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Pretreatment of Lignocellulosic Materials for Efficient Bioethanol Production

Galbe, Mats LU and Zacchi, Guido LU (2007) In Advances in Biochemical Engineering/Biotechnology 108. p.41-65
Abstract
Second-generation bioethanol produced from various lignocellulosic materials,

such as wood, agricultural or forest residues, has the potential to be a valuable substitute

for, or a complement to, gasoline. One of the crucial steps in the ethanol production is

the hydrolysis of the hemicellulose and cellulose to monomer sugars. The most promising

method for hydrolysis of cellulose to glucose is by use of enzymes, i.e. cellulases. However,

in order to make the raw material accessible to the enzymes some kind of pretreatment is

necessary. During the last few years a large number of pretreatment methods have been

developed, comprising methods working at low pH, i.e. acid based,... (More)
Second-generation bioethanol produced from various lignocellulosic materials,

such as wood, agricultural or forest residues, has the potential to be a valuable substitute

for, or a complement to, gasoline. One of the crucial steps in the ethanol production is

the hydrolysis of the hemicellulose and cellulose to monomer sugars. The most promising

method for hydrolysis of cellulose to glucose is by use of enzymes, i.e. cellulases. However,

in order to make the raw material accessible to the enzymes some kind of pretreatment is

necessary. During the last few years a large number of pretreatment methods have been

developed, comprising methods working at low pH, i.e. acid based, medium pH (without

addition of catalysts), and high pH, i.e. with a base as catalyst. Many methods have been

shown to result in high sugar yields, above 90% of theoretical for agricultural residues,

especially for corn stover. For more recalcitrant materials, e.g. softwood, acid hydrolysis

and steam pretreatment with acid catalyst seem to be the methods that can be used to

obtain high sugar and ethanol yields. However, for more accurate comparison of different

pretreatment methods it is necessary to improve the assessment methods under real

process conditions. The whole process must be considered when a performance evaluation

is to be made, as the various pretreatment methods give different types of materials.

(Hemicellulose sugars can be obtained either in the liquid as monomer or oligomer sugars,

or in the solid material to various extents; lignin can be either in the liquid or remain

in the solid part; the composition and amount/concentration of possible inhibitory compounds

also vary.) This will affect how the enzymatic hydrolysis should be performed(e.g. with or without hemicellulases), how the lignin is recovered and also the use of the

lignin co-product. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Assessment · Enzymatic hydrolysis · Lignocellulose · Pretreatment · Review
in
Advances in Biochemical Engineering/Biotechnology
editor
Olsson, Lisbeth and
volume
108
pages
41 - 65
publisher
Springer
external identifiers
  • wos:000250578300002
  • scopus:34548783309
ISSN
0724-6145
ISBN
978-3-540-73650-9
DOI
10.1007/10_2007_070
language
English
LU publication?
yes
id
6137070e-7ba6-441c-94b9-e11decaea047 (old id 627657)
date added to LUP
2007-11-30 11:23:55
date last changed
2017-11-05 04:39:04
@inbook{6137070e-7ba6-441c-94b9-e11decaea047,
  abstract     = {Second-generation bioethanol produced from various lignocellulosic materials,<br/><br>
such as wood, agricultural or forest residues, has the potential to be a valuable substitute<br/><br>
for, or a complement to, gasoline. One of the crucial steps in the ethanol production is<br/><br>
the hydrolysis of the hemicellulose and cellulose to monomer sugars. The most promising<br/><br>
method for hydrolysis of cellulose to glucose is by use of enzymes, i.e. cellulases. However,<br/><br>
in order to make the raw material accessible to the enzymes some kind of pretreatment is<br/><br>
necessary. During the last few years a large number of pretreatment methods have been<br/><br>
developed, comprising methods working at low pH, i.e. acid based, medium pH (without<br/><br>
addition of catalysts), and high pH, i.e. with a base as catalyst. Many methods have been<br/><br>
shown to result in high sugar yields, above 90% of theoretical for agricultural residues,<br/><br>
especially for corn stover. For more recalcitrant materials, e.g. softwood, acid hydrolysis<br/><br>
and steam pretreatment with acid catalyst seem to be the methods that can be used to<br/><br>
obtain high sugar and ethanol yields. However, for more accurate comparison of different<br/><br>
pretreatment methods it is necessary to improve the assessment methods under real<br/><br>
process conditions. The whole process must be considered when a performance evaluation<br/><br>
is to be made, as the various pretreatment methods give different types of materials.<br/><br>
(Hemicellulose sugars can be obtained either in the liquid as monomer or oligomer sugars,<br/><br>
or in the solid material to various extents; lignin can be either in the liquid or remain<br/><br>
in the solid part; the composition and amount/concentration of possible inhibitory compounds<br/><br>
also vary.) This will affect how the enzymatic hydrolysis should be performed(e.g. with or without hemicellulases), how the lignin is recovered and also the use of the<br/><br>
lignin co-product.},
  author       = {Galbe, Mats and Zacchi, Guido},
  editor       = {Olsson, Lisbeth},
  isbn         = {978-3-540-73650-9},
  issn         = {0724-6145},
  keyword      = {Assessment · Enzymatic hydrolysis · Lignocellulose · Pretreatment · Review},
  language     = {eng},
  pages        = {41--65},
  publisher    = {Springer},
  series       = {Advances in Biochemical Engineering/Biotechnology},
  title        = {Pretreatment of Lignocellulosic Materials for Efficient Bioethanol Production},
  url          = {http://dx.doi.org/10.1007/10_2007_070},
  volume       = {108},
  year         = {2007},
}