Process for recovering and upgrading hydrocarbons from oil shale and tar sands

A process for recovering hydrocarbons from oil shale or tar sands solids and simultaneously for cracking, desulfurizing, and demetalating the recovered hydrocarbons, comprising contacting the oil shale or tar sands solids with a water-containing fluid under superatmospheric pressure, at a temperature in the range of from about 600.degree.F. to about 900.degree.F., in the absence of externally supplied hydrogen, and in the presence of an externally supplied, sulfur-resistant catalyst, selected from the group consisting of at least one basic metal carbonate, basic metal hydroxide, transition metal oxide, oxide-forming transition metal salt, and combinations thereof, wherein said catalyst is present in a catalytically effective amount, wherein the transition metal in the oxide and salt is selected from the group consisting of the transition metals of Groups IVB, VB, VIB, and VIIB;

• wherein the metal in the basic metal carbonate and hydroxide is selected from the group consisting of alkali metals;
• wherein sufficient water is present in the water-containing fluid and said pressure is sufficiently high so that the water in the water-containing fluid has a density of at least 0.10 gram per milliliter and serves as an effective solvent for the recovered hydrocarbons;
• and lowering said temperature or pressure or both, to thereby make the water in the water-containing fluid a less effective solvent for such hydrocarbons and to thereby form separate phase.