Nickel catalyst supported on mayenite/CaO for the catalytic steam reforming of a tar model compound

Abstract

In this work, a Ni-mayenite/CaO catalyst was synthetized, characterized and tested as a tar reforming catalyst for a gas with a composition typical of a biomass gasification process under lower temperature conditions than commercial reforming catalysts. Moreover, a reduced Ni content of 5 wt% was used and different operating variables (temperature, steam excess and presence of H₂, CO₂, CO and CH₄) were studied. It was confirmed that regardless the variations in the composition of the gas entering the reforming reactor, the conversion of toluene (used as tar model compound) was complete at 700 ºC and high space velocities (ca. 90000 h⁻¹ with respect to total gas and ca. 5 kg_toluene/kg_{reduced cat}·h) with minimal coke deposition. In addition, reaction-regeneration cycles were conducted under different regeneration temperatures and gas mixtures for the removal of the deposited solid carbon. Finally, the catalytic activity of this novel catalyst was tested against several commercial catalysts at 700 ºC, demonstrating the superior performance of the 5 % Ni-mayenite/CaO compared to any of the Ni-based commercial catalysts studied.