The effect of CO2 feeding on syngas quality in autothermal reforming of methane over Ni-Al2O3 catalyst: possibility of CO2 conversion to hydrogen

The main object of this research is the development of a mathematical framework to investigate the effect of CO2 feeding on the quality of produced syngas in an industrial autothermal reforming over Ni-Al2O3 catalyst. The considered reformer is consist of two main parts including the combustion and catalytic sections aligned in a series structure. The combustion chamber as a perfectly mixed reactor is simulated by the CHEMKIN package considering different detailed kinetic mechanisms including DRM 22, GRI 1.2, and GRI 3.0. The tabular catalytic reactor is heterogeneously modeled based on the mass and energy balance equations considering heat and mass transfer resistances in the gas and catalyst phases. The accuracy of developed model and considered thermal mechanisms are compared to plant data. After selection of an accurate thermal kinetic model, the effect of CO2 injection on the conversion of CH4 and CO2 and the quality of produced syngas are investigated at steady state conditions. Based on the simulation results, increasing the CO2 to CH4 molar ratio in the range of 0.2–2.0 could increase the CO2 conversion in the applied reformer up 30.83%.