Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.807966
Title: Studies of intensified liquid-liquid extractions in small-channel contactors and their scale-up
Author: Garciadiego Ortega, Eduardo
Awarding Body: UCL (University College London)
Current Institution: University College London (University of London)
Date of Award: 2020
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Abstract:
This thesis presents a series of investigations focused on scaling-up intensified liquid-liquid flow processes from single-channel to commercial-scale. The process investigated consists of liquid-liquid extractions of U(VI) from nitric acid to an organic phase. These extractions are relevant to the safety and sustainability of the nuclear fuel cycle. The intensified contactor consists of a tee-junction feeding to a channel with small internal diameter (1 to 4 mm) operating under segmented flow pattern. Segmented flow contactors intensify liquid-liquid extractions in uranium recovery processes because they provide intense mixing, short diffusion distances, and large interfacial area at low energy input. Using high-speed imaging, UV-Vis spectroscopy, pressure gradient measurements, and dimensional analysis, the operation and design trade-offs are quantitatively identified with focus on scale-up. A finite-element model is used to corroborate the experimental mass transfer results. The scale-up is achieved via numbering-up, which increases the number of process units instead of making one larger unit. Economic parallelisation requires effective flow distribution. Multiphase flow distribution has been a persistent problem in the path towards commercialisation. This problem is addressed by modelling a double manifold with a resistance network model and a novel method to quantify maldistribution, derived from multivariate statistical analysis. The relationships between the hydraulic resistances with maldistribution, pumping power, and the number of channels are quantified. Finally, the single-channel results and the flow distributor model are used to design, build, and test a modular multichannel segmented flow contactor prototype. The design and commissioning steps are described along with the experimental maldistribution results, including flow distribution and mass transfer results. The multichannel contactor can be operated with different number of channels at any time, thus changing a long-standing paradigm in reactor design. This promises to accelerate process development by facilitating the transition from bench to pilot and commercial scales.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.807966  DOI: Not available
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