Abstract: Production of cumene by alkylation of benzene with propylene on a solid phosphoric acid catalyst, using a first step with a plurality of catalyst beds in series and a second step with a single catalyst bed, using an overall benzene/propylene molar ratio of at least 6:1, continuously delivering the benzene to the first bed, continuously delivering a series of streams of liquid propylene respectively to the first bed and, in the form of a cold stream, between each pair of contiguous beds, and using a benzene/propylene molar ratio higher than 16:1 at the inlet of each bed of the first step, and higher than 25:1 at the inlet of the bed of the second step.

Abstract: This invention describes a process for producing branched C.sub.7 -C.sub.9 -mono-olefins by polymerizing a mixture of propylene and butenes over phosphoric acid catalysts at temperatures and pressures which ensure a homogeneous liquid phase and recycling the fraction containing over C.sub.9 olefins.

Abstract: The copper and palladium ethylene-oxidation catalyst used in the preparation of vinyl acetate is regenerated in a process including deposition of the metals from solution in a Daniell-type galvanic cell and subsequent reconversion to the halides.

Abstract: Palladium and copper ethylene-oxidation catalysts, used in production of vinyl acetate, are regenerated by a process including electrolytic deposition of the metals and subsequent reconversion to halides.

Abstract: The palladium and copper ethylene-oxidation catalysts used in vinyl acetate production are regenerated by a process including a galvanic displacement of the metals from solution and their reconversion to halides.