Organic sulfur compound distribution

Thiophene (C4H4S) is representative of the organic sulfur compounds that are hydrogenated in the commercial hyditodesulfurization of petroleum naphtha. Estimate both the combined and effective diflfusivities for thiophene in hydrogen at 660 °K and 3.04 MPa in a catalyst with a BET surface area of 168 m2/g, a porosity of 0.40, and an apparent pellet density of 1.40 g/cm3. A narrow pore sized distribution... 

Application of these methods showed that the distribution of types of organic sulfur compound(s) (OSC) in crude oils is variable. In other words, the ratio of thermally labile to more resistant sulfur has a large range in crude oils. Geochemically, the large range is expected and understandable because of variations in source, maturity and other alteration processes. 

Studies of sulfur-containing organic compounds in coal provide information on the origin of organic sulfur and the transformation of sulfur compounds during coal maturation. The distribution and types of organic sulfur compounds in coal have profound implications for desulfurization processes. 

As already assumed the intramolecular incorporation of sulfur into the organic matter is not a random process (20).The distribution of the sulfur compounds will depend on the chemical capacity of the molecules present during early diagenesis in each kind of organic matter to accept an inorganic sulfur atoms. These two different types of organic matter enable the intramolecular incorporation of sulfur in different molecules, and consequently result in different distribution patterns of organic sulfur compounds. 

Distribution of Organic Sulfur Compounds in Mesozoic and Cenozoic Sediments from the Atlantic and Pacific Oceans and the Gulf of California... 

Gas chromatography - mass spectrometry data of the "aromatic hydrocarbon" fractions of nearly 100 Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) sediment samples have been re-examined for the occurrence of organic sulfur compounds (OSC). Approximately 70% of the samples contain OSC with varying distribution patterns, although isoprenoid thiophenes are invariably present. 

Modem GCMS analysis and sample preparation techniques have overcome many the analytical problems associated with the investigation of organic sulfur compounds associated with potential reactions between elemental sulfur and organic matter during analysis (Hayes, 1967). Shimoyama and Katsumata (2001) examined the distribution of aromatic thiophenes in Murchison detecting benzothiophene, dibenzothiophene, alky-substituted dibenzothiophenes, and benzo-naphthothiophenes at concentrations levels of 0.3 ppm (Table 1) confirming earlier studies (Basile et al., 1984). 

Schouten S., De Loureiro M. R. B., Sinninghe Damste J. S., and de Leeuw J. W. (2001a) Molecular biogeochemistry of Monterey sediments, Naples Beach, California I. Distributions of hydrocarbons and organic sulfur compounds. In The Monterey Formation from Rocks to Molecules (eds. C. M. Isaacs and J. Rullkotter). Columbia University Press, New York, pp. 150-174. 

The physical properties of the principal constituents of natural gas are Hsted in Table 5. These gases are odorless, but for safety reasons, natural gas is odorized before distribution to provide a distinct odor to warn users of possible gas leaks in equipment. Sulfur-containing compounds such as organic mercaptans, aUphatic sulfides, and cycHc sulfur compounds are effective odorants at low concentrations and are added to natural gas at levels ranging from 4 to 24mg/m. ... 

Two different enzyme systems have been described, one uses cytochrome P-450 to activate oxygen whereas the other employs flavin adenine dinucleotide (FAD). Both the cytochrome P-450 and the flavin monooxygenase systems have broad substrate specificities and oxidize and oxygenate a variety of organic nitrogen or sulfur compounds. The enzymes have a widespread distribution and have been detected in animals, plants, fungi and bacteria. Their function appears to be primarily one of detoxification of xenobiotics. Microbial enzymes... 

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