Development of a Novel Ultrasound Assisted Hydrothermal Pretreatment Strategy for the Production of Bioethanol from Chili Post-Harvest Residue

Abstract

A novel ultrasound assisted hydrothermal pretreatment strategy was evaluated for the production of bioethanol from chili post-harvest residue. Various process parameters affecting pretreatment were optimized by adoptin a Taguchi design. The optimum conditions of pretreatment were sonication time for 10 min, biomass loading of 25% w/w and pretreatment time for 45 min. Under optimized conditions 0. 436 g of reducing sugar per g of dry biomass (g/g) was observed. The hydrolyzate is devoid of major fermentation inhibitors like furfural, 5-hydroxymethylfurfural and organic acids like citric acid, propionic acid, succinic acid and formic acid. Fermentation of the non-detoxified hydrolyzate yielded 1.84% of ethanol. To the best of our knowledge this is the first report on ultrasound assisted hydrothermal pretreatment of chili post-harvest residue. The main highlight of this strategy of pretreatment is that the pretreated biomass can be directly used for hydrolysis without any neutralization, washing and drying.