Integrated process for synthetic natural gas production from coal and coke-oven gas with high energy efficiency and low emission

There was a rapid development of coal to synthetic natural gas (SNG) projects in the last few years in China. The research from our previous work and some other researchers have found coal based SNG production process has the problems of environmental pollution and emission transfer, including CO2 emission, effluent discharge, and high energy consumption. This paper proposes a novel co-feed process of coal and coke-oven gas to SNG process by using a dry methane reforming unit to reduce CO2 emissions, more hydrogen elements are introduced to improve resource efficiency. It is shown that the energy efficiency of the co-feed process increases by 4%, CO2 emission and effluent discharge is reduced by 60% and 72%, whereas the production cost decreases by 16.7%, in comparison to the conventional coal to SNG process. As coke-oven gas is a waste gas in most of the coking plant, this process also allows to optimize the allocation of resources.