An evaluation of kinetic models for the simulation of Claus reaction furnaces in sulfur recovery units under different feed conditions

Abstract

The modified Claus process is one of the major processes employed to convert hydrogen sulfide to elemental sulfur from acid gas. Kinetic models provide a better estimation of Claus reaction furnace effluents, however, kinetics of the coupled reactions are complex and depend upon the feed composition and conditions. Previous studies focused on fitting the kinetic parameters to better approximate the furnace effluents of the observed plants. In this work, a proposed kinetic model based on key global reactions is examined with different feed conditions and acid gas compositions without parameter fitting. Results of the proposed reduced model are compared with plant data, published data from lab-scale experiments, results of a detailed reaction mechanism and of a reduced kinetic model from the literature. Overall, a good agreement is found with each case for the prediction of the reaction furnace effluent temperature and compositions by the proposed model. The proposed model is computationally efficient for Computational Fluid Dynamics design, and optimization and control studies for Claus reaction furnaces.