Sulfur compound distribution

These examples illustrate recent interest in investigating the potential of sulfur compound distributions for improving our understanding of geologic influences in determining variations in composition of crude oils with relation to source and evolution history. 

Several distinct maturity-related trends emerge through detailed examination of the traces (Figure 10). There are variations in both the relative abundance of different compound classes and within individual compound classes. The most marked trend is an increase in abundance of alkylbenzothiophenes relative to alkylthiophenes. This is clearly seen in Figure 11 where the ratio of these two compound classes is plotted with respect to depth. There is also an apparent shift in the internal carbon number distributions of both the alkylbenzothiophenes and alkylthiophenes. Specifically, there appears to be a preferential loss of short-chain alkylthiophenes and alkylbenzothiophenes (e.g. methylthiophenes decrease relative to dimethylthiophenes). The exception to this depth trend is the sample from 2480m which appears less mature (on the basis of sulfur compound distribution) than the adjacent sample of shallower depth (2020m). 

The major part of the sulfur contained in crude petroleum is distributed between the heavy cuts and residues (Table 8.10) in the form of sulfur compounds of the naphthenophenanthrene or naphthenoanthracene type, or in the form of benzothiophenes, that is, molecules having one or several naphthenic and aromatic rings that usually contain a single sulfur atom. 

Rail, H.T., C.J. Thompson, H.J. Coleman and R.L. Hopkins (1972), "Sulfur compounds in crude oil". Bureau of Mines Bull. No. 659. Distributed by National Technical Information Service (NTIS), US Dpt of Commerce, Springfield, VA. 

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. ... 

Isotope effects also play an important role in the distribution of sulfur isotopes. The common state of sulfur in the oceans is sulfate and the most prevalent sulfur isotopes are (95.0%) and (4.2%). Sulfur is involved in a wide range of biologically driven and abiotic processes that include at least three oxidation states, S(VI), S(0), and S(—II). Although sulfur isotope distributions are complex, it is possible to learn something of the processes that form sulfur compounds and the environment in which the compounds are formed by examining the isotopic ratios in sulfur compounds. 

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... 

FCC feed, sulfur compounds in, 11 716 FCC unit emissions, 11 714 controlling, 11 689-694 FCC unit regenerators, 11 713 air distribution systems in, 11 726 catalyst emissions from, 11 714—715 CO2 emissions from, 11 720—721 configuration and mechanical hardware in, 11 722-731 cyclones in, 11 726-728 design of, 11 722-723 flue gas handling in, 11 729 fluidization in, 11 723-725 nitrogen oxide emissions from,... 

FT is most compatible with existing distribution for conventional diesel and only minimal adjustments are required to obtain optimal performance from existing diesel engines. Physical properties of FT are very similar to No. 2 diesel fuel, and its chemical properties are superior in that the FT process yields middle distillates that, if correctly processed (as through a cobalt-based catalyst), contain no aromatics or sulfur compounds. 

Natural gas is a clear, odorless, tasteless gas made of very short and simple hydrocarbons, mostly methane (CH ). According to the DOE, over half of the homes in the United States are heated with natural gas. Natural gas is also used in homes to fuel stoves, hot water heaters, and clothes dryers. In industry, natural gas is a common raw ingredient in paints, plastics, fertilizers, and medicines. Before natural gas is distributed, a sulfur compound is added to it... 

Figure I. Equilibrium distribution of sulfur compounds as a function of pE at pH 7 and 25°C. Total concentration of compounds is 10 3M. Ph2s n atm-is about 50 times + [HS])...

The distribution of sulfur compounds in crude oils has been studied extensively since the 1890s and it has become possible to note various generalities. For example, the proportion of sulfur will increase with the boiling point... 

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