Abstract

                                Pearl millet biomass represents an unused source for biofuel production. Bioconversion of pearl millet biomass to ethanol is significantly hindered by the structural complexity of the biomass. Pretreatment is required to prepare the pearl millet biomass for enzymatic hydrolysis. The efficiency of combination of chemical (acid, alkaline hydro- gen peroxide and lime) with hydrothermal pretreatment on pearl millet was investigated in the present study. Combination of acid with hydrothermal pretreated hydrolysate (160ËšC – 10 min, 12.5 % - TS) showed maximum recovery of fermentable sugars 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 remov- al of the hemicellulose and lignin for maximum recovery of fermentable sugars. At elevated temperature, lignin particles migrate from inner side of the biomass to outer surface of the biomass. The effect of pretreatment on the pearl millet biomass was characterized by SEM.

Key words : structural complexity, Lime + hydrothermal pretreatment, Enzymatic hydrolysis