Effect of processing conditions on the improvement of properties and recovering yield of Moroccan oil shale

. In the present work, Moroccon Tarfaya oil shale was treated by acids and different solvents under supercritical conditions, successively. Experimental results showed clearly that residual mineral matter had a significant effect on the yield and composition of the resulting organic fraction. Indeed, the oil yields obtained from some samples, 43% and 56%, respectively, were much higher than that from the sub-layer, 18%. In addition, the yield of recuperation and quality of extracted oils were largely dependent on the nature of solvents (toluene, water, shale oil). Thus, phenol was shown to be a very efficient modifier for the supercritical extraction of organic matter from Tarfaya oil shale with toluene, affording a good yield of recovery and a suitable maturation of organic matter. The pitches prepared by mixing phenol and toluene contained more aromatics and had a high char yield (46%) at 950 °C compared to those obtained by extraction with supercritical toluene alone.