Abstract:

Three kinds of waste catalyst powder M1-M3 were used as raw materials to prepare the catalysts. These catalysts had different waste catalyst powder mixing ratios. The denitration performance of these catalysts was tested and evaluated at the initial and after 16000 hours. At the same mass addition ratio, the initial performance of the new catalyst prepared by adding waste catalyst powder M1 and M2 was about 30% lower than that of the catalyst M0-0 without adding waste catalyst powder, and the activity degradation rate was obviously faster. It also indicated that the higher the proportion of waste catalyst powder, the greater the negative impact. It was recommended that the proportion of high-quality powder should be controlled. The physical and chemical analysis of the waste catalyst powder and the prepared catalyst were carried out by means of laser particle size analyzer, surface acid adsorption analyzer (NH₃-TPD) and X-ray fluorescence spectrometer (XRF). The microscopic characteristics of the waste catalyst powder could not be fully restored. The effective active components were low and the impurity content was high. These resulted in poor specific microscopic characteristics and low surface acidity of the catalysts, which were the main reason for the poor denitrification performance of the catalysts. In order to achieve the quality of waste catalyst powder close to the original titanium tungsten powder and effectively used for the preparation of new catalysts, it was necessary to further improve the particle size, micro-pores, impurity content and surface acidity of the waste catalyst powder.

Key words: selective catalytic reduction denitrification, waste catalyst powder, mixing proportion, activity deterioration, mechanism analysis

摘要：

以3种品质的废SCR脱硝催化剂粉料M1、M2和M3为原料，与原生钛钨粉M0掺加制备了不同质量掺比的脱硝催化剂，分别对其初始脱硝性能和在实际烟气中运行16000h后的脱硝性能进行跟踪检测评价。实验结果表明，在相同质量掺加比时，掺加废催化剂粉料M1和M2的新催化剂初始性能比未掺加废催化剂粉料M0-0性能降低约30%以上，且运行16000h后的活性劣化速率明显偏快。废催化剂粉料掺加比例越高，负面影响越大。废催化剂的资源化回用应使用高品质粉料，且需严格控制其掺加比。借助激光粒度仪、表面酸量吸附仪（NH₃-TPD）以及X射线荧光光谱仪（XRF）等对废催化剂粉料和所制备的催化剂进行了理化分析，废催化剂粉料微观特性无法完全恢复，杂质含量高，是造成新制备催化剂脱硝性能不佳及使用中活性劣化速率快的主要原因。要实现废催化剂粉料大比例用于新催化剂制备，需进一步提高废催化剂粉料的粒径、微观孔隙、表面酸性及降低杂质含量。

关键词: 选择性催化还原脱硝, 废催化剂粉料, 掺加比例, 活性劣化, 机理分析