Ethanol production from steam pretreated sugarcane bagasse via simultaneous saccharification and fermentation (SSF) using cellulase and b.glucosidase enzymes

Cellulosic ethanol was produced via simultaneous enzymatic hydrolysis and fermentation of steam pretreated sugarcane bagasse. Sugarcane bagasse underwent steam pretreatments at Log Ro 3.05-4.09, under catalysed (SO2 2% and H2SO4 0.25%) and uncatalysed conditions. Digestibilities of the steam pretreated bagasse were assessed via enzymatic hydrolysis using cellulase (Celluclast 1.5L) and B-glucosidase (Novozym 188) enzyme formulations at 2% WIS, 40 ºC, pH 4.8, 72h under continuous stirring (200 rpm). SO2-catalysed steam pretreated bagasses produced at moderate severities (180 or 190 ºC, 5 minutes) presented digestibilities up to 82%. Hemicellulose removal influenced pretreatment efficiency rather than delignification. SO2-steam pretreated bagasses were processed by SSF (simultaneous saccharification and fermentation) at 5% WIS loading. Yields of 0.40-0.41 g ethanol/g glucose (approx. 80% of the theoretical) and high selectivity through ethyl alcohol were obtained for all investigated conditions, leading to a potential production of 230 L ethanol/ ton dry bagasse.