再生方法对V2O5/AC催化剂同时脱硫脱硝活性的影响

 考察了水洗再生、Ar热再生和5%NH3-95%Ar还原再生对V2O5/AC催化剂同时脱硫脱硝活性的影响. 结果表明,水洗再生虽然可洗去反应过程中沉积在催化剂表面的含硫物质,但也能将部分活性组分V2O5转化生成的VOSO4洗去,使催化剂的脱硫脱硝活性降低. Ar热再生后催化剂的脱硝活性与新鲜样品相同,但脱硫活性很低. 经5%NH3-95%Ar还原再生后,催化剂的脱硫活性可恢复到新制备时的水平,同时脱硝活性大大提高,这是由于催化剂表面除了原有的脱硝活性位V2O5外,又形成了新的活性位NH+4/NH-2. 还原再生过程产生的SO2与NH3在室温下反应生成固体亚硫酸铵盐,可实现硫的资源化,简化了后续处理工艺.

Effect of Regeneration Method on Activity for Simultaneous Removal of SO2 and NO over V2O5/AC Catalyst-Sorbent

The regeneration of a used V_2O_5/AC catalyst-sorbent, which is active for simultaneous removal of SO_2 and NO from flue gas, was studied using different methods. Water-washing caused the loss of a considerable amount of V from the catalyst surface and consequently could not rejuvenate the initial activity of the catalyst. Thermal regeneration by Ar showed better results, but the activity for SO_2 removal could not be fully recovered due to the presence of residue sulfur and the loss of carbon in the catalyst. Reductive regeneration by 5%NH_3-95%Ar displayed the best results, the SO_2 removal activity could be completely revived and the NO removal activity improved greatly. The results of IR and XPS showed that a large amount of nitrogen function groups, NH +_4/NH -_2, were formed and enhanced the NO removal activity. Ammonia could also react with the formed SO_2 to produce ammonium sulfite at the reactor outlet, which simplified the post-treatment process.