In oil and gas refineries, sulfur recovery units(SRUs) are considered to be one of the most important units due to their environmental and economic importance. The Claus reaction furnaces are essential parts of this unit. The SRU must be improved to comply with tightening environmental laws. The knockout drums protect the reaction furnace from the severe thermal shock caused by the incoming water in the acid gas. In this study, utilizing kinetic modeling the impact of input water amount on sulfur recovery was explored. As a result of decreasing the water content from 8% to nill in the input acid gas, the H2S/SO2 ratio increased by 1.8 units, whereas the SRU efficiency decreased by 2%. The H2S/SO2 ratio increases the performance of Claus reaction furnace and the SRU ultimately. Therefore, In order to prevent severe thermal shocks, it is extremely important to use the knockout drums to control the water amount.
