Numerical and experimental studies on mixing and product species distribution in a claus reactor

Claus process is commonly used for hydrogen sulfide treatment. Improvement of thermal and reactants species distribution in the Claus process impacts the efficiency of the chemical reactions to subsequently impact the Claus process efficiency. Different mixing chamber configurations are investigated here in order to determine the optimum configuration for achieving the best reactants mixing characteristics for seeking distributed reaction regimes. It is found that configurations that provide promising mixing characteristics possess a recirculation zone generated inside the mixing chamber. However, configurations where mixing depends on shear layer do not give good and effective mixing characteristics. Some configurations show very good mixing characteristics, but they are not effective for use in Claus process. This is because Claus process needs very high but controlled operating temperatures and the mixing alters the regions of desirable temperatures. Furthermore high thermal stresses imposed by some of these configurations can cause failure from the associated high thermal stresses. Experimental studies on the fate of hydrogen sulfide under Claus condition in methane-air flame under well mixed conditions are performed. The results showed that hydrogen sulfide initially oxidizes to form SO ₂ immediately upon its introduction in the high temperature zone of the reactor. The SO ₂ so formed then reacts with H ₂S to form sulfur in the reactor. The results also revealed that hydrogen sulfide enhances the formation of higher series of hydrocarbon from methane/air combustion. This was not observed for methane air flames.