatic hydrocarbon by using pressurized moving bed multi-layer hydrogenation coal is characterized in that methane, hydrogen and CO + CO are less than or equal to 20%, 80-100% and less than or equal to 20% in hydrogen gasifying agent entering a hydrogen gas section (A)₂+H₂O+N₂≤10％，H₂S≤ 0.5％，O₂Less than or equal to 0.5 percent; the height-diameter ratio of a gasification bed layer of the hydrogen gas section (A) is 1-8; the number of hydrogenation layers is determined according to the characteristics of coal types, the yield of methane and tar, the number is not limited to 3 layers, and the distance between the hydrogenation layers is determined according to the hydrogenation chemical reaction activity of coal; water gas section(B) The height-diameter ratio of the residual coke gasification bed layer is 0.5-3.5; resistance adjusting devices are arranged at the water gas outlet (3) and the hydrocarbon-rich hydrogen gas outlet (5) so as to eliminate mutual gas cross between the hydrogen of the lower coke hydrogenation layer (17A) and the water gas of the water gas section (B).

5. The method for preparing natural gas and co-producing fuel oil and aromatic hydrocarbon by multi-layer hydrogenation of coal through a pressurized moving bed is characterized in that the temperature of a hydrocarbon-rich hydrogen gas outlet (5) is 300-500 ℃, and preferably 400 ℃; the highest temperature of the water gas section (B) is a dry slag gasification mode below the ash melting point temperature or a slag gasification mode above the ash melting point temperature.

6. According to the scheme, the method for producing natural gas and co-producing fuel oil and aromatic hydrocarbon by multilayer hydrogenation coal through the pressurized moving bed is characterized in that the temperature of a semicoke hydrogenation gasification layer (13) of a hydrogen gas section (A), an upper coke hydrogenation gasification layer (15), a lower coke hydrogenation gasification layer (17), a dry distillation layer (11) and a drying layer (10) is controlled by adjusting the hydrogen components, the temperature and the flow entering a semicoke hydrogenation layer inlet (4), an upper coke hydrogenation layer inlet (4A) and a lower coke hydrogenation layer inlet (4B), and further the gas temperature and the components of a hydrocarbon-rich hydrogen gas outlet (5) are controlled.

7. According to the scheme, the method for preparing natural gas and co-producing fuel oil and aromatic hydrocarbon by multilayer hydrogenation of coal through the pressurized moving bed is characterized in that the yield ratio of water gas and hydrocarbon-rich hydrogen gas is controlled by adjusting the flow ratio of oxygen-rich water vapor (28A) entering a water gas section (B) to hydrogen (36A) entering the hydrogen gas section (A).

8. According to the scheme, the method for preparing natural gas and co-producing fuel oil and aromatic hydrocarbon by using the pressurized moving bed multi-layer hydrogenated coal is characterized in that the process pressure of a pressurized coal gasification bed is 1-3 MPa, or 3-6 MPa, or 6-10 MPa; the process pressure for preparing the fuel aromatic hydrocarbon by coal tar hydrogenation is 8-15 MPa.

9. According to the scheme, the method for co-producing fuel oil and aromatic hydrocarbon by using the pressurized moving bed multi-stage hydrogenation coal for preparing natural gas is characterized in that the coal as fired is lignite, bituminous coal and anthracite, or lignite, bituminous coal and anthracite added with a catalyst; pulverized coal with the granularity of 6-50 mm, or 15-80 mm, or the granularity of less than 6 mm; when the coal as fired is non-caking coal, no stirrer is arranged.

10. According to the scheme, the method for co-producing fuel oil and aromatic hydrocarbon by using the pressurized moving bed and the multi-layer hydrogenation of coal is characterized in that the hydrogen gas section (A) and the water gas section (B) are respectively provided with a temperature thermocouple and thermocouple insertion holes (D) and (E) so as to detect and regulate the bed layer temperature of the hydrogen gas section and the water gas section.

The invention has the following positive effects:

during normal production, the steam required by the water gas reaction realizes self-sufficiency, thereby saving the investment of a coal-fired steam boiler, saving energy, reducing environmental pollution, reducing water resource consumption and CO₂Compared with the pure Fischer-Tropsch route coal-based natural gas, the invention has no fine desulfurization, catalytic synthesis of methane and H₂O is generated, a dehydration process is not carried out, and the yield of fuel oil and aromatic hydrocarbon raw materials, namely coal tar, is greatly increased, so that the investment, energy consumption and CO of coal-based natural gas are greatly reduced₂Emissions and product costs.

② compared with the pure Fischer-Tropsch route coal oil preparation, the invention has no special production of CO and H₂Coal gasifier, without adjusting H₂CO conversion process with/CO ratio, without fuel catalytic synthesis and H₂O production step, oil-water separation step, oily wastewater treatment step, and the like, whereby ton oil: investment is reduced by 50%, oxygen consumption is reduced by 75%, water resource consumption is reduced by 50%, and CO is reduced₂The emission is reduced by 50%, and the environmental pollution is greatly reduced.

And thirdly, the methane-rich hydrogen gas is adopted for coal pyrolysis and dry distillation, so that the yield of the coal tar is greatly increased, and the coal tar has the advantages of mild temperature, good quality of the coal tar and high additional value, is used for preparing oil and aromatic hydrocarbon by hydrogenation, and can greatly reduce the production cost.

And fourthly, the consumption of raw fuel coal, water resources and oxygen of the coal-based natural gas and oil is greatly reduced, and the investment is saved.

Coal hydrogenation direct C +2H₂＝CH₄The reaction heat for generating methane is used for pyrolysis, dry distillation and gasification of raw material coal, drying and dehydration and heating of raw coal, and is also used for heating jacket circulating water to produce water vapor required by water gas reaction, the heat is fully coupled and utilized, and the heat efficiency of coal-based natural gas and fuel oil is effectively improved.

Sixthly, because the method for co-producing the fuel oil and the aromatic hydrocarbon by the coal-based natural gas has no coal-fired steam boiler during normal production, the method not only eliminates the environmental pollution of the coal-fired boiler and simplifies the production process, but also can be used for producing fuel CH of system power and steam₄And the hydrogen production tail gas (33A) and the methane tail gas (40C) are both from raw material coal after coal tar production, so that the yield ratio of tar, namely fuel oil aromatic hydrocarbon, to the coal-based natural gas is effectively increased, and the economic benefit of the scheme is further improved.

Drawings

Fig. 1 is a schematic diagram of the main structure and process flow of a gas furnace of the method for producing natural gas and co-producing fuel oil and aromatic hydrocarbon by using pressurized moving bed multi-layer hydrogenated coal.

In the figure:

1. a steam oxygen gasifying agent inlet;

2. a cooling water inlet of the jacket shell of the gas furnace;

3. a water gas outlet;

4. a semicoke hydrogenation layer inlet;

4A, an inlet of an upper coke hydrogenation layer;

4B, inlet of lower coke hydrogenation layer

5. A hydrocarbon-rich hydrogen gas outlet;

6. a cooling water outlet of the jacket shell of the gas furnace;

7. feeding dry raw material coal into a furnace;

7A. wet feed coal;

7B, a furnace-entering raw material coal drying device;

8. locking the coal;

9. a coal distributor;

10. drying the layer;

11. a dry distillation layer;

12. a stirrer;

13. a semicoke hydrogenation gasification layer;

14. a semicoke hydrogenation layer;

15. an upper coke hydrogenation gasification layer;

16. an upper coke hydrogenation layer;

17. the lower coke hydrogenation gasification layer;

17A, a lower coke hydrogenation layer;

18. a manhole;

18A. residual coke accumulation layer;

18B, a discharging structure;

19. a gas collection zone;

20. a water gas reaction layer;

21. an oxidizing combustion layer;

22. a layer of ash;

23. a pressure-bearing jacket shell of a gas furnace;

23A, a gas furnace jacket circulating cooling water gas-liquid separator, namely a jacket steam drum;

jacket steam and piping;

24. locking with ash;

25. slag;

26. driving steam and pipelines;

27. oxygen for gasification and a pipeline;

a saturation column for stripping water vapor with oxygen (recovery of steam heat in water gas wash water);

28. oxygen saturated with water vapor and piping;

28A, oxygen-enriched steam containing superheated steam and a pipeline;

28b, a water gas dust separator;

29. a steam superheater;

30. a water gas waste heat steam boiler;

31. a water gas washing and gas waste heat recovery device;

32. a water gas CO shift step;

32A, an inorganic gas water treatment process;

33.CO₂、H₂s, acid gas removal process;

combustible tail gas and pipelines with recovery value, which are discharged in the acid gas removal process, and a tail gas combustion boiler are removed;

make-up hydrogen and pipeline, hydrogen used for making up coal hydrogenation reaction and consuming;

33C, hydrogen sulfide and pipeline, Claus sulfur recovery process 33D;

33D. Claus Sulfur recovery Process

34. High concentration of CO₂And a pipeline;

34A. high concentration CO of desaturation column 27A₂And a pipeline for recovering oxygen dissolved in the circulating hot water by gas stripping;

35. a hydrogen header pipe;

35a. hydrogen circulator;

35b. a hydrogen heater;

36. when the vehicle is started, a nitrogen or hydrogen electric heating device is put into the furnace;

36A, furnace hydrogen and a main pipe;

37. a tar dust separator;

38. a hydrocarbon-rich hydrogen gas waste heat recovery process device;

38A, circulating heat conducting liquid and a loop, wherein the heat conducting liquid and the loop are used for transferring the heat of the hydrogen-rich coal gas to a raw coal normal-pressure drying device 7B;

39. a hydrocarbon-rich hydrogen gas cooling and oil-water separation process device;

39A. separated coal tar and water;

40.H₂S、COS、CO、CO₂acid gas, hydrogen and methane separation process units;

40A, circulating hydrogen and pipelines from the separation process device 40 and the dehydrogenation gas main pipe 35;

40B.H₂s, COS and a line leading from the separation process apparatus 40 to the Claus sulfur recovery step 33D;

40C.CO、CO₂and a line from the separation process unit 40 to a combustion engine tail gas boiler 45;

40D, separating the coal-based natural gas methane product separated by the process device 40;

40F, hydrogen and a pipeline from the separation process device 40, and a device 42 for preparing fuel oil aromatic hydrocarbon by coal tar hydrogenation;

40E, coal-made natural gas and pipelines for power of a combustion engine;

41. a coal tar gas water separation device;

41A, coal tar and a pipeline;

41B, organic gas water and a pipeline;

41C. An organic gas water treatment device;

42. preparing fuel aromatic hydrocarbon by coal tar hydrogenation;

42a. fuel products;

42b. aromatic products;

43. a gas turbine unit for converting the heat energy of natural gas into mechanical power;

44. a generator set for converting mechanical power into electric power; and the device is combined with a gas turbine, so that the output ratio of natural gas and electric power can be adjusted, and the benefit maximization of a co-production device is ensured.

45. The gas turbine tail gas boiler is used for producing high-pressure steam by using oxygen and heat rich in gas turbine tail gas and combusting combustible components in process tail gas;

46. a steam turbine;

46A, recycling fuel oil, aromatic hydrocarbon, phenol and ammonia by-products and other steam and pipelines;

47. the deep energy-saving air cooling island is used for condensing the dead steam discharged by the steam turbine into liquid water;

48. the air compressor is used for providing compressed air for oxygen generation;

48A, compressed air and a pipeline for oxygen production;

49. the electric power-assisted air compressor is powered on to ensure output when the power steam is insufficient, and the electric power generator generates power when the power steam is excessive;

50. an oxygen production workshop;

a-a hydrogen gas section;

b-water gas section;

C. -an intermediate gas collection box;

D. -a hydrogen gas section thermocouple insertion port;

E. -a water gas section thermocouple insertion port;

G. and an intersegmental transition section.

Detailed Description

With regard to the gasification furnace: firstly, designing and manufacturing a pressurized gas furnace containing a water gas section and a hydrogen gas section and equipment of each process unit, and then transporting the pressurized gas furnace to an installation site for installation in place, process piping, electrical instrument installation, corrosion prevention and heat preservation, system leakage test, pressure test and debugging qualification, so that the pressurized gas furnace has the structure and the function required by design.

Then, sequentially paving 300mm thick gas furnace ash residues on a grate of the water gas section, wherein the required granularity of a water vapor gasification layer is 20-80 mm, and the coke thickness is 2000 mm; adding coke with the granularity of 20-80 mm and the thickness of 3000mm into a coke hydrogenation gasification layer of a hydrogen gas section (A), adding semicoke with the thickness of 3000mm into a semicoke hydrogenation gasification layer, adding weakly caking coal or non-caking coal with the granularity of 20-80 mm and the thickness of 2000mm into a dry distillation layer, and adding weakly caking coal or non-caking coal with the granularity of 20-80 mm and the thickness of 1000mm into a dry layer.

Firstly, air is used at a rate of 5000-10000 Nm/hour³The flow rate of the gas is sent into the furnace at the temperature rise rate of 50 ℃/h, and the gas is discharged from a hydrocarbon-rich hydrogen gas outlet; about 6 hours, because the ignition point of coke is about 350 ℃, the phenomenon that the temperature of an oxygen combustion layer in the water gas section exceeds the temperature of air entering a furnace begins to occur, and when the temperature of the oxygen combustion layer rapidly rises to about 700 ℃, the air is discharged after a water gas outlet pipe in the water gas section; can add a proper amount of nitrogen into the air entering the furnace to reduce the O content₂And (3) controlling the temperature rise rate of the oxygen combustion layer to be about 100 ℃/h, gradually changing the temperature rise of air into an oxygen-water vapor mixed gasifying agent after the temperature of the oxygen combustion layer reaches 900-1000 ℃, and controlling the temperature not to rise any more so as to prevent the water gas section from being over-temperature scabbed.

Secondly, adding hot nitrogen which has the same temperature with the flue gas at the water gas outlet into the hydrogen gas section (A) through a hydrogen inlet of the hydrogen gas section at the flow rate of 3/h of 5000-10000 Nm per hour, and emptying the hot nitrogen at a hydrogen gas outlet to further heat coke, semicoke and raw material coal of the hydrogen gas section, wherein a proper amount of air can be supplemented into the hot nitrogen (actually, oxygen is supplemented, the highest temperature of a coke hydrogenation gasification layer and a semicoke hydrogenation gasification layer is not more than 900 ℃), so that the heating rate is accelerated by utilizing the combustion heat of the oxygen and the coke;

when the temperature of the dry distillation layer of the hydrogen gas section is higher than 400 ℃, the stirrer can be started to run at a low speed in real time, and the coal feeding device starts the automatic control loop so as to automatically feed raw material coal in due time.

Fourthly, when the highest temperature of a coke hydrogenation gasification layer and a semicoke hydrogenation gasification layer reaches 600 degrees centigrade, starting system pressure boosting at the rate of 1MPa per hour, and paying attention to the pressure boosting process as much as possible: the pressure difference between the water gas outlet and the hydrogen inlet is reduced to be close to zero, so that the gas in the hydrogen gas section is prevented from descending into the water gas collector and flowing out of the water gas outlet.

And fifthly, when the pressure is increased to 2MPa, turning off the oxygen in the hot nitrogen for 30 minutes, or turning off the oxygen, and after the temperature of a hot spot is reduced to 100 ℃, changing the hot nitrogen into the furnace into hot hydrogen into the furnace at the flow rate of 5000-10000 Nm3/h, so that the hydrogen gas section is switched into a process for preparing the hydrogen-rich hydrocarbon gas, and the hydrogen gas section is gradually increased at the rate of 1MPa per hour, and finally the pressure is stabilized at the process specified pressure.

Controlling the furnace temperature:

controlling the temperature of an oxygen combustion layer of the water gas section to be 30-80 ℃ below an ash melting point through the steam-oxygen ratio in the furnace; the hydrogen gas section controls the highest temperature of the semicoke hydrogenation section to be less than or equal to the ash melting point T by controlling the hydrogen temperature and the methane content in the hydrogen₂(ii) temperature;

controlling the components of the hydrocarbon-rich hydrogen gas: the content of methane in the hydrocarbon-rich hydrogen gas is finally controlled to be 30-60% and the content of the methane in the hydrocarbon-rich hydrogen gas is finally controlled to be 50-300 g/Nm/coal tar by controlling the flow rate, the temperature and the content of the methane in the hydrogen gas entering the furnace according to the activity and the volatile components of the coal³And regulating the yield of coal tar, namely fuel oil and natural gas.

With respect to hydrocarbon-rich hydrogen gas heat recovery, purification, separation and oxygen-free olefin production:

because the water vapor contained in the hydrogen-rich coal gas comes from the raw material coal, namely the moisture content of the coal as fired is a key determining factor of the temperature of the hydrogen-rich coal gas discharged from the furnace and is also a key factor of the amount of the coal gas wastewater, the raw material coal normal pressure drying device 7B is additionally arranged before the raw material coal enters the gasification furnace, and the heat in the hydrogen-rich coal gas is transferred to a heat source for drying the raw material coal by utilizing the circulating heat-conducting liquid and the loop 38A so as to reduce the moisture in the raw material coal and effectively reduce the organic wastewater of the coal gas.

As the water vapor in the hydrocarbon-rich hydrogen gas is greatly reduced, the residual heat is also greatly reduced, and the equipment cost is also reduced.

Due to CO in the hydrocarbon-rich hydrogen gas、CO₂The content is low, after cooling and oil-water separation, different separation processes are designed according to the use of methane: if the methane is mainly used as Liquefied Natural Gas (LNG), cryogenic separation is adopted to extract hydrogen, and if the methane is mainly used as a process for preparing olefin by using methane without oxygen, a Pressure Swing Adsorption (PSA) process is adopted to extract hydrogen so as to greatly reduce the process energy consumption; if the methane is mainly sold by a pipeline, other separation processes can be adopted to reduce the separation cost.

The method comprises the following steps of water gas waste heat recovery, purification and separation and hydrogen production:

because the raw material coal of the water gas is all the residual coke of hydro-gasification, the coal gas has no tar, less methane content and about 700 ℃ temperature, the water gas discharged from the furnace can be removed by a common dry cyclone dust collector to obtain more than 98 percent of dust, then the dust is cooled by a hydrogen heater and a steam superheater to 200-300 ℃, the dust enters a waste heat steam boiler, the heat is converted into process steam heat energy, the temperature is reduced to about 250 ℃, the dust enters a water gas washing and waste heat recovery device adopting the 2011100943882 patent technology, the excess water steam in the water gas is converted into the water steam in the gasification agent entering the furnace, the excess water steam content in the coal gas is too high, the over-temperature inactivation of a CO conversion catalyst is caused, the excess water steam in the coal gas is converted into the water steam which can enter the furnace again, the CO conversion catalyst is protected, the gasification water steam is obtained, and the discharge amount of the coal.

The final purpose of the water gas production is to produce hydrogen for preparing fuel oil aromatic hydrocarbon by hydrogenation coal gasification and coal tar hydrogenation. CO conversion in water gas, wherein water vapor in the water gas is utilized, deep conversion with the change rate of more than 95% is adopted to obtain hydrogen as much as possible, the converted gas is called conversion gas, and the component of the conversion gas is mainly H₂And CO₂Because the PSA system is decarbonized by a dry method through pressure swing adsorption, the process is simple, the energy consumption is low, the automation degree is high, the hydrogen yield can reach 98 percent, and the separated CO is₂Wherein the composition contains small amount of CO and CH₄The combustible materials should be recycled, and the heat quantity is more than 400kJ/Nm³CO of₂The steam is sent to a gas turbine tail gas boiler to produce steam, the best use of the materials is realized, and the separated hydrogen is used as the hydrogenHydrogen rich hydrogen gas is fed into the hydrogen main pipe.

Regarding the yield of the aromatic hydrocarbon of the fuel oil prepared by coal tar hydrogenation:

hydrogen consumption per ton of oil is about 800Nm³When the yield ratio of the aromatic hydrocarbon/natural gas of the fuel oil is 400kg/1000m³In the process, the volume ratio of hydrogen consumption is 320/2000-16%, namely the hydrogen required by the hydrogenation of coal tar to prepare the fuel aromatic only accounts for 1/7.25-14% of the total hydrogen consumption;

if better economic benefit is expected, the yield ratio of oil gas (natural gas/fuel oil aromatic hydrocarbon) needs to be changed, and the method can be realized by changing the outlet temperature of the gasification furnace, the components and the flow of a hydrogen gasification agent entering the gasification furnace, the process pressure of the gasification furnace, the coal feeding rate, the flow ratio of hydrogen and oxygen-enriched water vapor and the type of raw material coal. The method adopts the aged anthracite, does not produce coal tar, can produce natural gas completely, adopts low-rank lignite rich in coal tar, and can ensure that the yield of the coal tar reaches 600kg/km by adding other process operations favorable for increasing the yield of the coal tar³SNG (SNG-synthetic natural gas).