Evaluation of oil yield from Jordanian oil shales

In this paper, the influences of particle size, grade and pyrolysis tempera ture on the oil yield have been evaluated in a laboratory scale reactor. Fi ve categories of particle sizes from two different oil shale samples were p yrolyzed by employing a fixed bed retorting system. The reactor and the oil shale sample were heated at a constant rate and nitrogen gas was used to p urge the sample, continuously, in order to remove the pyrolysis products fr om the reactor as well as to reduce secondary reactions. The liquid product s were condensed and collected in a series of cold glass-traps and the off- gases analysed for their hydrocarbon and non-hydrocarbon species. Subsequen t experiments were carried out, employing a thermogravimetric analyser, usi ng only the four smallest particle sizes under similar conditions as applie d to the fixed bed retort. The activation energy was determined by using th e integral method. The pyrolysis of the investigated shales was found to co mply with first-order kinetics within the limits of experimental error. Inc reasing the particle size resulted in a small rise in the liquid oil yield, but simultaneously the total gaseous production was decreased. (C) 1999 El sevier Science Ltd. All rights reserved.