Two-temperature stage biphasic CO2-H2O pretreatment of lignocellulosic biomass at high solid loadings.
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%).
Department of Chemical and Biomolecular Engineering, Olin Hall, Cornell University, Ithaca, New York 14853, USA.
Jeremy S
JS
Luterbacher
Jefferson W
JW
Tester
Larry P
LP
Walker
D018533:Biomass; D002241:Carbohydrates / Q000302:isolation & purification*; D002245:Carbon Dioxide / Q000737:chemistry*; D025924:Chromatography, Supercritical Fluid; D006358:Hot Temperature; D008031:Lignin / Q000737:chemistry*; D008897:Panicum / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D014934:Wood / Q000737:chemistry
D002241:Carbohydrates; D014867:Water; C036909:lignocellulose; D002245:Carbon Dioxide; D008031:Lignin