Thesis (Ph. D.)--State University of New York at Binghamton, Department of Chemistry. / Includes bibliographical references.

In this thesis, the aim was to develop resins which are platinum and gold specific to be utilized for the early removal of these metals from the industrial feed. Efforts were therefore directed towards the synthesis of silica based resins with active centra which were designed for platinum and gold specificity respectively. The large chlorometallate ions in the feed stream were characterized in terms of physical parameters relevant to phase distribution namely distortability (RD), charge density, softness (σ) etc. Matching cations for each of the types were investigated. In order to attempt the design of platinum specific resins different structural amines were used to aminate the silicone precursor and subsequently to fix these onto the silica framework. Two different solvents i.e. alcohol and dmf were used for this process, resulting in two sets of resins with different properties. For gold specific resins, various polyethers were attached to a different type of silicone precursor, which was attached to the silica framework. The design was based on previous experience with these ions with reference to their behaviour towards different types of cations. The platinum species PtCl6 2- and PtCl4 2-, the gold species AuCl4 -, as well as the most important contaminants in the feed stream were typified bearing in mind size, charge, charge density and distortability. Different types of cationic centra having differences in charge density, stereochemical crowding and extent of hydrophobicity were synthesized and tested both as solvent extractants (where possible) and silica based resins. The results indicated that partly screened secondary ammonium cationic resin species, which could be regarded as “intermediate”, proved to be satisfactory both in their high percentage extraction for PtCl4 2- and rejection of contaminants like chlororhodates, chloroiridates(III) and FeCl4 -. It was, however, necessary to work at a redox potential where iridium(IV) in the form of IrCl6 2- is absent. Various 2-aminoalkane resins were prepared with variation in the length of alkane group and synthesized in the two different solvents. The latter resulted in two sets of resins with different compactness also having significantly different properties with reference to platinum specificity, HCl effect and stripping potential. The 2- aminobutane and 2-aminoheptane resins both proved to be very satisfactory platinum specific resins with respect to selectivity, platinum capacity and stripping potential. The various physical parameters could be utilized to accommodate the chemical behaviour. To obtain gold specific resins, experiments were performed with resins having oxygen-donor atoms which can readily be protonated to form onium type cations for example amides and ether oxygen atoms. In the case of the latter, various polyethers with a different number of ether groups (polyether groups linked by ethylene and propylene groups) and variations of hydrophobicity (by substitution) have also been studied. Linked to the polyether groups were alkane and aryl groups. Those having 8 to 10 ether groups and aromatic tail ends proved to be moderately successful in terms of gold capacity and sharp breakthrough curves of their columns, however, platinum could not be very effectively rejected.

This thesis describes a simple method for the separation of strontium from an excess of barium using ion exchange techniques. This process has been applied to the separation of strontium and rubidium in barites. The resin used is Dowex-50 (200-400 mesh, hydrogen form) and the column dimensions are 1.1 by 8 cm. The column is eluted at room temperature with 1.5 M hydrochloric acid at a flow rate of approximately 1 ml/ min. Strontium and rubidium from two samples of barites were analysed using a solid-source mass spectrometer to determine strontium-87/strontium-86 ratios. The above chemical techniques have also been employed in the separation of strontium and rubidium from galenas. The concentration of strontium in one sample of galena (U.B.C. No. 1) has been determined using isotope dilution techniques. The results show an absence of strontium in the galena sample studied. Finally the common strontium ratios of two barite samples are compared with common lead ratios of associated galenas (Slawson and Austin, 1962) and a possible correlation between these ratios has been observed. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Factors affecting the centrifugal separation of apple parenchyma cell serum were investigated for three important cultivars from the Okanagan Valley of British Columbia; Mcintosh, Red Delicious, and Winesap. The factors studied included cultivar, maturity, maceration treatment, and centrifugation time and speed. Observations included yield of cell serum, relative serum clarity, pulp and serum viscometric properties, alcohol insoluble solids, soluble solids, serum pH, particle size and tissue firmness. The pulp viscometric property, viscosity at a shear rate of 100 sec⁻¹, was the observation which primarily influenced juice yields. The increased separation obtained for Mcintosh > Red Delicious > Winesap was attributed to pulp viscosity values. Relative serum clarity was influenced by serum soluble solids when centrifugation time was constant at six minutes or by the serum pH and pulp viscosity at maturity one (0 storage). Increased centrifugation speed and time markedly improved the yield of cell serum for the factors evaluated. Maceration treatments reduced the average particle diameter from 330 μm to 229 μm and the pulp viscosity values. At 5,500 and 8,000 rpm, higher yields were obtained when the particle size was small. At 10,500 rpm or 14,500 rpm, higher serum yields were obtained with larger particle sizes. Consideration of the particle size (> 100 μm) and shape (non-spherical), along with sedimentation theory indicated the separation followed Newton's Law. The high yields obtained with the larger particle size at high rpm confirmed a low drag force coefficient (C[sub D] = .5). Although a slight reduction in particle size and viscosity was observed when parenchyma tissue was subjected to ultrasonic vibration, no improvement was obtained in serum yield or clarity. The centrifugal separation of apple parenchyma cell serum was shown to be feasible. The efficiency of the separation improved as pulp viscosity decreased and speed or time of centrifugation increased. The tissue particle size evaluated was of secondary importance for the separations observed. / Land and Food Systems, Faculty of / Graduate

No description available.

No description available.

Vita. / Digitized by Kansas Correctional Industries

Call number: LD2668 .T4 1957 C48 / Master of Science

Research project submitted in fulfillment of the academic requirements for the Masters Degree in Technology: Chemical Engineering, Durban University of Technology, 2010. / Globally there is renewed interest in the production of alternate fuels in the form of bioethanol and biodiesel. This is mainly due to the realization that crude oil stocks are limited hence the swing towards more renewable sources of energy. Bioethanol and biodiesel have received increasing attention as excellent alternative fuels and have virtually limitless potential for growth. One of the key processing challenges in the manufacturing of biofuels is the production of high purity products. As bioethanol is the part of biofuels, the main challenge facing bioethanol production is the separation of high purity ethanol. The separation of ethanol from water is difficult because of the existence of an azeotrope in the mixture. However, the separation of the ethanol/water azeotropic system could be achieved by the addition of a suitable solvent, which influences the activity coefficient, relative volatility, flux and the separation factor or by physical separation based on molecular size. In this study, two methods of high purity ethanol separation are investigated: extractive distillation and pervaporation. The objective of this project was to optimize and compare the performance of pervaporation and extraction distillation in order to produce high purity ethanol. The scopes of the investigation include:  Study of effect of various parameters (i) operating pressure, (ii) operating temperature, and (iii) feed composition on the separation of ethanol-water system using pervaporation.  Study the effect of using salt as a separating agent and the operating pressure in the extractive distillation process. The pervaporation unit using a composite flat sheet membrane (hydrophilic membrane) produced a high purity ethanol, and also achieved an increase in water flux with increasing pressure and feed temperature. The pervaporation unit facilitated separation beyond the ethanol – water system azeotropic point. It is concluded that varying the feed temperature and the operating pressure, the performance of the pervaporation membrane can be optimised. v The extractive distillation study using salt as an extractive agent was performed using the low pressure vapour-liquid equilibrium (LPVLE) still, which was developed by (Raal and Mühlbauer, 1998) and later modified by (Joseph et al. 2001). The VLE study indicated an increase in relative volatility with increase in salt concentration and increase in pressure operating pressure. Salt concentration at 0.2 g/ml and 0.3 g/ml showed complete elimination of the azeotrope in ethanol-water system. The experimental VLE data were regressed using the combined method and Gibbs excess energy models, particular Wilson and NRTL. Both models have shown the best fit for the ethanol/water system with average absolute deviation (AAD) below 0.005. The VLE data were subjected to consistency test and according to the Point test, were of high consistency with average absolute deviations between experimental and calculated vapour composition below 0.005. Both extractive distillation using salt as an extractive agent and pervaporation are potential technologies that could be utilized for the production of high purity ethanol in boiethanol-production.

Submitted in fulfillment of the requirements for the degree of Master of Engineering, Durban University of Technology, Durban, South Africa, 2015. / There are various types of separation processes used in industries, such as, distillation, liquid-liquid extraction and gas absorption. Liquid-liquid extraction (LLE) is a separation process that involves mass transfer from a liquid mixture to an immiscible extraction solvent. This process is generally used where the mixture cannot be separated by fractional distillation due to close relative volatilities of the mixture components or for heat sensitive components. LLE is rated as the second most important separation process after distillation and it is widely used in chemical engineering industries. Different types of columns are available for LLE. Reciprocating and vibrating plate extraction columns are mechanically agitated extraction columns. In this research a vibrating plate extraction column was utilised. It uses perforated plates with down-comers. The perforations provide passage for the dispersed phase, while down-comers provide passage for the continuous phase. The effectiveness of a vibrating plate extractor was previously investigated but limited research was conducted on the effect of the different tray designs and agitation levels (as the product of amplitude and frequency of vibration). These variables affect the hydrodynamics and mass transfer in the column. The determination of the optimum process parameters is important in achieving the highest separation efficiency of the vibrating extraction column. The focus of this research is to test the effect of different tray designs in order to enhance the separation process efficiency. All tests were conducted using the toluene-acetone-water system as a standard test system proposed by the European Federation for Chemical Engineering, (1985). The experiments were conducted to test the effect of mass transfer on the hydrodynamics of the system while changing the agitation levels, downcomers and hole diameters. A comparative investigation was conducted on straight segment and circular downcomers, then hole diameters analysis was performed on the effective downcomer Comparison of the effect of the tray design types on the amount of acetone extracted was utilised to select the effective tray. Tray with the circular downcomer and 3.0 mm hole diameter had high dispersed phase holdup values and with the highest percentage amount of acetone extracted (95.05%) was obtained compared to other tray designs investigated.