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ساخت زئولیت HZSM-5 در محیط حاوی یون فلوئورید و بررسی عملکرد آن در فرآیند تبدیل متانول به پروپیلن

نوع مقاله: مقاله پژوهشی


1 دانشکده مهندسی شیمی و نفت، دانشگاه صنعتی شریف، تهران، ایران

2 شرکت پژوهش‌و فناوری‌پتروشیمی


در این تحقیق زئولیت HZSM-5 در محیط حاوی یون فلوئورید ساخته شد و عملکرد آن در فرایند تبدیل متانول به پروپیلن مورد بررسی قرار گرفت. از نمک پتاسیم فلوئورید به عنوان ماده تأمین کننده این یون استفاده شد. خصوصیات فیزیکی-شیمیایی کاتالیست‌ها با استفاده از آنالیزهای XRD، FESEM، N2 Adsorption/Desorption وNH3-TPD شناسایی شدند. الگوی XRD تشکیل ساختار کریستالی مرتبط با زئولیت HZSM-5 را در زئولیت سنتز شده با پتاسیم فلوئورید (نمونه F-HZSM-5) تائید کرد. تصاویر FESEM زئولیت F-HZSM-5 تغییر در مورفولوژی و افزایش اندازه ذرات را در مقایسه با نمونه مرجع HZSM-5 نشان داد. نتایج آنالیز NH3-TPD کاهش غلظت کل مکان‌های اسیدی را در زئولیت F-HZSM-5 نشان داد. فعالیت نمونه‌ها در یک راکتور بستر ثابت و در شرایط عملیاتی یکسان بررسی شد. کاتالیست F-HZSM-5 نسبت به نمونه مرجع HZSM-5 طول عمر کمتری را نشان داد. با این حال، این کاتالیست در مدت 10 روز فعالیت به‌ترتیب متوسط انتخاب‌پذیری پروپیلن و نسبت پروپیلن به اتیلن 8/41 و 9/ 10 را داشته است.



عنوان مقاله [English]

Construction of HZSM-5 Zeolite in Medium Containing Fluoride Ion and Its Performance in the Conversion of Methanol to Propylene

نویسندگان [English]

  • somayeh ahmadpour 1
  • Fereydoon Yaripour 2
  • Farhad Khorasheh 1
1 Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran
چکیده [English]

In this research, HZSM-5 zeolite was made in medium containing fluoride ions, and its performance in the process of methanol to propylene conversion was investigated. Potassium fluoride was used as the supplying material for this ion. Physical-chemical properties of catalysts were determined by using XRD, FESEM, N2 adsorption/desorption and NH3-TPD analysis. The XRD pattern confirmed the formation of crystalline structure associated with zeolite HZSM-5 in potassium fluoride-synthesized zeolite (F-HZSM-5 specimen). FESEM images of F-HZSM-5 zeolite showed a change in morphology and an increase in particles size compared to the reference sample HZSM-5. Results of the NH3-TPD analysis showed a reduction in the concentration of total acid sites in the F-HZSM-5 zeolite. The activity of the samples in a fixed-bed reactor and in the same operating conditions was investigated. The F-HZSM-5 catalyst showed less lifetime in comparison with the reference sample. However, this catalyst over a period of 10 days had an average selectivity of propylene and a propylene/ethylene ratio of 41.8 and 10.9, respectively.

کلیدواژه‌ها [English]

  • HZSM-5 zeolite
  • conversion of methanol to propylene
  • potassium fluoride
  • mineralizer
[1]. Bleken F. L., Chavan S., Olsbye U., Boltz M., Ocampo F. and Louis B., “Conversion of methanol into light olefins over ZSM-5 zeolite: Strategy to enhance propene selectivity,” Applied Catalysis A: General, Vol. 447, pp.178-185, 2012.##

[2]. Xu T., Zhang Q., Song H. and Wang Y., “Fluoride-treated H-ZSM-5 as a highly selective and stable catalyst for the production of propylene from methyl halides,” Journal of Catalysis, Vol. 295, pp. 232-241, 2012.##

[3]. Zhang L., Song Y., Li G., Zhang Q., Zhang S., Xu J., Deng F. and Gong Y., “F-assisted synthesis of a hierarchical ZSM-5 zeolite for methanol to propylene reaction: ab-oriented thinner dimensional morphology,” RSC Advances, Vol. 5(75), pp. 61354-61363, 2015.##

[4]. Ivanova S., Lebrun C., Vanhaecke E., Pham-Huu C. and Louis B., “Influence of the zeolite synthesis route on its catalytic properties in the methanol to olefin reaction,” Journal of Catalysis, Vol. 265(1), pp. 1-7, 2009.##

[5]. Houdek J. M. and Andersen J., “On-purpose propylene-technology developments,” In UOP LLC, Presented at the ARTC 8th Annual Meeting, 2005, April.##

[6]. Guenther D. R., “Investigation of the hydrocarbon pool species responsible for methanol to olefin catalysis on acidic zeolite and zeotype catalysts,” Doctoral Dissertation, University of Southern California, 2010.##

[7]. Yaripour F., Shariatinia Z., Sahebdelfar S. and Irandoukht A., “Effect of boron incorporation on the structure, products selectivities and lifetime of H-ZSM-5 nanocatalyst designed for application in methanol-to-olefins (MTO) reaction,” Microporous and Mesoporous Materials, Vol. 203, pp. 41-53, 2015.##

[8]. Ke J. A. and Wang I., “Elucidation of the role of potassium fluoride in the chemical and physical nature of ZSM-5 zeolite,” Materials Chemistry and Physics, Vol. 68(1), pp.157-165, 2001.##

[9]. Louis B. and Kiwi-Minsker L., “Synthesis of ZSM-5 zeolite in fluoride media: an innovative approach to tailor both crystal size and acidity,” Microporous and Mesoporous Materials, 74(1), pp. 171-178, 2004.##

[10]. Arichi J. and Louis B., “Toward microscopic design of zeolite crystals: advantages of the fluoride-mediated synthesis,” Crystal Growth and Design, Vol. 8(11), pp.3999-4005, 2008.##

[11]. Belarbi H., Lounis Z., Hamacha R., Bengueddach A. and Trens P., “Textural properties of ZSM-5 nanocrystals prepared in alkaline potassium fluoride medium,” Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 453, pp. 86-93, 2014.##

[12]. Nigro E., Mostowicz R., Crea F., Testa F., Aiello R. and Nagy J. B., “Synthesis and characterization of ZSM-5 in fluoride medium: the role of NH4+ and K+ cations,” Studies in Surface Science and Catalysis, Vol. 105, pp.309-316, 1997.##

[13]. Qin Z., Gilson J. P. and Valtchev V., “Mesoporous zeolites by fluoride etching,” Current Opinion in Chemical Engineering, Vol. 8, pp.1-6, 2015.##

[14]. Li J., Liu M., Guo X., Dai C. and Song C., “Fluoride-mediated nano-sized high-silica ZSM-5 as an ultrastable catalyst for methanol conversion to propylene,” Journal of Energy Chemistry, 2017.##

[15]. Aiello R., Crea F., Nigro E., Testa F., Mostowicz R., Fonseca A. and Nagy J. B., “The influence of alkali cations on the synthesis of ZSM-5 in fluoride medium,” Microporous and Mesoporous Materials, Vol. 28(2), pp. 241-259, 1999.##

[16]. Liu C., Gu W., Kong D. and Guo H., “The significant effects of the alkali-metal cations on ZSM-5 zeolite synthesis: From mechanism to morphology,” Microporous and Mesoporous Materials, Vol. 183, pp. 30-36, 2014.##

[17]. Losch P., Pinar A. B., Willinger M. G., Soukup K., Chavan S., Vincent B., Pale P. and Louis B., “H-ZSM-5 zeolite model crystals: Structure-diffusion-activity relationship in methanol-to-olefins catalysis,” Journal of Catalysis, 345, pp. 11-23, 2017.##

[18]. Leofanti G., Padovan M., Tozzola G. and Venturelli B., “Surface area and pore texture of catalysts,” Catalysis Today, Vol. 41(1), pp. 207-219, 1998.##

[19]. Yang Y., Sun C., Du J., Yue Y., Hua W., Zhang C., Shen W. and Xu H., “The synthesis of endurable B–Al–ZSM-5 catalysts with tunable acidity for methanol to propylene reaction,” Catalysis Communications, Vol. 24, pp.44-47, 2012.##

[20]. Ahmadpour J. and Taghizadeh M., “Selective production of propylene from methanol over high-silica mesoporous ZSM-5 zeolites treated with NaOH and NaOH/tetrapropylammonium hydroxide,” Comptes Rendus Chimie, Vol. 18(8), pp. 834-847, 2015.##

[21]. Rostamizadeh M. and Yaripour F., “Dealumination of high silica H-ZSM-5 as long-lived nanocatalyst for methanol to olefin conversion,” Journal of the Taiwan Institute of Chemical Engineers, Vol. 71, pp. 454-463, 2017.##

[22]. Tang Z., Zhang P., Han W., Lu G. and Lu J., “Butene catalytic cracking to ethylene and propylene on fluorinated ZSM-5-based catalyst,” Reaction Kinetics, Mechanisms and Catalysis, Vol. 108(1), pp. 231-239, 2013.##

[23]. Álvaro-Muñoz T., Márquez-Álvarez C. and Sastre E., “Aluminium chloride: a new aluminium source to prepare SAPO-34 catalysts with enhanced stability in the MTO process,” Applied Catalysis A: General, Vol. 472, pp. 72-79, 2014.##

[24]. Svelle S., Joensen F., Nerlov J., Olsbye U., Lillerud K. P., Kolboe S. and Bjørgen M., “Conversion of methanol

into hydrocarbons over zeolite H-ZSM-5: Ethene formation is mechanistically separated from the formation of higher alkenes,” Journal of the American Chemical Society, Vol. 128(46), pp. 14770-14771, 2006.##

[25]. Bjørgen M., Svelle S., Joensen F., Nerlov J., Kolboe S., Bonino F., Palumbo L., Bordiga S. and Olsbye U., “Conversion of methanol to hydrocarbons over zeolite H-ZSM-5: On the origin of the olefinic species,” Journal of Catalysis, Vol. 249(2), pp. 195-207, 2007.##

[26]. Barnicki S. D., “Synthetic Organic Chemicals,” Handbook of Industrial Chemistry and Biotechnology, Springer, pp. 307-389, 2012##

[27]. Zimmermann H. and Walzl R., “Propene,” Ullmann›s Encyclopedia of Industrial Chemistry, 2013.##