Reduction of Nitrogen Monoxide(NO) with Ammonia in Sulfur Dioxide-Containing Gas on Activated Carbon and Vanadium Pentaoxide-Loaded Activated Carbon

Abstract

The reduction of NO_x with NH₃ in SO₂-containing gas on activated carbon and V₂O₅-loaded activated carbon was investigated by using a small scale fixed-bed reactor at 408 K. Various gases consisting of NO, SO₂, NH₃, H₂O and O₂ were subjected to the experiment. Activated carbons tested in this experiment were produced from coals which were used in power generation plants.
The amount of NO adsorbed on activated carbon was very small, whereas the removal efficiency of NO_x increased slightly, when O₂ was added to NO. It was assumed that NO was oxidized to NO₂ and then adsorbed on activated carbon. By adding NH₃ in a mixture of NO and O₂, the NO_x removal increased. It increased with the increase of NH₃/NO mole ratio, but it leveled off at NH₃/NO mole ratio larger than 1.
The removal efficiency of NO_x over activated carbon decreased with the increase of SO₂ concentration, whereas activated carbon impregnated with V₂O₅ showed higher activity than the original one. It was found that activated carbon impregnated with V₂O₅ had a higher activity for simultaneously removing SO₂ and NO_x in flue gas.