Merox process (mercaptan oxidation) was developed in the 40s of the XX century by the American company UOP for desulfurization of natural and liquefied gases, gasoline and kerosene fractions treatment.
Desulphurization of gases by Merox process includes amine removal of hydrogen sulfide, carbonyl sulfide and alkaline mercaptan removal. Alkaline mercaptan removal is carried out by preliminary alkalization of feedstock from residual hydrogen sulfide followed by extraction of mercaptans from gas and regeneration of alkaline solution in the presence of homogeneous phthalocyanine catalyst and oxygen.To achieve low total sulfur content in the treated gas produced disulfides are washed out with light naphtha. Disulfides dissolved gasoline fraction is supplied to the hydrotreating feedstock.