干/湿混法对中温SCR催化剂碱土金属中毒的影响

为探究碱土金属中毒规律以及中毒方法对中毒的影响，采用干混法和湿混法模拟CaO和MgO对商业催化剂的中毒过程。研究中毒后催化剂脱硝特性的改变及差异，并对催化剂中毒前后催化剂物理、化学性能变化进行探究。结果表明：湿混法模拟SCR催化剂中毒后脱硝效率的降低大于干混法；模拟中毒实验应该采用干混法；湿混法对于催化剂比表面积、孔径分布、表面V5+含量以及化学吸附氧的不利影响强于干混法；CaO对催化剂脱硝效率的降低大于MgO。2种中毒方法的对比研究为延长催化剂寿命提供了理论依据。

Effect of dry/wet mixing on alkaline earth metal poisoning in commercial medium temperature SCR catalyst

In order to investigate alkaline earth metal poisoning and the effects of poisoning methods on their poisoning, the dry mixing and wet mixing methods were used to simulate the commercial catalysts poisoning induced by CaO and MgO under laboratory conditions. The changes and differences of denitrification characteristics of catalysts between before and after poisoning were studied through the denitration test bench, as well as their physicochemical and chemical properties. The results showed that the decrease of denitrification efficiency for the poisoned SCR catalyst after simulated wet mixing was more than simulated dry mixing, thus the dry mixing method should be adopted in the poisoning experiment simulation. The wet mixing method had a stronger adverse effect on the specific surface area, pore size distribution, surface V5+ content, and chemisorbed oxygen of catalyst than the dry mixing method. The denitration efficiency reduction for the catalyst by CaO was greater than MgO. This study provided a reasonable solution for the subsequent catalyst poisoning simulation, and also a theoretical basis for prolonging the catalyst life.