Mercury oxidation in flue gas using gold and palladium catalysts on fabric filters

The feasibility of oxidizing elemental mercury in coal combustion flue gas using catalytic material impregnated onto fabric filters was explored. TiO2, Au/TiO2, and Pd/Al2O3 were studied based on promising results in previous research. Several fabric coating methods were investigated to determine the best way to load a filter. A spray coat method was found to have the highest initial loading and had the lowest losses after simulated pulse-jet cleaning. The oxidation performance of the catalyst-coated filters was tested using a simulated flue gas in a bench-scale reactor under conditions similar to those found in a baghouse. Au/TiO2 and Pd/Al2O3 were effective, yielding mercury oxidation ranges of 40-60% and 50-80%, respectively. A 19 kW research combustor equipped with a baghouse was used to fire a range of coals and further test the performance of Pd/Al2O3. Results obtained warrant further development of this technique as a means of mercury pollution control.