Pretreatments to enhance the digestibility of wheat straw

Wheat straw is a sufficient agricultural by-product with a low market price. The biofuel produced from lignocellulosic material exhibits energetic, economic and environmental benefits in contrast to bio-ethanol from starch or sugar. Until now, physical and chemical difficulty caused by the close connection of the main components of lignocellulosic biomass, discourage the hydrolysis of cellulose and hemicellulose to fermentable sugars. The main purpose of pretreatment is to enhance the enzyme accessibility improving digestibility of cellulose. Every pretreatment has a particular effect on the fraction of cellulose, hemicellulose and lignin, thus different pretreatment methods and conditions should be selected for the development of subsequent hydrolysis and fermentation steps. This paper reviews the most importance technologies for ethanol production from lignocellulose and its represent several vital qualities that should be marked for low-price and promote pretreatment processes.