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Two‐temperature stage biphasic CO 2 –H 2 O pretreatment of lignocellulosic biomass at high solid loadings
Author(s) -
Luterbacher Jeremy S.,
Tester Jefferson W.,
Walker Larry P.
Publication year - 2012
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.24417
Subject(s) - hardwood , lignocellulosic biomass , biomass (ecology) , chemistry , sugar , monosaccharide , particle size , pulp and paper industry , cellulose , agronomy , botany , food science , organic chemistry , biology , engineering
Most biomass pretreatment processes for monosaccharide production are run at low‐solid concentration (<10 wt%) and use significant amounts of chemical catalysts. Biphasic CO 2 –H 2 O mixtures could provide a more sustainable pretreatment medium while using high‐solid contents. Using a stirred reactor for high solids (40 wt%, biomass water mixture) biphasic CO 2 –H 2 O pretreatment of lignocellulosic biomass allowed us to explore the effects of particle size and mixing on mixed hardwood and switchgrass pretreatment. Subsequently, a two‐temperature stage pretreatment was introduced. After optimization, a short high‐temperature stage at 210°C (16 min for hardwood and 1 min for switchgrass) was followed by a long low‐temperature stage at 160°C for 60 min. Glucan to glucose conversion yields of 83% for hardwood and 80% for switchgrass were obtained. Total molar sugar yields of 65% and 55% were obtained for wood and switchgrass, respectively, which consisted of a 10% points improvement over those obtained during our previous study despite a 10‐fold increase in particle size. These yields are similar to those obtained with other major pretreatment technologies for wood and within 10% of major technologies for switchgrass despite the absence of chemical catalysts, the use of large particles (0.95 cm) and high solid contents (40 wt%). Biotechnol. Bioeng. 2012; 109:1499–1507. © 2011 Wiley Periodicals, Inc.