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Petroleum refining processes provide the daily requirements of energy for the global market. Each refining process produces wastes that have the capacity to harm the environment if not properly disposed of. The treatment of refinery waste is one of the most complex issues faced by refinery managers. Also, the hazardous nature of these wastes makes them rather costly to dispose of for the refineries. In this thesis, system analysis tools are used to design a program that allows for the selection of the optimal control, minimization and treating options for petroleum refinery waste streams. The performance of the developed model is demonstrated via a case study. Optimal mitigation alternatives to meet the emission reduction targets were studied by evaluating their relative impact on the profitable operation of the given facility. It was found that the optimal mitigation steps was to reduce emission precursors by conducting feed switches at the refinery. In all cases, the optimal solution did not include a capital expansion of the emission control facilities and equipment.

The fouling characteristics of a desalted crude oil were investigated in a systematic investigation. There are two main parts in this study, the dry bulk tests (dehydrated crude oil) and the wet bulk tests (to which desalter brine was added). Three barrels of desalted crude oil provided by Amoco Oil Company were studied. For the dry bulk tests, no brine was added to the crude oil. The effects of fluid velocity and surface temperature on fouling were investigated. The higher the surface temperature the greater the fouling was observed. Fouling decreased with an increase of fluid velocity. Fluid velocity had a stronger effect on fouling at low surface temperatures than at high surface temperatures. It was also observed that the fouling behavior of crude oil depended on small difference in composition. The threshold surface temperatures for the initiation of fouling were 400-450 °F (3.0 ft/sec), 525-550 °F (5.5 ft/sec), 550-600 °F (8.0 ft/sec) and about 600 °F (10.0 ft/sec) for Barrel No. 2 and Barrel No. 3. For Barrel No. 1 however, the threshold surface temperatures were about 550 °F (3.0 ft/sec) and 600 °F (5.5 ft/sec). For the wet bulk tests, a certain amount desalter brine (weight percentage = 0.8%) was added to the crude oil for each run. The effects of fluid velocity, surface temperature and the presence of brine on fouling were investigated. Higher surface temperature enhanced fouling considerably. Fouling was reduced as fluid velocity was increased. It was shown that brine had a strong effect on fouling. No fouling occurred for velocities of 5.5 and 8.0 ft/sec at a surface temperature of 350 °F which was a condition for which an aqueous phase was present and the salt remained in solution. Significant fouling occurred for velocities of 5.5 and 8.0 ft/sec at a surface temperature operated at a low 400 °F (Tb = 300 °F) which was a condition for which the aqueous phase at the heat transfer surface was dissolved or boiled to extinction and the salt was deposited on the heat transfer surface. / Graduation date: 1991

Petroleum refining processes provide the daily requirements of energy for the global market. Each refining process produces wastes that have the capacity to harm the environment if not properly disposed of. The treatment of refinery waste is one of the most complex issues faced by refinery managers. Also, the hazardous nature of these wastes makes them rather costly to dispose of for the refineries. In this thesis, system analysis tools are used to design a program that allows for the selection of the optimal control, minimization and treating options for petroleum refinery waste streams. The performance of the developed model is demonstrated via a case study. Optimal mitigation alternatives to meet the emission reduction targets were studied by evaluating their relative impact on the profitable operation of the given facility. It was found that the optimal mitigation steps was to reduce emission precursors by conducting feed switches at the refinery. In all cases, the optimal solution did not include a capital expansion of the emission control facilities and equipment.

An Othmer recirculating still and a standard packed column fractionating unit were used in determining the equilibrium flash vaporization and true boiling point curves respectively, for eight samples of crude oils from producing oil-fields in Alberta. The EFV curves, at 10 mm. absolute pressure were also obtained for these samples. Determinations at atmospheric pressure were used for modifying Okamoto and Van Winkle's correlation, which allows the prediction of the EFV curves from the TBP curves, for application to crude oils. The correlation relates the 50 percent points and the slopes of the two curves. In spite of its simplicity, it results in predicted curves of good accuracy. It is believed that this method is suitable for a large number of crudes and can give dependable phase equilibrium data. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering, 2016 / The sulfur removal methods from petroleum products have become an important research topic. Sulfur poisons the catalysts found in vehicles engines and it is also a major air pollutant (Nehlsen, 2005). Recent sulfur specifications require refineries to produce ultra-clean products (Ma et al., 2002). This work aims at exploring a batch adsorptive desulfurization technique using a polymer-supported imidation agent (PI) as an adsorbent. The test was carried out at atmospheric pressure and on two commercial diesel fuels with sulfur contents of 5200 (Case 1) and 670 (Case 2) mg/kg which resembles the feed and outlet streams from the hydrodesulfurization (HDS) reactor respectively. The adsorbent was synthesized according to the procedure described by Shiraishi et al. (2003), BET, FTIR, SEM equipped with EDS and TGA were used for charaterization of the adsorbent. The PI was successfully synthesized and its surface area was 0.5333 m2/g which was incredibly lower than that of the PI synthesized by Fadhel (2010). Hence carbon nanotubes (CNTs) were added to the solution with the aim of improving the sulfur removal efficiency of PI. The obtained results indicated that PI with CNTs yield better results than PI without CNTs. In overall, the lowest sulfur content of 3462 mg/kg (33% removal efficiency) and 26 mg/kg (96% removal efficiency) for Case 1 and Case 2 respectively were obtained. Furthermore, the adsorbents were most effective at lower mixing rates (150 – 400 rpm), longer contact time (30 – 40 hours), practically high adsorbent amount (1 g) and moderate lower temperatures (25 – 50 ºC). The Freundlich adsorption isotherm model was the best fit to the experimental data in both Case 1 and Case 2. The kinetic model that best fitted well the experimental data is the pseudo-second-order model for both Case 1 and Case 2. The kinetic rate constant for Case 2 (4.079 x 10-3g/mg.min) was greater than that for Case 1 (6.75 x 10-5g/mg.min) thus indicating that fuel with low sulfur content has a higher sorption uptake than fuel with high sulfur content. Based on the results obtained in this study, it is suggested that the adsorption of sulfur at high sulfur content fuel is not capable to be used as a complimentary method to the HDS process. On the other hand, at low sulfur content fuel, there is an opportunity for combining this method with the traditional HDS method to achieve ultra-clean fuel. / GR2016