Thermal solvent extraction of a sunbury oil shale kerogen

Thermal solution of an aromatic Sunbury oil shale kerogen was studied using three solvents: toluene above its critical temperature, methylcyclohexane above its critical temperature, and tetralin at subcritical temperatures. Sixty-six thermal solutions tests were conducted which included twenty-nine isothermal tests using all three solvents and thirty-seven linear-heating tests using tetralin. Maximum kerogen conversions to soluble products, as determined by low temperature ash analyses, were 49% for extraction with toluene (37% above Fischer assay oil yield on a water-free basis), 58% for extraction with methylcyclohexane (69% above Fischer assay oil yield), and 80% for extraction with tetralin (150% above the oil yield from Fischer assay). The results confirmed observations of previous investigators of the importance of available hydrogen during thermal solution of highly aromatic eastern U.S. oil shales. Product coking appeared to be especially prevalent in extractions with hydrogen-