Influence of heating rate on the pyrolysis of Jordan oil shale

Oil shale samples from Jordan were pyrolysed in a fixed bed reactor at a heating rate varied from 2 to 30 degreesC min(-1) up to a final temperature of 520 degreesC under nitrogen and nitrogen/steam atmosphere. The influence of heating rate on the yield and composition of the oil, gases, water, and spent shale was determined. It was observed that the oil yield was increased as the heating rate was increased from 2 to 10 degreesC min (1). Increasing the heating rate up to 30 degreesC min (1) caused a slight reduction in the oil yield. The main gases produced were H-2, CO, CO2 and CH4 and also minor concentrations of alkane and alkenes gases. By increasing the heating rate from 2 to 30 degreesC min (1), the evolution of the hydrocarbon gases were increased. The oil was analysed for the elemental analysis and the atomic H/C ratio was obtained. The oils were fractionated into chemical classes (aliphatics, aromatics, esters, and polars compounds) using a mini-column liquid chromatography. The alkanes and alkenes hydrocarbon gases were increased with increasing heating rate. Alkene/alkane hydrocarbon gas ratios were determined and were linked to secondary reactions. (C) 2002 Elsevier Science B.V. All rights reserved.