Hydrocracking with aqueous phosphomolybdic acid

This patent describes a method for preparing a catalyst wherein aqueous phosphomolybdic acid is heated in the presence of a hydrocarbonaceous material and a gas selected from the group consisting of a hydrogen-containing gas, a hydrogen sulfide-containing gas and mixtures thereof to convert the phosphomolybdic acid to a solid catalyst. The improvement described here comprises: (a) forming a mixture of a first hydrocarbonaceous material comprising at least about 10 weight percent constituents boiling above about 10500F. and the aqueous solution of phosphomolybdic acid in an amount to provide in the mixture from about 0.2 to 2 weight percent molybdenum, calculated as elemental metal, based on the first hydrocarbonaceous material. The aqueous solution comprises from about 3 to about 5 weight percent molybdenum derived from the phosphomolybdic acid to produce a catalyst precursor concentrate; (b) introducing at least a portion of the catalyst precursor concentrate into a second hydrocarbonaceous material having a different boiling point range from the first hydrocarbonaceous material; (c) heating the mixture resulting from step (a) or the mixture resulting from step (b) in the presence of a gas selected from the group consisting of hydrogen-containing gas, hydrogen sulfide-containing gas, and mixtures thereof at conditions to convert the phosphomolybdic acid to a solid molybdenum-containing catalyst