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

Abstract

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.

Description

technical field [0001] The invention relates to a synthetic natural gas process and system, in particular to a one-step coal-to-synthetic natural gas process and its system. Background technique [0002] As the current smog continues to increase and environmental protection requirements continue to increase, energy conservation, emission reduction, and consumption reduction have become research hotspots in the field of coal chemical industry. As a clean and efficient energy product, natural gas has been paid more and more attention by people. In recent years, the domestic demand for natural gas has been increasing day by day. In order to meet the current domestic demand for natural gas, on the one hand, the government actively imports natural gas from abroad; Conversion, reducing transportation costs. At the same time as a strategic technical reserve to ensure my country's energy security. [0003] The traditional coal-to-natural gas process is to adjust the crude gas pr...

AI Technical Summary

Problems solved by technology

For this process, there are many high-temperature methanation equipment, the heat exchange network is complicated, and the investment cost of the device is relatively high

[0011] Based on this feature, someone proposed to use an isothermal methanation reactor to control a relatively low temperature at the outlet of the reactor by by-product saturated steam, and at the same time connect two low-temperature adiabatic methanation reactors in series. The disadvantage of this process is that it can only By-product saturated steam, the quality of which is poor and cannot be used to drive the turbine

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