Abstract

                               Due to the depletion of the world petroleum energy reserves and the increased public concern about global warming are strongly attracting worldwide interest in alternative fuels. Bioconversion of pearl millet biomass to ethanol is significantly hindered by the structural complexity of the biomass. Pretreatment is required to prepare pearl millet biomass for enzymatic hydrolysis. The efficiency of combination of chemicals (acid, alkaline H2O2 and lime) with hydrothermal pretreatment on pearl millet was investigated in the present study. Combination of acid with hydrothermal pretreated hydrolysate (160ºC -10 min) showed maximum recovery of fermentable sugar (41.78±0.64 g /100 g of biomass) even though, lime + hydrothermal pretreated biomass were found to be effective in the enzymatic hydrolysis rate. The main aim of the pretreatment is to remove hemicellulose and lignin for maximum recovery of fermentable sugars. At elevated temperature, lignin particles migrated from inner to outer surface of the biomass. The effect of pretreatment on the pearl millet biomass was characterized by SEM.

Key words : Thermal treatment, Lignocellulosics, Biofuel