Oxidative mechanisms of sulfur fuels

Sulfur fuels characteristically bum with flames that are pale blue, sometimes very intensely so. This color comes about from emissions as a result of the reaction 

Most studies of sulfur-fuel oxidation have been performed using hydrogen sulfide, H2S, as the fuel. Consequently, the following material will concentrate on understanding the H2S oxidation mechanism. Much of what is learned from 

FIGURE 8.11 Approximate explosion limits for stoichiometric mixtures of hydrogen sulfide 

The main reaction scheme for the low-temperature oxidation of H2S, although not known explicitly, would appear to be 

The addition of reaction (8.98) to this scheme is necessary because of the identification of S20 in explosion limit studies. More importantly, Merryman and Levy [41] in burner studies showed that S20 occurs upstream from the peak of the SO concentration and that elemental sulfur is present still further upstream in the preignition zone. 

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