脱硝催化剂的失活机理及其再生技术

采用SEM、XRD和XRF对电厂失活脱硝催化剂进行表征,探讨其失活原因和机理。结果表明:电厂脱硝催化剂失活的主要原因是活性组分V的流失及碱金属K、碱土金属Ca和As元素造成的催化剂中毒,烟气中飞灰的沉积也有一定的影响。经吹扫、水洗、酸洗和V负载再生,催化剂的各项物化性质基本恢复,NOx转化率基本达到新鲜催化剂的水平。水洗主要去除催化剂中的碱金属,酸洗主要去除As2O3,负载V补充催化剂活性组分。V再生催化剂在较高温度下的抗硫性能更好。

Deactivation mechanism and regeneration technologyof denitration catalyst

The deactivated catalystin a power plant was characterized by SEM,XRD and XRF,and the deactivation reason and mechanism were discussed. The results show that the loss of active component vanadium and the catalyst poisoning caused byalkali metal K,alkaline earth metal Ca as well as As are main causes for this catalyst deactivation,furthermore,the deposition of fly ash in flue gas also has a certain effect. By purging,water washing,acid washing and vanadium load regeneration,the physicochemical properties of the catalysts are basically recovered and the NO_x conversion rate almost reached the level of fresh catalyst. Water washing is used for removal of alkali metals in the catalyst,acid washing for removal of As₂O₃,V loading for supplement of active components of the catalyst. The V-regenerated catalyst has better sulfur resistance at hightemperature.