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dc.contributor.authorXiao, Ning
dc.date.accessioned2017-11-28T13:11:44Z
dc.date.available2017-11-28T13:11:44Z
dc.date.issued2017-11-13
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/269754
dc.description.abstractThis project was aimed to use a purple non-sulphur bacterium, Rhodopseudomonas palustris, as a biocatalyst for hydrogen production, from the waste of biodiesel manufacturing, crude glycerol. The goal of this project was to understand the fundamentals relevant to scaling up the process and developing an off the shelf product. The first objective was to determine the ability of R. palustris to generate hydrogen by non-growing cells in comparison to that by growing cells. Similar average hydrogen production rates and energy conversion were found for both processes but a significant difference in the hydrogen yield was observed. Hydrogen production reached ~ 80 % of the theoretical maximum hydrogen yield by non-growing R. palustris, about eight-fold of that reached by growing R. palustris. The high yield suggested that it is economically appealing to use non-growing R. palustris as the biocatalyst for continuous hydrogen production. To accomplish the proposed scale-up systems, understanding its product formation kinetics is the key. It was found that the hydrogen production rate is not growth-associated and depends solely on the dry cell mass with a non-growth associated coefficient of 2.52 (Leudeking–Piret model dP/dt=2.52 X). Light is vital for hydrogen production by non-growing R. palustris, in terms of light intensity and wavelength range. It was found that excessive or insufficient light intensity may constrain the performance. Only photons of light with appropriate wavelengths can excite cytochrome bacteriochlorophyll complexes II in R. palustris to generate hydrogen. Among white LEDs, infrared LEDs, and incandescent light bulbs, at the same light intensity, infrared LEDs gave the best results in the H2 production rate and energy conversion by non-growing cells, 22.0 % ± 1.5 % higher than that with white LEDs and around 25-30 times of that by incandescent light bulbs. It was found that non-growing R. palustris can be immobilised in alginate beads to give similar H2 production rates as that by cells suspended in media. This preliminary result pointed the direction of developing an off the shelf product of immobilised non-growing R. palustris as a biocatalyst for continuous hydrogen production.
dc.description.sponsorshipCambridge – KACST Joint Research Programme
dc.language.isoen
dc.rightsAll Rights Reserveden
dc.rights.urihttps://www.rioxx.net/licenses/all-rights-reserved/en
dc.subjectpurple non-sulphur bacterium
dc.subjectbiocatalyst
dc.subjectRhodopseudomonas palustris
dc.subjecthydrogen production
dc.subjectLeudeking–Piret model
dc.subjectLEDs
dc.subjectcell immobilisation
dc.subjectdry cell mass
dc.titleUse of a Purple Non-Sulphur Bacterium, Rhodopseudomonas palustris, as a Biocatalyst for Hydrogen Production from Glycerol
dc.typeThesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnameDoctor of Philosophy (PhD)
dc.publisher.institutionUniversity of Cambridge
dc.publisher.departmentDepartment of Chemical Engineering and Biotechnology
dc.date.updated2017-11-28T11:56:47Z
dc.identifier.doi10.17863/CAM.16680
dc.publisher.collegeChurchill College
dc.type.qualificationtitlePhD in Chemical Engineering
cam.supervisorSlater, Nigel
rioxxterms.freetoread.startdate2017-11-28


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