以偏钛酸溶胶为载体的SCR脱硝催化剂的制备及性能研究

Preparation and Performance Study of SCR Denitrification Catalyst with Carrier of Metatitanic Acid Sol

催化剂是NH3法选择性催化还原(SCR)脱硝技术的核心,催化剂的低温活性、选择性和稳定性直接影响到NOx的脱除效果。SCR脱硝催化剂的性能主要取决于催化剂活性组分和催化剂载体。以工业级硫酸氧钛为原料,采用均匀沉淀法和直接沉淀法制备了2种偏钛酸溶胶,并以偏钛酸溶胶为载体,采用同步浸渍法加载V2O5和WO3成分,分别制出脱硝催化剂样品。在固定床反应器中,测试催化剂的脱硝性能,并通过比表面积测定、扫描电镜等方法对催化剂微观结构进行研究。试验表明,以直接沉淀法制备的SCR脱硝催化剂活性较高,在实验条件下NO脱除率最高可达88.5%。

The catalyst is the key of the NH3 based selective catalytic reduction(SCR) denitrification technology.The low-temperature activity,selectivity and stability of the catalysts influence the NOx removal efficiency directly.The performances of SCR denitrification catalysts are mainly determined by the active component and the carrier of catalysts.Taking industrial grade titanyl sulfate as the raw material,two kinds of metatitanic acid sols were prepared through homogeneous precipitation method and direct precipitation method respectively;taking metatitanic acid sol as the carrier,the synchronous immersion method was used to load the components of V2O5 and WO3,and then the denitrification catalyst samples were prepared.In the fixed-bed reactor,the denitrification performances of catalyst were tested,and the catalyst microstructures were studied through determining the specific surface area,scanning electron microscope and so on.The tests showed that the activity of SCR denitrification catalyst prepared through the direct precipitation method was relatively high.The maximum NO removal efficiency could reach 88.5% under the test conditions.