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High‐solids biphasic CO 2 –H 2 O pretreatment of lignocellulosic biomass
Author(s) -
Luterbacher Jeremy S.,
Tester Jefferson W.,
Walker Larry P.
Publication year - 2010
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.22823
Subject(s) - corn stover , chemistry , panicum virgatum , hemicellulose , lignocellulosic biomass , biomass (ecology) , cellulosic ethanol , hardwood , cellulose , arundo donax , xylose , furfural , miscanthus , biorefinery , bioenergy , biofuel , hydrolysis , agronomy , botany , raw material , food science , fermentation , microbiology and biotechnology , organic chemistry , biology , catalysis
A high pressure (200 bar) CO 2 –H 2 O process was developed for pretreating lignocellulosic biomass at high‐solid contents, while minimizing chemical inputs. Hardwood was pretreated at 20 and 40 (wt.%) solids. Switchgrass, corn stover, big bluestem, and mixed perennial grasses (a co‐culture of big bluestem and switchgrass) were pretreated at 40 (wt.%) solids. Operating temperatures ranged from 150 to 250°C, and residence times from 20 s to 60 min. At these conditions a biphasic mixture of an H 2 O‐rich liquid (hydrothermal) phase and a CO 2 ‐rich supercritical phase coexist. Following pretreatment, samples were then enzymatically hydrolyzed. Total yields, defined as the fraction of the theoretical maximum, were determined for glucose, hemicellulose sugars, and two degradation products: furfural and 5‐hydroxymethylfurfural. Response surfaces of yield as a function of temperature and residence time were compared for different moisture contents and biomass species. Pretreatment at 170°C for 60 min gave glucose yields of 77%, 73%, and 68% for 20 and 40 (wt.%) solids mixed hardwood and mixed perennial grasses, respectively. Pretreatment at 160°C for 60 min gave glucan to glucose yields of 81% for switchgrass and 85% for corn stover. Biotechnol. Bioeng. 2010;107: 451–460. © 2010 Wiley Periodicals, Inc.