제올라이트 담체상의 디벤조티오펜 수첨탈황반응에서 저온활성 및 선택성

김문찬

Journal of the Korean Industrial and Engineering Chemistry, Vol.9, No.1, 101-106, February, 1998

Export Citation

제올라이트 담체상의 디벤조티오펜 수첨탈황반응에서 저온활성 및 선택성

Activity and Selectivity in Low Temperature for Dibenzothiophene Hydrodesulfurization based Zeolite Support

김문찬

초록

제올라이트를 담체로 사용하여 활성금속으로 코발트와 몰리브덴을 담지시킨 촉매와 상용공정에 사용되는 NiMo/γ-Al₂O₃ 촉매를 제조하여, 저온에서의 DBT 탈황활성과 선택성에 대하여 비교하였다. 고정층 고압 연속흐름반응기에서 수행된 탈황반응에서, 저온 영역인 200℃와 225℃에서는 제조된 NiMo/γ-Al₂O₃ 촉매보다 CoMo/zeolite 촉매에서 탈황활성이 더 높았으며, 275℃ 이상의 고온 영역에서는 NiMo/γ-Al₂O₃ 촉매의 탈황활성이 더 높게 나타났다 NiMo/γ-Al₂O₃ 촉매에서는 biphenyl과 cyclohexylbenzene이 주생성물인데 비하여 zeolite를 담체로 사용한 촉매의 경우 알킬화반응이 일어나 생성물 분포가 매우 다름을 보여주고 있으며, 알킬화반응과 수소첨가반응의 두 가지 경로를 통해서 최종 생성물질인 alkylcyclohexane을 생성하는 것으로 추정된다. 제올라이트 담체상에서 molybdenum은 flesh 촉매에서 MoO₃ 형태로 존재하고 있으며, aged 촉매상에서는 MoO₃와 MoS₂ 형태로 황화되어 있음을 알 수 있었다.

Two types of CoMo/zeolite as well as NiMo/γ-Al₂O₃ were prepared and their activities and selectivities of low-temperature dibenzothiophene(DBT) hydrodesulfurization(HDS) were studied in high pressure fixed bed reactor. The HDS activities of CoMo/zeolites were higher than that of NiMo/γ-Al₂O₃ at temperatures below 225℃ while they were lower than that of NiMo/γ-Al₂O₃ at temperatures higher than 275℃. The main products from NiMo/γ-Al₂O₃ were biphenyl and cyclohexylbenzene. The product distribution of CoMo/zeolite catalysts was different from that of NiMo/γ-Al₂O₃. It is speculated that DBT is converted to alkylcyclohexane over zeolite based catalysts through both alkylation and hydrogenation reactions. The crystal structure of molybdenum was MoO₃ in fresh zeolite support while mixtures of MoO₃ and MoS₂ were observed in the aged catalyst.

[References]

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Gier TE, Stucky GD, Zeolites, 12, 770 (1992)
Nay NK, Spare AV, Broderick DH, Gates BC, J. Catal., 57, 509 (1979)
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[1] Imelik B, Naccache C, Coudurier G, Praliaud H, Meriaudeau P, Gallezot P, Martin GA, Verdrine JC, "Metal-Supported and Metal-Additive Effects in Catalysis," Elsevier, N.Y., 247 (1982)

[2] Cerveney L, "Catalytic Hydrogenation," 1st ed., Elsevier, N.Y., p. 150 (1986)

[3] Nagai M, Uchino O, Okubo J, Omi S, 11th IZC Proceedings, pp. 161 (1996)

[4] Kim MC, Kim KL, Korean J. Chem. Eng., 13(1), 1 (1996)

[5] Meier WM, Olson DH, Baerlocher C, "Atlas of Zeolite Structure Type," 4th ed. Elsevier, 105-146 (1996)

[6] Gier TE, Stucky GD, Zeolites, 12, 770 (1992)

[7] Nay NK, Spare AV, Broderick DH, Gates BC, J. Catal., 57, 509 (1979)

[8] Moorooka S, Harmin CE, Chem. Eng. Sci., 32, 125 (1977)

[9] Lipsch JMJG, Schuit GCA, J. Catal., 15, 179 (1969)