Low-Temperature Catalytic Gasification of Lignin and Cellulose with a Ruthenium Catalyst in Supercritical Water

TLDR

The study aims to evaluate ruthenium‑catalyzed biomass gasification in supercritical water at ~400 °C. The authors used a ruthenium catalyst in supercritical water to gasify lignin and cellulose at ~400 °C. Gasification of lignin and cellulose at 400 °C with ruthenium in supercritical water yielded 30 % and 70 % gas, respectively, mainly CH₄, with no solid product; without water or catalyst, gasification was minimal and produced a brown solid, and formaldehyde decomposed to CH₄, CO₂, and H₂ with ruthenium but to methanol and CO₂ without catalyst.

Abstract

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.