Thermodynamic equilibrium calculations for the reforming of coke oven gas with gasification gas

Thermodynamic analyses of the reforming of coke oven gas with gasification gas for syngas were investigated as a function of coke oven gas-to-gasification gas ratio (1-3), oxygen-to-methane ratio (0-1.56), pressure (25-35 bar) and temperature (700-1100 degrees C). Thermodynamic equilibrium results indicate that the operating temperature should be approximately 1100 degrees C and the oxygen-to-methane ratio should be approximately 0.39, where about 80% CH4 and CO2 can be converted at 30 bar. Increasing the operating pressure shifts the equilibrium toward the reactants (CH4 and CO2); increasing the pressure from 25 to 35 bar decreases the conversion of CO2 from 73.7 % to 67.8 %. The conversion ratio of CO2 is less than that in the absence of O-2. For a constant feed gas composition (7 % O-2, 31 % gasification gas, and 62 % coke oven gas), a H-2/CO ratio of about 2 occurs at temperatures of 950 degrees C and above. Pressure effects on the H-2/ CO ratio are negligible for temperatures greater than 750 degrees C. The steam produced has an effect on the hydrogen selectivity, but its mole fraction decreases with temperature; trace amounts of other secondary products are observed.