Supercritical Methanol Depolymerization and Hydrodeoxygenation of Maple Wood and Biomass-Derived Oxygenates into Renewable Alcohols in a Continuous Flow Reactor

Supercritical methanol depolymerization and hydrodeoxygenation (SCM-DHDO) of biomass is a technology to produce C-2-C-9 alcohols in a single reaction step. Previous research has shown that this technology is effective in batch reactors but produces large amounts of undesired CO and H-2 gas from the reforming of the methanol that make the process economically infeasible. In this work, we show that methanol reforming can be minimized to provide the stoichiometric amount of H-2 required for hydrodeoxygenation by recycling the product gases. We also show that methanol can be synthesized during the SCM-DHDO process with a sufficient cofeed of CO and H-2. In addition, we demonstrate that the catalyst is stable for more than 100 h time on stream in a continuous packed bed reactor using glycerol as a model feedstock. The alcohol yields from glycerol in the fixed bed exceeded yields from batch reactions. In a single pass system, the conversion of cellulose and maple wood to alcohols was obtained by first solubilizing in methanol and then converting to monoalcohols over a fixed bed of catalyst.