Process for obtaining a fuel with diesel fraction by oligomerization of olefins or mixtures thereof

摘要

The present invention relates to a process for obtaining a fuel containing a diesel fraction having cetane number equal to or higher than 48 and content of aromatic compounds less than 0.4 percent by weight, using light olefins or mixtures thereof as starting products, wherein the process comprises the following phases: - oligomerization of the aforementioned olefins containing 2 to 10 carbon atoms in the presence of synthetic zeolites containing silicon, titanium and aluminium oxides wherein the molar ratio SiOi2/Ali2Oi3 is in the range of 100 to 300, wherein the molar ration SiOi2/TiOi2 being greater than 41 and the amount of extra-structural titanium oxide is zero or less than 25 percent by weight, based on the total weight of titanium oxide being present; carried out at a temperature ranging from 180 to 300 degC, at a pressure greater than 4 MPa and weight spatial rate equal to or higher than 1 he-1 to obtain a stream substantially consisting of oligomerized (Ci5-Ci24) hydrocarbons containing 5 to 24 carbon atoms; - distillation of the stream obtained from oligomerization to separate a stream of hydrocarbons containing 12 to 24 carbon atoms from a stream of hydrocarbons containing 5 to 12 carbon atoms; - hydrogenation of the separated stream of hydrocarbons containing 12 to 24 carbon atoms.