Utilization of lignocellulosic waste for ethanol production:udEnzymatic digestibility and fermentation of pretreated shea tree sawdust

摘要

Enzymatic hydrolysis and fermentation methods were evaluated on alkaline peroxide pretreated shea treeudsawdust conversion to ethanol. Optimum pretreatment conditions of 120 oC reaction temperature, 30 min reaction time,udand 20 mL L−1 of water hydrogen peroxide concentration (1%(v/v)H2O2) solubilized 679 g kg−1 of hemicellulose andud172 g kg−1 of lignin. 617 g kg−1 cellulose was retained in the solid fraction. The maximum yield of reducing sugar withudoptimized enzyme loadings by two enzyme preparations (cellulase and β-glucosidase) was 165 g kg−1 of dry biomass.udThe ethanol yield was 7.35 g L−1 after 72 h incubation period under the following conditions: 2% cellulose loading,udenzyme concentration was 25 FPU (g cellulose)−1 loading, yeast inoculums was 10% (v/v), 32 oC, and pH 4.8. Theudpretreatments gave information about the hindrances caused by lignin presence in lignocellulosic materials and thatudhemicelluloses are better hydrolyzed than lignin, thereby enhancing enzymatic digestibility of the sawdust material