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Coke 침적에 의한 Mg-La/ZSM-5 촉매의 비활성화에 관한 연구
A Study on the Catalytic Deactivation of Mg-La/ZSM-5 by Coke Deposition
경희대학교 화학공학과/산학협력기술원
Department of Chemical Engineering, Industrial Liaison Research Institute, KyungHee University, Korea
HWAHAK KONGHAK, December 2000, 38(6), 767-773(7), NONE
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Abstract
본 연구에서는 MTO(methanol-to-olefin) 반응에 있어서 ZSM-5 촉매의 주요 활성점으로 여겨지는 강산점을 중심으로 코크 침적에 따른 활성변화 양상과 산도와의 상관관계를 조사하였다. 먼저 촉매의 비활성화 과정에 관한 속도식을 공간속도에 대한 활성감소의 실험자료를 이용하여 유도하였으며 이로부터 비활성화 속도상수를 도출하였다. 본 반응에서의 비활성화 차수는 1.5차에 접근함을 알 수 있었다. 또한 금속(Mg, La) 양이온이 HZSM-5에 이온교환될 경우 강산점인 Bronsted 산점의 양이 조절될 수 있음을 확인하였다. 강산점의 산량변화와 활성과의 상호관계는 프로필렌의 경우 선택도 및 수율이 강산점량의 증감에 따라 선형적으로 비례함을 볼 수 있었으나, 에텐의 경우 비례관계를 발견할 수 없었다. 탄소침적으로 인하여 비활성화된 촉매를 재생한 결과, 촉매활성이 확연히 회복됨을 알 수 있었으며 측정된 비활성화 속도상수는 비활성화 과정과 잘 연계됨을 관찰할 수 있었다. 또 재생반응을 반복할수록 그 재생효율은 점차적으로 감소하였다.
Generally, strong acid sites were understood as the main active site for the methanol-to-olefin(MTO) reaction over the ZSM-5 catalyst. In this study, the correlation between the catalytic activity and the extent of deactivation by coke deposition was found to be quite proportional mainly due to the changes in the amount of the strong acid sites. The kinetic expression including the catalytic deactivation was able to be derived and the deactivation rate constants were estimated. From this kinetic study of catalytic deactivation in the MTO reaction, the value of the deactivation rate constant(k'd) was 0.195 hr-1 at 350℃. From the results of NH3-TPD measurement, it was found that the amount of strong acid sites were controllable by the ion-exchange of metal counterion. The selectivity and yield of propylene were found to be proportional to the amount of strong acid sites. Regeneration of the deactivated catalyst was carried out by burning off the deposited carbon using an air and the catalytic activity was recovered quite significantly. It was found that the estimated deactivation rate constants represent the degree of deactivation fairly well. The regeneration efficiency was gradually decreased by repeating regeneration.
References
Hattori H, Chem. Rev., 95(3), 537 (1995)
Chen NY, Reagan WJ, J. Catal., 59, 123 (1979)
Ono Y, Imai E, Mori T, Z. Phys. Chem. N. F., 115, 99 (1979)
Ono Y, Mori T, J. Chem. Soc.-Faraday Trans., 77, 2209 (1981)
Chang CD, Chem. Eng. Sci., 35, 619 (1980)
Chang CD, Chem. Tech., 17, 624 (1987)
Chang CD, "Hydrocarbons from Methanol," Dekker, New York (1983)
Chang CD, J. Catal., 86, 289 (1984)
Cynthia TW, J. Catal., 86, 297 (1984)
Choung SJ, Appl. Catal., 64, 173 (1990)
Topsoe NY, Pedersen K, Derouane EG, J. Catal., 70, 41 (1981)
Butt JB, Petersen EE, "Activation, Deactivation and Poisoning of Catalysts," Academic Press, New York (1988)
Groten WA, Woiciechowski BW, Hunter BK, J. Catal., 125, 311 (1990)
Magnoux P, Guisnet M, Mignard S, Cartraud P, J. Catal., 106, 235 (1987)
Yoon KH, Park SE, Chun HJ, HWAHAK KONGHAK, 21(1), 1 (1983)
Sotelo JL, Ind. Eng. Chem. Res., 35(4), 1300 (1996)
Ison A, Gorte RJ, J. Catal., 89, 150 (1984)
Iwamoto M, Yahiro H, Shundo S, Yu Y, Mizuno N, Appl. Catal., 69, 15 (1991)
Misono M, Kondo K, Chem. Lett., 1001 (1991)
Yogo K, Tanaka S, Ihara M, Hishiki T, Kikuchi E, Chem. Lett., 1025 (1992)
Sato S, Yu Y, Yahiro H, Mizuno N, Iwamoto M, Appl. Catal., 70, L1 (1991)
Fogler HS, "Elements of Chemical Reaction Engineering," Prentice Hall, New Jersey (1992)
Butt JB, Chem. Eng. Sci., 33, 1321 (1978)
Petersen EE, J. Catal., 98, 380 (1986)
Sapre AV, Chem. Eng. Sci., 52(24), 4615 (1997)
Corma A, Gonzalez-Alfaro V, Orchilles AV, Appl. Catal. A: Gen., 129(2), 203 (1995)
Bibby DM, Milestone NB, Aldridge LP, J. Catal., 97, 493 (1986)
Jong SJ, Pradhan AR, Wu JF, Tsai TC, Liu SB, J. Catal., 174(2), 210 (1998)
Chen NY, Reagan WJ, J. Catal., 59, 123 (1979)
Ono Y, Imai E, Mori T, Z. Phys. Chem. N. F., 115, 99 (1979)
Ono Y, Mori T, J. Chem. Soc.-Faraday Trans., 77, 2209 (1981)
Chang CD, Chem. Eng. Sci., 35, 619 (1980)
Chang CD, Chem. Tech., 17, 624 (1987)
Chang CD, "Hydrocarbons from Methanol," Dekker, New York (1983)
Chang CD, J. Catal., 86, 289 (1984)
Cynthia TW, J. Catal., 86, 297 (1984)
Choung SJ, Appl. Catal., 64, 173 (1990)
Topsoe NY, Pedersen K, Derouane EG, J. Catal., 70, 41 (1981)
Butt JB, Petersen EE, "Activation, Deactivation and Poisoning of Catalysts," Academic Press, New York (1988)
Groten WA, Woiciechowski BW, Hunter BK, J. Catal., 125, 311 (1990)
Magnoux P, Guisnet M, Mignard S, Cartraud P, J. Catal., 106, 235 (1987)
Yoon KH, Park SE, Chun HJ, HWAHAK KONGHAK, 21(1), 1 (1983)
Sotelo JL, Ind. Eng. Chem. Res., 35(4), 1300 (1996)
Ison A, Gorte RJ, J. Catal., 89, 150 (1984)
Iwamoto M, Yahiro H, Shundo S, Yu Y, Mizuno N, Appl. Catal., 69, 15 (1991)
Misono M, Kondo K, Chem. Lett., 1001 (1991)
Yogo K, Tanaka S, Ihara M, Hishiki T, Kikuchi E, Chem. Lett., 1025 (1992)
Sato S, Yu Y, Yahiro H, Mizuno N, Iwamoto M, Appl. Catal., 70, L1 (1991)
Fogler HS, "Elements of Chemical Reaction Engineering," Prentice Hall, New Jersey (1992)
Butt JB, Chem. Eng. Sci., 33, 1321 (1978)
Petersen EE, J. Catal., 98, 380 (1986)
Sapre AV, Chem. Eng. Sci., 52(24), 4615 (1997)
Corma A, Gonzalez-Alfaro V, Orchilles AV, Appl. Catal. A: Gen., 129(2), 203 (1995)
Bibby DM, Milestone NB, Aldridge LP, J. Catal., 97, 493 (1986)
Jong SJ, Pradhan AR, Wu JF, Tsai TC, Liu SB, J. Catal., 174(2), 210 (1998)
