Environmentally friendly technologies for obtaining high sugars concentrations from invasive woody species

Abstract

The efficient utilization and conversion of inexpensive invasive raw materials into bioethanol following a biorefinery approach is a priority in the research field of renewable fuel. With this purpose, Acacia dealbata wood samples were pretreated with 1-ethyl-3-methylimidazolium acetate under optimized conditions, and the resulting solids were employed as a substrate for enzymatic hydrolysis. Enzymatic assays were performed according to a complete factorial experimental design, in which the effects of two independent variables (liquor to solid ratio and enzyme to substrate ratio) on the kinetics and yields of the xylan and cellulose saccharification were assessed. The Response Surface Methodology was employed for optimizing the experimental conditions. High sugar concentrations (around 80 g/L), and favorable polysaccharide conversions (CCG = 79.4% and XnCX = 77.9%). were predicted by the model under the selected operational conditions (6 g liquor/g substrate, 22 FPU/g). The results reported in this work compare well with other studies dealing with either other ionic liquids or classical pretreatments, using the same raw material or other woody substrates.