Advances in Merox™ Process and Catalysis for Thiol Oxidation

The UOP Merox (TM) process is an efficient and economical catalytic process developed for the treatment of petroleum fractions to remove sulfur present as thiols or to directly convert thiols to less-objectionable disulfides. The key to this oxidation process is a metal-chelate redox catalyst which selectively catalyzes the oxidation of thiols with oxygen as the oxidant without causing undesirable oxidation of hydrocarbons. In this paper, we discuss the Merox (TM) process and mechanisms by which the catalyst selectively oxidizes thiols. Additionally, we discuss the development of promoted thiol oxidation catalyst systems which eliminate the use of caustic media in the oxidation process.