典型陶瓷基体对催化滤芯中催化剂分散及脱硝活性的影响

Effect of ceramic matrices on dispersion of loaded catalyst and De NOx activity of catalytic filters

具有脱硝除尘一体化功能的催化滤芯在小型燃烧烟气处理中具有广泛的应用前景。采用3种典型商用陶瓷滤芯,涂覆V2O5-WO3-Mo O3/Ti O2脱硝催化剂,制备了具有脱硝除尘一体化功能的催化滤芯材料,考察了陶瓷滤芯的化学成分和孔径结构对NH3-SCR脱硝性能的影响。XRD、XRF、SEM、压汞等分析测试结果表明:碱金属与碱土金属元素含量低且孔径分布均匀的纤维状结构陶瓷滤芯,促进了催化剂分散,提升了脱硝活性,且降低了压降。催化滤芯在220~380℃、过滤面速度1 m·min-1、NH3/NO=1条件下脱硝率大于90%;抗水蒸气(15%,体积分数)和SO2中毒(3×10-2%,体积分数)测试表明催化滤芯在260~450℃温区内依然保持脱硝率大于90%,可满足催化滤芯实际工业应用要求。

There is a wide application prospect for the development of a catalytic filter with simultaneous De NOxand de-dust function in the De NOx treatment of flue gas from small furnace. Three kinds of typical commercial ceramic filters were used to prepare catalytic De NOx filters by coating method, and their catalytic performance were investigated on different flue gas condition. The XRD, XRF, SEM and MIP results demonstrate that the ceramic filter with little alkali/alkaline earth metal and uniform pore distribution will promote the dispersion and De NOx activity of the catalytic particles as well as the decreased pressure drop. The NO conversion can be above 90% in the temperature range of 220—380℃（face velocity = 1 m·min^-1, NH3/NO = 1）, and the NO conversion can still maintain above 90% after introduction of H_2O（15%, vol） and SO2（3×10^-2%, vol） in the temperature range of 260—450℃. The excellent De NOx performance of the catalytic filter meets well the demands of practical industrial application.