Kinetic modeling and optimization of Claus reaction furnace

Abstract

Optimization of Claus sulfur recovery plants requires a reliable kinetic model to describe the reaction furnace and waste heat boiler. In order to develop a suitable kinetic model for prediction of reaction furnace and waste heat boiler effluents, several reaction schemes were tested and the best reaction set was selected. The kinetic parameters of the best reaction scheme were optimized and different reactor networks were analyzed using the optimum reaction set. The modified model results were in good agreement with the experimental measured plant data both before and after waste heat boiler (The mean absolute errors were 7.62% and 7.88% respectively). In addition, the effects of increasing ammonia and oxygen content of feed, and air to acid gas ratio on reaction furnace effluents were investigated through various case studies. An optimization study was performed to control the operating variables of an operating sulfur recovery unit in order to obtain optimum conditions (including maximum reaction furnace temperature), maintain H2S to SO2 ratio at constant 2 and lower COS emissions from waste heat boiler.