Supercritical fluid extraction of Moroccan (Timahdit) oil shale with water

Timahdit oil shale was subjected to supercritical water extraction. The res ults reveal significant difference in oil yields and composition when compa red with those obtained from conventional pyrolysis. In addition, the effec t of temperature and residence time on the supercritical water extraction o f oil was investigated in a set of three experiments. The results revealed that the yield and the fraction of paraffins and aromatics increase while t he percentage of asphaltenes decreases as the temperature is increased from 380 to 400 degrees C. The residence time was found to affect the yield and the fraction of asphaltenes and polar compounds. (C) 1999 Elsevier Science B.V. All rights reserved.