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dc.contributor.advisorKoros, William
dc.contributor.authorXu, Liren
dc.date.accessioned2014-01-10T18:00:00Z
dc.date.available2014-01-10T18:00:00Z
dc.date.issued2013-09-25
dc.identifier.urihttp://hdl.handle.net/1853/50130
dc.description.abstractOlefin/paraffin separation is a large potential market for membrane applications. Carbon molecular sieve membranes (CMS) are promising for this application due to the intrinsically high separation performance and the viability for practical scale-up. Intrinsically high separation performance of CMS membranes for olefin/paraffin separations was demonstrated. The translation of intrinsic CMS transport properties into the hollow fiber configuration is considered in detail. Substructure collapse of asymmetric hollow fibers was found during Matrimidᆴ CMS hollow fiber formation. To overcome the permeance loss due to the increased separation layer thickness, 6FDA-DAM and 6FDA/BPDA-DAM polyimides with higher rigidity were employed as alternative precursors, and significant improvement has been achieved. Besides the macroscopic morphology control of asymmetric hollow fibers, the micro-structure was tuned by optimizing pyrolysis temperature protocol and pyrolysis atmosphere. In addition, unexpected physical aging was observed in CMS membranes, which is analogous to the aging phenomenon in glassy polymers. For performance evaluation, multiple "proof-of-concept" tests validated the viability of CMS membranes under realistic conditions. The scope of this work was expanded from binary ethylene/ethane and propylene/propane separations for the debottlenecking purpose to mixed carbon number hydrocarbon processing. CMS membranes were found to be olefins-selective over corresponding paraffins; moreover, CMS membranes are able to effectively fractionate the complex cracked gas stream in a preferable way. Reconfiguration of the hydrocarbon processing in ethylene plants is possible based on the unique CMS membranes.
dc.language.isoen_US
dc.publisherGeorgia Institute of Technology
dc.subjectGas separations
dc.subjectCarbon molecular sieve
dc.subjectEthylene/ethane
dc.subjectMembrane-distillation
dc.subjectPropylene/propane
dc.subjectHollow fiber
dc.subjectMembrane
dc.subjectOlefin/paraffin
dc.subject.lcshAlkenes
dc.subject.lcshMembrane separation
dc.subject.lcshMolecular sieves
dc.subject.lcshGas separation membranes
dc.titleCarbon molecular sieve hollow fiber membranes for olefin/paraffin separations
dc.typeDissertation
dc.description.degreePh.D.
dc.contributor.departmentChemical Engineering
dc.contributor.committeeMemberBrayden, Mark
dc.contributor.committeeMemberBucknall, David
dc.contributor.committeeMemberFuller, Tom
dc.contributor.committeeMemberHess, Dennis


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