Regeneration of waste SCR catalyst by air lift loop reactor
来源期刊：中南大学学报(英文版)2013年第5期
论文作者：LEE Jung-bin EOM Yong-seok KIM Jun-han CHUN Sung-nam
文章页码：1314 - 1318
Key words：nitrogen oxide; regeneration; selective catalyst reduction; air lift loop reactor catalyst
Abstract: 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 mol/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 (NH4VO3) and 0.075 mol/L ammonium paratungstate (5(NH4)2O·12WO3·5H2O) to 0.1 mol/L H2SO4 significantly increases the activity of the waste catalyst.
LEE Jung-bin, EOM Yong-seok, KIM Jun-han, CHUN Sung-nam
(Technology Commercialization Office, Korea Electric Power Research Institute, Daejeon 305-380, Korea)
Abstract: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 mol/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 (NH4VO3) and 0.075 mol/L ammonium paratungstate (5(NH4)2O·12WO3·5H2O) to 0.1 mol/L H2SO4 significantly increases the activity of the waste catalyst.
Key words:nitrogen oxide; regeneration; selective catalyst reduction; air lift loop reactor catalyst
