The invention relates to a method of producing substitute natural gas by methanation of synthesis gas, mainly solving problems, namely large using amount of recycle gas and high energy consumption of compressors, of high-temperature methanation reactions in the prior art. According to the technical scheme adopted by the method, the method comprises: a) a step of providing a high-temperature methanation reaction zone including n-stage series-connected reactors, with the n being not less than 2; b) a step of dividing the synthesis gas raw materials containing H2, CO, CO2 and H2O into n sections and respectively feeding the n sections of the synthesis gas raw materials into inlets of the reactors at all stages in the high-temperature methanation reaction zone, wherein a stream flowing out of an outlet of each of the reactors except the reactor at the final stage enters the inlet of the reactor at the next stage, the stream Vn flowing out from the reactor at the final stage is divided into Vn' and Vn'', and the stream Vn' is condensed and circulated to the inlet of the reactor at the first stage; c) a step of providing a low-temperature methanation reaction zone including m-stage series-connected reactors, with the m being not less than 2; and d) a step of feeding the stream Vn'' into the low-temperature methanation reaction zone, and substitute natural gas is obtained after the reaction. By the technical scheme, the problems are solved well and the method can be used in industrial production of the substitute natural gas from the synthesis gas.

Method of producing substitute natural gas by methanation of synthesis gas

The invention relates to a method of producing substitute natural gas from synthesis gas, mainly solving problems, namely large using amount of recycle gas, high energy consumption of compressors and short service lifetime of catalysts, of high-temperature methanation reactions in the prior art. According to the technical scheme adopted by the method, the method comprises: a) a step of providing a high-temperature methanation reaction zone including n-stage series-connected reactors, wherein the n is not less than 2, each reactor is divided into m sections of catalyst layers and the m is not less than 2; b) a step of dividing the synthesis gas raw materials into n sections and respectively feeding the n sections of the synthesis gas raw materials into inlets of the reactors at all stages in the high-temperature methanation reaction zone, wherein each section of the synthesis gas raw materials that enters a reactor is then divided into m streams and the m streams respectively enter the corresponding catalyst layers; c) a step of allowing a stream flowing out of an outlet of each of the reactors except the reactor at the final stage to enter the first section of catalyst layer in the reactor at the next stage; and d) a step of shunting the stream Vn flowing out from the reactor at the final stage to obtain a part Vn', and circulating the stream Vn' after the Vn' is condensed to the inlet of the reactor at the first stage. By the technical scheme, the problems are solved well and the method can be used in industrial production of substitute natural gas from synthesis gas.

Method of producing substitute natural gas from synthesis gas

The invention belongs to the field of chemical industry and in particular relates to a non-circulating methanation process of coal-based synthetic natural gas and liquefied natural gas. The process comprises the following concrete steps: introducing coal-based synthetic gas subjected to sulfur-tolerant shift and low-temperature methanol elution desulfurization and decarbonization into an ultra-precision purifier; enabling the total sulfur content to be less than 0.02 ppm, the chlorine content to be less than 0.01 ppm and the heavy metal content to be less than 0.01 ppm in the synthetic gas entering the methanation process; dividing the synthetic gas into three, four or five parts; enabling the synthetic gas parts to enter main methanation reactors respectively; enabling all gas at the outlet of the final main methanation reactor to enter auxiliary methanation reactors for continuous methanation reaction in sequence; cooling and dehydrating to obtain the synthetic natural gas (SNG) meeting the requirements, or adding a cryogenic separation liquefication process to obtain the liquefied natural gas (LNG). The process has the advantages of no circulating compressor, low investment, high energy utilization rate and low running expense.

Non-circulating methanation process of coal-based synthetic natural gas and liquefied natural gas

System and method for preparing alternative natural gas

The invention discloses a synthetic natural gas prepared from one-step process coal and a system thereof. The synthetic natural gas is prepared by the following steps: H2S and other impurities are removed from normal-temperature crude coal gas to obtain purified gas; the purified gas is preheated, subjected to removal of sulfur and other impurities, and divided into two streams; the first purified gas stream enters a thermal-insulation methanation reactor to perform methanation reaction; the reaction gas from the thermal-insulation methanation reactor is cooled by a steam superheater, and sent into an isothermal methanation reactor together with the second purified gas stream; the reaction gas from the isothermal methanation reactor is divided into two streams; the first reaction gas stream is cooled, pressurized by a recycle gas compressor, and sent into the thermal-insulation methanation reactor together with the first purified gas stream; and the second reaction gas stream is cooled, subjected to condensate separation by a condensate separator, and sent into a second absorption tower of a low-temperature methanol washer to remove CO2 and water, thereby obtaining the synthetic natural gas. The method has the advantages of simple technique, brief process, and low device operation and investment cost, and can centrally recover heat energy and coproduce high-quality steam.

Synthetic natural gas prepared from one-step process coal and system thereof

The invention discloses a methanation process of synthetic natural gas prepared from coal. Purified and decarbonized synthetic gas prepared from coal is divided into three parts, wherein the first part of the synthetic gas is fed into a first methanation reactor after being mixed with recycle air; gas at the outlet of the first methanation reactor is fed into a second methanation reactor after being mixed with the second part of the synthetic gas; gas at the outlet of the second methanation reactor is fed into a third methanation reactor after being mixed with the third part of the synthetic gas; after the gas is cooled in the third methanation reactor, a part of the gas is fed into a recycle compressor, boosted and used as the recycle gas, and the rest of the gas is sequentially fed into a fourth methanation reactor, a fifth methanation reactor or a sixth methanation reactor to be subjected to methanation; the dry basis content of methane in the gas at the outlet of the final methanation reactor is larger than 95%; and then the synthetic natural gas (SNG) meeting requirements is obtained through cooling, compressing and dehydrating. The methanation process has the advantages of small recycle gas quantity, high energy utilization rates and saved investment.

A methanation process of synthetic natural gas prepared from coal

Methanation technology for preparing non-recycling gas of SNG or LNG from coke-oven gas

Novel methanation reaction process for preparing synthetic natural gas

The invention belongs to the technical field of methanation catalysts and particularly relates to a coal-produced natural gas catalyst for reacting at high temperature conditions and a preparation method of the coal-produced natural gas catalyst. The preparation method comprises the following steps: adding a mixed salt solution of 15.43g/L-39.62g/L of active substances and 14.52g/L-83.15g/L of aid into a constant temperature storage tank 1, and adding heated 8%-12% of K2CO3 into a constant temperature storage tank 2; simultaneously adding reaction liquid in the constant temperature storage tank 1 and the constant temperature storage tank 2 into a strong centrifugal reactor, and controlling relative flow speed so as to maintain the pH in the reactor to be 7.8-8.5; carrying out aging, washing, drying, roasting and forming on precipitates, so as to obtain the coal-produced natural gas catalyst. The coal-produced natural gas catalyst has high strength, good activity, thermal stability, carbon resistance and high temperature resistance and excellent properties such as conversion; the preparation method is simple and the cost is low.

Novel coal-produced natural gas catalyst and preparation method thereof

The invention belongs to the field of chemical engineering and particularly relates to a process of a series quenching adiabatic fixed bed methanation reactor. The process comprises the following steps: (1) dividing synthesis gas passing through an ultra-fine reactor into N paths, enabling divided synthesis gas to enter the upper end of each catalyst bed layer of the reactor; (2) mixing fresh synthesis gas entering a section of catalyst bed layer with water vapor and circulating gas and then enabling the mixed gas to enter a section of bed layer; (3) mixing fresh synthesis gas entering the Mth section of catalyst bed layer with quenched gas coming from the outlet of the (M-1)th section of bed layer, and then enabling the mixed gas to enter the Mth section of catalyst bed layer; (4) pressurizing desalted water with a desalting water pump and then enabling the desalted water to enter the lower end of each bed layer of the reactor, wherein the desalted water can be used for quenching high-temperature gas at the outlet of each bed layer of the reactor.

Wang Chengshuo

Papers

A methanation process of synthetic natural gas prepared from coal

Methanation technology for preparing non-recycling gas of SNG or LNG from coke-oven gas

Novel methanation reaction process for preparing synthetic natural gas

Novel coal-produced natural gas catalyst and preparation method thereof

Series quenching adiabatic fixed bed methanation reactor and process