Comparison of Chemical Pretreatment Methods for Cellulosic Biomass

The variety in physiochemical characteristics of cellulosic biomass reveals the need for pretreatment technologies to help in the rapid and efficient conversion of carbohydrate polymers into fermentable sugars. Suitable pretreatment methods enhance the enzymatic hydrolysis of biomass because of the crystalline structure of cellulose and the complex structure of lignin and hemicellulose. The choice of pretreatment method affects on the sugar yield, avoids the degradation of sugars derived from hemicellulose and minimize the formation of inhibitors for subsequent fermentation steps. A suitable process should minimize heat and power requirements to be cost effective in operation. The present review focuses on various chemical pretreatment methods for lignocellulosic biomass based on recent reports in literature. An analysis of the methods shows that the composition of biomass is the main factor in the selection of pretreatment method.