Thermodynamic characteristics of reactants and energy conversion in steam reforming of calcium carbide furnace off-gas to produce hydrogen

•Built chemical equilibrium model for furnace gas steam reforming.•Revealed characteristics of conversion ratio and yield, especially reaction heat.•Given the highest H2/CO mole ratio in equilibrium system.•Developed a method to determine appropriate conditions for H2 production process.

In this study, to reveal the thermodynamic reaction mechanism and the conversion characteristics of material and energy for the steam reforming of multi-component materials, a chemical equilibrium model was constructed, and the reaction mechanism of the steam reforming of calcium carbide furnace off-gas (CCFG) was also identified. The conversion characteristics of material and energy were ascertained by assessing four independent reactions and their reverse reactions. And the effects of temperature, pressure and steam-to-gas ratio on the conversion ratios of CO and CH4, the yield of H2 and the reaction heat were investigated. In addition, a method for determining the process parameters of steam reforming based on the follow-up utilization scheme of CCFG was proposed; the method involves using a four-panel diagram that plots parameters of the steam reforming process. Thus, the range of H2/CO mole ratio that could be obtained from the equilibrium system of steam reforming of CCFG was determined.