Process and apparatus using a plurality of catalytic beds in series for the production of gas oils with a low sulphur content

摘要

A process for hydrotreating gas oils comprises: at least one first step a) for hydrodesulphurization in which said gas oil cut and hydrogen are passed over a catalyst disposed in a fixed bed; at least one subsequent second step b) in which a gas fraction containing at least a portion of the hydrogen sulphide contained in the total effluent from said first step is recovered along with an effluent that is depleted in hydrogen sulphide; and at least a third step c) in which at least a portion of the effluent depleted in hydrogen sulphide from step b) and hydrogen are passed over a catalyst disposed in a fixed bed that is identical to or different from that used in step a). The quantity of catalyst used in the first step is strictly more than 50% by weight of the total quantity of catalyst used in said process.