Catalytic oxidation of mercaptans and removal of naphthenic acids, catalyst toxins, and toxin precursors from petroleum distillates

摘要

A process is disclosed for the catalytic oxidation of mercaptans in a sour petroleum distillate containing difficultly oxidizable mercaptans, catalyst toxins and catalyst toxin precursors. The process comprises treating said distillate in contact with an alkaline solution and extracting naphthenic acids from the distillate; treating the substantially naphthenic acids-free distillate in contact with an oxidizing agent and an alkaline solution of a metal phthalocyanine catalyst, oxidizing the residual catalyst toxins and toxin precursors contained therein and converting a portion of the mercaptans to disulfides; passing the resulting reaction mixture through a bed of solid adsorbent particles and adsorbing the oxidized toxins and toxin precursors and the metal phthalocyanine solution thereon; treating the toxin-free and toxin precursor-free distillate in contact with an alkaline solution and a supported metal phthalocyanine catalyst in the presence of an oxidizing agent; and recovering a distillate substantially free of mercaptans.