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.

This study evaluates the possibilities to produce new materials, starting from Moroccan oil shales, for different applications. More specifically, the authors aimed to demonstrate that the organic fraction of the oil shales could be used as a precursor of carbon foams and graphitizable carbons, after appropriate chemical treatments resulting in the "maturation" of this organic phase. First, the researchers studied the optimization of experimental conditions and the identification of various parameters influencing the yield and composition of oils obtained by the supercritical extraction of Moroccan oil shale. The effect of various experimental parameters, such as mineral matter, thermal treatment temperature (T), treatment duration (t) and solvent type, was studied. The experimental results obtained show clearly that the organic matter contained in the Moroccan Tarfaya oil shale (sub-layer R 3 ) can be recovered by phenol under the following optimal conditions: T = 390 °C, t = 2.5 hours using phenol as a solvent with an amount of 15 g for each 10 g of sub-layer R 3 carbonate-free oil shale (RH) . The results reveal that the yield and composition of the oil obtained by extraction with phenol is markedly different from those obtained by extraction with toluene, quinoline or withoutThe effect of various parameters on the supercritical extraction of Moroccan oil shales … solvent. Furthermore, the phenol has a very significant role in increasing the recovery yield and the degree of maturation of the obtained oil. It was shown that phenol was a suitable extraction solvent to produce graphitizable carbon at a relatively low temperature, below 1800 °C.

This study focuses on investigating the effect of various solvents on the supercritical extraction of organic matter from Moroccan oil shales, with the goal of determining the optimal operating conditions that result in a high yield of high-quality oil rich in aromatic compounds. The results of this study demonstrate that the extraction yield and quality of the extracted oil heavily depend on the chosen operating conditions for supercritical or subcritical extraction of organic matter from oil shale. Additionally, the study found that phenol can effectively degrade oil shale and enable extraction of nearly all the organic matter, even under mild conditions (T = 390°C, P = 1.2 MPa, Time = 2.5 h. Furthermore, the oils obtained through this extraction process are of high quality, with a rich content of maltenes, and a higher concentration of aromatic compounds and lower levels of sulfur than those obtained using other solvents.