Technique for synthesizing natural gas from coke oven gas by sulfur-resistant methanation

Abstract

The invention relates to a technique for synthesizing natural gas from coke oven gas by sulfur-resistant methanation, which comprises the following steps: carrying out oil removal, naphthalene removal, benzene removal and removal of other impurities on the coke oven gas, directly carrying out two-stage methanation reaction on a supported molybdenum-base sulfur-resistant methanation catalyst, carrying out ferric oxide crude desulfurization and activated carbon fine desulfurization, carrying out cleaning reaction by Ni-base methanation reaction, and finally, carrying out cryogenic liquefaction to separate out impurities N2, H2, H2O and a small amount of CO2, thereby obtaining the liquefied natural gas product with the methane content of up to 99%. The technique has the advantages of simple technical process, less equipment investment, and comprehensive energy consumption and high quality of the natural gas product.

Description

technical field [0001] The invention belongs to a process for synthesizing natural gas, in particular to a process for synthesizing natural gas through sulfur-resistant methanation of coke oven gas. Background technique [0002] my country is the world's largest coke producer, consumer and exporter. In 2012, my country's coke output reached 443 million tons, if one ton of coke produced 430m 3 Calculation of coke oven gas, the by-product coke oven gas in that year alone was as high as 190.5 billion m 3 , of which about 70% of the coke oven gas is used for coke oven heating and domestic gas, while the remaining nearly 57 billion m 3 Coke oven gas has not been utilized, resulting in serious waste of resources and environmental pollution. Coal-based natural gas is a high-quality, efficient and safe clean energy. In recent years, with the rapid increase of natural gas demand in my country, the gap between domestic natural gas supply and demand has gradually increased, which i...

AI Technical Summary

Problems solved by technology

In 2012, my country's coke output reached 443 million tons, if one ton of coke produced 430m 3 Calculation of coke oven gas, the by-product coke oven gas in that year alone was as high as 190.5 billion m 3 , of which about 70% of the coke oven gas is used for coke oven heating and domestic gas, while the remaining nearly 57 billion m 3 Coke oven gas has not been utilized, resulting in serious waste of resources and environmental pollution

The sulfur-tolerant methanation catalyst not only has the performance of methanation and organic sulfur hydrogenation, but also has the catalytic performance of water vapor shift and inverse water vapor shift. The water generated by methanation and the H of coke oven gas 2 The reverse water vapor shift reaction inevitably occurs and eventually reaches equilibrium, resulting in CO and CO in the syngas 2 It is difficult to convert completely, which affects the yield of natural gas; the existing sulfur-tolerant methanation catalysts are all multifunctional catalysts for the conversion and methanation of coal gasification synthesis gas. Due to the large difference in composition of coke oven gas and coal gasification synthesis gas, There are many uncertainties

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