Challenges and Opportunities for Producing Bioethanol from Lignocellulosic Biomass

Energy is the lifeline of global economy. Diminishing fossil fuel reserves and increased concerns over environmental pollution accelerated the need to look for renewable and environmentally sustainable energy sources. In this context, ethanol derived from biomass is advocated as a prominent contributor to offer a potential means to meet our energy needs. Being abundant and outside the human food chain makes lignocellulosic biomass, suitable and sustainable for ethanol production. Several schemes for the conversion of lignocellulosics into sugars have already been demonstrated in laboratory and pilot plant scale. The general procedure involves pretreatment of feedstock followed by hydrolysis to obtain fermentable sugars which are then converted to ethanol by fermentation. The present paper reviews the technological advancements made to date and the challenges involved in each of these processing steps. A procedure to calculate theoretical ethanol yields is also described.