This study presents the first preliminary evaluation of oil (bitumen) recovery from the Middle Jurassic Sargelu oil shale using the Fischer Assay, thermal dissolution, and both direct and indirect hydrogenation methods. Three oil shale samples were collected from the Sargelu Formation at three locations in the Zagros Mountains of southwestern Iran. The results showed no significant difference in oil yield between the standard Fischer Assay and the modified Fischer Assay, despite variations in the final temperature and residence time. The maximum oil yields obtained from the standard and modified Fischer Assays were 34.29 and 33.70 wt.% of organic matter (OM), respectively. However, the modified Fischer Assay improved the quality of the recovered oil by increasing the API gravity from 18.30 to 24.82 and reducing the viscosity from 7.34 to 4.13 cP. Thermal dissolution experiments using different solvents demonstrated that methanol was the most effective solvent, producing the highest oil yield at 350°C after 4 hours. Oil recovery varied considerably with solvent type, ranging from 23.1 to 59.4 wt.%
of OM. Direct hydrogenation, conducted under hydrogen pressures of 20 and 30 bar at relatively low temperatures, achieved a maximum oil yield of 53.68 wt.% of OM. Indirect hydrogenation using a 25 wt.% aqueous sodium formate (HCOONa) solution at 380°C for 5 hours produced an oil yield of 51.59 wt.% of OM, whereas indirect hydrogenation in the presence of water and zinc further increased the yield to 62.93 wt.% of OM. Overall, the results demonstrate that both thermal dissolution and hydrogenation are more effective than conventional pyrolysis for enhancing oil (bitumen) recovery from the Sargelu oil shale. The highest oil yield was achieved through indirect hydrogenation at 400°C with a reaction time of 2 hours, highlighting the potential of this method for maximizing bitumen recovery
from the Sargelu oil shale