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1 w y wz 9«( 1y) 63~68, 2006 J. f the Krean Sciety fr Envirnmental Analysis Ÿ w k y w w w p xá **Á vá *Áy y*áy ** š w ywœw, *w» ( ) y, **» w y œw Water Inhibitin and Tungsten Lading Effect f SCR ver NMO Sang-Hyun Chi, D-Kyung Lee**, Sung-Pil Ch, Jun-Yub Lee*, Sung-H Hng*, and Sung-Chang Hng** Department f Chemical Engineering, Krea University, Seul , Krea *Pwer Engineering Research Institude, Krea Pwer Engineering C., Inc., Yngin-si , Krea **Department f Envirnmental Engineering, Kynggi University, Suwn-si , Krea Selective Catalytic ReductinG(SCR) f nitric xide with ammnia is widely recgnized the mst prminent techlgy t remve NOx. NMO catalyst has a great activity at lw temperature belw 200 C in SCR. hwever, in the presence f H 2 O, NOx remval efficiency significantly decreased. in present study, H 2 O inhibiting effect was investigated in SCR f NOx and tungsten laded NMO catalyst was studied NOx remval efficency in the presence f H 2 O. As a result f SCR in the presence f water, H 2 O adsrbed at active site cmpetitively with NH 3 and it turned ut that H 2 O effect as a inhibitin. tungsten laded NMO catalyst was increased NOx remval efficency and it was high activity at 250~300 C. it was estimated that the applicatin is pssible with the SCR catalyst. Key wrds : Natural manganese re, Selective catalytic reductin, H 2 O inhibitin, DeNOx 1. ƒ,, k y l NOx, z (N 2 O), w ( 30%), w ww Ÿyw (, PAN ) j». k y NOx w» ƒ š. k y j y, y V, W, M, Cu, Ni, Fe, Mn y, TiO 2, Al 2, SiO 2, y k, p š 1-5). y SCR y j x ¾ vanadia-titania ƒ ƒ w y. TiO 2 w ù ƒ š, y NH 3 w. 300~400 C y ùkü. x ¾ SCR j š (zelite ), (V ), (Pt ) ù. SCR Pt ƒ 250 C. w V ( 350 C z) 200 C w y j w. 200 C w SCR š y. w y y-y T whm crrespndence shuld be addressed.

2 64 xá Á vá Áy yáy y ù» š y k y y k y, VOC, CO y š. š ƒ 2%~20%¾ sw y w w inhibitin. w w w V ƒ š 250 C w y w w y 300 C k y. 6,7) w vanadia-titania w» w y w y š x ƒ š W. W ƒ vanadia-titania vanadia-alumina vanadia-zircniaalumina manganese-alumina z š 8-11). y y y š y» š y y k y mw ƒ w. Markvart 12) Singredj 13) w MnO 2 ù k y K y w SCR y x. Park 14,15) Lee Ÿ w SCR y ùkü š šw, SO 2 w inhibitin w w. Ÿ w w w wš, ƒw y w. 2. x e 2.1. x Ÿ p w w. Ÿ x jaw crusher rll mill w w š, sieve w s³ particle diameter 0.36 mm w. Table 1 NMO yw p e w. NMO w Ÿ w w wš, 60 C ƒ. NMO yww slurry k yw 1 z rtary vaccum evapratr[eyela C. N-N series] w 70 C k. z 110 C dry ven 24 w z 5 C/min Tubular furnace 400 C 4 air» w w x e x e Fig. 1 ƒ,», ƒ».» x š d e ü 8 mm, 60 cm w, d š w» w quartz wl w. x Table 3 w.» œ ƒ MFC (Mass Flw Cntrller, MKS C.) w w. w, œ N 2ƒ bubbler mw w w» w, œ w w» w jacket xk bubbler circulatr w (50 C) y g. NO NH 3ƒ w» NH 4 - N, NH 4 -NO 2 wš ƒ Table 1. Cmpsitin and physical prperties f NMO (a) Chemical Analyses(wt.%) Cmpnent Mn SiO 2 Al 2 Fe CaO MgO balance O 2 f Mn and Fe wt. % (b) Physical Prperties Mean particle size(mm) Density(kg/m 3 ) 3980 Pre vlume(cm 3 /g) (5~3000ç) Surface area(m 2 /g) 20.0

3 Ÿ w k y w w w p 65 Fig. 1. Schematic diagram f a fixed bed reactr. Table 2. Experimetal cnditins in a fixed bed reactr Inlet gas cnc. (N 2 balance) Particle size (µm) 359 Temperature ( C) NO x (ppm) 210 NH 3 (ppm) 210 O 2 (%) 3(10,15) H 2 O (%) 8 Space velcity (hr 1 ) 60,000 Ttal flw (cc/min) 500» w heating band 180 C w w. d w» w NO ƒ»(uras 10E, Hartman & Braun C.) yw Ÿ»(42C HL, Therm Ins.) w. NO 2 ƒ 5 ppm (9L, Gas Tec. C.) w» yw Ÿ» w. (3M, 3La, 3L, Gas Tec. C.) w, ƒ»(center 310, Center Technlgy Crp.) w d w z psychmetric chart w vl% y w. 3. š 3.1. w š ƒ 2%~20%¾ sw y w w inhibitin. w w w V ƒ š 250 C w y w w y 300 C k y 6,16). Ÿ w Á NO NH 3 SCR NOx y w Fig. 2 ùkü. y ƒ y w š NO 2 ƒ j ƒw y wù y NO y w» 90% k z ùküš. w w, š w y w y wù, w t NO y v w w k z j w ù kû. w NO w». Fig. 2. The effect f H 2 O n NOX cnversin and utlet NO 2, NH 3 ver NMO s.v.=60,000 hr 1, NO=190, NO 2

4 66 xá Á vá Áy yáy 17) Kijlstra Mn/Al 2 w 2vl% n-ff x ww ƒ y» 30% w w š, œ w y» 85% z w. w n-ff x w inhibitin deactivatin w. w k psitive effect š w. 18) NMO, Mn/Al 2, Mn/CeO 2 w w ùkù y inhibitin z deactivatin ùkù š w diffusin w š w. Ÿ k w» w w w ƒ ƒ ü sw w q. Fig. 3 w w» w H 2 O(n-ff) x ùkü. k k w œ w z 2 y w w, z œ w» k y z w. w œ x ww œ y j w, ƒ j ƒ w. w n-ff x ww inhibitin ƒ ƒwù œ w» y z w. w Ÿ w y w k ƒ w š q Fig. 3. The effect f H 2 O(n-ff) n NO X cnversin and utlet NH 3 slip ver NMO. s.v.=60,000 hr 1, NO=190, NO 2 / NH 3 =1.0 at 180 C. Fig. 4. Decline f NO cnversin with time after H 2 O feed at 180 C. s.v.=60,000 hr 1, NO=190, NO 2 = 20, H 2 lng run test ww Fig. 4 ùkü. œ z 10 ¾ inhibitin ƒ ƒwù 10 z l y ƒ, 90 z œ w» y z w w w inhibitin y w w w Ÿ k w ùkù ƒ j wùƒ ƒ w inhibitin w y w y, NMO w y e w w. k y ƒ w y TiO 2 ù w,» l l wš. inhibitin g y j» w Ÿ SCR ƒ l l w w w. 8,11) Fig. 5~6 l l ƒƒ 3, 6% NMO w k x. l l NOx cnversin 250 C w wù w. ƒ Outlet NO 2 l l NH 3 y w NO 2 w q NMO y w Fig. 7 ùkü. y

5 Ÿ w k y w w w p 67 Fig. 5. The effect f tungsten lading% n NO X cnversin ver NMO. s.v.=60,000 hr 1, NO=190, NO 2 Fig. 6. The effect f tungsten lading% n utlet NH 3 cncentratin ver NMO. s.v.=60,000 hr 1, NO=190, NO 2 / NH 3 y w NO 2 y w, NO 2 ƒ NOx y ƒ. Ÿ l l 6% 300 C NOx y j ƒw 91% š y ùkü, Ÿ w k ƒ w š q. 4. Ÿ SCR w y ùkü y w Fig. 7. The effect f tungsten lading% n NH 3 xidatin ver NMO. s.v.=60,000 hr 1, NO=190, NO 2 =20, H 2. n-ff x ww œ w» y z w w w inhibitin y w. w w y w SCR ww SCR l l NMO w y w 250 C w y wù NOx y j ƒw. y x y w NO 2 NOx y ƒw. Ÿ l l 6% 250~300 C NOx y 90% y ùkü, Ÿ w k ƒ w š q.» sƒ Á šy x œ l ( y : )». š x 1. T. P. Kbylinski and B. W. Taylr, The Catalytic Chemistry f Nitric Oxide; Part(II) Reductin f Nitric Oxide ver Nble Metal Catalysts, J. Catal., 1974, 33, 376.

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