Hydrolytic hydrogenation of hemicellulose over metal modified mesoporous catalyst

Abstract

The hydrolytic hydrogenation of hemicellulose arabinogalactan, into sugars, sugar alcohols and furfurals was carried out in a batch reactor using modified mesoporous MCM-48 material incorporated with ruthenium metal into the framework. The bi-functional catalytic materials, MCM-48 and Ru–MCM-48 were synthesized, characterized and investigated in the title reaction at total pressure of 20bar hydrogen, using an initial arabinogalactan concentration of 0.4wt%, at 458K. The transformation of the hemicellulose consists of arabinogalactan hydrolysis to the monosaccharides, l-arabinose and d-galactose followed by the subsequent hydrogenation to sugar alcohols, arabitol and galactitol or dehydration of the monomers to furfural and 5-hydroxymethylfurfural. The yields of the main products, i.e. sugars, sugar alcohols and furfurals were varied depending on the strength of the acid sites and the presence of metal in the structure of the ruthenium modified catalyst. Ru–MCM-48 displayed high catalytic activity and the sugar alcohols were obtained selectively from the hemicellulose. The catalytic performance of the mesoporous MCM-48 catalysts with respect to the catalyst structure, acidity and presence of the metal was evaluated.