SCR Catalyst Management - Wpca.info

Effects of Sulfur in Fuel• SO 2 oxidation, undesired side reaction in SCR catalyst2SO 2 + O 2 2SO 3• Rate depends on T and catalyst formulation• Occurs in the bulk mass of catalyst materialSO 3 /H 2 SO 4 aerosols cause the “Blue Plume”• SO 3 reacts with NH 3 to form ammonium bisulfate (ABS) and ammoniumsulfate (AS)NH 3 + SO 3 + H 2 O NH 4 HSO 4 (ABS)NH 4 HSO 4 + NH 3 (NH 4 ) 2 SO 4 (AS)2NH 3 + SO 3 + H 2 O (NH 4 ) 2 SO 4 (AS)• AS is dry, powdery compound• ABS is sticky, viscous compound that can plug catalyst and foul otherequipment17