Abstract: A process is described for converting synthesis gas in the presence of a catalyst comprising at least one group VIII element dispersed on a support comprising alumina modified by aqueous impregnation of quaternary ammonium silicate and comprising in the range of about 3% by weight to about 9.5% by weight of silica. Said support can optionally also comprise at least one oxide selected from the group formed by rare earth oxides, alkaline-earth oxides and zirconium oxide.

Abstract: A process is described for synthetizing hydrocarbons from a mixture comprising carbon monoxide and hydrogen in the presence of a catalyst comprising at least one group VIII metal supported on a silica-alumina prepared by co-precipitating and calcining at a temperature in the range from about 500° C. to about 1200° C. for at least 6 hours such that said silica-alumina has a specific surface area of less than 260 m2/g. Said catalyst is used in a fixed bed or in suspension in a liquid phase of a three-phase reactor.

Abstract: A process is described for synthesizing hydrocarbons from a mixture comprising carbon monoxide and hydrogen in the presence of a catalyst comprising at least one group VIII metal supported on a silica-alumina prepared by co-precipitating and calcining at a temperature in the range from about 500° C. to about 1200° C. for at least 6 hours so that said silica-alumina has a specific surface area of less than 260 m2/g. Said catalyst is used in a fixed bed or in suspension in a liquid phase of a three-phase reactor.

Abstract: A process is described for synthetizing hydrocarbons from a mixture comprising carbon monoxide and hydrogen in the presence of a catalyst comprising at least one group VIII metal supported on a silica-alumina prepared by co-precipitating and calcining at a temperature in the range from about 500° C. to about 1200° C. for at least 6 hours such that said silica-alumina has a specific surface area of less than 260 m2/g. Said catalyst is used in a fixed bed or in suspension in a liquid phase of a three-phase reactor.

Abstract: A supported cobalt-based catalyst is described, characterized in that the carrier has an average particle diameter, measured by means of Coulter LS230, ranging from 70 to 250 &mgr;m, a surface area higher than 175 m2/g and a pore volume higher than 0.35 cm3/g, measured with the B.E.T. method. The above catalyst is particularly useful in the Fischer-Tropsch reaction.

Abstract: Catalytic composition comprising a larger quantity of Cobalt, in metal form or in the form of a derivative, and smaller quantities of Ruthenium and Tantalum, in metal form or in the form of a derivative, the above elements being dispersed on a carrier selected from the oxides of at least one of the elements selected from Si, Ti, Al, Zn, Sn, Mg.

Abstract: A process for the preparation of a catalyst comprising sequential deposition of cobalt or a cobalt compound, and scandium or a scandium compound, on an inert carrier oxide, which catalyst can be used in the conversion of synthesis gas according to the Fischer-Tropsch process.

Abstract: A catalyst composition containing cobalt and tantalum on an inert carrier, and having utility in Fischer-Tropsch syntheses.

Abstract: Process for the preparation of a catalyst including an inert support, cobalt, ruthenium and a third element selected from scandium and yttrium, comprising at least the following steps:1) Preparation of a first catalytic precursor (A) containing cobalt and the inert support: subsequent calcination, reduction and passivation;2) Preparation of a second catalytic precursor (B) containing cobalt, ruthenium and the inert support, by means of the deposition of ruthenium on the first catalytic support (A): subsequent calcination, reduction and passivation3) Preparation of the final catalyst by means of the deposition of an element selected from scandium and yttrium on the catalytic precursor (B); subsequent calcination, reduction and passivation.