Kinetic modeling of a Claus reaction furnace and waste heat boiler: Effects of H2S/CO2 and H2S/H2O ratio on the production of hazardous gases in an industrial sulfur recovery unit

In this study, the reaction furnace (RF) and waste heat boiler (WHB) were modeled using a kinetic model developed from key reactions to determine how the input feed in the various acid gas scenarios affects the Sulfur Recovery Unit's (SRU's) thermal stage for industrial application. The modeling results showed that, while keeping other parameters constant, a decrease in the H2S/CO2 and H2S/H2O ratios leads to an increase in the production of hazardous gases such as CO, SO2, and COS in the Waste Heat Boiler (WHB). Consequently, this leads to a decrease in the efficiency of the Sulfur Recovery Unit (SRU). When the temperature profile is altered, the Claus reaction pathway changes unfavorably, consequently affecting the overall efficiency of the Claus process. The accuracy of the kinetic model decreases as the acid gas becomes more dilute, significantly impacting the temperature profile. The accuracy of these results was confirmed through industrial data spanning from typical acid gas to sweet gas, with a Mean Absolute Percentage Error (MAPE) ranging from 26.18 to 47.37.