Ethanol production from fractionated eucalyptus wood

Abstract

Eucalyptus globulus wood (EGW) is a lignocellulosic material with high cellulose and hemicellulose content, suitable for the simultaneous production of hemicellulosic and cellulosic ethanol. Processing of EGW by autohydrolysis yields a liquid phase rich in hemicellulosic-derived compounds (13.73 kg of xylooligosaccharides/ 100 kg of raw material). The liquid phase was processed by membranes, achieving a concentrated-liquor of 52.9 g of xylooligosaccharides/L. The liquor from membrane processing was hydrolyzed with sulphuric acid, detoxified and fermented. The maximal concentration of ethanol from liquid phase was 19.3 g/L (volumetric productivity Qp=0.19 g/Lh and YP/S=0.38 g/g). The solid phase from autohydrolysis was submitted to delignification organosolv, obtained a solid with 81 kg of cellulose/100 kg of delignified solid. The simultaneous saccharification and fermentation of delignified solid was carried out, achieving 62.7 g/L of ethanol with cellulose to ethanol conversion of 92% (based in a cellulose content of delignified solid).