CS2 Formation in the Claus Reaction Furnace: A Kinetic Study of Methane−Sulfur and Methane−Hydrogen Sulfide Reactions

Improving the understanding of reaction kinetics of CS2 formation in the Claus plant front-end reaction furnace (RF) is a key step in developing strategies to reduce CS2 formation and, consequently, the environmental impact of Claus plants. Specifically, experiments were carried out in a high-temperature flow reactor with pressures of 101−150 kPa, temperatures of 800−1250 °C, and residence times of 90−1400 ms to study the kinetics of CH4−S2 and CH4−H2S reactions; these conditions are typical of those encountered in the Claus RF. The reaction between methane and sulfur was found to be very rapid, resulting in complete consumption of sulfur in less than 100 ms at 1100 °C with formation of CS2 and H2S as the primary sulfur-containing products. At higher temperature (>1000 °C), the produced H2S decomposes with a proportional increase in CS2 formation. A simple rate expression for CS2 formation was obtained, and a kinetic model was developed to describe H2S formation/consumption in the CH4−S2 system. In the CH...