Biorefinery approaches for the production of fuels and chemicals from lignocellulosic and algal feedstocks

Abstract

The fuels and chemicals produced from the fossil-derived petroleum are on the verge of completion. As a result, petro-refinery-based commodity prices are rising despite their increasing demand. Moreover, the greenhouse gas emissions from petro-based fuels are devastating to the environment. Thus, the concerns over the search for alternative, renewable and green sources of fuels and platform chemicals have been raised. Among the explored bio-based sources, the biorefinery potential of lignocellulosic and algal feedstocks has been found to be the most promising due to their sustainability and versatility of multi-product generation. This chapter reviews the biorefinery approaches in various thermochemical and biological conversion routes of lignocellulosic and algal feedstocks for co-producing biofuels and biochemicals that can be widely applied in the industrial sectors like energy, food, pharmaceuticals, cosmetics and textiles. From lignocellulosic biomass, the co-production technologies of chemicals and fuels via lignin and sugar (C5 and C6) platforms have been focused. On the other hand, the generation of bioactive components such as lipids, carbohydrates and proteins from algae along with co-production of biofuels and biochemicals is also discussed. The utilization of recycle streams like crude glycerol and spent biomass residues is emphasized in the algal biorefineries. Finally, the current industrial scenarios of both lignocellulosic and algal biorefineries are outlined.