Thermal and Catalytic Cracking of Athabasca VR and Bitumen
Abstract
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.
Description
Keywords
Engineering--Chemical
Citation
Eshraghian, A. (2017). Thermal and Catalytic Cracking of Athabasca VR and Bitumen (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/28305