Pretreatment of lignocellulosic wastes for biofuel production: A critical review

Protection of environment is of immediate concern and this can only be achieved by avoiding the use of chemicals for fuel production. Lignocellulosic waste is becoming popular as a feedstock for biofuel production. The can be converted into usable form for biofuel production by using a suitable pretreatment method. Different pretreatment methods have been used by researchers which are physical, chemical, physico-chemical, biological and combined pretreatments. Evidently chemical pretreatment is found to be more expensive as a large amount of chemicals are used for pretreating the lignocellulosic substrate. It has been shown that combined pretreatments are more effective as compared to single pretreatment and there is an extensive scope of combinations which can also be applied in future. Recent review critically discusses and compares different pretreatment methods, biomass resources, chemical composition of different agricultural biomass and the use of this biomass for bioenergy generation. Various pretreatment processes used for bio-hydrogen, bio-methane, bio-ethanol, bio-methanol bio-butanol and bio-diesel production are also discussed.