失活钒钛基SCR催化剂性能表征及其再生

摘要

Deactivation and regeneration of V2O5/TiO2 catalyst for elimination of NO were studied, lhe spent V2O5/TiO2 catalyst sample was from a domestic power plant, which had been operated for 20000h. The spent V2O5/TiO2 catalyst was characterized by SEM, EDS, XRD and BET techniques to reveal the deactivation mechanism. The regeneration of V2 O5/TiO2 catalyst was conducted by washing with aqueous solution of 0.5 mol/L H2SO4 or 0.01mol/L HF. The results showed that the actvity of the spent catalyst dropped greatly in comparison with the fresh catalyst. The reason was that the spent catalyst was heavily covered by ash which blocked the active sites and plugged the pores. After the spent catalyst was washed with aqueous solutions of 0.01mol/L HF, the activity of regenerated catalyst was improved significantly due to effective removal of sili- con dioxide covered on the spent catalyst, a main composition of the ash.%主要研究了钒钛基脱硝催化剂失活机理及再生。采用SEM、EDS、XRD、BET等手段对国内某家燃煤火电厂运行20000h的SCR脱硝催化剂进行表征,然后使用0.5mol/L的硫酸和0.01mol/L的氢氟酸对运行过的催化剂进行了清洗再生并通过烟气模拟-催化剂活性测试系统考察了催化剂的脱硝活性。结果表明,相比于新鲜催化剂,运行后的催化剂活性明显下降,孔容和比表面积有所下降,其表面存在着组成复杂的飞灰,飞灰主要成分为SiO2;采用0.01mol/L氢氟酸溶液清洗能够明显恢复催化剂的脱硝活性,这是因为氢氟酸可以有效清除失活催化剂表面的SiO2。