Browsing by Author "Eshraghian, Afrooz"

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    Application of low-cost waste material from the petroleum industry in wastewater treatment and polymer composites
    (2022-07-28) Eshraghian, Afrooz; Sundararaj, Uttandaraman; Ponnurangam, Sathish; Yarranton, Harvey
    In this thesis, diverse applications of solid petroleum waste, including asphaltene and clay, are discussed. As part of this thesis, it is hypothesized that asphaltene and clay interact with polymers and pollutants in wastewater. By interacting with pollutants, they can adsorb pollutants, and by interacting with polymers, they can disperse in polymers, and thus can be used as adsorbents for wastewater treatment and as fillers in polymer composites. To use asphaltene for adsorbing pollutants from wastewater, it is hypothesized that asphaltene functionalization will change the surface properties of asphaltene, leading to enhanced adsorption. Acid-treated asphaltene is used as an adsorbent for the removal of methyl orange from wastewater. Modified asphaltene has a large surface area and oxygen and nitrogen functionalities, leading to 96% removal of MO from 20 mg/L MO solution. Moreover, the Freundlich isotherm model, pseudo-second-order, and intraparticle diffusion models describe the adsorption process very well. In addition, the asphaltene can be easily regenerated using ethanol, and the removal percent is still 64% after five cycles.The second part investigates the compatibility of different asphaltenes, with different polymers including polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), and polycarbonate (PC). By careful choice of the polarity of asphaltene-polymer pairs, mixing technique, and melt viscosity of the polymer, the dispersion of asphaltenes and final properties of composite materials can be tuned. For example, at 2.5 wt.% of asphaltene, more polar asphaltene showed 26% and 177% larger asphaltene agglomerates in PP and PS, respectively, than the less polar asphaltene. In the third part of this thesis, clay functionalization is hypothesized to improve clay-polymer interactions. Thus, the effect of nanoclay, representative of clay waste from petroleum industry, on dielectric properties in the X-band (8.2-12.4 GHz) of synthesized nitrogen-doped carbon nanotube (N-CNT)/nanoclay/ polyvinylidene fluoride (PVDF) nanocomposites is investigated. The incorporation of nanoclay improves the dielectric properties, i.e., the dissipation factor of N-CNT/PVDF nanocomposites. For instance, incorporation of 0.5 wt% nanoclay into N-CNT/PVDF nanocomposite at 1.0 wt% N-CNT loading results in 61% and 57% reduction in the dissipation factor and agglomeration area ratio, indicating improved N-CNT dispersion in PVDF.
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    Thermal and Catalytic Cracking of Athabasca VR and Bitumen
    (2017) Eshraghian, Afrooz; Husein, Maen; Yarranton, Harvey; Karan, Kunal
    There is a keen interest in upgrading heavy oil in order to meet current and future demand for liquid hydrocarbon fuels coupled with a need to enhance transportability of heavy crudes. In this study, thermal cracking of Athabasca vacuum residue (AVR) was conducted at different operating conditions such as residence time, pressure of the reactor unit, stirring rate, and temperature and different asphaltenes content in presence and absence of alumina nanoparticles (NP) and drill cuttings (DC). A closed reactor system, an autoclave, was employed. Despite the abundance of literature on thermal cracking of heavy crude, very few reports have in fact employed a closed system arrangement. Alumina NP was formulated in situ by thermal decomposition of dispersed aqueous solution of the aluminium nitrate in the heavy oil medium. Its performance was compared with its commercial counterpart. Drill cuttings, a by-product of drilling fluid reconditioning, was also evaluated as a thermal cracking catalyst. The yield of the different fractions, the total energy consumption, the pressure buildup in the reactor, and the oAPI gravity and viscosity of the liquid product were used to evaluate the impact of each parameter. Thermogravimetry analysis (TG/DTA) of the produced asphaltenes and toluene isolubles (TI), high-temperature simulated distillation (HTSD) analysis of the liquid product and gas chromatography (GC) of gaseous product were performed to characterize the different fractions. Results show that the effect of given parameter depends on the asphaltenes content of the feedstock. Removing asphaltenes from the feedstock shifted the reactions to produce more overall asphaltenes. The high surface area provided by dispersed NP and high content of DC in the heavy oil, increased the TI yield, while improved the viscosity of the maltene product. On the other hand, the mechanism of coke inhibition in presence of a specific concentration of DC could be elucidated from scanning electron microscopy (SEM) photographs analysis of the toluene insoluble (TI) fraction.