Investigation of sulfur chemistry with acid gas addition in hydrogen/air flames

Investigations on the effect of acid gas (H₂S and CO₂) addition in hydrogen/air flame are presented. The specific equivalence ratios examined include Claus conditions (Φ=3.0) as well as stoichiometric conditions (Φ=1.0) and fuel-lean conditions (Φ=0.5). Two different acid gas compositions of 100% H₂S, and 50% H₂S/50% CO₂ are reported. Addition of pure hydrogen sulfide acid gas deteriorated the rate of hydrogen oxidation in the hydrogen/air flame. Combustion of hydrogen sulfide alone formed sulfur dioxide rather than more favorable elemental sulfur. In contrast combustion of 50% H₂S/50% CO₂ acid gas stream produced faster decomposition/production of H₂S, SO₂, and H₂. Presence of carbon monoxide was a distinct mark on the release of oxygen from CO₂ into the reaction pool. The presence of carbon monoxide triggered the formation of other sulfurous-carbonaceous compounds, such as COS and CS₂.