BioEnergy Research

, Volume 4, Issue 4, pp 225–245

Bioconversion of Lignocellulose into Bioethanol: Process Intensification and Mechanism Research

Article

DOI: 10.1007/s12155-011-9125-7

Cite this article as:
Huang, R., Su, R., Qi, W. et al. Bioenerg. Res. (2011) 4: 225. doi:10.1007/s12155-011-9125-7

Abstract

Biofuels produced from lignocellulosic biomass can significantly reduce the energy dependency on fossil fuels and the resulting effects on environment. In this respect, cellulosic ethanol as an alternative fuel has the potential to become a viable energy source in the near future. Over the past few decades, tremendous effort has been undertaken to make cellulosic ethanol cost competitive with conventional fossil fuels. The pretreatment step is always necessary to deconstruct the recalcitrant structures and to make cellulose more accessible to enzymes. A large number of pretreatment technologies involving physical, chemical, biological, and combined approaches have been developed and tested at the pilot scale. Furthermore, various strategies and methods, including multi-enzyme complex, non-catalytic additives, enzyme recycling, high solids operation, design of novel bioreactors, and strain improvement have also been implemented to improve the efficiency of subsequent enzymatic hydrolysis and fermentation. These technologies provide significant opportunities for lower total cost, thus making large-scale production of cellulosic ethanol possible. Meanwhile, many researchers have focused on the key factors that limit cellulose hydrolysis, and analyzing the reaction mechanisms of cellulase. This review describes the most recent advances on process intensification and mechanism research of pretreatment, enzymatic hydrolysis, and fermentation during the production of cellulosic ethanol.

Keywords

Lignocellulose Cellulose Cellulosic ethanol Pretreatment Enzymatic hydrolysis Multi-enzyme complex Enzyme recycling High solids Bioreactors Metabolic engineering Pentose fermentation Tolerance Substrate characteristics Cellulase adsorption 

Abbreviations

SSF

Simultaneous saccharification and fermentation

SSCF

Simultaneous saccharification and co-fermentation

ARP

Ammonia recycle percolation

SAA

Soaking in aqueous ammonia

AFEX

Ammonia fiber explosion

HCW

Hot-compressed water

NMO

N-methyl-morpholine-N-oxide

EG

Endoglucanase

CBH

Cellobiohydrolase

BG

β-glucosidase

CBR

Conventional batch reactor

MBR

Membrane bioreactor

RBR

Roller bottle reactors

CBM

Cellulose-binding module

CAC

Cellulose accessibility to cellulase

DP

Degree of polymerization

SEC

Size exclusion chromatography

MALLS

Multi-angle laser light scattering

Copyright information

© Springer Science+Business Media, LLC. 2011

Authors and Affiliations

  1. 1.State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and TechnologyTianjin UniversityTianjinPeople’s Republic of China