Influence of final calcination temperature and calcium addition on the properties of titania-based sulfur recovery catalysts

Compared to traditional alumina Claus catalysts, titania based sulfur recovery catalysts demonstrate improved initial activity for the recovery of elemental sulfur from both hydrogen sulfide and sulfur dioxide and are less prone to aging by sulfation. The influence of the preparation mode on the properties of titania catalysts is studied in detail: With increasing calcination temperature, surface area drastically decreases, whereas mechanical strength goes through a minimum, with only minor modifications of total pore volume and catalytic activity. Addition of calcium during catalyst preparation hinders the loss of mechanical properties while allowing a higher calcination temperature. Hydrothermal aging of such catalysts is therefore limited during operation in the plant.