Experimental and numerical studies of sulfur chemistry in H2/O2/SO2 flames

✍ Scribed by Michael R. Zachariah; Owen I. Smith

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 774 KB
• Volume: 69
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(87)90026-5

✦ Synopsis

The structure of low pressure (100-150 Torr) rich H2/O2 flames doped with SO2 has been investigated both experimentally and numerically in order to clarify the chemistry of sulfur laden flames. Equivalence ratios from 1.35 to 2.4 have been examined, with peak temperatures between 1800 and 1450K. The basic features of the concentration profiles suggest a two stage flame as most of the hydrogen-oxygen chemistry is complete early on (5-7 mm). The sulfur chemistry is, by comparison, continually adjusting itself to changes in temperature and radical concentrations.

Numerical simulations accurately predict the general features of these flames, allowing for a detailed description of the important chemistry in various regions of the flame. SO: is found to be the dominant sulfur species even in the very rich flames, although H2S is by far the most thermodynamically favored species. SO is rapidly formed in the main reaction zone; however, it never achieves partial equilibrium with SO2, as has previously been surmised. $2 is found to be the second most dominant sulfur species and is also not in partial equilibrium. The role of HSO2 as a channel for radical recombination is shown to be extremely important to the distribution of sulfur species. The calculations also suggest that sulfur chemistry is fast enough to perturb the partial equilibrium of O-atoms in the postflame region. Increasing the initial concentration of SO2 results in preferential formation of $2 at the expense of H2S. Introduction of H2S instead of SO2 results in a flame which by 6 mm is indistinguishable from its SO2 doped counterpart.