Supercritical fluid extraction of Uinta Basin bitumens

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:229589

Subramanian, M; Deo, M D; Hanson, F V ^[1]

---

1. Univ. of Utah, Salt Lake City, UT (United States)

The supercritical fluid extraction (SFE) of bitumens from four major Uinta Basin (Utah) oil sand deposits was studied using propane as the solvent. The deposits studied included Whiterocks, Asphalt Ridge, PR Spring, and Sunnyside. The volatilities (components with boiling point < 811 K) were 46.6, 53.5, 45.5, and 40.9 wt%; the molecular weights were 653, 426, 670, and 593 g/gmol; and the asphaltene contents (pentane insolubles) were 2.9, 6.8, 19.3, and 23.6 wt% for the Whiterocks, Asphalt Ridge, PR Spring, and Sunnyside bitumens, respectively. The SFE experiments were carried out at five combinations of three different pressures (5.6 MPa, 10.4 MPa, and 17.3 MPa) and three temperatures (339 K, 380 K, and 422 K). The cumulative extraction yield increased with increase in solvent density at all operating conditions for all four bitumens. Maximum yields of 45 wt% were obtained at the highest solvent density for the Whiterocks bitumen. The extraction products obtained were significantly upgraded relative to the bitumens. Comparatively lighter fractions were extracted in the earlier stages of extraction for all the four bitumens whereas heavier extracts were obtained at higher extraction-solvent densities. The asphaltene contents of the residual fractions were significantly higher than the asphaltene contents predicted on a prorated basis for all four bitumens. This trend was due to the extraction of cosolubilizing components which kept the asphaltenes in suspension in the bitumen. It was concluded that solute polarity played a significant role in the extraction yields of the four bitumens. The Whiterocks bitumen, which was the least polar bitumen based on asphaltenes analyses, gave higher extraction yields compared to the bitumens from the other three deposits at all five operating conditions.

• OSTI ID: 229589
• Report Number(s): CONF-9502114--Vol.2
• Country of Publication: United States
• Language: English

Related Subjects

04 OIL SHALES AND TAR SANDS
ASPHALTENES
BITUMENS
OIL SAND DEPOSITS
PARTICLE SIZE
PHYSICAL PROPERTIES
PROPANE
SOLVENT EXTRACTION
SOLVENT PROPERTIES
SUPERCRITICAL STATE