An extensive experimental programme tested an l-SEP unit with air and water. This provided data on the separation efficiency and pressure drop across the l- SEP, as they varied with changing inlet conditions, geometry and outlet restrictions. The main conclusion from this work is that the resistance on the outlets directly affects the efficiency of the separator. Although it is possible to optimise the performance by changing 'the geometry, a small change in inlet conditions, common in oil and gas applications, causes the performance to change. _By using an identified relationship between the differential pressure and the operating conditions, an optimum performance over a much wider range of inlet conditions can be achieved. This work has contributed to the field of gas/liquid separation in axial-flow cyclones by demonstrating that manipulating the differential pressure between the outlets can control the separation efficiency. The relationship developed between the optimum differential pressure and the inlet conditions has not been identified in any of the literature available at the time of this work.

No description available.

Studies of analytical systems involving onium and basic dye cations and solvent extraction methods. The original intention of this project was to study selected onium extractions in continuation of previous work carried out in this laboratory. The extraction of Cr(VI) with onium salts into organic solvents had been studied by previous workers who had shown that Cr(VI) could just as readily be extracted from acid solution without the addition of an onium salt. A study has been made of the effect of various onium compounds, and different organic solvents on this extraction. The effect of pH, as well as interfering ions was studied. In the present study, in spite of the colour stability of the complex and the coefficient of variation being 0.4%, a low apparent molar absorptivity was obtained.

No description available.

No description available.

The application of pervaporation to the dehydration of aprotic solvents was investigated in this study. The performance of a commercial membrane, Celfa CMC-VP-31, was evaluated for the dehydration of tetrahydrofuran (THF) and dimethylformamide (DMF). The membrane was demonstrated to successfully dehydrate THF and calculations of water and THF permeance performed. When the membrane was applied to the dehydration of DMF, delamination of the top selective layer was observed and thus the membrane was deemed unsuitable for DMF dehydration. ' Polyaniline (PAni) was identified as a suitable candidate polymer for the formation of an aprotic solvent stable hydrophilic pervaporation membrane. PAni was synthesised in the lab and preparation conditions optimised and scaled-up to produce polymer with consistent batch to batch properties, in suitable quantities, to fabricate���· membrane sheets with sufficient surface area for testing. Casting solutions comprising of 20 wt% PAni were stabilised using an amine, 4-methyl piperidine, to prevent gelation and cross-linking prior to casting. Membranes were cast on a polyester non-woven backing and phase inverted in water to produce an asymmetric membrane structure. Scanning Electron Microscopy was used to examine the structure of the membranes formed. The effects of thermal treatment on the membrane film and polymer were investigated by a number of analytical techniques in order to devise a suitable procedure for membrane stabilisation. Thermally cross-linked PAni membranes were demonstrated to be water selective and stable in THF, DMF, ethyl acetate and ethanol. Permeance correlations with temperature were constructed to describe the performance of the membrane discs tested during solvent dehydration and compared to experimental data. Transport across the membrane was reported to be solubility dominated for all of the solvent systems tested. Finally, an examination of the reproducibility of membrane performance was made and further tests performed, to better understand variations observed in membrane pervaporation performance.

No description available.

No description available.

No description available.

This work was carried out to investigate whether Marangoni convection would occur during the absorption of carbon dioxide into amine and amine/carbonate solutions in a packed column and a stirred cell in which the liquid was in turbulent flow regime and liquid surface was periodically and randomly renewed. In addition, the present investigation was extended to study the kinetics of the reaction of carbon dioxide with amine and amine/carbonate solutions and the effect of increased temperature (i.e. 25°C - 40°C) on the reaction rates and Marangoni convection in the above solutions in the stirred cell. By desorbing an inert tracer oxygen with the simultaneous absorption of carbon dioxide into amine and amine/carbonate solutions in the packed column and the stirred cell respectively, it was shown that the physical liquid-phase mass transfer coefficient was substantially increased by the CO2-amine and C02-amine/carbonate chemical abosrption processes. Hence, the occurrence of Marangoni convection in the liquid-phase in these two systems was confirmed. It was also observed that the intensity of Marangoni convection could be inhibited by the presence of stagnant film of contaminants in the packed column and completely suppressed in the stirred cell. Marangoni convection was found to be more pronounced in amine/carbonate solutions than in amine solutions of the same feed concentration of amine. The reasons for this behaviour was discussed. The intensity of Marangoni convection was also found to show a tendency of decrease with the increase of temperature. Under the present investigation condition, from the experimental results, the reaction of carbon dioxide with monoethanolamine (MEA) appeared to follow simple second-order chemical reaction kinetics. However, the rate of absorption of C02 into aqueous diethanolamine (DEA) solution was consistent with the kinetics reported by other workers who found the reaction being overall third order. Besides, the experimental results appeared to indicate that the reaction of carbon dioxide and DEA was catalysed by CO2 ion in DEA/carbonate solutions. The reaction rate constant for each of the systems mentioned was calculated. Finally, the values of the equilibrium constant, Keq, for MEA and DEA were determined at 25°C and 40°C respectively and were found to be in fairly good agreement with the corresponding values reported by previous workers.