fm

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "fm"

Transcription

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.

6 68 xá Á vá Áy yáy 2. H. Bsch and F. Janssen, Catalytic Reductin f Nitrgen Oxides, A Review n the Fundamentals and Technlgy, Catal. Tday, 1988, 2(4), G. Centi, S. Perathner, D. Biglin, and E. Giamell, Adsrptin and reactivity f NO n cpper-nalumina catalysts. 1. Frmatin f nitrate species and their influence n reactivity in NO and NH3 cnversin, J. Catal., 1995, 151, H. Yamashita, H. Yamada, and A. Tmita, Reactin f nitric xide with metal-impregnated carbn in the presence f xygen, Appl. 1991, Catal., Y. Teraka, K. Nakan, S. Kagawa, and W. F. Shangguan, Simultaneus Remval f Nitrgen Oxides and Diesel St Particulates Catalyzed pervskite-type Oxides, Appl. Catal., 1995, 5, L J. M. Jehng, G. De, B. M. Weckhuysen and I. E. Wachs, Effect f Water Vapr n the Mlecular Structures f Supprted Vanadium Oxide Catalysts at Elevated Temperatures, J. Mlecular Catal. A.,1996, 110, V. Turc, L. Lisi, R. Pirne and P. Ciambelli, "Effect f Water n the Kinetics f Nitric Oxide Reductin ver High-surface-Area V 2 Catalyst", Appl. Catal. 1994, 3, Jean-Marie Herrmann(F-4) and Jean Disdier(F-4), "Electrical prperties f V 2 -W EUROCAT catalysts evidence fr redx prcess in selective catalytic reductin (SCR) denox reactin", Catalysis Tday, 2000, 56, M. C. Paganini, L. D. Acqua, E. Giamell, L. Lietti, P. Frzatti, and G. Busca, "An EPR Study f the Surface Chemistry f the V 2 -W Catalyst: Redx Behaviur and State f V(IV)", J. Catal., 1997, 166, M. D. Amiridis, I. E. Wachs, G. De, J. M. Jehng, and D. S. Kim, "Reactivity f V 2 Catalysts fr the Selective Catalytic Reductin f NO by NH 3 : Influence f Vanadia Lading, H 2 O, and SO 2 ", J. f Catal. 1996, 161, P. Ciambelli, M. E. Frtuna, D. Sannin, and A. Baldacci, "The Influence f Sulphate n the Catalytic Prperties f V 2 -TiO 2 and W -TiO 2 in the reductin f Nitric Oxide with Ammnia", Catal. Tday, 1996, 29, M. Markvart and V. Put, Selective Reductin f Nitrgen Oxides by Ammnia Using Nn-platinum Catalysts, Ind. Chem. Eng., 1975, 15, L. Singredj, R. Kver, F. Kapteijn and J. Mulijn, Alumina Supprted Manganese Oxides fr the Lwtemperature Selective Catalytic Reductin f Nitric Oxide with Ammnia, App. catal. B: Envirn., 1992, 1, J. L. Lee, S. B. Kim and S. C. Hng, Characterizatin and reactivity f natural manganese re catalysts in the selective catalytic xidatin f ammnia t nitrgen, Chemsphere, 2003, 50, T. S. Park, S. K. Jeng, S. H. Hng and S. C. Hng, Selective Catalytic Reductin f Nitrgen Oxides with NH3 ver Natural Manganese Ore at Lw Temperature, Ind. Eng. Chem. Res., 2001, 40, V. Turc, L. Lisi, R. Pirne and P. Ciambelli, Effect f Water n the Kinetics f Nitric Oxide Reductin ver High-surface-Area V 2 Catalyst, Appl. Catal. 1994, 3, W. S. Kihlstra, J. C. M. C. Daamen, J. M. van de Graaf, B. van der Clinder, E. K. Pels, A. Bliek, Inhibitin and Deactivating Effects f Water n the Selective Catalytic Reductin n Nitric Oxide with Ammnia ver MnOx/Al 2, App. Catal. B: Envirn., 1996, 7, x, ƒ p y w SCR p, š w M. S. Thesis, 2001.