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dc.contributor.advisorHoltzapple, Mark T.
dc.creatorSierra Ramirez, Rocio
dc.date.accessioned2012-02-14T22:18:05Z
dc.date.accessioned2012-02-16T16:15:43Z
dc.date.available2012-02-14T22:18:05Z
dc.date.available2012-02-16T16:15:43Z
dc.date.created2010-12
dc.date.issued2012-02-14
dc.date.submittedDecember 2010
dc.identifier.urihttp://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8641
dc.description.abstractBecause of widespread availability, low cost, sustainability, and potential supply far greater than that of food crops, lignocellulosic biomass is one of the most promising feedstocks for producing biofuels through fermentation processes. Among lignocellulose choices, poplar wood is appealing because of high energy potential, above-average carbon mitigation potential, fast growth, and high yields. Lignocellulose structural features limit accessibility of enzymes or microorganisms. To overcome these limitations, pretreatment is required. Among several choices of pretreatment, lime pretreatment is preferred because lime is the cheapest alkali, safest to handle, easy to recover, and compatible with oxidants. The main effect of lime pretreatment is to degrade lignin, which occurs with good carbohydrate preservation and is enhanced with oxidants. Among several choices of oxidant, oxygen and air are preferred because of low cost and widespread availability. This study systematically assesses the effects of lime pretreatment on poplar wood using four different modes: long-term oxidative, long-term non-oxidative, short-term constant pressure, and short-term varying pressure. Long-term pretreatments use temperatures between 25 and 65° C, air if oxidant is used, and last several weeks. Short-term pretreatments use temperatures between 110 and 180° C, pressurized oxygen, and last several minutes to hours. Pretreatment was assessed on the basis of 3-day enzymatic digestibility using enzyme loadings of 15 FPU/g glucan in raw biomass. The results were used to recommend pretreatment conditions based on highest overall yield of glucan (after combined pretreatment and enzymatic hydrolysis) for each pretreatment mode. For each pretreatment mode, kinetic models for delignification and carbohydrates degradation were obtained and used to determine the conditions (temperature, pressure, and time) that maximize glucan preservation subjected to a target lignin yield. This study led to conclude that the most robust, and selective mode of lime pretreatment is varying pressure.en
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.subjectLimeen
dc.subjectpretreatmenten
dc.subjectkinetic modelingen
dc.subjectpoplar wooden
dc.subjectlignocelluloseen
dc.titleKinetic Modeling and Assessment of Lime Pretreatment of Poplar Wooden
dc.typeThesisen
thesis.degree.departmentChemical Engineeringen
thesis.degree.disciplineChemical Engineeringen
thesis.degree.grantorTexas A&M Universityen
thesis.degree.nameDoctor of Philosophyen
thesis.degree.levelDoctoralen
dc.contributor.committeeMemberMannan, Sam
dc.contributor.committeeMemberGlover, Charles
dc.contributor.committeeMemberEngler, Cady
dc.type.genrethesisen
dc.type.materialtexten


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