Method for producing a petrol with low sulphur and mercaptan content

A process for the treatment of a gasoline containing sulfur compounds, olefins and diolefins, the process comprising at least the following stages:

• a) the gasoline, hydrogen and a hydrodesulfurization catalyst comprising an oxide support and an active phase comprising a metal from group VIb and a metal from group VIII are brought into contact in at least one reactor at a temperature of between 210 and 320° C., at a pressure of between 1 and 4 MPa, with a space velocity of between 1 and 10 h−1 and a ratio of the hydrogen flow rate, expressed in standard m3 per hour, to the flow rate of feedstock to be treated, expressed in m3 per hour at standard conditions, of between 100 Sm3/M3 and 600 Sm3/m3, so as to convert at least a part of the sulfur compounds into H2S,
• b) at least a part of the effluent resulting from stage a) without removal of the H2S formed, hydrogen and a hydrodesulfurization catalyst comprising an oxide support and an active phase consisting of at least one metal from group VIII are brought into contact in at least one reactor at a temperature of between 280 and 400° C., at a pressure of between 0.5 and 5 MPa, with a space velocity of between 1 and 10 h−1 and a ratio of the hydrogen flow rate to the flow rate of feedstock to be treated which is greater than that of stage a), said temperature of stage b) being higher than the temperature of stage a), and
• c) a stage of separation of the H2S formed and present in the effluent resulting from stage b) is carried out.