当前位置： SCI文献检索 > Biotechnology for Biofuels期刊下所有文献 > Improving the enzymatic hydrolysis of thermo-mechanical fiber from Eucalyptus urophylla by a combination of hydrothermal pretreatment and alkali fractionation.

Improving the enzymatic hydrolysis of thermo-mechanical fiber from Eucalyptus urophylla by a combination of hydrothermal pretreatment and alkali fractionation.

Abstract：

BACKGROUND:The recalcitrance of lignocellulosic biomass is a major limitation for its conversion into biofuels by enzymatic hydrolysis. The use of a pretreatment technology is an essential step to diminish biomass recalcitrance for bioethanol production. In this study, a two-step pretreatment using hydrothermal pretreatment at various temperatures and alkali fractionation was performed on eucalyptus fiber. The detailed chemical composition, physicochemical characteristics, and morphology of the pretreated fibers in each of the fractions were evaluated to advance the performance of eucalyptus fiber in enzymatic digestibility. RESULTS:The hydrothermal pretreatment (100 to 220°C) significantly degraded hemicelluloses, resulting in an increased crystallinity of the pretreated fibers. However, as the pretreatment temperature reached 240°C, partial cellulose was degraded, resulting in a reduced crystallinity of cellulose. As compared to the hydrothermal pretreatment alone, a combination of hydrothermal and alkali treatments significantly removed hemicelluloses and lignin, resulting in an improved enzymatic hydrolysis of the cellulose-rich fractions. As compared with the raw fiber, the enzymatic hydrolysis rate increased 1.1 to 8.5 times as the hydrothermal pretreatment temperature increased from 100 to 240°C. Interestingly, after a combination of hydrothermal pretreatment and alkali fractionation, the enzymatic hydrolysis rate increased 3.7 to 9.2 times. Taking into consideration the consumption of energy and the production of xylo-oligosaccharides and lignin, an optimum pretreatment condition was found to be hydrothermal pretreatment at 180°C for 30 min and alkali fractionation with 2% NaOH at 90°C for 2.5 h, in which 66.3% cellulose was converted into glucose by enzymatic hydrolysis. CONCLUSIONS:The combination of hydrothermal pretreatment and alkali fractionation was a promising method to remove hemicelluloses and lignin as well as overcome the biomass recalcitrance for enzymatic hydrolysis from eucalyptus fiber. In addition, the various techniques applied in this work constituted an efficient approach to understand the underlying chemical and morphological changes of the cellulose-rich fractions.

journal_name

Biotechnol Biofuels

journal_title

Biotechnology for biofuels

authors

Sun S,Cao X,Sun S,Xu F,Song X,Sun RC,Jones GL

doi

10.1186/s13068-014-0116-8

subject

Has Abstract

pub_date

2014-08-20 00:00:00

pages

116

issue

issn

1754-6834

pii

116

journal_volume

pub_type

杂志文章

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Improving the enzymatic hydrolysis of thermo-mechanical fiber from Eucalyptus urophylla by a combination of hydrothermal pretreatment and alkali fractionation.