Monday, May 2, 2011
Grand Ballroom C-D, 2nd fl (Sheraton Seattle)
Fresh green, dried green, and ripe Arundo donax has been tested for the production of ethanol via steam explosion pretreatment, enzymatic hydrolysis and fermentation. The work has been devoted to highlight the influence of the water content within the starting biomass and drying procedure on carbohydrate accessibility by enzymes as potential consequence of the ripeness and fibre hornification. Fresh green Arundo having a dry matter (DM) of 25% was treated as received, oven-dried green and ripe Arundo (DM 80%) have both been humidified to reach a moisture content of 75% before steam explosion at 210 °C for 10 minutes. The exploded biomass has been washed with hot water (65 °C) for the extraction of soluble hemicellulose and potential inhibitors. The insoluble residue has been submitted to enzymatic hydrolysis with a mix of cellulolytic, hemicellulolytic and ß-glucosidase enzymes, then fermented by Saccharomyces c., in a bench scale SHF procedure. The process has been evaluated in terms of sugars recovery and ethanol yield. The drying of fresh biomass has highly depressed the yield of cellulose hydrolysis (68 vs 91%), while is resulted slightly lower (88%) in ripe Arundo. In the latter case, however, the ethanol concentration achieved in the fermentation broth is resulted higher because of higher cellulose content in raw material. As whole, 131 g, 103 g and 162 g of ethanol have been obtained from the glucan content of 1 kgDM of fresh green, dried green, and ripe Arundo respectively.