The Bitumen Upgrading of Nigerian Oil Sand by Supercritical Carbon Dioxide Modified with Alcohols

Abstract

The experimental study of bitumen extraction from Nigerian oil sand by supercritical carbon dioxide was carried out using a high-pressure extractor. Fifty grams (50 g) of oil sand was placed into a 100-mL extractor at a temperature of 110 °C and pressures of 50, 60, or 65 MPa for the interaction with pure carbon dioxide or modified by the addition of 3 g of ethanol or 2-propanol in three runs to investigate the co-solvent effect on recovery. The liquid recovery of bitumen, using pure carbon dioxide, was determined to be equal to 16.3%, on average, after three runs over the entire pressure range, with a maximum of 18.5% at 50 MPa. The addition of ethanol improved liquid recovery, while the addition of 2-propanol worsened it by ∼5% (on average). The maximum liquid recovery of 24.5% after three runs, using ethanol-modified carbon dioxide, was observed at 60 MPa. The average outgassing losses obtained with the addition of co-solvents increased in the following order: pure carbon dioxide (16.1%), ethanol (19.5%), 2-propanol (24.93%). The obtained bitumen fractions were upgraded by rejection of asphaltenes and petcoke. Chromatographic analysis (gas chromatography−mass spectroscopy, coupled with total ion chromatography (GC-MS TIC)) has shown that the composition of the collected fractions after the first runs is lighter than that observed after the subsequent runs. The fuel-related physicochemical properties of the extracted bitumen fractions were calculated using Khan's correlations based on the refractive indices. The obtained characteristics matched those observed in the published data of maltene of Athabasca bitumen.

Supercritical carbon dioxide extraction of petroleum on kieselguhr

“…Hence, a comprehensive investigation on the extracts at the molecular level is needed, especially on the polar and heavy components in source rock and crude oil. A recent paper [20] reported the CO 2 SFE bitumen extraction from oil sand is relevant to the subject matter.…”

Vaporization of Crude Oil by Supercritical CO2 at Different Temperatures and Pressures: Example from Gorm Field in the Danish North Sea

“…The vaporizing capacity of SC-CO 2 can be further increased with the addition of cosolvents. For example, the vapor recovery of Halfdan oil was increased by 6–7% with the addition of 7.5% of methanol, acetone, or isopropanol at 60 °C and 30–60 MPa. , Extracting bitumen from oil sand at 110 °C and 50–65 MPa, the outgassing losses reached as much as 30–40% with the addition of water and isopropanol, compared to 0.27% when the oil sand was heated at 120 °C in the oven for 1 h. , …”

Density and Viscosity of CO2 + Ethanol Binary Systems Measured by a Capillary Viscometer from 308.15 to 338.15 K and 15 to 45 MPa

“…12 Rudyk et al reported that the introduction of ethanol, as a hydrogen bond acceptor, could benefit the extraction of oil with CO 2 under high pressure and increase the solubility of oil in CO 2 . 8,12,13 As mentioned above, the investigation of density and viscosity variation in CO 2 + ethanol binary systems under high pressure and high temperature could provide theoretical foundation and supporting data in unconventional oil and gas development. Generally speaking, a capillary viscometer is widely applied in viscosity measurement, 14 such as falling-ball viscometer, 15 rolling-ball viscometer, 16,17 vibrating-wire viscometer, 18 and rotating-body viscometer.…”

“…Meanwhile, the extraction recovery for crude oil in CO 2 could be significantly enhanced with alcohol . Rudyk et al reported that the introduction of ethanol, as a hydrogen bond acceptor, could benefit the extraction of oil with CO 2 under high pressure and increase the solubility of oil in CO 2 . ,, …”