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dc.contributor.advisorHoltzapple, Mark T.en_US
dc.creatorSierra Ramirez, Rocioen_US
dc.date.accessioned2006-04-12T16:06:27Z
dc.date.available2006-04-12T16:06:27Z
dc.date.created2005-12en_US
dc.date.issued2006-04-12
dc.identifier.urihttp://hdl.handle.net/1969.1/3316
dc.description.abstractLignocellulosic biomass (e.g., poplar wood) provides a unique and sustainable resource for environmentally safe organic fuels and chemicals. The core of this study is the pretreatment step involved in bioconversion processes. Pretreatment is required to realize high yields vital to commercial success. The focus of the pretreatment step is to methodically change key features of the biomass to favor enzymatic hydrolysis. This work assesses the compositional changes due to oxidative and non-oxidative longterm lime pretreatment of poplar wood (up to 4 weeks of pretreatment) at mild temperatures (25ºC to 65ºC), and their effect on the enzymatic yield of glucan and xylan. The most important pretreatment yield of lignin was 54 g lignin remaining/100 g lignin in raw biomass, and was accomplished for 4-week lime pretreatment at 65ºC in oxidative conditions. The corresponding pretreatment yields of glucan and xylan were 85.9 g glucan recovered/100 g glucan in raw biomass and 80.2 g xylan recovered/100 g xylan in raw biomass respectively. For poplar wood oxidatively pretreated with lime for 4 weeks at 65ºC and enzymatically hydrolyzed with an enzyme loading of 15 FPU/g glucan in raw biomass during a 3-day period, the best overall yields of glucan and xylan, were 80.7 g glucan hydrolyzed/100 g glucan in raw biomass and 66.9 g xylan hydrolyzed/100 g xylan in raw biomass respectively. The corresponding hydrolysis yields were 94.0 g glucan hydrolyzed/100 g glucan in treated biomass and 83.5 g xylan hydrolyzed/100 g xylan in treated biomass respectively. Because there is a previous study of long-term lime pretreatment of corn stover (Kim, 2004), the data obtained in this work show the effect of using woody lignocellulose as substrate. From the comparison, resulted that in the case of poplar wood oxidatively pretreated at 65ºC for 4 weeks, less lignin was removed and more carbohydrates were solubilized, however the hydrolysis yield of glucan was almost equal and the hydrolysis yield of xylan was higher than the reported by Kim for corn stover oxidatively pretreated at 55ºC for 4 weeks. The overall yield of glucan resulted lower in the case of poplar wood because of the lower pretreatment yield of glucan. Thus, it is important to complete the mass balances including an analysis on the pretreatment liquor to determine if the solubilized glucan was degraded.en_US
dc.format.extent688205 bytes
dc.format.mediumelectronicen_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherTexas A&M Universityen_US
dc.subjectPretreatmenten_US
dc.subjectlignocelluloseen_US
dc.subjectenzymatic hydrolysisen_US
dc.subjectlimeen_US
dc.subjectlong-termen_US
dc.titleLong-term lime pretreatment of poplar wooden_US
dc.typeBooken
dc.typeThesisen
thesis.degree.departmentChemical Engineeringen_US
thesis.degree.disciplineChemical Engineeringen_US
thesis.degree.grantorTexas A&M Universityen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelMastersen_US
dc.contributor.committeeMemberDavison, Richarden_US
dc.contributor.committeeMemberEngler, Cadyen_US
dc.contributor.committeeMemberGlover, Charlesen_US
dc.type.genreElectronic Thesisen_US
dc.type.materialtexten_US
dc.format.digitalOriginborn digitalen_US


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