Integrated biogas dry reforming and steam–iron process for renewable hydrogen production

Abstract

Biogas conversion is a promising route for distributed green hydrogen production, contributing to carbon neutrality by utilizing CH4 and CO2 as feedstocks. This study evaluated the integration of biogas dry reforming with the steam–iron process for hydrogen production. Synthetic biogas mixtures (CH4/CO2 = 1.5 and 1) were tested at 700 and 800 °C. Three 1 wt% Rh catalysts are prepared by Pechini, surfactant-assisted sol–gel, and wet impregnation and evaluated over 20 h Fe2O3 and Ti(5%)/Fe2O3 are used as oxygen carriers in 10 redox cycles, including reduction at 700 °C and steam oxidation at 700, 600, or 500 °C. The impregnated Rh catalyst provides the best balance between activity and carbon deposition. Operating at 800 °C in reforming and 600 °C in oxidation minimizes methane slip and carbon deposition, enabling hydrogen production with very low CO, CO2, and CH4 concentrations.