失活SCR烟气脱硝催化剂再生工艺工业试验研究

Research on the Industrial Scale-Up of Regeneration Technology for the Deactivated SCR Flue-Gas De-NO_x Catalyst

SCR烟气脱硝催化剂在广泛使用的同时,失活催化剂大量产生。对失活催化剂进行再生,经济和环保意义重大。以某燃煤电厂运行了近25 000 h的失活SCR烟气脱硝催化剂为研究对象,在分析催化剂失活原理基础上,对催化剂再生过程中主要影响因素(压缩空气吹灰压力、超声清洗时间、清洗液硫酸浓度等)进行研究,并介绍失活催化剂再生处理步骤,包括清灰、预清洗、深度清洗、活性组分负载、热处理等。各类检测结果表明,采用所研发的方案进行再生,失活催化剂中碱金属、碱土金属及硫酸盐等污染物被有效清除,催化剂通孔率高达98.7%,比表面积明显恢复,相对活性提升至99%,抗压强度及单层催化剂SO_2/SO_3转化率符合使用要求,即失活脱硝催化剂各理化、工艺性能及其机械强度得到了有效恢复,可以再安装于脱硝反应器中继续使用。

While the SCR flu-gas de-NOx catalyst has been used widely,a large number of deactivated catalyst are produced.Thus it is of great importance to regenerate those deactivated catalysts for economic purpose and environmental protection.The deactivated SCR flue gas denitrification catalyst which has been put into operation for nearly 25 000 hours in a coal-fired power plant is taken as the research object.Based on the deactivation principle of the catalyst,the main influencing factors(compressed air soot blowing pressure,ultrasonic cleaning time,etc.)in the regeneration process of the catalyst are analyzed.Then the regeneration process of deactivated catalyst is introduced,including ash removal,pre-cleaning,deep cleaning,active component loading,heat treatment and so on.The various testing results show that the pollutants such as alkali metal,alkaline earth metal and sulfate in the deactivated catalyst are removed effectively after regeneration process with the developed technology.The through-cell ratio of the catalyst reaches up to 98.7%.The specific surface area is obviously recovered and the relative activity of the regenerated catalyst is remarkably improved to 99%.The compressive strength and the single layer SO2/SO3 conversion rate of the catalyst are able to satisfy the application requirements,which means the physicochemical properties,the process performance and the mechanical strength of regenerated catalyst are effectively recovered for the continuing usage in the denitrification reactor.