INTEGRATED KRAFT PROCESSING AND ENZYMATIC HYDROLYSIS OF RESIDUAL FOREST BIOMASS: DEVELOPING A SUGAR PLATFORM FOR THE PULP INDUSTRY

摘要

The present work envisages the implementation of forest-based biorefineries coupled to pulp and paperrnproduction, in order to maximize the economic and environmental performance of this industry. By-products andrnwaste streams from wood processing and forest exploitation should thus be valorised. The high polysacchariderncontent of these lignocellulosic residues makes them attractive to be upgraded through biochemical conversionrnprocesses, as a sugar platform for the production of fuels, chemicals and materials. This study, focused on thernPortuguese pulp and paper industry, targeted the production of sugars solutions from eucalyptus residues generated inrnpulp manufacturing – fines (wood shaving rejects), branches and bark – coupled to some fast-growing native forestrnspecies – acacia, giant reed, willow and miscanthus. Taking advantage of the pulp and paper industrial know-how andrnequipment, kraft pulping was applied as an alkaline pretreatment prior to enzymatic hydrolysis.This strategy was veryrneffective for the direct conversion of the lignocellulosic materials tested (except eucalyptus bark) into concentratedrnsugar solutions (> 100 g/L).Enzymatic hydrolysis of fines kraft pulp achieved 95%-yield of glucan conversion.rnTheintegrated process provided 504 kg of monosaccharides per metric tonne (dry basis) of eucalyptus fines, whilernwith the remaining materials 371-467 kg of monosaccharides per metric tonne of biomass was achieved.