Catalytic filter for the removal of dust and NOx at low temperature

Abstract

The catalytic filter was fabricated by supporting selective catalytic reduction (SCR) catalyst on the low-density ceramic (LDC) for the removal of dust and nitrogen oxides (NOx) in the flue gases at relative low temperature. MnOx–ZrO2/TiO2 catalyst was selected as SCR catalyst. The NOx and dust removal efficiency, filter resistance, regeneration performance and anti-sulfur performance were investigated. The result showed that the NOx removal efficiency at 180°C reached 98.4% (1 m/min filtration velocity) for 6 wt% MnOx–ZrO2/TiO2 catalytic filter with Mn/Zr molar ratio of 2. Furthermore, MnOx–ZrO2/TiO2 catalytic filter performed good anti-sulfur performance. In the presence of 10 vol% water vapor and 100 ppm SO2 at 180 °C, the NOx removal efficiency for MnOx–ZrO2/TiO2 catalytic filter could retain up to 83.2% and it could recover to 91.8% when the water vapor and SO2 were cut off. MnOx–ZrO2/TiO2 catalytic filter showed the high dust removal efficiency of 99.99% and the low filter resistance of less than 200 Pa. The filter resistance of MnOx–ZrO2 /TiO2 catalytic filter could maintain 235.7 Pa after 200 times pulse blowback. The result illustrated that MnOx–ZrO2/TiO2 catalytic filter showed good regeneration performance.