A process for converting scrap plastic material into a high quality transportation fuel. The plastic material is granulated and mixed with granulated solid carbonaceous fuel e.g. coal and liquid hydrocarbonaceous solvent e.g. waste motor oil to produce a plastic-containing sludge. The plastic-containing sludge is liquefied in a closed autoclave while in contact with hydrogen gas. A pumpable slurry from the autoclave is heated and fractionated in a fractionation zone to produce a hydrocarbonaceous distillate which may be used for transportation fuel. A bottoms stream from the fractionation zone comprising liquid hydrocarbonaceous material and inorganic material is reacted by partial oxidation to produce nontoxic slag and raw synthesis gas, fuel gas or reducing gas which may be purified in a gas purification zone.