Pretreatment Methods for Producing Bioethanol from Biomass

Bioethanol is a renewable energy resource used in the whole world. Bioethanol can be used by itself or mixing with oil in different rates. Utilizing lignocellulose biomass as a renewable energy resource has a significant role on producing ethanol. Using food materials for producing bioethanol will cause increasing in food prices and some social problems. Because of this reason, we need to realize on producing second generation of bioethanol, which can replace the first-generation bioethanol produced from food materials and compete with oil prices. Lignocelluloses raw materials consist of complex cellulose, hemicelluloses and lignin structures. These complex structures must be divided into simple sugar elements. There is a need for pretreatment methods for hydrolyzing fermented sugar in a fast and effective way. Pretreatment processes can be grouped as physical, physicochemical, chemical and biological methods. The biomass after pretreatment can be easily divided as biologically and thus, access of enzymes to raw materials accelerates. It is a significantly important matter for the selected pretreatment methods to be cheap, simple, effective and environmentally safe.