Vapour pressure is an important property in the chemical and engineering industries. There are / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, 2007

Thesis (MScEng)--University of Stellenbosch. / ENGLISH ABSTRACT: Aerosol synthesis involves the formation of condensable product species by gas-phase reaction, and the simultaneous growth of particles by coagulation. For the production of ceramic particles, reaction temperatures higher than 700 K are commonly used, and a maximum fusible particle size is observed. Coagulation-controlled growth yields spherical particles up to the maximum fusible size (approximately < 50 nm). Such particles coalesce rapidly and completely upon collision with other particles, whereas larger particles reach a meta-stable equilibrium for solid-state coalescence. Agglomerates with weak Van der Waal's bonds between particles inevitably form in the cooling/collection process. Coagulation of particles larger than the maximum fusible particle size yields agglomerates with significant neck growth between the primary particles. Spherical ceramic particles in the order of 1 J-Lm are favourable precursors for bulk electronic applications that require high purity. Such large spherical particles may possibly be produced in conditions of seed growth, which involves the deposition of small newly formed clusters onto larger existing particles. The central focus of the present work is to evaluate whether spherical ceramic particles significantly larger than the maximum fusible size may be produced by seed growth. The evaluation is done by modelling of process constraints and interpretation of published results. The modelling of constraints is based on a mathematical framework for comparison of different values of reactor design parameters. This framework comprises a simplified model system, a typology of quantities, and isolation of a set of independent design parameters. Comparison is done on the basis of fixed initial (seed) and final (product) particle sizes. The reactor design framework is used to evaluate the hypothesis on spherical seed growth, by assessing whether a reactor can be designed that satisfies all the process constraints. Future extension of the framework may allow optimisation for seed growth in general. The model system assumes laminar flow and isothermal conditions, and neglects the effect of reactor diameter on wall-deposition. The constraints are graphically represented in terms of the design parameters of initial reactant concentration and seed concentration. The effects of different temperatures and pressures on the constraints are also investigated. In a separate analysis, the suitability of turbulent flow for seed growth is assessed by calculating Brownian and turbulent collision coefficients for different colliding species. As turbulent intensity is increased, the seed coagulation rate is the first coagulation rate to be significantly enhanced by turbulence, resulting in a lowering of the maximum seed concentration allowed by the constraint for negligible seed coagulation. This tightening of a constraint by turbulence is the justification for considering only laminar flow for evaluating the hypothesis on spherical seed growth. Quantitative application of the model of constraints, as well as experimental and modelling results from the literature, did not demonstrate that significant spherical seed growth is possible without seed coagulation (agglomeration). As part of the conceptual effort in becoming familiar with aerosol reactor engineering, a simple two-mode plug-flow aerosol reactor model was developed, and verified with published results. This model has some novel value in that it translates the equations for aerosol dynamics into the terminology of reactor engineering. / AFRIKAANSE OPSOMMING: Aerosol sintese behels die gelyktydige chemiese vorming van 'n kondenseerbare spesie en die groei van partikels deur koagulasie. Temperature hoër as 700K word gewoonlik vir die aerosol sintese van keramieke gebruik. Partikels bo 'n sekere grootte kan nie saamsmelt nie. Koagulasie- beheerde groei lewer sferiese partikels tot en met die maksimum saamsmeltbare partikelgrootte (ongeveer < 50 nm). Wanneer sulke partikels bots, smelt hulle vinnig en volledig saam. Groter partikels bereik egter 'n meta-stabiele ewewig vir vastestof samesmelting. Agglomerate met swak Van der Waal's bindinge tussen partikels vorm onvermydelik wanneer die aerosol afgekoel word en die produk versamel word. Koagulasie van partikels groter as die maksimum saamsmeltbare grootte, lewer agglomerate met noemenswaardige nekvorming tussen primêre partikels. Sferiese keramiekpartikels in die ordegrootte van 1Mmis geskikte intermediêre produkte vir die vervaardiging van soliede eletroniese komponente waarvoor hoë materiaalsuiwerheid vereis word. Sulke groot sferiese partikels kan moontlik geproduseer word in toestande waar klein nuutgevormde partikels deponeer op groter bestaande partikels (saadpartikels). Die hoof-fokus van die huidige werk is om vas te stelof sferiese keramiekpartikels wat noemenswaardig groter is as die maksimum saamsmeltbare grootte, geproduseer kan word met die metode van saadpartikel-groei. Die moontlikheid word ondersoek deur 'n model van prosesbeperkings te maak, en deur gepubliseerde resultate te vertolk. Die model van prosesbeperkings is gegrond op 'n wiskundige raamwerk vir die vergelyking van verskillende waardes van reaktor ontwerp-parameters. Hierdie raamwerk bestaan uit 'n vereenvoudigde model-sisteem, 'n tipologie van verskillende soorte groothede, en die identifikasie van 'n stelonafhanklike ontwerp-parameters. Verskillende parameter-waardes word vergelyk vir dieselfde aanvanklike (saad) en resulterende (produk) partikelgroottes. Die reaktorontwerp-raamwerk word gebruik om die hipotese van sferiese saadpartikel-groei te evalueer, deur vas te stelof 'n reaktor ontwerp kan word wat aan al die prosesbeperkings voldoen. Mettertydse verfyning van die raamwerk kan dit moontlik geskik maak vir die optimering van saadpartikel-groei in die algemeen. Die model-sisteem is gebaseer op die aannames dat vloei laminêr en temperatuur konstant is, en die effek van reaktor-diameter op deponering op die reaktorwand word verontagsaam. Die posesbeperkings word grafies voorgestel in terme van oorspronklike reaktant-konsentrasie en saadpartikel-konsentrasie. Die effek van verskillende temperature en drukke op die prosesbeperkings word ook ondersoek. 'n Systaande ondersoek word gedoen oor die toepaslikheid van turbulente vloei vir saadpartikel- groei, deur botsings-koeffisiënte vir Brown-beweging en turbulensie te vergelyk. Wanneer turbulensie verhoog word, styg die koaguleringstempo van saadpartikels beduidend voordat ander koaguleringstempo's beduidend toeneem. Dit noodsaak 'n verlaging in die maksimum toelaatbare saadpartikel-konsentrasie om saadpartikel-koagulasie te verhoed. Hierdie verskerping van 'n prosesbeperking deur turbulente vloei, is die rede hoekom slegs laminêre vloei beskou word in die evaluering van die hipotese van sferiese saadpartikel-groei. Kwantitatiewe toepassing van die model van beperkings, asook eksperimentele en modellerings- resultate vanuit die literatuur, het nie getoon dat noemenswaardige groei van sferiese keramiekpartikels verkry kan word sonder saadpartikel-koagulasie (agglomerasie) nie. As deel van die proses om aerosol reaktor-ingenieurswese konsepsueelonder beheer te kry, is 'n eenvoudige twee-modus propvloei aerosol reaktor modelontwikkel. Die resultate van die model is bevestig deur vergelyking met gepubliseerde resultate. Hierdie model het die nuwigheid dat dit die vergelykings vir aerosol dinamika uitdruk in die terminologie van reaktor-ingenieurswese.

Sasol's Research and Development Division has identified several proprietary gas-liquid reactions where very low superficial gas velocities « 0.8 cmls) are required to obtain desired conversions in a bubble column reactor. A review of existing literature has shown that research in bubble column reactors is typically conducted in the superficial gas velocity range of 1 - 40 cmls. Traditionally bubble column reactors are designed via the application of empirical correlations which are only valid under specific conditions. There is a danger of under or over design if incorrect nonadjustable parameters such as liquid dispersion coefficients, mass transfer coefficients and gas hold-up values are used. To this extent, a hydrodynamic study was undertaken at superficial gas velocities lower than 0.8 cmls, to determine whether existing correlations are valid in this little investigated superficial gas velocity regime. Three bubble column reactors were designed and set up to perform hydrodynamic studies: • 22 cm inner diameter QVF glass column, 190 cm tall • 30 cm inner diameter 304 stainless-steel column, 200 cm tall • 30 cm inner diameter QVF glass column, 80 cm tall All measurements were undertaken in an air/water system. Gas hold-up measurements revealed that at the investigated gas flow rates, the gas hold-up was less than 1 % and as such was not investigated extensively. Partition plates were installed into the bubble columns and residence time distribution measurements were undertaken. The bubble columns were found to behave identically to the well known tanks in series model (Levenspiel, 1962). Liquid dispersion coefficients were measured via two methods. Batch liquid measurements were undertaken via the method of Ohki and Inoue (1970) and continuous liquid residence time distribution measurements were also undertaken. Data reduction was performed for both methods using the axial dispersion model to regress the liquid dispersion coefficient EL_ Both methods yielded equivalent results. The effect of distributor plate geometry on EL was also investigated and proved not to affect EL. It was found that existing literature correlations developed at higher superficial gas velocities failed to accurately predict the measured dispersion coefficients obtained in this study_ Correlation of the EL values with column diameter and superficial gas velocity showed EL to be a weak function of diameter as compared to existing correlations. This will have a significant effect on scale-up to larger column diameters. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2005.

The aim of the thesis was to optimise the separation and purify an amino acid solution consisting of mono-valent amino acids. Amino acids have historically been separated by chromatographic separation for analytical requirements but separation commercially has not been possible due to the close physical and chemical properties of the amino acids. The study looks at two amino acids, isoleucine and alpha amino butyric acid and used operating and process variables to conclude whether a commercial application is possible. A 3m glass column operating at atmospheric conditions was set up in the development laboratory at SA Bioproducts for test work. Pulse tests were carried out to evaluate the separation of the individual amino acids and the samples were analysed using HPLC. The column incorporated a jacket which allowed for constant temperature during the experiments. Experiments started initially with the column being tested for hydraulic consistency and this was done using resin in the Na+ ionic form and passing a NaCI feed stream over the resin as a pulse. A base case was chosen and this using a feed volume of 0.1 bed volume, an eluant flow of 1 bed volume per hour, feed concentrations of 2% and an operating temperature of 75°C. The resin was used in the Na+ ionic form, with a particle size of 320llm, and a height of 1.5m. Results of the base case indicated a low resolution of 38%, and low recoveries at 11.85% at purities of 86%. Evident from the chromatogram was that isoleucine was held more strongly than AABA by the resin as isoleucine was eluted last. Increasing the concentration of the feed to 4% moved the peaks closer and caused more overlapping thereby decreasing the recovery. Decreasing the concentration resulted in better separation. From the results it was concluded that the separation was dependant on concentration. The next variable which was studied was the effects of changing the feed pulse volume. For this the feed volume was increased to 0.2BV and this ended up shifting the chromatogram to the right, with lower separation efficiency being measured. The effects of eluant flowrate were studied next. Decreasing the eluant flowrate to O.SBVIh resulted in sharper peaks and less overlapping. The conclusion reached was that the higher the contact time between the amino acids and the resin, the greater would be the separation efficiency. Increasing the flowrate of the eluant reduced the contact time and more overlapping was observed. The effects of temperature were also investigated. The experiment carried out at 90°C, showed very similar separation to the base case with higher recoveries. Decreasing the temperature to 30°C decreased the separation efficiency drastically. The experiments proved that an increase in temperature increased the kinetics, and allowed the amino acids to enter and exit the bead quicker. Once operating conditions have been evaluated, the resin was converted to the Ca2+ ionic form, and all other conditions were run according to the base case. ' From the chromatogram it was obvious that the amino acids were held more strongly by the resin and the retention time was increased thereby increasing the recovery. Changing the particle size of the resin from 320~m to 220~m increased the separation efficiency due to the faster kinetics. Increasing the height of the resin was attempted by adding more resin to the column. The separation efficiency was increased. Finally a optimised experiment was attempted where a 2% feed solution was used, feed volume was 0.1 BV, temperature of 90°C, eluate flow of O.SBV Ih, resin in the Ca2+ ionic form, with a particle size range of. 21 0-230~m, and resin height of 1.8m. The chromatogram indicated high peak separation efficiencies and high recoveries. The results indicated that the study was feasible. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2005.

Human consumption of water contaminated with faecal polIutants is the source of most sanitation related diseases. Excreta related diseases can be controlIed by improvements in excreta disposal. The primary consideration is to remove contact between the people and the faecal matter. The conventional waterborne sewage system is not an achievable minimum standard in dense peri-urban areas in the short term, due to its high cost. A need for a cost effective system that is easily maintained and does not require electricity or highly skilled labour for developing communities in South Africa was identified. The objective of this investigation was to assess the suitability of the Anaerobic Baffled reactor (ABR) as a primary onsite treatment system for low-income communities. The ABR is a high-rate compartmentalised anaerobic bioreactor, the design of which promotes the spatial separation of microorganisms. The trials were conducted on a 3200 L pilot-scale reactor placed at Kingsburgh wastewater treatment works, which receives only domestic wastewater. The ABR proved to be stable and consistent in its performance. Operating at a hydraulic retention time of 22.5 h, the reactor effiuent was ca. 200 mgCODIL. The 0,45flm filtered (soluble) COD was 100 mgIL, indicating there was approximately 100 mgIL of COD in the effluent that was in particulate form. The ABR achieved 60%VSS and 50%TSS removal with effiuent TSS content of about 225 mgIL. The system was hydraulicalIy overloaded and organicalIy under loaded. The Biochemical Methane Potential tests showed that 60% of the COD in the effiuent was biodegradable, and the effluent COD could be reduced to less than 100 mgCODIL if the HRT is increased giving a possible removal of 80%. The analytical campaign revealed that we were sampling at peak flow, when COD was high. The average COD fed to the reactor was much lower than that showed by routine analysis and the ABR had a "true" COD removal of 42%. The reactor was able to handle the daily variation ofthe wastewater. Settling tests were done to measure how much of the suspended solids in the ABR are retained at the operating upflow velocity. The method selected was shown to have an error that ranged from 5 to 42%, and the ABR was retaining between 60 and 90% ofsolids in the reactor at an upflow velocity of O.5m/h. The preliminary work with the fabric membrane showed great potential benefits that can be gained if it had to be included. It showed good ability to remove indicator organism and solids that contributed a lot to the effiuent COD. The membrane had 5 log removal of indicator organism and 80% reduction of COD. The membrane was operated for a short time before clogging; its operational lifespan needs to be greatly extended before it can be used with the reactor in a community. Since there is no nutrient removal in the AER, the effiuent can be used for food production provided sufficient pathogens removal is achieved. Provided that the first compartment can be modified and the concentration of pathogens in the effluent is sufficiently reduced, the ABR can be considered for use in a community. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2005.

The vapour recirculation apparatus of Moodley [2002] was modified, reconstructed, and commissioned in order to be used in the acquisition of high-pressure vapour-liquid equilibrium (HPVLE) data at low temperatures. The original equipment of Moodley [2002] was modified with the aim of achieving the desired operating temperature range which the original equipment was unable to achieve. Major modifications were carried out on the cooling circuit allowing the equipment to reach temperatures as low as -30°C, a significant improvement to the original equipments minimum attainable temperature of -5°C. Modifications were also successfully carried out on the vapour recirculation pump of Moodley [2002], which failed when operated over extended periods at high pressures thus enabling the equipment to operate at pressures up to 10.0 bar, an improvement on the previous pressure operating limit of 6.9 bar. The operating limits of the equipment were tested through measurement of pure-component vapour-pressures of isopentane at temperatures between -14 and +27.9°C and pressures up to 10.1 bar and on propane at temperatures between -30.1 and +26.0°C and pressures up to 9.7 bar. The isopentane vapour-pressure measurements had an average deviation of ±0.49% when compared to literature data while the propane vapour-measurements had a maximum average deviation of ±0.35% when compared to literature data indicating that the equipment was capable of measuring accurate vapour-pressure data at temperatures down to -30°C and pressures up to 10.0 bar. The equipment was thereafter used in the acquisition of binary HPVLE data. Considerable time was spent developing and practicing the techniques used in the binary HPVLE measurements. Binary measurements were performed on the test system propane + 1- propanol at 19.9°C. To gain more confidence in the binary HPVLE measurements another test system, propane + isopentane was selected and binary HPVLE measurements were performed at 25°C and 0°C. The equipment was able to reproduce relatively accurate binary HPVLE results for the test systems at the selected isotherms. The equipment was thereafter used in the acquisition of a new set of binary HPVLE data for the propane + isopentane system at -10°C however owing to time constraints and chemical availability the acquisition of a complete set of data was not possible. The binary HPVLE data was thereafter regressed via the direct method. The Peng-Robinson (PR) equation of state (EOS) and the Soave-Redlich-Kwong (SRK) EOS were each coupled with the Mathias Copeman alpha function together with the Wong-Sandler mixing rule and the NRTL local composition model and applied to the binary systems at each of the isotherms investigated. Regressed data showed a relatively good agreement with measured experimental data for both binary systems investigated at all of the isotherms except the new -10°C isotherm of the propane + isopentane system. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.

During the course of this thesis the UNIFAC method (group-based method) was regressed to individual Px(T) binary datasets, and the results are compared to the regression results using the Wilson, NRTL, and UNIQUAC equations (component-based models). It is shown that these component-based methods best represent the experimental data when the comparisons are restricted to those systems defined by only two UNIFAC maingroups. For those systems requiring three or more maingroups, however, the regressions using the UNIFAC method (i.e. the group-based approach) are shown to provide the best reproducible results. Evaluations are also presented on the ability of the UNIFAC and mod. UNIFAC (Do.) methods to reproduce experimental activity coefficients at infinite dilution for single and co-solvent systems. For the case of single solvent-systems the newly developed MRR combinatorial expression (Moller, 2010) is evaluated as a direct combinatorial replacement for both methods, although it was originally developed only for estimating activity coefficients at infinite dilution in alkane-solvents. Overall, it is shown that the best results are obtained using the mod. UNIFAC (Do.) method, and that poor results are obtained when trying to use the MRR combinatorial as a direct combinatorial replacement in either method (for systems other than alkane-solvents). Given the favourable results obtained using the mod. UNIFAC (Do.) method, the model was used to generate pseudo data points at multiple temperatures for regression using the NRTL equation, where parameters quadratic in temperature were fitted. It is shown that one may introduce unnecessary errors when translating these predictions into the model parameters of the NRTL equation. In order to eliminate these potential “losses in translation,” a new liquid activity coefficient model/methodology is being proposed. Instead of using group contribution methods as second-choice data generators, it is proposed that these predictive methods be employed in a more direct fashion in process simulations. Instead of regressing experimental data using component-based methods such as NRTL and Wilson, the error in the predicted results are regressed by layering one of these methods on top of a group contribution method like mod. UNIFAC (Do.). This is the fundamental idea behind the proposed hybrid methodology/models. Results are presented for two hybrid models, where the NRTL and Wilson equations are used to correct for the predictions made using the mod. UNIFAC (Do.) method. These methods are being called NRTL-FAC(Do.) and Wilson-FAC(Do.) respectively. In most cases, it is shown that the overall regression results using these new models are as good as or better than the individual models making them up. All experimental data used in this dissertation was obtained from the Dortmund Data Bank (DDBST Software and Separation Technology GmbH, 2009), and all predictions made using the UNIFAC and mod. UNIFAC (Do.) methods were calculated using the Consortium parameters (The UNIFAC Consortium, 2008). / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.

The determination of limiting activity coefficients in liquid mixtures has become an important tool in chemical engineering. It has been investigated intensively during the past in order to find new alternatives and improved methods for its accurate detennination. The limiting activity coefficient is a fundamental thermodynamic quantity which measures the solution non-ideality and acts as a correction factor to deviations from Raoult's Law. This dissertation involves the determination of limiting activity coefficients using the inert gas stripping (IGS) technique only. It is considered to be the best method as it is a direct method involving exact concentrations of components in the mixtures encountered in industry. A comprehensive study of activity coefficients at infinite dilution for various systems, using the inert gas stripping (IGS) method has been undertaken. Various other methods and their suitability have also been discussed but preference is given to the superior quality of measurements obtained using the inert gas stripping technique. Extensive research has been conducted into the background and origination of the technique. Various improvements of the equilibrium cell designed by various authors for different types of systems have been outlined along with the various equations derived by the authors. The equipment was designed for use with the double-cell technique as well as the single-cell technique and in some cases both techniques were used. The techniques involve the use of a dilutor cell in which the highly diluted, volatile solute is stripped from a liquid solution using the inert gas nitrogen, introduced into the cell through capillaries and dispersed through the solution as small bubbles, at a constant flow rate. Analysis of the stripped solution is accomplished through the use of a gas chromatograph; the peak areas obtained from these analyses as well as the residence times and other system data such as temperature, pressure, mass and flow rate were used to compute the infinite dilution activity coefficient through the use of the various equations available in literature. The original equipment was designed for the use of the single cell technique by Soni (2004). Various modifications have been made to the equipment in order to measure limiting activity coefficients of more diverse systems with high accuracy. A major change to the equipment was the introduction of a second saturation cell of similar design to the dilutor cell. This enabled the determination of activity coefficients at infinite dilution of difficult systems i.e. systems where the solvent volatility is high and for higher order systems. The equipment was redesigned and built using ideas and improvements by previous researchers in the field and commissioned using test systems that have been classed as easy systems for this technique. The new equipment is now applicable to almost all systems, however good separation in the GC column could be a problem for complex systems. The determination of infinite dilution activity coefficients for one-component solute + onecomponent solvent systems and multi-component solvent systems were accomplished. The systems that were investigated consisted of a mixture of components of alkanes, alkenes, phenols and ketones, mostly in binary mixtures. Multi-component mixtures have also been investigated in the form of ternary systems involving a binary solvent mixture at varying concentrations, and a solute in order to show the diversity, uniqueness and efficiency of the IGS technique. Major variables affecting the system (the dilutor cell), namely the stripping gas flow rate and the dilutor cell temperature, were also investigated for all systems. Two test systems, cyclohexane in 1-methyl-2-pyrrolidone (NMP) and n-heptane in NMP were used to determine if the equipment is operating properly by comparing values obtained, to literature values where the inert gas stripping technique was used to determine the activity coefficients at infinite dilution. Another test system n-hexane in NMP was used to compare the two techniques, Le. the results of the single cell technique with the results of the double cell technique. The experimental results were thereafter compared to published literature values. Systems where the inert gas stripping technique has not been used to determine activity coefficients at infinite dilution were also investigated. These systems include 1-hexene in 0- cresol as well as the ternary systems '-hexene in various concentrations of NMP + o-cresol. A thorough literature survey has been completed and the relevant theory has been summarized. The validity of the equations proposed by Bao and Han (1995), Duhem and Vidal (1978), Leroi et a!. (1977), Hovorka and Dohnal (1997) and Krummen et al. (2000) for the determination of activity coefficients at infinite dilution were investigated. The experimental values obtained were consistent with literature values, with percentage errors of less than 1 % where the same equation was used to determine the limiting activity coefficient. Comparing limiting activity coefficients with the values obtained from other equations proposed by other authors mentioned above resulted in deviations no greater than 2.5 %, and where possible limiting activity coefficients were compared to values obtained from the single-cell technique. The theory section of this thesis covers all the various formulae (and where possible a summary of their derivation) used in the analysis of results. Some limiting activity coefficients for the systems involving n-heptane, n-hexane, n-hexene, cyclohexane, o-cresol and n-methyl-2-pyrrolidone under various experimental conditions have been reported making it readily available for use in other works. The effect of two major variables temperature and inert gas flow rate on the limiting activity coefficients with regard to all the systems studied have also been investigated and reported. This was also done in order to check that the data was reproducible. A sensitivity analysis was also performed in order to check the effect that certain measured variables would have on the limiting activity coefficient. These errors are estimated possible errors and may not exist at all, so not much consideration was given to this when reporting limiting activity coefficients for the various systems. The maximum error range for any given limiting activity coefficient as determined by the sensitivity analysis is ±11 %. The inert gas stripping technique is also extended to the determination of Hendry's constants. The actual values for the Hendry's constants were not determined but a comprehensive study of its determination was undertaken by Miyano et al. (2003) and summarized here. In addition the suitability and diversity of the inert gas stripping technique has been outlined, along with the advantages and disadvantages of the technique. The various designs of equilibrium cells have been outlined taking into account mass transfer considerations as proposed by Richon et al. (1980). The assumptions and limits of the method have also been outlined and must be taken into consideration when using the technique. A detailed description of the equipment setup and experimental procedure has been provided. The purpose, suitability, operation and applicability, of the various pieces of equipment used to make up the final equipment have been discussed in detail. Details for consideration when designing the equilibrium cells have also been provided. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2008.

The chemical and process industries rely largely on filtration processes to separate solid-liquid process / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.

A number of industrially relevant separation processes involve carboxylic acids. Carboxylic acids are also amongst the various oxygenated products found in aqueous waste streams or as by-products of industrial operations in Sasol’s Fischer Tropsch processes. Other by-products include alcohols and ketones. Accurate vapour-liquid-equilibrium (VLE) data are required for the efficient and optimal modeling and simulation of these processes. In addition, removing and separating these components will help to prevent their pollution and the associated impact on the environment. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2009.