Show simple item record

dc.contributor.authorBrown, Jacob Leslie
dc.date.accessioned2018-07-02T10:29:01Z
dc.date.available2018-07-02T10:29:01Z
dc.date.issued2018-07-20
dc.date.submitted2018-06-29
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/277690
dc.description.abstractThis thesis is dedicated to the exploration of fluid phases confined in nanoporous materials using Nuclear Magnetic Resonance (NMR) techniques, with an aim to benefit catalysis research. Included in this report are studies of pure fluids and their mixtures, confined in titania and silica catalyst supports. These investigations are conducted at industrially-relevant, high-temperature (≥ 180 °C) and high-pressure conditions (up to 13 bar), made possible by a pilot-scale chemical reactor unit, designed to operate inside the strong magnetic fields of an NMR spectrometer. NMR spectroscopy, relaxation and pulsed field gradient (PFG) diffusion experiments were performed on each of the systems discussed in this report. Cyclohexane was initially studied inside a porous titania catalyst support at 188 °C and various pressures up to 13 bar. The adsorption and desorption processes of the cyclohexane were observed, revealing a number of previously unobserved phenomena. In addition to an overall, averaged diffusion coefficient, a slow diffusion coefficient was observed within the PFG NMR data attributable to surface diffusive processes occurring within the material. Additionally, T1 relaxation studies were found to provide experimental evidence for the differing configurations of adsorbed layers on the adsorption and desorption branch of the isotherm. Cyclohexane was subsequently studied alongside fluorobenzene in a series of silica catalyst supports of 6 nm, 10 nm and 20 nm pore size. In doing this, it was hoped that the multiple phenomena observed in the titania experiments might be deconvoluted, allowing a greater level of insight. The diffusivities of the fluids were found to differ significantly between the materials, and greater evidence was found of the slow-diffusing surface phase in each of the materials. Additionally, concentrations of cyclohexane and fluorobenzene in the gas and adsorbed layers inside the pore space were calculated via the results of the PFG NMR experiments, providing a map of confined phase behaviour. Competitive adsorption effects were found to become more significant, the smaller the pore size of the material. The results of the cyclohexane and fluorobenzene in silica studies were modelled, using approaches available in the literature, which were found to give varying levels of prediction. The data set acquired in this thesis was found to provide a useful standard, against which current and future models of confined phase behaviour might be verified. Jacob Leslie Brown
dc.description.sponsorshipCambridge Trusts Cambridge Australia Scholarships Trinity College IChemE Andrew Fellowship
dc.language.isoen
dc.rightsAll rights reserved
dc.rightsAll Rights Reserveden
dc.rights.urihttps://www.rioxx.net/licenses/all-rights-reserved/en
dc.subjectNMR
dc.subjectPFG
dc.subjectDiffusion
dc.subjectPhase Behaviour
dc.subjectNanopores
dc.subjectPorous Media
dc.subjectNitrogen Adsorption
dc.subjectBET
dc.subjectAdsorption
dc.subjectCatalysis
dc.subjectMesopore
dc.subjectMicropore
dc.subjectSurface Diffusion
dc.subjectFast Exchange
dc.subjectSilica
dc.subjectTitania
dc.subjectVapour-Liquid Equilibrium
dc.subjectVLE
dc.subjectEquation of State
dc.subjectEOS
dc.titleVapour-Liquid Equilibria within Nanoporous Media
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.updated2018-06-29T16:46:12Z
dc.identifier.doi10.17863/CAM.25028
dc.publisher.collegeTrinity College
dc.type.qualificationtitlePhD in Chemical Engineering
cam.supervisorGladden, Lynn Faith
cam.thesis.fundingfalse
rioxxterms.freetoread.startdate2018-06-29


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record