(48a) Compositional Effect of Varying Feedstocks on Heavy Oil Upgrading By Supercritical Water
Crude oil prices have shown big fluctuations around 150 and 35 $/barrel during 2008-2016. Such a volatile and unpredictable oil price tendency, which is being drastically affected by political issues, forces energy policy makers to focus on alternative energy conversion technologies for energy security. On the other hand, one third of Worldâ??s recoverable oil reserves are in a form of heavy oil. Therefore developing alternative oil upgrading technologies with improved conversion and tunable selectivity providing low coke and improved light liquid yield are of desire. However, the variations in feedstock chemistry due to the source of the heavy oil affect economics of investments to a great extent. Supercritical fluids can be used for the development of alternative and innovative heavy oil upgrading processes and supercritical water (SCH2O) having decreased dielectric constant and increased ionic product values is a potential candidate for the reactive extraction and thereby upgrading of heavy oils in an intensified process scheme. These altered physicochemical properties of water enable it to mimic hydrocarbons for reactive extraction purposes and also to increase [H3O+] concentrations for triggering acid-catalyzed cracking reactions. Domestic tar sand samples together with feedstocks of state-of-the art heavy oil upgrading units (Delayed Cokers - DCU), namely 50/70 bitumen from 2 different refineries in Turkey, 70/100 pen bitumen, and by product of Base Oil Unit, PDA bitumen, were used for the experiments. The reactions were carried out at 440 °C and 30MPa for 1 hour with water/oil ratio of 2 in a home-made 10 cm3, SS316, bomb reactor. Characterization was done by GPC, H-NMR, DSC, TGA, FTIR, XRD, GC-Simdist, API, SEM images and SARA analysis. The coke-liquid-gas yield, coke type and boiling point distribution of liquids were shown to be influenced from the feedstock chemistry. Varying conversions with scattered selectivity values have been obtained. Modeling studies will be carried out to derive a tool for the prediction of conversion and selectivity of the reactions for a given feed under certain conditions as a part of a complementary study.