Selective reduction method of the content of benzene and light unsaturated compounds in the hydrocarbon fraction

摘要

PROBLEM TO BE SOLVED: To reduce the content of benzene or unsaturated compounds in a raw material at a low cost without deteriorating the octane number by passing a hydrocarbon fraction raw material through a distillation zone equipped with a hydrogenating zone and then passing an effluent from the distillation zone containing a specific hydrocarbon through a paraffin isomerizing zone. ;SOLUTION: (A) A raw material 1 mostly containing (A₁)≥5C hydrocarbons and further (A₂) 1-6C unsaturated compounds including benzene is treated in a distillation zone containing a catalyst bed 3 combined with a hydrogenating reactional zone to hydrogenate at least a part of the compounds (A₂) in the presence of a hydrogenating catalyst and hydrogen (4c) and (4d) in the zone. An effluent from the reactional zone is at least partially introduced into the distillation zone so as to ensure the continuity of the distillation. The effluent 9 with an extremely reduced content of the hydrocarbons (A₁) is finally taken out of the top of the distillation zone and a part of the effluent 9 containing 5-6C paraffins is treated in the presence of an isomerizing catalyst and isomerized in an isomerizing zone 18.;COPYRIGHT: (C)1997,JPO