Studies of the Ethanol Steam Reforming Reaction in a Membrane Reactor

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dc.contributor.authorLim, Hankwonen
dc.contributor.committeechairOyama, Shigeo Teden
dc.contributor.committeememberMarand, Evaen
dc.contributor.committeememberCox, David F.en
dc.contributor.committeememberDavis, Richey M.en
dc.contributor.departmentChemical Engineeringen
dc.date.accessioned2014-03-14T20:18:46Zen
dc.date.adate2007-11-28en
dc.date.available2014-03-14T20:18:46Zen
dc.date.issued2007-11-13en
dc.date.rdate2008-11-28en
dc.date.sdate2007-11-19en
dc.description.abstractThe subject of this dissertation is advanced inorganic membranes and their application in membrane reactors (MRs). The reaction studied is the ethanol steam reforming (ESR) reaction using Co-Na/ZnO catalysts, chosen because of their high activity and stability. The Co-Na/ZnO catalysts were prepared by a co-precipitation method and it was found that promotion with a moderate amount of Na (1.0 wt%) produced a catalyst with stable ethanol conversion and product selectivity. Higher cobalt loading, higher W:E ratio, higher reaction temperature, and lower space velocity enhanced the conversion of ethanol to H2 and CO2 while reducing the formation of undesirable acetaldehyde. Acetaldehyde was a primary product of the ESR reaction. Studies of the effect of hydrogen permeance on the ESR reaction at 623 K were performed in MRs equipped with silica-based and palladium-based membranes of different hydrogen permeances, and the highest ethanol conversion enhancement of 44 % and hydrogen molar flow enhancement of 69 % compared to a packed-bed reactor (PBR) were obtained in a MR fitted with a membrane with the highest hydrogen permeance. An operability level coefficient (OLC), defined as the ratio of the hydrogen permeation and hydrogen formation rates, was suggested as a useful tool for estimating performances of MRs for different reforming reactions such as methane dry reforming (MDR), methane steam reforming (MSR), methanol steam reforming (MeSR), and ethanol steam reforming (ESR) reactions. Studies of the effect of pressure (1-10 atm) on the ESR reaction at 623 K were carried out in a PBR and a MR fitted with a Pd-Cu membrane prepared by an electroless plating of palladium and copper at 333 K. Comparison studies showed that increasing pressure in both reactors resulted in decreasing ethanol conversions and increasing hydrogen molar flows. Compared to the PBR, higher ethanol conversions and hydrogen molar flows were obtained in the MR for all pressures studied. Increasing pressure was favorable for enhancing ethanol conversion and hydrogen molar flow in the MR compared to the PBR, and the highest ethanol conversion enhancement of 48 % with the highest hydrogen molar flow enhancement of 55 % was obtained at 10 atm in the MR.en
dc.description.degreePh. D.en
dc.identifier.otheretd-11192007-130256en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-11192007-130256/en
dc.identifier.urihttp://hdl.handle.net/10919/29675en
dc.publisherVirginia Techen
dc.relation.haspartDissertation_Hankwon_Lim.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectEthanol Steam Reformingen
dc.subjectHydrogen Selective Membraneen
dc.subjectMembrane Reactoren
dc.subjectOperability Level Coefficienten
dc.titleStudies of the Ethanol Steam Reforming Reaction in a Membrane Reactoren
dc.typeDissertationen
thesis.degree.disciplineChemical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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