Use of new reaction kinetics for COS formation to achieve reduced sulfur emissions from claus plants

A simulation study of COS formation in the tubes of the waste heat boiler (WHB) located just after the reaction furnace of a Claus plant is reported. First, the kinetics of the COS forming reaction were obtained from a recently completed experimental program in our laboratory. The predictions for COS formation from the newly developed kinetic model were compared with the data from an actual industrial waste heat boiler and found to be in good agreement. The simulation results showed that up to a 50% reduction in the COS production may be achieved by operating the WHB at the maximum allowable gas mass velocity in the WHB tubes coupled with the use of a smaller diameter tube. These reductions have major implications on the overall sulfur recovery from Claus plants.