Integrated Process of Coke-Oven Gas Tr-Reforming and Coal Gasification to Methanol with High Carbon Utilization and Energy Efficiency

The hydrogen to carbon (H/C) ratio of coal gasified gas in the range 0.2-1.0, far less than the desired value for the coal to methanol process. Therefore, a water gas shift unit is needed to raise the H/C ratio, which results in a great deal of CO2 emission and carbon resource waste. At the same time, there is 7 x 10(10) m(3) coke-oven gas (COG) produced in coke plants annually in China. The hydrogen-rich COG consists of 60% hydrogen and 26% methane. However, a massive amount of COG is utilized as fuel or discharged directly into the air, which makes a waste of precious hydrogen resources and causes serious environmental pollution. This paper proposes an integrated process of coke-oven gas and coal gasification to methanol, in which a tri-reforming reaction is used to convert methane and CO2 to syngas. The carbon utilization and energy efficiency of the new process increase about 25% and 10%, whereas CO2 emission declines by 44% in comparison to the conventional coal to methanol process.