Low temperature catalytic co-solvent gasification of biomass for hydrogen rich gas

In this study, 6 different solvents were used as co-solvent in hydrothermal gasification of biomass under subcritical water conditions, and their effects on gasification and hydrogen yields were investigated. At 350 °C, synergistic effects were observed on hydrogen production with NMP and THF co-solvents. The hydrogen yields were 3.5 (±0.1) mol H2/kg feed for NMP, and 3.1 mol H2/kg feed for THF. For both NMP and THF, synergistic increases in total gas volumes and hydrogen yields were higher at increasing concentrations up to 25%. At 25% solvent concentration, 4.1 (±0.2) mol H2/kg feed hydrogen yield was obtained with NMP and 3.5 (±0.2) mol H2/kg feed hydrogen yield was obtained with THF. The hydrogen yield increased up to 25.5 (±0.7) mol H2/kg feed, and 24.0 (±0.1) mol H2/kg feed with NiCl2/CaO and KOH/CaO catalyst combinations with co-solvent NMP. Catalyst combinations were more effective than the single catalysts in hydrogen production.