Method for purifying and liquefying coalbed gas
Technical field: The invention relates to the goaf, the mining purifying the exhausted oxygen-containing mixed gas, a the liquefication uses method for purifying and liquefying coalbed gas. Background technology: The current domestic oxygen-containing coal bed gas research start purifying and liquefying, 2007 years 7 month, Beijing in favour of International investment Company limited and mining industries limited liability Company group yangquan in Shanxi yangquan jiancheng 1st seat device for purifying and liquefying oxygen-containing coal bed gas, the daily processing capacity of the device to 5000 cubic meters, the process flow comprises: supercharging-decarburization, sulfur-anhydro-liquefied denitrification, deoxy-storage and transportation. The existing process for purifying and liquefying oxygen-containing coal bed gas flow is first pressurized and then deoxy, the problem of this kind of method is not safe, the treatment of raw coal seam on small production capacity, cannot meet the production needs. Utility model content: The purpose of this invention is to provide a method for purifying and liquefying of coal-bed methane, the method solves the problems in the prior art that the deoxidization after pressure boosting is not safe, the treatment of raw coal seam on small production capacity, cannot meet the production requirements. The invention for solving the technical problems, the invention adopts the technical scheme is:a method for purifying and liquefying coalbed gas, the method is to solve the safety problem of mixed coal bed gas compressor: the oxygen, nitrogen, carbon dioxide is safe separation. The concentration of the mixed gas is from 30% to 95% or more, of the gas quality, means and methods for the expansion of the mixed gas, the method of the present invention is characterized in: the booster pre-deoxidation, the safety of the supercharging is ensured; deoxy the catalytic process bears the sulfur , with bears the sulfur , save the desulfurizing link costs, its running cost in coke method than 20% ; the mature MEA+MDEA decarbonization process, using solid desiccant adsorption and the physical adsorption, the adsorption material 4A molecular sieve; the mixed refrigeration process and: because of raw materials in the coal N2 content is very high, the denitrification tower design is added, the coal by falling-film separation principle of removing N2, in order to guarantee the product LCBM has relatively high calorific value; enhancing the daily processing capacity, a capacity of the conventional natural gas LNG. Method for purifying and liquefying of coal-bed methane is realized through the following process: the raw material coal bed gas-deoxy-boost-decarburization-anhydro-denitrification-storage and transportation. Deoxy: bears the sulfur catalytic deoxidation process in coal bed gas of raw materials is 70Kpa part of the gas under the deoxidizing gas in mixed, after preheating by the preheater into the reactor, in the 500-700 the [...] temperature range [...] , methane and oxygen reaction generated in the catalyst bed layer CO2 and H2 O; escapes the oxygen into the preheater temperature of the reaction raw material gas after heat transfer, steam generated by the waste-heat boiler heat recovery, a gas cabinet after cooling; supercharging: after being first enters minute fluid pot the coal the coal, the conveying process from the liquid that is produced in removing the coal; to filter the particle size greater than 5 microns of removing the liquid and the solid, in order to avoid liquid into the supercharger, the supercharger causing damage; the coal after filtering entering the supercharger compresses 1.05 MPa, and then through a cooler cooling to 35 the decarbonization into the [...] ; decarburization: adopts the mature MEA +MDEA (ethanolamine) (methyl diethanolamine) decarbonization process flow, coal-bed methane is filtered, compressed after the 35 [...] , 1.05 MPa entering CO2absorption tower tower bottom , entering at the top of the absorption tower of the countercurrent contact MEA solution, in order to absorb in the coal-bed methane CO2; of gas from the absorption tower enter the top of the tower from the filter, will be greater than the 5 micron liquid removing, then it enters the dehydration; rich amine solution from the absorption tower the bottom of the tower, the heating heat exchanger after throttling the rich and poor, enters the amine a regeneration tower; amine actifier column the top of the tower to the cooler cools the gas phase by the 60-70 the [...][...] , the separated gas inlet emptying system, liquid reflux all returns amine a regeneration tower, from the amine amine actifier column the regenerated tower bottom heater heating, vapor to return to a regeneration tower; liquid phase passes through the rich amine first / poor amine heat exchanger cooling the booster pump poor amine ; entering the absorbing tower, begin a new cycle; dehydration: in using solid desiccant adsorption of the physical adsorption, the adsorption material 4A molecular sieve, adsorption temperature of the 35 [...] , pressure 1.0 MPa, time 8 hours; regeneration temperature the 300 [...] , pressure 1.05 MPa, time 5.5 hours; cold-blow time 2.5 hours; denitrification: using mixed refrigeration process, it is used in multi-component mixture to be condensed, condensing the characteristics of the light components, they are sequentially condensed, throttle; evaporation obtain different temperature level cold, corresponding to the natural gas in all the components of the final condensing and liquefied; the refrigerant mainly comprises two: one is by N2, C1, C2, C3 mixed refrigerant; the other is an ammonia auxiliary refrigerant, by deoxidizing the raw materials of the gas separating filter, compressed, carbon dioxide removal, dehydration after the 35 [...] , 1.0 MPa respectively through the auxiliary refrigeration, the mixed refrigeration is -154 [...] , 0.896 MPa LCBM of; the -153.8 the throttling step-down obtained [...] , 0.3 MPa LCBM of the product; to ensure that the transport process without gasification LCBM, the product subcooling 0.6 the storage tank into a LCBM [...] ; storage and transportation: according to the stored pressure of the product LNG storage mode can be divided into atmospheric pressure storage and pressure storage, the item product LCBM comprehensive consideration of various conditions of the storage with pressure, mode of transportation tank vehicle. The beneficial results of this invention are: the compression of the security is guaranteed, before cooling the process in the process of separation is, in particular to the compression in the explosion limit of the gas purity; strong processing capacity, the daily handling improved by one order of magnitude, the daily processing capacity is quite conventional natural gas LNG; reduce coal mining process emptying of gas in pollution of the atmosphere, improving the utilization rate of exhaust gas; using old pond can be a large number of development of residual gas, expanding the mixed coal bed gas transport using radius. The Figure illustrates: Figure 1 is the invention in diagram sulfur catalyst catalytic deoxidation process. Figure 2 is the invention in a schematic diagram the mixed refrigeration process. Specific embodiment: In Figure 1 in, a method for purifying and liquefying coalbed gas technique, deoxy: bears the sulfur catalytic deoxidation process in coal bed gas of raw materials is 70Kpa part of the gas under the deoxidizing gas in mixed, after preheating by the preheater into the reactor, in the 500-700 the [...] temperature range [...] , methane and oxygen reaction generated in the catalyst bed layer CO2 and H2 O; escapes the oxygen into the preheater temperature of the reaction raw material gas after heat transfer, steam generated by the waste-heat boiler heat recovery, a gas cabinet after cooling; In Figure 2 the, method for purifying and liquefying of coal-bed methane is realized through the following process: the raw material coal bed gas-deoxy-boost-decarburization-anhydro-denitrification-storage and transportation: in Figure 1, and then after being pressurized; pressurizing: after being first enters minute fluid pot the coal the coal, the conveying process from the liquid that is produced in removing the coal; to filter the particle size greater than 5 microns of removing the liquid and the solid, in order to avoid liquid into the supercharger, the supercharger causing damage; the coal after filtering entering the supercharger compresses 1.05 MPa, and then through a cooler cooling to 35 the decarbonization into the [...] ; decarburization: adopts the mature MEA +MDEA (ethanolamine) (methyl diethanolamine) decarbonization process flow: through filtering of coal-bed methane, compressed after the 35 [...] , 1.05 MPa entering CO2absorption tower tower bottom , entering at the top of the absorption tower of the countercurrent contact MEA solution, in order to absorb in the coal-bed methane CO2; of gas from the absorption tower enter the top of the tower from the filter, will be greater than the 5 micron liquid removing, then it enters the dehydration; rich amine solution from the absorption tower the bottom of the tower, the heat exchanger after throttling after heating the solution, enters the amine a regeneration tower; ammonia regeneration tata to the cooler cools the gas phase by the 60-70 the [...][...] , the separated gas inlet emptying system, liquid reflux all returns amine a regeneration tower, from the amine amine actifier column the regenerated tower bottom heater heating, vapor to return to a regeneration tower; liquid phase passes through the rich amine first / poor amine heat exchanger cooling the booster pump poor amine ; entering the absorbing tower, begin a new cycle; dehydration: in using solid desiccant adsorption of the physical adsorption, the adsorption material 4A molecular sieve, adsorption temperature of the 35 [...] , pressure 1.0 MPa, time 8 hours; regeneration temperature the 300 [...] , pressure 1.05 MPa, time 5.5 hours; cold-blow time 2.5 hours; denitrification: using mixed refrigeration process, it is used in multi-component mixture to be condensed, condensing the characteristics of the light components, they are sequentially condensed, throttle; evaporation obtain different temperature level cold, corresponding to the natural gas in all the components of the final condensing and liquefied; the refrigerant mainly comprises two: one is by N2, C1, C2, C3 mixed refrigerant; the other is an ammonia auxiliary refrigerant, by deoxidizing the raw materials of the gas separating filter, compressed, carbon dioxide removal, dehydration after the 35 [...] , 1.0 MPa respectively through the auxiliary refrigeration, the mixed refrigeration is -154 [...] , 0.896 MPa LCBM of; the -153.8 the throttling step-down obtained [...] , 0.3 MPa LCBM of the product; to ensure that the transport process without gasification LCBM, the product subcooling 0.6 the storage tank into a LCBM [...] ; storage and transportation: according to the stored pressure of the product LNG storage mode can be divided into atmospheric pressure storage and pressure storage, the item product LCBM comprehensive consideration of various conditions of the storage with pressure, mode of transportation tank vehicle. The invention relates to a method for purifying and liquefying coalbed gas, the method is used for purifying and liquefying the exhausted oxygen-containing mixed coalbed gas of worked-out areas and mining areas, and the method is mainly realized through the following process: raw material coalbed gas-deoxidation-pressure boosting-decarburization-dehydration-denitrification-storage and transportation, wherein, the dioxidation is carried out as follows: the sulfur-tolerant catalytic deoxidation process mixes the raw material coalbed gas with part of deoxidizing circulating gas in a gas cabinet at 70KPa, the mixed gas enters a reactor after pre-heating by a pre-heater, methane and oxygen are reacted in a catalyst bed within a certain temperature range to generate CO2 and H2O; then the pressure boosting is carried out, the MEA plus MDEA decarburization process is adopted for decarburization, the physical absorption method is utilized for dehydration, the mixed refrigerant process is adopted for denitrification, and the storage and the transportation are carried out according to the standards. The method solves the problems that the deoxidization after pressure boosting is unsafe and the daily processing capacity of the raw material layer for production is small of the prior art. The method can be widely used for purifying and liquefying the exhausted oxygen-containing mixed coalbed gas of the worked-out areas and the mining areas. 1, a method for purifying and liquefying coalbed gas, which is characterized in that the method is realized through the following process: the raw material coal bed gas-deoxy-boost-decarburization-anhydro-denitrification-storage and transportation: deoxy: bears the sulfur catalytic deoxidation process in coal bed gas of raw materials is 70Kpa part of the gas under the deoxidizing gas in mixed, after preheating by the preheater into the reactor, in the 500-700 the [...] temperature range [...] , methane and oxygen reaction generated in the catalyst bed layer CO2 and H2 O; escapes the oxygen into the preheater temperature of the reaction raw material gas after heat transfer, steam generated by the waste-heat boiler heat recovery, a gas cabinet after cooling; supercharging: after being first enters minute fluid pot the coal the coal, the conveying process from the liquid that is produced in removing the coal; to filter the particle size greater than 5 microns of removing the liquid and the solid, in order to avoid liquid into the supercharger, the supercharger causing damage; the coal after filtering entering the supercharger compresses 1.05 MPa, and then through a cooler cooling to 35 the decarbonization into the [...] ; decarburization: adopts the mature MEA +MDEA (ethanolamine) (methyl diethanolamine) decarbonization process flow: through filtering of coal-bed methane, compressed after the 35 [...] , 1.05 MPa entering CO2absorption tower tower bottom , entering at the top of the absorption tower of the countercurrent contact MEA solution, in order to absorb in the coal-bed methane CO2; of gas from the absorption tower enter the top of the tower from the filter, will be greater than the 5 micron liquid removing, then it enters the dehydration; rich amine solution from the absorption tower the bottom of the tower, the heating heat exchanger after throttling the rich and poor, enters the amine a regeneration tower; ammonia regeneration tata to the cooler cools the gas phase by the 60-70 the [...][...] , the separated gas inlet emptying system, liquid reflux all returns amine a regeneration tower, from the amine amine actifier column the regenerated tower bottom heater heating, vapor to return to a regeneration tower; liquid phase passes through the rich amine first / poor amine heat exchanger cooling the booster pump poor amine ; entering the absorbing tower, begin a new cycle; dehydration: in using solid desiccant adsorption of the physical adsorption, the adsorption material 4A molecular sieve, adsorption temperature of the 35 [...] , pressure 1.0 MPa, time 8 hours; regeneration temperature the 300 [...] , pressure 1.05 MPa, time 5.5 hours; cold-blow time 2.5 hours; denitrification: using mixed refrigeration process, it is used in multi-component mixture to be condensed, condensing the characteristics of the light components, they are sequentially condensed, throttle; evaporation obtain different temperature level cold, corresponding to the natural gas in all the components of the final condensing and liquefied; the refrigerant mainly comprises two: one is by N2, C1, C2, C3 mixed refrigerant; the other is an ammonia auxiliary refrigerant, by deoxidizing the raw materials of the gas separating filter, compressed, carbon dioxide removal, dehydration after the 35 [...] , 1.0 MPa respectively through the auxiliary refrigeration, the mixed refrigeration is -154 [...] , 0.896 MPa LCBM of; the -153.8 the throttling step-down obtained [...] , 0.3 MPa LCBM of the product; to ensure that the transport process without gasification LCBM, the product subcooling 0.6 the storage tank into a LCBM [...] ; storage and transportation: according to the stored pressure of the product LNG storage mode can be divided into atmospheric pressure storage and pressure storage, the item product LCBM comprehensive consideration of various conditions of the storage with pressure, mode of transportation tank vehicle.