A solution of 0.1 mol/L to 1.0 mol/L H2SO4 can dissolve alkali metals and alkaline earth metals which weaken an active site of SCR catalyst. The waste catalyst washed with 0.5 mol/L H2SO4 regained the best catalytic a...A solution of 0.1 mol/L to 1.0 mol/L H2SO4 can dissolve alkali metals and alkaline earth metals which weaken an active site of SCR catalyst. The waste catalyst washed with 0.5 mol/L H2SO4 regained the best catalytic activity. When a concentration of the sulfuric acid is less than 0.5 mol/L, sufficient cleaning effects cannot be obtained. In contrast, when the concentration is greater than 1.0 tool/L, the active components, vanadium and tungsten are undesirably eluted. The total BET surface of the catalyst regenerated by air lift loop reactor showed almost the same as that of fresh catalyst due to the removal of insoluble compounds which may be penetrated into pores of catalyst. The addition of a solution of 0.075 mol/L ammonium vanadate （NHnVO3） and 0.075 mol/L ammonium paratungstate （5（NH4）20· 12WO3-5H20） to 0.1 mol/L H2SO4 significantly increases the activity of the waste catalyst.展开更多
环己酮肟气相Beckmann重排反应RBS-1催化剂在高温反应时易失活,导致催化剂费用居高不下。为提高技术经济性,实现失活催化剂性能的高效恢复,系统研究RBS-1催化剂失活机理、再生手段及催化性能。采用N_(2)物理吸附-脱附技术考察催化剂失...环己酮肟气相Beckmann重排反应RBS-1催化剂在高温反应时易失活,导致催化剂费用居高不下。为提高技术经济性,实现失活催化剂性能的高效恢复,系统研究RBS-1催化剂失活机理、再生手段及催化性能。采用N_(2)物理吸附-脱附技术考察催化剂失活前后与再生前后的比表面积及孔结构变化,并结合XRD、FT-IR和^(29)Si MAS NMR表征技术探讨了RBS-1催化剂在失活与再生过程中活性中心的演变规律。研究发现,失活RBS-1催化剂物相结构保持完好,但BET比表面积和孔体积均有明显降低,说明催化剂失活主要为积炭覆盖催化剂活性位点并堵塞孔道所致。针对积炭堵孔导致的催化剂失活问题,采用烧炭、含氮化合物改性处理构建巢式硅羟基活性位点等手段对失活催化剂进行再生研究。结果表明,在530℃下烧炭能将催化剂表面及孔道内的大部分积炭烧除,催化剂性能可恢复90%以上;对脱炭后的催化剂进一步改性处理,最优催化剂性能可恢复98%以上。展开更多
基金Project(2009T100100602) supported by the Korea Institute of Energy Technology Evaluation and Planning,Korea
文摘A solution of 0.1 mol/L to 1.0 mol/L H2SO4 can dissolve alkali metals and alkaline earth metals which weaken an active site of SCR catalyst. The waste catalyst washed with 0.5 mol/L H2SO4 regained the best catalytic activity. When a concentration of the sulfuric acid is less than 0.5 mol/L, sufficient cleaning effects cannot be obtained. In contrast, when the concentration is greater than 1.0 tool/L, the active components, vanadium and tungsten are undesirably eluted. The total BET surface of the catalyst regenerated by air lift loop reactor showed almost the same as that of fresh catalyst due to the removal of insoluble compounds which may be penetrated into pores of catalyst. The addition of a solution of 0.075 mol/L ammonium vanadate （NHnVO3） and 0.075 mol/L ammonium paratungstate （5（NH4）20· 12WO3-5H20） to 0.1 mol/L H2SO4 significantly increases the activity of the waste catalyst.
文摘环己酮肟气相Beckmann重排反应RBS-1催化剂在高温反应时易失活,导致催化剂费用居高不下。为提高技术经济性,实现失活催化剂性能的高效恢复,系统研究RBS-1催化剂失活机理、再生手段及催化性能。采用N_(2)物理吸附-脱附技术考察催化剂失活前后与再生前后的比表面积及孔结构变化,并结合XRD、FT-IR和^(29)Si MAS NMR表征技术探讨了RBS-1催化剂在失活与再生过程中活性中心的演变规律。研究发现,失活RBS-1催化剂物相结构保持完好,但BET比表面积和孔体积均有明显降低,说明催化剂失活主要为积炭覆盖催化剂活性位点并堵塞孔道所致。针对积炭堵孔导致的催化剂失活问题,采用烧炭、含氮化合物改性处理构建巢式硅羟基活性位点等手段对失活催化剂进行再生研究。结果表明,在530℃下烧炭能将催化剂表面及孔道内的大部分积炭烧除,催化剂性能可恢复90%以上;对脱炭后的催化剂进一步改性处理,最优催化剂性能可恢复98%以上。
