Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.349775
Title: The effects of cell environment upon electro-organic synthesis
Author: Ellis, Keith Gordon
ISNI:       0000 0001 3446 0628
Awarding Body: University of Southampton
Current Institution: University of Southampton
Date of Award: 1983
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Abstract:
The indirect epoxidation of propane has been studied across a wide range of conditions in a bipolar trickle bed reactor with the aim of maximising the production rate of propylene oxide. The overall performance is limited by depletion of propylene in the aqueous phase and the effect of changing parameters on the space-time yield, energy consumption and selectivity for the process has been demonstrated. An important factor in cell performance is the arrangement of bipolar elements within the reactor. The best arrangement is an 'in-line' array with each Raschig ring exactly below the one above. Alternative electrode materials including a novel carbon material manufactured by the pyrolysis of hardboard have been investigated. The selectivity of the process to propylene oxide is high (ca. 97%) and is independent of operating conditions. The distribution of by-products changes both with propylene oxide concentration (time) and operating conditions. Mechanisms giving rise to the important by-products are discussed. This synthesis has been extended to other gaseous olefins and the epoxidation of ethene, 1-butene, cis 2-butene and trans 2-butene carried out under conditions which give reasonable results for propene. The selectivities are again high but the current efficiencies low due to the bulk phase chemical reactions being slower than the electrochemical generation of oxidant. The effect of a turbulence promoting mesh spacer placed in the flow channel of a small parallel plate cell on the paired hydrodimerisation of methyl acrylate and dehydrodimerisation of diethyl malonate has been studied. Selectivity, space-time yield and energy consumption for the process are all improved over a range of Reynolds numbers by use of the mesh. These results indicate that the interaction of cell design with the chemistry of the reaction is important and that even seemingly small changes in cell geometry or environment can affect the yield and efficiency of organic electrosynthesis.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.349775  DOI: Not available
Keywords: Physical chemistry
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