Simultaneous demetalization and hydrocracking of heavy hydrocarbon oils

A process for simultaneous demetalization and hydrocracking of a heavy hydrocarbon oil, a substantial portion of which boils above 524.degree. C., which comprises:

• (a) passing a slurry of said heavy hydrocarbon oil and from about 0.01 to 25 wt % of carbonaceous additive particles in the presence of hydrogen through a confined vertical hydrocracking zone, said hydrocracking zone being maintained at a temperature between about 400.degree. and 500.degree. C., a pressure of at least 3.5 MPa and a space velocity of up to 4 volumes of hydrogen oil per hour per volume of hydrocracking zone capacity,
• (b) causing the carbonaceous particles within the hydrocracking zone to undergo partial liquifaction leaving porous particles of carbonaceous material and mineral matter which are inert to further hydrogenation and depositing within the porous network of said porous particles metal-containing residues from the feedstock, thereby causing said porous particles to increase in density and settle to the bottom of the hydrocracking zone,
• (c) removing from the top of said hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen and vaporous hydrocarbons and a liquid phase comprising heavy hydrocarbons, and
• (d) removing from the bottom of said hydrocracking zone a portion of the hydrocracking zone contents containing said porous particles with adsorbed metal-containing residues from the feedstock.