ZSM-5촉매상에서 메탄올로부터 저급올레핀 생성에 관한 연구

정종헌; 이준원; 이현구

HWAHAK KONGHAK, Vol.31, No.3, 279-286, June, 1993

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ZSM-5촉매상에서 메탄올로부터 저급올레핀 생성에 관한 연구

A Study of Methanol Conversion to Light Olefins over ZSM-5 Catalyst

정종헌, 이준원, 이현구

초록

HZSM-5촉매상에서 메탄올 전환반응 실험을 실시하여 250℃ 근처에서는 메탄올로부터 DME（dimethylether）로의 탈수반응만이 일어나고, 310℃ 근처에서는 올레핀의 자촉매반응으로 인하여 방향족화 반응이 급격히 진행됨을 관찰하였다. 또한 반응물에 물을 첨가할 경우 생성물 중에 저탄소수 올리핀과 방향족 탄화수소가 증가하며, 촉매기공 내의 물의 방출효과에 의하여 촉매의 비활성화 정도가 감소되는 것을 확인하였다. 금속함침으로 변형된 촉매의 경우 금속이온이 일부 B산점의 H⁺이온과 이온교환되어 B산이 감소하고, 또한 금속이온 및 산화물 형태로 존재할 경우에는 L산으로 작용할 수 있어 산점의 재분산 현상이 일어나는 한편, 촉매표면에서는 소성과정에서 금속산화물이 형성되므로 기공막힘 현상이 일어나는 것을 알 수 있었다. 이러한 연유로 금속함침에 의하여 촉매의 반응성과 비활성화 정도가 HZSM-5촉매의 경우보다 감소하며, 특히 메탄올의 100% 전환상태에서 저탄소수 올레핀의 선택도를 크게 향상시킬 수 있었다.

From the experimental results of methanol conversion over HZSM-5 catalyst, it was observed that around 250℃ methanol was only dehydrated to DME（dimethylether） and the aromatization was promoted by the autocatalytic reaction of light olefins around 310℃. When water was added to the reaction mixture, the selectivities to light olefins and aromatics were found to increase and the degree of deactivation to decrease due to the ateam distillative effect exerted by water present in the pore. In case of HZSM-5 catalysts modified by metal impregnation, it was noticed that the Br nsted acid sites decreased because of the partial ion-exchange of H⁺ ions by metal ions and that redistribution of acid sites occurred since metal ions and metal-oxides gave rise to an increase in the Lewis acid sites. Also, it is evident that the crystalline metal oxide formed on the catalyst surface during the course of calcination played the role of pore-plugging. For these reasons, the metal impregnated HZSM-5 catalysts showed lower activity and lower rate of deactivation in comparison to the HZSM-5. In particular, the modified catalysts gave substantially higher selectivities to light olefins at the level of 100% conversion of methanol.

[References]

Liang J, Li H, Zhao S, Guo W, Wand R, Ying M, Appl. Catal., 64, 31 (1990)
Woo MU, Kim MH, Rhee HK, Lee WY, HWAHAK KONGHAK, 25(4), 427 (1987)
Woo MW, Rhee HK, HWAHAK KONGHAK, 27(5), 603 (1989)
Anderson JR, Foger K, Mole T, Rajadhaksha RA, Sanders JV, J. Catal., 58, 114 (1979)
Chang CD, Chem. Eng. Sci., 35, 619 (1980)
Oudejans JC, Vanden Dostekamp PF, Bekkum HV, Appl. Catal., 3, 109 (1982)
Anderson JR, Mole T, Christov V, J. Catal., 61, 477 (1980)
Ison A, Gorte RJ, J. Catal., 89, 150 (1984)
Minchev C, Kanazirev V, Kosova L, Penchev V, Gunsser W, Schmidt F, "Proceeding, 5the International Congress on Zeolites," (Rees, L.V. ed.), p. 355, Heyden, Philadelphia (1980)
Stencel JM, Rao VUS, Diehl JR, Rhee KH, Dhere AG, Deangelis RJ, J. Catal., 84, 109 (1983)
Rhee KH, Rao VUS, Stencel JM, Zeolites, 3, 337 (1983)
Mcintosh RJ, Seddon D, Appl. Catal., 6, 307 (1983)
Okado H, Shoji H, Sano T, Ikai S, Hangimara H, Takaya H, Appl. Catal. A: Gen., 41, 121 (1988)

[Referenced By]

[1] Liang J, Li H, Zhao S, Guo W, Wand R, Ying M, Appl. Catal., 64, 31 (1990)

[2] Woo MU, Kim MH, Rhee HK, Lee WY, HWAHAK KONGHAK, 25(4), 427 (1987)

[3] Woo MW, Rhee HK, HWAHAK KONGHAK, 27(5), 603 (1989)

[4] Anderson JR, Foger K, Mole T, Rajadhaksha RA, Sanders JV, J. Catal., 58, 114 (1979)

[5] Chang CD, Chem. Eng. Sci., 35, 619 (1980)

[6] Oudejans JC, Vanden Dostekamp PF, Bekkum HV, Appl. Catal., 3, 109 (1982)

[7] Anderson JR, Mole T, Christov V, J. Catal., 61, 477 (1980)

[8] Ison A, Gorte RJ, J. Catal., 89, 150 (1984)

[9] Minchev C, Kanazirev V, Kosova L, Penchev V, Gunsser W, Schmidt F, "Proceeding, 5the International Congress on Zeolites," (Rees, L.V. ed.), p. 355, Heyden, Philadelphia (1980)

[10] Stencel JM, Rao VUS, Diehl JR, Rhee KH, Dhere AG, Deangelis RJ, J. Catal., 84, 109 (1983)

[11] Rhee KH, Rao VUS, Stencel JM, Zeolites, 3, 337 (1983)

[12] Mcintosh RJ, Seddon D, Appl. Catal., 6, 307 (1983)

[13] Okado H, Shoji H, Sano T, Ikai S, Hangimara H, Takaya H, Appl. Catal. A: Gen., 41, 121 (1988)