Low-temperature catalytic gasification of lignin and cellulose with a ruthenium catalyst in supercritical water

Lignin and cellulose were gasified at 400 °C with gas yields of 30% and 70%, respectively, in supercritical water with a ruthenium catalyst. In both cases, the main gas product was CH₄ and no solid product was formed. Without water or catalyst, lignin and cellulose were gasified slightly and a brown solid product was formed. The decomposition of formaldehyde was also demonstrated in supercritical water. Formaldehyde was rapidly decomposed to gases such as CH₄, CO₂, and H₂ with ruthenium, whereas formaldehyde was converted into methanol and CO₂ without catalyst. The catalytic conversion of biomass with ruthenium in supercritical water is an efficient method for biomass gasification at temperatures of ∼400 °C.