Development of Catalysts for Sweetening Jet Fuel, from Laboratory to Industrial Scale

Fuel sweetening is a process that transforms sulfur compounds into neutral compounds by eliminating their acidity and corrosiveness through oxidation reactions. The catalysts developed for this application must achieve high mercaptan conversion while meeting specific required physical, composition, and stability characteristics. To this end, cobalt tetrasulfonated phthalocyanine (CoTsPc) catalysts were successfully synthesized; changes were made to the synthesis, achieving operational improvements in both the phthalocyanine synthesis and sulfonation stages, as well as better utilization of raw materials, obtaining better characteristics for the sweetening process with caustic solutions with high mercaptan conversions at laboratory level, which led to the synthesis scale-up and pilot plant testing stages. Due to their excellent performance, the catalysts were manufactured at industrial level and tested for jet fuel sweetening at an industrial refinery plant; however, the product did not meet specifications during the first industrial test. The success of the second industrial test depended on a deep analysis of the catalytic behavior and adjustment of the plant operating variables owing to the introduction of feedstocks that were heavier than those the catalysts had been designed for.