Hydrogen carbon-oxygen-sulfur system

The H-C-O-S System. Following the usual convention, the hydrogen-carbon-oxygen-sulfur system is represented as a tetrahedron with the four pure elements at the apexes as depicted by Figure 1. In the reduction of sulfur dioxide by fossil fuels, if we assume the fuel to be the sole... 

In this chapter, we develop a mass balance model of the fractionation in reacting systems of the stable isotopes of hydrogen, carbon, oxygen, and sulfur. We then demonstrate application of the model by simulating the isotopic effects of the dolomitization reaction of calcite. 

The complex nature of coal as a molecular entity (2,3,24,25,35,37,53) has resulted ia the chemical explanations of coal combustion being confined to the carbon ia the system. The hydrogen and other elements have received much less attention but the system is extremely complex and the heteroatoms, eg, nitrogen, oxygen, and sulfur, exert an influence on the combustion. It is this latter that influences environmental aspects. 

N s are the numbers of atoms of carbon (C), sulfur (S), hydrogen (H), halogens (X), and oxygen (O) in the molecule. P is the total system pressure. is the vapor pressure of the compound at the flash point temperature. 

As can be seen in Fig. 2-1 (abundance of elements), hydrogen and oxygen (along with carbon, magnesium, silicon, sulfur, and iron) are particularly abundant in the solar system, probably because the common isotopic forms of the latter six elements have nuclear masses that are multiples of the helium (He) nucleus. Oxygen is present in the Earth s crust in an abundance that exceeds the amount required to form oxides of silicon, sulfur, and iron in the crust the excess oxygen occurs mostly as the volatiles CO2 and H2O. The CO2 now resides primarily in carbonate rocks whereas the H2O is almost all in the oceans. 

Many of the non metals such as hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, chlorine, and iodine are essential elements, and most are used in quantities for beyond the trace levels. Nevertheless, most of the chemistry of these elements in biological systems is more closely associated with organic chemistry than with inorganic chemistry. 

It therefore comes as no great surprise that within our solar system itself, all 11 of the principal elements found in man are in the top 20 in terms of abundance, with five of them figuring in the top ten — hydrogen, carbon, nitrogen, oxygen, and sulfur. When we consider the abundance of these 11 obviously essential elements in the earth s crust (Fig. 1.2), we find that no less than six of them (hydrogen, oxygen, and the four alkali and alkaline... 

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