Articles & Issues

Conflict of Interest: In relation to this article, we declare that there is no conflict of interest.

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

All issues

구리이온이 교환된 모더나이트형 제올라이트 촉매상에 암모니아에 의한 질소산화물 제거반응의 속도식 연구

A Kinetic Study for Selective Catalytic Reduction of NO by NH3 over Cu-exchanged Modernite Type Zeolite Catalyst

정창모 최훈 추수태 남인식 김영걸

Chung CM Choi H Choo ST Nam IS Kim YG

HWAHAK KONGHAK, December 1996, 34(6), 790-796(7), NONE

Download PDF

Abstract

SCR기술의 촉매로 사용되는 CuHM촉매에 대한 반응속도론적 연구를 연속식 고정층 반응기에서 수행하고 Hougen-Watson 방법론에 의해 반응 mechanism과 반응속도식이 유도되었다. NO와 암모니아가 서로 다른 활성점에 흡착하여 반응한다는 dual site catalysis LHHW(Langmuir- Hinshelwood-Hougen-Watson) model이 SCR반응의 공간속도(168,000-431,000hr^-1)와 온도(150- 500℃)에 대해 모델의 예측성을 확인하였으며, 이를 통하여 model을 제안하였고, 반응기 공간속도적 현상인 온도에 따른 NO전환율의 최고치 현상을 잘 표현함을 알 수 있었다. 이러한 SCR 반응온도에 따른 NO전환율의 최고치는 NO환원반응의 활성화에너지가 약 14 kcal/mol이고 암모니아 산화반응에 대한 활성화에너지는 NO환원반응의 약 3배의 값을 가짐으로써 설명되었다. 또한 NO와 암모니아의 공급비의 변화에 대한 NO와 암모니아의 전환율도 예측할 수 있었다.

A Kinetic Study for SCR(Selective Catalytic Reduction) of NO by NH₃ over copper exchanged modernite type zeolite catalyst has been made in a fixed-bed flow reactor based upon Hougen-Watson formalism. A dual site catalysis LHHW(Langmuir-Hinshelwood-Hougen- Watson) model, represented by two primary reactions which are NO reduction and NH₃ oxidation reactions, was derived. The model well predicted the experimental data with appropriate activation and adsorption energies within the range of experimental condition which are T=150-500℃, space velocity=168,000-431,000hr^-1. The activation energy of NH₃ oxidation has been found to be three times greater than that of the NO reduction, 14kcal/ mole. As a result, the model is able to describe the maximum conversion of NO which is typical for SCR reaction. Furthermore, the model is capable of predicting the effect of NO/NH3 feed ratio on NO removal activity.

Keywords

NO_x SCR Mordenite Kinetic LHHW

References

Nam IS, Chem. Ind. Technol., 6(2), 31 (1991)
Otto K, Shelef M, Kummer JT, J. Phys. Chem., 74, 2690 (1970)
Otto K, Shelef M, J. Phys. Chem., 85, 308 (1973)
Bauerle GL, Wu SC, Nobe K, Ind. Eng. Chem. Prod. Res. Dev., 14(4), 268 (1975)
Takoudis CG, Schmidt LD, J. Phys. Chem., 87, 958 (1983)
Kato A, Matsuda A, Kamo T, Nakajima F, Kuroda H, Narita T, J. Phys. Chem., 85, 4099 (1981)
Tagaki M, Kawai T, Soma M, Onishi T, Seiyama T, Bull. Chem. Soc. Jpn., 50, 1431 (1977)
정창모, 석사학위논문, 포항공과대학 (1993)
Miyamoto A, Yamazaki Y, Hittori T, Inomota M, Murakami Y, J. Catal., 74, 144 (1982)
Nam I, Eldridge JW, Kittrell JR, Ind. Eng. Chem. Prod. Res. Dev., 14(4), 123 (1986)
Williamson WB, Lunsford JH, J. Phys. Chem., 80, 2664 (1976)
Nam I, Eldridge JW, Kittrell JR, Stud. Surf. Sci. Catal., 38, 589 (1988)
Hwang UC, Nam IS, Kim YG, HWAHAK KONGHAK, 28(1), 104 (1990)
최은영, 석사학위논문, 포항공과대학 (1991)
Marquardt DW, J. Soc. Ind. Appl. Math., 11, 431 (1963)
Fogler HS, "Elements of Chemical Reaction Engineering," Prentice-Hall International Inc. (1992)
Ham SW, Choi H, Nam IS, Kim YG, Catal. Today, 11, 611 (1992)