Thermodynamic Equilibrium Calculations for the Reforming of Coke Oven Gas with Gasification Gas

Abstract

AbstractThermodynamic 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 °C). Thermodynamic equilibrium results indicate that the operating temperature should be approximately 1100 °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 O2. For a constant feed gas composition (7 % O2, 31 % gasification gas, and 62 % coke oven gas), a H2/CO ratio of about 2 occurs at temperatures of 950 °C and above. Pressure effects on the H2/CO ratio are negligible for temperatures greater than 750 °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.