| 초록 |
Manganese oxide catalysts prepared by a precipitation method with various precipitants were investigated for the low-temperature selective catalytic reduction (SCR) of NOx with NH3 in the presence of excess O2. The active MnOx catalysts, precipitated with sodium carbonate and calcined in air at moderate temperatures such as 523 and 623 K, have the high surface area, the abundant Mn4+ species, and the high concentration of surface oxygen on the surface. The amorphous Mn3O4 and Mn2O3 were mainly present in this active catalyst. The carbonate species appeared to help adsorb NH3 on the catalyst surface, which resulted in the high catalytic activity at low temperatures. The catalytic filter which can remove dust and NOx simultaneously was prepared and tested in the laboratory and the pilot plant. The catalytic bag filter with 2.0 cm3/cm2/sec of permeability, 380g/m2 of catalyst loading and 37.50 m2 of filtering area was prepared by MnOx scattering and PTFE foam coating processes. This MnOx-coated bag filter showed 85% NOx conversion at 423 K with a space velocity of 2.0×106 h-1. |
