Patent ID: 6783661
Filing Date: 2004-08-31
Classification: C10G

Abstract:
A process for producing oils with a high viscosity index from a feed containing constituents with boiling points of more than about 300Â° C. comprisinga) reacting hydrogen with the feed or with a mixture of the feed with at least a fraction of a stream recycled from c), in the presence of a catalyst comprising at least one amorphous non zeolitic matrix and at least one metal or compound of a metal from group VIII of the periodic table and/or at least one metal from group VIB to produce an effluent; b) fractionating at least a portion of the liquid effluent obtained from a) so as to separate at least one oil residue comprising mainly constituents with viscosity indices which are higher than that of the feed; c) fractionating at least a portion of the oil residue obtained in b) by thermal diffusion into oil fractions with high viscosity indices and separating the oil fractions in accordance with their viscosity index, and recycling at least part of at least one fraction with low viscosity index from c) to a).