Process for selective capture of arsenic in gasolines rich in sulphur and olefins

A process for capturing organometallic impurities comprising at least one of a heavy metal, silicon, phosphorous, and arsenic, contained in a hydrocarbon feed, comprising contacting the feed with a capture mass consisting essentially of at least one metallic element in catalytic amounts selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), lead (Pb) and zinc (Zn) deposited on a porous support selected from at least one of aluminas, silica, silica-alumina, and titanium, or magnesium oxides used alone or as a mixture with alumina or silica-alumina, the metallic element prior to said contacting being in the sulphide form with a degree of sulphurization of at least 60%, and in which the feed to be treated is a catalytically cracked gasoline containing 5% to 60% by weight of olefins, 50 ppm to 6000 ppm by weight of sulfur and traces of arsenic in amounts in the range 10 ppb to 1000 ppb by weight,

• wherein said capture mass is core-sulphurized,
• wherein said capture mass is brought into contact with the feed to be treated and a stream of hydrogen in a manner such that the volume ratio of the hydrogen stream to the feed to be treated under the reaction conditions is in the range of 50 to 800 Nm3/m3, wherein in the feed the degree of hydrogenation of the olefins is less than 30% and the degree of hydrogenation of aromatic compounds is less than 10%, and
• wherein the resultant treated feed has a lower degree of hydrogenation of the olefins than that resulting from the use of a comparable catalyst containing molybdenum in addition to said at least one metallic element, and while reducing the arsenic content to less than 5 mircograms per liter.