Analysis for sulphur compound types in heavy crudes

It has been well established that the sulfur containing components of crude oil are corrosive, decrease catalyst efficiency, and release noxious vapors during their chemical reactions. Consequently, the processing of high sulfur feeds reduces refining capacity and increases the cost of the final products. Furthermore, the polycyclic aromatic sulfur heterocycles (PASH) may pose mutagenic and/or carcinogenic hazards. Specific classes of sulfur compounds have been found to be more objectionable than others, while some are considered beneficial in limited applications. Thus, it is important to identify the organosulfur classes which are undesirable for the specific application and to ascertain the concentration limits which are deleterious. The sulfur compounds in crude oils may be expected to undergo two types of reactions-addition (usually to heavy metal sales) and oxidation. The former was the basis for the sulfur class analyses performed by Ball under the auspices of API project 48. The method has found application recently; however, it requires large samples, is time and manpower intensive, and has been proved only for the lightest fractions of petroleum. The latter method, that of oxidation, has been the basis for several sulfur compound type analyses in crude oil and its fractions. They have used both themore » of these techniques for the analyses of sulfur compound types in heavy crudes and their fractions. They wish to report on the applicability of, and their modification to, some of these techniques and present their findings.« less