Lignocellulosic biofuel production: review of alternatives

Abstract

Global environmental protection is of immediate concern that can only be achieved by avoiding the use of fossil fuels and tailpipe emissions. In addition, investment on waste disposal is not economical; however, recycling of the same waste for renewable energy production is favorable in the economic and social development of the society in an eco-friendly manner. Utilization of biodegradable wastes, such as agricultural and forestry residues, and non-edible plant matter for value-added bioproducts is a promising, inexpensive, and abundant clean substitute of fossil fuels. There has been extensive research on the conversion of lignocellulosic materials to biofuels over the past few decades. The recalcitrance of lignin in crop residues, however, impedes polysaccharide accessibility and its transformation into commercially significant choice of value-added products. Traditional physiochemical and thermal methods are hampered by high-cost processing steps in pretreatment and saccharification, and also require additional maintenance and care due to the generation of eco-unfriendly compounds. Recent advances in novel consolidated bioprocessing through mixed consortium are promising choices to reduce both the number of operational steps and the production of inhibitors with higher conversion efficiency. Although biofilm-based technologies have been successfully applied for wastewater and solid waste treatment, their potential application in biofuel production has been unexplored. The present review focuses on the state-of-the-art development of biofuel production by mixed consortium and also recent strategies to improve biofuel yield including the metabolic pathway construction.