Chapter 20

Biochemical Conversion of Ethanol from Lignocellulose: Pretreatment, Enzymes, Co-Fermentation, and Separation (pp. 347-384)
Authors:  (Xian-Bao Zhang and Ming-Jun Zhu, School of Bioscience & Bioengineering, South China University of Technology, Guangdong Province, P.R. China)
Bioethanol produced from lignocellulosic materials, such as agricultural and forest
residues, has the potential to replace the limited fossil oil due to its high efficiency and
renewability. The conversion of ethanol from cellulosic biomass is mainly involved in
four steps: pretreatment, holocellulose (cellulose and hemicellulose) hydrolysis,
fermentation and ethanol separation. The purpose of pretreatment is to improve the
hydrolysis of cellulose by diminishing the physicochemical structural and compositional
factors hindering the hydrolysis, so that the loading and mixtures of enzymes can be
optimized and the hydrolysis and fermentation can be maximized. Separation technology,
just like the other steps, has a great impact on ethanol yield. In the work, we reviewed the
current popular pretreatment technologies, enzymatic hydrolysis, fermentation strains,
separation techniques and recent advances for ethanol production from lignocellulose.