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dc.contributor.advisorBessarabov, D.G.en_US
dc.contributor.advisorNeomagus, H.W.J.P.en_US
dc.contributor.authorVermaak, L.en_US
dc.date.accessioned2020-11-05T07:10:38Z
dc.date.available2020-11-05T07:10:38Z
dc.date.issued2020en_US
dc.identifier.urihttps://orcid.org/0000-0002-3807-8570en_US
dc.identifier.urihttp://hdl.handle.net/10394/36252
dc.descriptionMEng (Computer & Electronic Engineering), North-West University, Potchefstroom Campus
dc.description.abstractHydrogen, as energy carrier, is expected to play an indispensable role in the future energy prospects. Subsequently, significant advancements in research and development of hydrogen-based technologies, in the areas of low cost hydrogen production, separation/purification, hydrogen storage (e.g. compression, liquid, chemical compounds etc.), hydrogen distribution and hydrogen transportation, are required. Among several technologies under consideration for hydrogen infrastructure, the use of an electrochemical hydrogen separator is very probable, since both hydrogen purification/separation and hydrogen compression (for storage purposes) are integrated and addressed. Some advances have already been made in this field, including the development of high-temperature membranes, doped with phosphoric acid, to overcome the limitations associated with conventional low-temperature membranes. However, limited studies had been performed on these membranes and their operations under various conditions and feed compositions are largely unexplored. The first part of the work reported, addresses the aforementioned issue through experimental investigation of the performance of a high-temperature TPS-based membrane under various feed compositions (containing CH₄, CO₂ and NH₃, balance hydrogen) over a temperature range of 100-160°C. The performance parameters used included polarisation curves, electrochemical impedance spectroscopy, hydrogen purity, hydrogen separation selectivity, hydrogen flux/permeability, and general efficiencies (current, voltage and power). Results showed that a high purity hydrogen (>99.9%) was achieved, from a low purity feed (20% H₂) with the H₂/CH₄ mixtures. Also, hydrogen purities of 98-99.5 % were achieved with 10% CO₂ in the feed and 96-99.5% with 50% CO₂ in the feed stream. Moreover, electrochemical hydrogen separation was rendered inappropriate for separating hydrogen–rich streams containing NH₃. The second part of the work focussed on the poisoning effect of CO on Pt. An integrated approach of high-temperature operation and Pt-Ru as bimetallic catalyst was implemented and tested with a 2% CO (balance hydrogen) inlet. The performance of Pt-Ru/C and Pt/C was compared under the same operating conditions. The electrochemical active surface area was then determined to evaluate the CO poisoning of the two catalysts. In generaral, Pt-Ru showed better CO tolerance over the entire temperature range (80-160°C). Also, temperature played a crucial role in the mitigation of CO poisoning in the case of Pt-Ru.
dc.language.isoenen_US
dc.publisherNorth-West University (South Africa)en_US
dc.subjectElectrochemical hydrogen separation/purification
dc.subjectProton exchange membrane(PEM)
dc.subjectPhosphoric acid (PA)-doped polybenzimidazole (PBI) membrane
dc.subjectTPS membrane
dc.subjectHigh-temperature
dc.subjectPolarisation curve
dc.subjectElectrochemical impedance spectroscopy (EIS)
dc.subjectGas chromatograph (GC)
dc.subjectPt-based catalyst
dc.subjectCyclic voltammetry (CV)
dc.subjectElectrochemical active surface area (ECSA)
dc.subjectCO poisoning
dc.subjectCO-stripping
dc.titleHigh temperature electrochemical hydrogen membrane separation using a PGM-based catalysten_US
dc.typeThesisen_US
dc.description.thesistypeMastersen_US
dc.contributor.researchID22730389 - Bessarabov, Dmitri Georgievich (Supervisor)en_US
dc.contributor.researchID12767107 - Neomagus, Hendrik Willem Johannes P. (Supervisor)en_US


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