An integrated process of coke-oven gas trireforming and coal to methanol with high carbon utilization and energy efficiency

The hydrogen to carbon (H/C) ratio of coal gasified gas ranges of 0.2-1.0, far less than the desired value for the coal to methanol process. Therefore, a water gas shift (WGS) unit is needed to raise the H/C ratio, which results in a great deal of CO2 emission and carbon resource waste. On the other side, in the coking process, massive coke-oven gas (COG) is not been fully used, with a high H/C ratio at 6.5, consisting of 60% hydrogen and 26% methane. Proposed in this paper is an integrated process of coke-oven gas and coal gasification to methanol, in which a tri-reforming reaction is used to convert methane and carbon dioxide to syngas. The carbon utilization efficiency of the new process increases to 65% from 40% of the current coal to methanol process, while the carbon dioxide emission declines by 44%.