MODELING THE MODIFIED CLAUS PROCESS REACTION FURNACE AND THE IMPLICATIONS ON PLANT-DESIGN AND RECOVERY

The calculation of product composition, flow rate and temperature of t he modified Claus process reaction furnace is typically done by assumi ng either thermodynamic equilibrium or by empirical methods fitted to plant data. This paper extensively reviews the literature on the Claus reaction furnace and compares equilibrium and empirical results of th e predicted concentrations of the key components: hydrogen (H-2), carb on monoxide (CO), carbonyl sulphide (COS) and carbon disulphide (CS2). The implication of the reaction furnace model on the overall plant de sign and sulphur recovery is subsequently presented. It is well known that results of equilibrium calculations do not match plant data taken both before and after the waste heat boiler (WHB). Moreover, even tho ugh results of empirical methods do not match plant data taken before the WHB, one empirical method provides the best fit of highly scattere d data taken after the WHB and provides a conservative plant design an d estimates of sulphur recovery and emissions.