Study on V₂O₅-WO₃-TiO₂ catalytic filter for de-NO and particle separation

V₂O₅-WO₃-TiO₂ catalytic filter was prepared for particle separation and denitration. TiO₂ was supported on mullite fiber filtration ceramic (FFC) by homogeneous precipitation method and V₂O₅-WO₃ denitration catalyst was loaded on TiO₂/FFC by impregnation method using the solution of V and W precursors. The BET surface area of TiO₂/FFC measured by N₂ adsorption was increased with TiO₂ loading. The results indicated that the surface modification by anatase TiO₂ improved the BET surface area of filters. The optimal mass ratio of V₂O₅ to WO₃ with 1:1 and catalyst loading of 7.5 wt% were determined. The performance tests for V₂O₅-WO₃-TiO₂ catalytic filters showed that NO conversion was more than 80% and filter resistance at the filtration velocity of 1 m min⁻¹ was 415 Pa. Moreover, the effects of filtration velocity and SO₂ or H₂O poisoning on NO conversion were investigated. Catalytic filters still showed approximately 80% NO conversion even if the filtration velocity reached 1.5 m min⁻¹. NO conversion decreased to 68% in the presence of 300 ppm SO₂ and 10 vol% H₂O at 280 °C, but it could be recovered to 85% after the removal of SO₂ and H₂O. (paper)