DEVELOPMENT OF A ZERO-EMISSIONS SULFUR-RECOVERY PROCESS .2. SULFUR-RECOVERY PROCESS-BASED ON THE REACTIONS OF H2S AND CO2 AT HIGH-TEMPERATURE

When H2S is heated above 600-degrees-C in the presence Of CO2, elemental sulfur and synthesis gas are formed. A sulfur-recovery process using this chemistry is as follows: H2S is heated in a high-temperature reactor in the presence Of CO2 and a suitable catalyst. The primary products of the overall reaction are S2, CO, H-2, and H2O. Small amounts Of COS, SO2, and CS2 also form. Rapid quenching of the reaction mixture to roughly 600-degrees-C prevents loss Of 82 during cooling. Carbonyl sulfide is removed from the product gas by hydrolysis back to CO2 and H2S. Unreacted CO2 and H2S are removed from the product gas and recycled to the reactor, leaving a gas consisting chiefly of H-2 and CO, which recovers the hydrogen value from the H2S. This process is economically favorable compared to the existing sulfur-recovery technology and allows emissions of sulfur-containing gases to be controlled to very low levels.