Patent ID: 7651606

Claim:
A process for producing gasolines with a low sulphur and mercaptans content, comprising treating a feed in at least two hydrodesulphurizations HDS 1 and HDS 2 operated in parallel on two distinct cuts of a gasoline feed, the feed corresponding to a gasoline from a catalytic cracking unit distilled into three fractions: a light fraction corresponding to a gasoline fraction with a boiling point of less than 100° C.; a heavy gasoline fraction corresponding to a gasoline fraction with a boiling point of more than 180° C.; a core fraction corresponding to an intermediate fraction between the light fraction and the heavy fraction; wherein hydrodesulphurization HDS 2 has a flow rate of hydrogen such that the ratio between the flow rate of hydrogen, expressed in normal m 3 per hour, and the flow rate of feed to be treated, expressed in m 3 per hour, under standard conditions, is less than 80% of the ratio of the flow rates employed for desulphurization in hydrodesulphurization HDS 1 , and wherein a mixture constituted by the light gasoline fraction and the intermediate fraction or the intermediate fraction alone is treated in the hydrodesulphurization HDS 1 , said treatment comprising bringing the gasoline to be treated into contact with hydrogen in one or more hydrodesulphurization reactors in series containing one or more catalysts suitable for carrying out selective hydrodesulphurization with a degree of mono-olefins hydrogenation of less than 60%, and in which the heavy fraction of the gasoline is treated in hydrodesulphurization HDS 2 , said treatment comprising bringing the gasoline to be treated into contact with hydrogen in one or more hydrodesulphurization reactors in series containing one or more catalysts suitable for carrying out hydrodesulphurization, hydrodesulphurization being carried out selectively or non-selectively, the degree of hydrogenation of the mono-olefins being less than 90% in the case of selective hydrodesulphurization, and wherein gasoline obtained in the process has a research octane number greater than or equal to 90.70 and a sulfur content less than or equal to 50 ppm.