Towards co-production of composite materials and bioenergy: Effects of enzymatic saccharification on the crystallinity, reactivity, and porosity of woody biomass

The objective of this study is to investigate the effects of different pretreatments and enzymatic saccharification levels on the crystallinity, reactivity, and porosity of solid residuals of woody biomass. Aspen wood flour was pre-treated with three different pretreatment agents, i.e., dilute acid, sodium hydroxide and peracetic acid, followed by different levels of enzymatic saccharification. The functional groups of solid residuals were analyzed using hydroxyl numbers to examine evidence of internal structural and chemical changes of the samples after each treatment in terms of hydroxyl group availability. The porosity and crystallinity of the solids were also evaluated using, respectively, nitrogen adsorption method (BET) and X-ray diffraction. The cell wall surface area, pore size, and pore volume will be determined from the BET method to discern the accessibility of the pre-treated substrates to enzymatic hydrolysis and also of the subsequent saccharification residues to value-adding conversion. X-ray diffractograms of samples subjected to different pretreatment processes and enzymatic hydrolysis levels will be evaluated. Crystallinity index, percent crystallinity, and cellulose crystallite size will be estimated for discussion of the implications to composite co-products to be produced from the saccharification residues.