GB711670A - Process for improving hydrocarbons boiling in the gasoline range - Google Patents

Abstract

Hydrocarbons boiling in the gasoline range are subjected to a catalytic treatment in the vapour phase and in the presence of hydrogen at 30-100 atmos. and 450-500 DEG C. in two stages, the first in the presence of a dehydrogenating catalyst comprising either platinum or nickel-tungsten-sulphide, as such or on a carrier, other than one activated with acid, to dehydrogenate any 6-membered ring naphthenes present, the products then being subjected to a hydrogenating cracking using nickel - tungsten - sulphide on acid - activated alumina. If desired, a further dehydrogenation stage may follow. The carrier in the first stage may be alumina and may contain an alkali metal, e.g. a potassium compound. Activation of the carrier for the second stage may be effected by treating with hydrogen halide or a substance producing it, e.g. hydrogen fluoride, benzene fluoride, ammonium fluoride or tert. butyl chloride. Space velocities are 0.5-5 kg./l./hr. and quantities of hydrogen 3-10 mols./mol. gasoline. An example compares the two-stage treatment of a crude petroleum fraction boiling at 113-191 DEG C. with single stage treatments. The first catalyst is a commercial Ni-W sulphide, the second precipitated alumina treated with HF and mixed with precipitated Ni-W sulphide (see Group 3).ALSO:A catalyst for reforming gasoline hydrocarbons comprises a nickel-tungsten-sulphide on acid-activated alumina. Activation may be effected with a hydrogen halide or substance producing it, e.g. hydrogen fluoride, benzene fluoride, ammonium fluoride or tert. butyl chloride. In an example, precipitated aluminium hydroxide is treated with HF solution; and mixed with the precipitate obtained by adding Ni (NO3)2 solution to an ammoniacal solution of (NH4)2 WS4 saturated with H2S, and acidifying with H2SO4 to pH 1.5. The alumina : F : W : Ni ratio is 100 : 0.3 : 26.9 : 4.3.