Process for the production of a gasoline with a low sulfur content

Process for treatment of a gasoline comprising diolefins, olefins, and sulfur-containing compounds including mercaptans, in which:

• Gasoline is injected into a distillation column (3) comprising at least one reaction zone (4) including at least a first catalyst comprising a substrate and at least one element of group VIII, with the injection being carried out at a level located below the reaction zone (4), in such a way as to bring into contact at least one fraction of the gasoline with the catalyst of the reaction zone (4) and to transform at least a portion of the mercaptans of said fraction into sulfur-containing compounds by reaction with the diolefins and to produce a desulfurized light gasoline that is drawn off at the top of said distillation column (3);
• with the process also comprising the following stages:
• An intermediate gasoline fraction is drawn off at a level located above the reaction zone (4) and below the top of the distillation column (3);
• A heavy gasoline comprising the majority of the sulfur-containing compounds is drawn off at the bottom of the column;
• In a demercaptization reactor (13), said intermediate gasoline fraction is brought into contact optionally with hydrogen, in the presence of a second catalyst in sulfide form comprising a substrate, at least one element selected from group VIII and at least one element selected from group VIB, with the element content of group VIII being between 1 and 30% by weight of oxide relative to the total weight of catalyst, the element content of group VIB being between 1 and 30% by weight of oxide relative to the total weight of the catalyst in such a way as to produce an effluent that contains sulfides;
• The effluent that is obtained from the demercaptization reactor is recycled in the distillation column (3).