Steam reforming of tars and light hydrocarbons in TRL-5 gasification-derived syngas over Ni/mayenite–CaO catalysts

Biomass gasification produces hydrogen-rich syngas but also generates tars and chlorine/sulfur contaminants that foul equipment and deactivate catalysts. Because Cl and S are removed at lower temperatures than those required for tar reforming (>800 °C), syngas reheating is usually necessary, leading to additional energy consumption. Lowering the reforming temperature would simplify gas cleaning and improve overall process efficiency. This study investigates a nickel-based catalyst supported on a mayenite/CaO matrix, specifically designed to operate at lower temperatures than conventional reforming catalysts. The catalyst was evaluated under real syngas conditions obtained from sorption-enhanced gasification and O 2 -steam gasification in a TRL-5 gasifier, using olive stones, grape seeds and municipal solid waste as feedstocks. An aliquot of the total syngas stream was treated, enabling assessment under industrially relevant and variable syngas compositions and flow conditions. Among the tested formulations, the catalyst containing 5 wt% Ni achieved near-complete reforming of tars and hydrocarbons at 725 °C, even at a high space velocity of 29,000 h −1 . Operating at this lower temperature significantly reduces the temperature gap with upstream contaminant removal, minimizing reheating requirements and associated thermal duty. Overall, the results demonstrate effective low-temperature reforming, supporting more compact gas-cleaning systems and improved energy efficiency in biomass gasification processes.