18
Design Considerations Continued
lHigh Sulfur Fuels
–SCR catalyst converts SO2 to SO3
–SO3 + NH3 form ammonium bisulfate (ABS)
–Adjust catalyst formulation to minimize SO2 oxidation
–Restrict low temp operation of SCR
lCatalyst Poisons
–Phosphorus
–Na, K
–Catalyst deactivation – lower catalyst life, increased reagent demand for high NOx reduction