Patent ID: 6042716
Filing Date: 2000-03-28
Classification: C10G

Abstract:
A process for transforming a gas oil cut into a diesel fuel having a cetane number of at least 49, less than 100 ppm of sulphur, less than 200 ppm of nitrogen and less than 10% by volume of aromatic compounds, comprising the following steps:a) passing the gas oil cut and hydrogen under denitrogenation and desulphurisation conditions in at least one step over a catalyst comprising a mineral support, at least one metal or metal compound from group VIB of the periodic table in a quantity, expressed as the weight of metal with respect to the weight of finished catalyst, of about 0.5% to 40%, at least one metal or metal compound from group VIII of the periodic table in a quantity, expressed as the weight of metal with respect to the weight of finished catalyst, of about 0.1% to 30%, and phosphorous or at least one phosphorous compound in a quantity, expressed as the weight of phosphorous pentoxide with respect to the weight of the support, of about 0.001% to 20% to produce an at least partially denitrogenated and desulfurised effluent;(b) steam stripping the effluent from step (a) and, optionally, recycling hydrogen therein for use in step (a);(c) passing at least a portion of the steam stripped effluent from step (b) with hydrogen under dearomatisation conditions over a catalyst comprising, on a mineral support having at least one halogen, at least one noble metal or noble metal compound from group VIII in a quantity, expressed as the weight of metal with respect to the weight of finished catalyst, of about 0.01% to 20% to produce a denitrogenated, desulfurised and dearomatised diesel fuel, and, optionally, recycling hydrogen for use in step (c);with the further provision that fresh hydrogen is introduced into steps (a) and (c) independently of each other and that recycle hydrogen from step (b) is recycled to only step (a) and recycle hydrogen from step (c) is recycled to only step (c).