OP-II-3

PP-III-36KINETICS OF HEMICELLULOSES HYDROLYSISBright T. Kusema 1 , Gerd Hilpmann 1 , Tea Tönnov 1 , Päivi Mäki-Arvela 1 ,Stefan Willför 2 , Tapio Salmi 1 , Dmitry Yu. Murzin 11 Laboratory of Industrial Chemistry and Reaction Engineering2 Laboratory of Wood and Paper ChemistryProcess Chemistry Centre, Åbo Akademi University, FI-20500 Åbo/Turku, FinlandE-mail: bright.kusema@abo.fiPolysaccharides derived from various renewable sources have drawn greatinterest nowadays. The interest is generated by their features such as the ability toproduce biodegradable and biocompatible new products as well as value-addedchemicals. Arabinogalactans (AG) and galactoglucomanans (GGM) are hemicelluseswhich are found in large quantities in most softwood species and they account for 15-25 weight % of the dry wood material. The structural basis of AG is a backbone of β-galactopyranosyl residues that are predominantly (1→3) – linked and most frequentlybranched with D-galactopyranosyl, L-arabinofuranosyl and D-glucuronic acid sidechains. The average ratio of galactose, arabinose and glucuronic acid in the AG isabout 5:1:0.08. GGM consists of a linear backbone of randomly distributed (1→4)-linked β-D-mannospyranosyl and (1→4)-linked β-D-glucopyranosyl units, with (1→6)-linked α-galactopyranosyl and β-D-galactopyranosyl units as single unit side units.The average ratio of galactose, glucose and mannose in GGM is about 0.5:1:4. Themolar mass of AG and GGM is 20 000 – 100 000 g/mol. Extraction of thehemicelluloses can easily be carried out with water at moderate temperetures. GGMcan be recovered in industrial scale from process waters in mechanical pulp mills.Therefore AG and GGM has a great potential to serve as a sustainable feedstock forvaluable chemicals [1, 2, 3]The focus of this research is to convert AG and GGM into valuable productsthrough a sugar platform which includes two processes: hydrolysis of thehemicellulose to monomers and catalytic transformation of the monomers into biobasedvaluable products. The topic is timely as hydrolysis of plant-derivedpolysaccharides to platform sugars in good yields is an increasingly important issue.AG and GGM have direct medical applications as health products. In foods, they areused as stabilizer, emulsifier, binder and sweetner. The monomers have applicationsas specialty sugars in the food, pharmaceutical and cosmetic industries [4, 5].506