Method for converting residues incorporating deep hydroconversion steps and a deasphalting step

Abstract

The invention concerns a method for converting heavy hydrocarbon feedstocks of which at least 50% by weight boils at a temperature of at least 300° C., and in particular vacuum residues. The feedstocks are subjected to a first step a) of deep hydroconversion, optionally followed by a step b) of separating a light fraction, and a heavy residual fraction is obtained from step b) of which at least 80% by weight has a boiling temperature of at least 250° C. Said fraction from step b) or the effluent from step a) is then subjected to a second step c) of deep hydroconversion. The overall hourly space velocity for steps a) to c) is less than 0.1 h. The effluent from step c) is fractionated to separate a light fraction. The heavy fraction obtained, of which 80% by weight boils at a temperature of at least 300° C., is sent to a deasphalting step e). The deasphalted fraction DAO is then preferably converted in a step f) chosen from ebullated bed hydroconversion, fluidised bed catalytic cracking and fixed bed hydrocracking.