Chemical and Biomolecular Engineering - Research Publications
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ItemReview of Membranes for Helium Separation and Purification(MDPI, 2017-03)Membrane gas separation has potential for the recovery and purification of helium, because the majority of membranes have selectivity for helium. This review reports on the current state of the research and patent literature for membranes undertaking helium separation. This includes direct recovery from natural gas, as an ancillary stage in natural gas processing, as well as niche applications where helium recycling has potential. A review of the available polymeric and inorganic membranes for helium separation is provided. Commercial gas separation membranes in comparable gas industries are discussed in terms of their potential in helium separation. Also presented are the various membrane process designs patented for the recovery and purification of helium from various sources, as these demonstrate that it is viable to separate helium through currently available polymeric membranes. This review places a particular focus on those processes where membranes are combined in series with another separation technology, commonly pressure swing adsorption. These combined processes have the most potential for membranes to produce a high purity helium product. The review demonstrates that membrane gas separation is technically feasible for helium recovery and purification, though membranes are currently only applied in niche applications focused on reusing helium rather than separation from natural sources.
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ItemData in brief on CO2 absorption-desorption of aqueous-based amino acid solvents with phase change behaviour(Elsevier, 2019-12-01)The data presented in this paper are related to the published research article “Development of aqueous-based phase change amino acid solvents for energy-efficient CO2 capture: The role of antisolvent” [1]. The raw and analyzed data include the equilibrium and kinetics of CO2 absorption, the density and concentration of different CO2-containing species at upper and lower liquid phases, and particle size distribution of solid particles precipitated during CO2 absorption of aqueous and aqueous-based amino acid solvents. In addition, the SEM images of solid precipitates at the end of CO2 absorption are presented. The detailed values of this phase change amino acid solvent are crucial for large-scale implementation of CO2 capture systems with phase change behavior.
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ItemPolymer of Intrinsic Microporosity (PIM-1) Membranes Treated with Supercritical CO2(MDPI AG, 2019-03-18)Polymers of intrinsic microporosity (PIMs) are a promising membrane material for gas separation, because of their high free volume and micro-cavity size distribution. This is countered by PIMs-based membranes being highly susceptible to physical aging, which dramatically reduces their permselectivity over extended periods of time. Supercritical carbon dioxide is known to plasticize and partially solubilise polymers, altering the underlying membrane morphology, and hence impacting the gas separation properties. This investigation reports on the change in PIM-1 membranes after being exposed to supercritical CO2 for two- and eight-hour intervals, followed by two depressurization protocols, a rapid depressurization and a slow depressurization. The exposure times enables the impact contact time with supercritical CO2 has on the membrane morphology to be investigated, as well as the subsequent depressurization event. The density of the post supercritical CO2 exposed membranes, irrespective of exposure time and depressurization, were greater than the untreated membrane. This indicated that supercritical CO2 had solubilised the polymer chain, enabling PIM-1 to rearrange and contract the free volume micro-cavities present. As a consequence, the permeabilities of He, CH4, O2 and CO2 were all reduced for the supercritical CO2-treated membranes compared to the original membrane, while N2 permeability remained unchanged. Importantly, the physical aging properties of the supercritical CO2-treated membranes altered, with only minor reductions in N2, CH4 and O2 permeabilities observed over extended periods of time. In contrast, He and CO2 permeabilities experienced similar physical aging in the supercritical treated membranes to that of the original membrane. This was interpreted as the supercritical CO2 treatment enabling micro-cavity contraction to favour the smaller CO2 molecule, due to size exclusion of the larger N2, CH4 and O2 molecules. Therefore, physical aging of the treated membranes only had minor impact on N2, CH4 and O2 permeability; while the smaller He and CO2 gases experience greater permeability loss. This result implies that supercritical CO2 exposure has potential to limit physical aging performance loss in PIM-1 based membranes for O2/N2 separation
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ItemOrganic solvent nanofiltration of binary vegetable oil/terpene mixtures: Experiments and modelling(ELSEVIER, 2019-03-01)Bio-derived solvents such as ρ-cymene, d-limonene and α-pinene represent feasible alternatives to n-11 hexane for the extraction of vegetable oils. However, the large-scale utilization of these solvents is 12 still limited mainly owing to their high boiling points and latent heats of vaporization. In this work, the 13 performance of composite polydimethylsiloxane/polyacrylonitrile (PDMS/PAN) organic solvent 14 nanofiltration membranes in the recovery of these solvents from their binary mixtures with canola oil 15 is investigated. The sorption isotherms of the mixtures were first studied using free-standing PDMS 16 films and the multicomponent Flory-Huggins model used to determine the resulting interaction 17 parameters. The partial solvent uptake decreased with increasing oil concentration in the mixture. On 18 the other hand, the partial oil uptake in the solvent mixture was higher than that of the pure oil which 19 was attributed to the swelling effects induced by solvents. The effects of feed concentration (10-30 20 wt. % oil), feed temperature (25-40 °C), transmembrane pressure (5-30 bar), and cross-flow velocity 21 (18-52 cm s-1) on the membrane performance were then studied in a cross-flow membrane setup. 22 Maxwell-Stefan formulations were combined with the ternary Flory-Huggins solubility model to 23 successfully describe these flux data.
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ItemTransport of terpenes through composite PDMS/PAN solvent resistant nanofiltration membranes(ELSEVIER SCIENCE BV, 2018-12-22)
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ItemCO2 capture from pre-combustion processes-Strategies for membrane gas separation(ELSEVIER SCI LTD, 2010-09)
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ItemEnhancing gas permeability in mixed matrix membranes through tuning the nanoparticle properties(ELSEVIER SCIENCE BV, 2015-05-15)
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ItemThe potential for use of cellulose triacetate membranes in post combustion capture(ELSEVIER SCI LTD, 2016-12)