A review of the production technologies of bioethanol, an eco-friendly automotive fuel, from non-edible and renewable lignocellulosic bioresources and agricultural wastes is presented, based on the recently developed patents and research works. The different technologies such as ammonia fibre/freeze explosion, organosolv process, ozonolysis, acid and/or enzymatic hydrolysis, simultaneous or separate saccharification and fermentation along with consolidated bioprocessing are described along with the major research trends to optimize their efficiencies of producing fuel ethanol from lignocellulosic biomass. Biological, thermo-chemical and enzymatic engineering aspects will be critically reviewed regarding the lignocellulosic biomaterials conversion into renewable and pollution-free fuel, bioethanol.
Keywords: Bioethanol, biomass, agricultural wastes, pretreatment, hydrolysis, saccharification, fermentation.