FIELD: petrochemical processes. SUBSTANCE: mercaptans and diolefins are simultaneously removed from long naphtha fraction in column-type distillation reactor for distilling butane fraction. Mercaptans react with diolefins to form sulfides, which boil at higher temperature than topped C4 and lighter part of naphtha. High-boiling sulfides are removed as distillation residues together with C5 and heavier materials. The former are preferably fed into stripping column wherein a portion thereof is topped and heavier portion is removed with sulfides. Resulting decreased volume of naphtha may be hydrogenised to convert sulfides into hydrogen sulfide and diolefins, which may be hydrogenised into olefins and alkanes. EFFECT: increased degree of thioetherification. 11 cl, 1 dwg, 2 tbl
