Location: Bioenergy Research Unit
Title: Optimizing hydrothermal pretreatment of sugarcane bagasse using response surface methodology Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 18, 2011
Publication Date: May 18, 2011
Citation: Da Cruz, S., Dien, B.S., Nichols, N.N., Saha, B.C., Cotta, M.A. 2011. Optimizing hydrothermal pretreatment of sugarcane bagasse using response surface methodology [abstract]. In: Proceedings of the Sixth Annual Frontiers in Bioenergy: U.S.-Brazil Symposium on Bioenergy Production, May 15-18, 2011, West Lafayette, Indiana. Paper No. 14. Technical Abstract: Sugarcane bagasse was characterized as a feedstock for production of ethanol using hydrothermal pretreatment. Reaction temperature and time were varied between 160-200 deg C and 5-20 min, respectively, using a response surface experimental design. The liquid fraction was analyzed for soluble carbohydrates and furans. The solid fraction was analyzed for structural carbohydrates and Klason lignin. Pretreatment conditions were evaluated based upon enzymatic extraction of glucose and xylose and conversion to ethanol using a simultaneous saccharification and fermentation scheme. The severity of the pretreatment should be sufficient to drive enzymatic digestion and ethanol yields, however, sugar losses and especially sugar conversion into furans needs to be minimized. As expected, furfural production increased with pretreatment severity and specifically xylose release. However, provided that the severity was kept below 4.0, production of furfural was below an inhibitory concentration and carbohydrate contents were preserved in the pretreated whole hydrolysate. There were significant interactions between time and temperature for all the responses except cellulose digestion. The models were highly predictive for cellulose digestibility (R^2 = 0.8596) and for ethanol production (R^2 = 0.9276), but less so for xylose extraction. Both cellulose digestion and ethanol production increased with severity. As furfural production increased as well, final pretreatment conditions will need to compromise to give a favorable yield while minimizing furfural concentration below an inhibiting concentration. The data here suggests this can be done by targeting a reaction temperature around 190 deg C and 17.2 min.