Fermentable sugars from lignocellulosic biomass: Technical challenges

Lignocelluloses, the most abundant renewable biomass on earth, are composed mainly of cellulose, hemicellulose, and lignin. Both the cellulose and hemicellulose fractions are polymers of sugars and thereby a potential source of fermentable sugars. Lignin can be used for the production of chemicals, combining heat and power, or for other purposes. Energy crisis and environmental pollution drive the scientific community toward the potential exploitation of lignocellulosic biomass. To crack their complex structures various pretreatment technologies including biological, mechanical, chemical methods, and various other combinational methods are available. We cannot relate the best and common pretreatment method to all types of the lignocellulosic biomass. It mostly depends on the type of lignocellulosic biomass and the desired products. The final aim of pretreatments must be improvement in the hydrolysis rate of lignocellulosic biomass. Currently, there is a large scope to investigate and restore the challenges in the pretreatment processes which finally leads to develop the tailor-made effective pretreatment methods for diverse types of lignocellulosic biomass.