Asphaltene reaction via supercritical fluid extraction
Supercritical fluid extraction (SFE) of bitumen was carried out in a continuous extractor using propane as the solvent at several temperatures and pressures. The asphaltene contents of the residual fractions in the extractor were compared to the asphaltene content of the original bitumen. Asphaltenes were defined as pentane insolubles in this study. It was found that the absolute asphaltene content of the residual fractions exceeded the asphaltene content of the original bitumen. Even when the asphaltene content was prorated by the weight percent of the residual material, it was found to be higher than the original asphaltene content. The data established that the types of compounds separating as asphaltenes changed as the nature of the mixture was altered by SFE. The data also indicated that it may be inappropriate to perform asphaltene material balances to assess the amount of precipitate. The original asphaltene content of a bitumen that is undergoing compositional changes in a sequence of operations may not be an accurate measure of the precipitating tendency of the bitumen in production and processing operations. The asphaltene content of the residual material varied depending on the extraction conditions and was as much as 3--5 times the original asphaltene content. The asphaltene content of the residual material was a maximum at the most efficient extraction condition which was in the vicinity of the critical temperature of propane. The H/C atomic ratio of the residual fractions was lower compared to the original bitumen, indicating that the ratio of polar to nonpolar compounds may also be important from precipitation considerations. Saturate and aromatic compounds were preferentially extracted and the ratio of asphaltenes to resins increased in the residual fractions relative to the original bitumen.
- Research Organization:
- Utah Univ., Salt Lake City, UT (United States). Dept. of Chemical and Fuels Engineering
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- FC21-89MC26268
- OSTI ID:
- 6680035
- Report Number(s):
- DOE/MC/26268-93/C0176; CONF-921142-2; ON: DE93008867
- Resource Relation:
- Conference: Eastern oil shale symposium, Lexington, KY (United States), 13-15 Nov 1992
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
02 PETROLEUM
ASPHALTENES
SUPERCRITICAL GAS EXTRACTION
BITUMENS
PROPANE
SOLVENT PROPERTIES
EXPERIMENTAL DATA
MEDIUM PRESSURE
PRESSURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
ALKANES
ASPHALTS
DATA
EXTRACTION
HYDROCARBONS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
SEPARATION PROCESSES
SOLVENT EXTRACTION
TAR
TEMPERATURE RANGE
040403* - Oil Shales & Tar Sands- Refining
020400 - Petroleum- Processing