Effect of CO₂ and N₂ concentration in acid gas stream on H₂S combustion

The Effect of the presence of nitrogen and carbon dioxide in H₂S acid gas stream is investigated. Concentrations of up to 30% of N₂ or CO₂ in H₂S stream have been examined. All cases were compared with the baseline case of 100% H₂S acid gas stream. Temperature measurements showed that injection of CO₂ or N₂ in the H₂S stream decreases the flame temperature. However, injection of CO₂ resulted in temperature increase downstream. Increase of carbon dioxide in the acid gas stream increased SO₂ mole fraction in the byproducts. In addition, the increase of CO₂ decreased the asymptotic value of H₂S at downstream locations. Furthermore, the presence of CO₂ decreased the amount of sulfur captured during the reaction process. This is attributed to increase in oxidizing medium in the reaction pool from the presence of carbon dioxide. The increase in oxygen fostered H₂S combustion to form higher amounts of SO₂. Subsequently, the amount of captured sulfur and asymptotic value of H₂S decreased. On the other hand, the presence of nitrogen in the acid gas stream did not affect the reaction process significantly. Nitrogen acted as an inert gas on the reactants and did not affect the reaction chemistry.