Hemicellulose hydrolysis and hydrolytic hydrogenation over proton- and metal modified beta zeolites

The hydrolytic hydrogenation of hemicellulose arabinogalactan using different beta zeolites as catalysts was studied in this work. The use of bifunctional Ru/beta zeolite catalysts leads to formation of valuable polyols (galactitol, arabitol) from hemicellulose. The presence of acid sites enhances hydrolysis of the hemicelluloses into sugars in addition to homogeneous hydrolysis while the Ru catalyzes further hydrogenation into polyols. Using bifunctional catalysts the stability of these polyols can be also enhanced because the side reactions to HMF and furfural were minimized, however formation of high molecular weight compounds (aggregates of sugars and humins) was still quite substantial.