Abstract: A process is described for the upgrading of hydrocarbon mixtures which boil within the naphtha range containing sulfur impurities, i.e. a hydrodesulfuration process with contemporaneous skeleton isomerization and reduced hydrogenation degree of the olefins contained in said hydrocarbon mixtures, the whole process being carried out in a single step. The process is carried out in the presence of a catalytic system comprising a metal of group VI B, a metal of group VIII and a carrier of acid nature consisting of a mesoporous silico-alumina.

Abstract: A process is described for the upgrading of hydrocarbon mixtures which boil within the naphtha range containing sulfur impurities, i.e. a hydrodesulfuration process with contemporaneous skeleton isomerization and reduced hydrogenation degree of the olefins contained in said hydrocarbon mixtures, the whole process being carried out in a single step. The process is carried out in the presence of a catalytic system comprising a metal of group VIB, a metal of group VIII and a carrier of acid nature consisting of a mesoporous silico-alumina.

Abstract: A process is described for the upgrading of hydrocarbon mixtures which boil within the naphtha range containing sulfur impurities, i.e. a hydrodesulfuration process with contemporaneous skeleton isomerization and reduced hydrogenation degree of the olefins contained in said hydrocarbon mixtures, the whole process being carried out in a single step. The process is carried out in the presence of a catalytic system comprising a metal of group VI B, a metal of group VIII and a carrier of acid nature consisting of a mesoporous silico-alumina.

Abstract: Fuel composition for internal combustion engines which comprises a larger portion of fuel and a smaller quantity of a composition of hydrocarbon oligomers almost totally saturated, characterized in that the above composition of almost totally saturated hydrocarbon oligomers: 1) is obtained by the oligomerization and subsequent hydrogenation of a hydrocarbon composition comprising basically C.sub.13 -C.sub.18, preferably C.sub.15 -C.sub.16, internal oligomers, in a quantity of more than 90% by weight, 2) is basically without any possible hydrocarbons having a number of carbon atoms equal to or less than 13, 3) has a viscosity at 100.degree. C. of betweem 5.0 and 12.0 cSt, particularly from 7.3 to 8.4 cSt.