Numerical Simulation of a High-Pressure Reactive Furnace in Recovering Sulfur from Sour Gas

Nowadays, the Claus process is one of the most efficient procedures to recover sulfur from acid gases. In the current study, the effect of working pressure and the role of initial species (sour gas, ammonia, carbon dioxide, hydrocarbon, nitrogen, and oxygen) are analyzed using COMSOL software. The reaction occurs between acid gases, which contain 88% H₂S, 10.5% CO₂, 0.49% N₂, and 1.01% CH₄ in terms of molar percentage, and pure air. A good agreement is obtained between the numerical simulation results and experimental data. According to the results, there is a direct correlation between the conversion rate of acid gases and the increase in pressure. However, this rise in reactor pressure also leads to an undesirable increase in the outlet temperature. It is also observed that reduction of hydrogen sulfide inflow decreases the sulfur monoxide production rate, which in turn significantly affects the reactor temperature and the sulfur recovery rate. The more the oxygen that enters the reactor, the more the hydrogen sulfides that change into sulfur.