Abstract: An apparatus for low-temperature NOx-reduction is disclosed, which is useful in boiler installations used at electric-generating plants. The apparatus employs one or a plurality of moving-bed reactors wherein a moving bed of common base-metal catalyst is used for selective catalytic reduction of NOx present in flue gas. The moving bed permits continuous introduction of fresh or regenerated catalyst, thus obviating the conventional problems of sulfur-poisoning and consequent reduction in catalytic activity with such catalysts. Due to the lower activation energies of such catalysts, an SCR utilizing the moving-bed reactors disclosed herein can be located downstream of the air heater, further improving electric-generating efficiency. Methods for low-temperature NOx reduction are also disclosed.

Abstract: An apparatus for low-temperature NOx-reduction is disclosed, which is useful in boiler installations used at electric-generating plants. The apparatus employs one or a plurality of moving-bed reactors wherein a moving bed of common base-metal catalyst is used for selective catalytic reduction of NOx present in flue gas. The moving bed permits continuous introduction of fresh or regenerated catalyst, thus obviating the conventional problems of sulfur-poisoning and consequent reduction in catalytic activity with such catalysts. Due to the lower activation energies of such catalysts, an SCR utilizing the moving-bed reactors disclosed herein can be located downstream of the air heater, further improving electric-generating efficiency. Methods for low-temperature NOx reduction are also disclosed.