Patent ID: 7390393

Claim:
A process for treatment of petroleum feedstocks of which at least 80% by weight boils above 340° C. and which contains at least 0.05% by weight of sulfur for producing at least one gas oil fraction with a sulfur content of at most 50 ppm by weight, which process comprises the following stages: a) ebullated-bed hydroconversion with a hydroconversion catalyst that is at least partly amorphous comprising passing an upward flow of liquid and gas into the ebullated bed, at a temperature of 300-550° C., a pressure of 2-35 MPa, an hourly space velocity of 0.1 h −1 to 10 h −1 in the presence of 50-5000 Nm3 of hydrogen/m3 of feedstock, whereby the net conversion of products boiling below 360° C. is 10-80% by weight, b) separation from the effluent of a gas that contains hydrogen, hydrogen sulfide formed in stage a) and a heavier fraction than the gas oil, and after the separation, said gas that conains hydrogen is recycled to stage a), c) hydrotreatment, by contact with at least one catalyst, of at least one distillate fraction that is obtained in stage b) and that includes a gas oil fraction, at a temperature of 300-500° C., a pressure of 2-12 MPa, an hourly space velocity of 0.1-10 h −1 and in the presence of 200-5000 Nm3 of hydrogen/m3 of feedstock, d) separation of hydrogen, gases and at least one gas oil fraction with a sulfur content of less than 50 ppm by weight, wherein the hydrogen that is separated in stage d) is recycled to stage a) with the gas that contains hydrogen separated in stage b), and all of the make-up hydrogen that is necessary to the process is brought to stage c).