The Activities And Application Of The V₂O₅-TiO₂Catalysts At Low Temperature

Selective catalytic reduction of NOx by ammonia （NH3-SCR） is the bestdeveloped and wide-spread method for NOx removal from stationary sources. The useof low-temperature SCR catalyst for NOx removal can reduce the cost of SCR system,and prolonged the catalyst life. Therefore, it’s important economically and practicallyto develop a high effectifive low-temperature SCR catalyst.V₂O₅/MoO₃-TiO₂and V₂O₅/WO₃-TiO₂catalysts were prepared by impregnatingmethod. The effects of the loading of V₂O₅and MoO₃on the activities of NOx SCRas well as SO₂oxidation over the V₂O₅/MoO₃-TiO₂catalyst were investigated. Theeffects of O2concentration, NH3/NO ratio, and space velocity on the catalytic activityover3wt%V₂O₅/6wt%MoO₃-TiO₂catalyst were also examined in the experiment.The investigations indicated that the NOx and SO₂conversions over the SCR catalystboth were enhanced as the V₂O₅loading increased. The MoO₃loaded on the surfaceof the catalyst obviously restrained the SO₂oxidation over the SCR catalyst. As theMoO₃loading increased to9wt%, the SO₂conversion over the V₂O₅/MoO₃-TiO₂catalyst was below1%.MgO and F-were loaded to modify the V₂O₅/MoO₃-TiO₂and V₂O₅/WO₃-TiO₂catalysts. The0.1wt%MgO loaded on the catalyst obviously promoted the NOx SCRactivity of the V-Mo-Ti SCR catalyst and the best MgO loading is0.1wt%. The bestF-loading was1.0wt%on the V-Mo-Ti catalyst. To V-W-Ti catalyst,1.5wt%F--loaded catalyst performed the best in the SCR of NOx.According to the actual flue gas conditions, the monomer of the low-temperatureSCR DeNOx process and equipment was designed, using laboratory-preparedhoneycomb catalyst in the reactor. At the low temperature of170²00℃, thedenitration system was stable. When the operating temperature was in240²60℃,the NOx conversion was above93%.