Using neoteric solvents in oil shale studies*
M. Koel1**, S. Ljovin1, K. Hollis2, and J. Rubin2
1Institute of Chemistry,
Akadeemia tee 15, Tallinn 12618, Estonia; 2Los Alamos National
Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
Abstract: The liquefaction, gasification, and other chemical
modifications of oil shale are challenging goals of chemistry and chemical
engineering. The use of new solvent systems, such as supercritical fluids
and ionic liquids, represents new avenues in the search of environmentally
benign technologies. Supercritical fluid extraction (SFE) with carbon
dioxide is particularly effective for the isolation of substances of
medium molecular weight and relatively low polarity. At elevated temperatures
it is possible to unite the breaking chemical bonds in the kerogen organic
matter and convert the former into oil with extraction using supercritical
fluids. Quantitative and qualitative information obtained at different
temperatures during SFE is providing some insight into the speciation
of hydrocarbons in geological samples. Ionic liquids were studied as
potential solvents for kerogen extraction. However, these chemical processes
are favored at elevated temperatures up to the thermal degradation temperature
of kerogen, 400 C. There were observed significant differences in the
chemical composition of extracted oil and from the oil from the classical
semicoking process of oil shale. An additional application would be
a combination of the two methodsthe use of supercritical carbon dioxide
to recover nonvolatile organic compounds from room-temperature ionic
liquid without using organic solvents.
*Lectures presented at the International Symposium
on Green Chemistry, Delhi, India, 10-13 January 2001. Other presentations
are published in this issue, pp. 77-203.
**Corresponding author.