Hekzagonal bor nitrür destekli katalizörler varlığında dimetil eter üretimi

Abstract

Hekzagonal bor nitrür (hBN), yüksek ısıl iletkenliği, elektriksel yalıtkanlığı, kimyasal ve mekanik dayanıklılığı gibi özellikleriyle son zamanlarda dikkat çeken bir malzemedir. Ayrıca, mezogözenekli yapısı sayesinde alternatif yakıt üretimi reaksiyonlarında destek malzemesi olarak kullanıma da uygundur. Çalışmanın amacı, hBN’nin alternatif yakıt üretimi reaksiyonunda katalizör destek malzemesi olarak kullanımının araştırılması ve metanolün (MeOH) dehidrasyonu ile dimetil eter (DME) üretimi çalışmalarında katalitik aktivite testlerinin gerçekleştirilmesidir. Bu amaçla, hBN yapısına farklı oranlarda (kütlece %1, 4 ve 8) silikotungstik asit (STA) emdirme yöntemiyle yüklenmiş ve malzemenin yüzey asitliği artırılmıştır. Sentezlenen katalizörler X-ışını difraktometresi (XRD), N2 adsorpsiyon/desorpsiyon (BET), endüktif olarak eşleştirilmiş plazma-optik emisyon spektrometrisi (ICP-OES), taramalı elektron mikroskobu-enerji dispersiv spektrum (SEMEDS) ve piridin-adsorplanmış numunelerin difüz yansıma kızılötesi Fourier dönüşüm spektroskopisi (DRIFTS) teknikleri ile karakterize edilmiştir. Katalizörlerin aktivite testleri ise farklı reaksiyon sıcaklıklarında (200-300 °C) ve farklı kütlece saatlik boşluk hızlarında (WHSV, 0,25-0,5 ve 1,0 saat−1) gerçekleştirilmiştir. Böylece reaksiyon sıcaklığının ve akış hızının DME seçiciliğine ve MeOH dönüşümüne etkisi incelenmiştir. Çalışma sonucunda 8STA@hBN katalizörü ile 275°C’de %100 DME seçiciliği elde edilmiştir. Katalizörlerin yapısındaki STA miktarının artmasıyla Bronsted asit siteleri arttığından hBN destekli katalizörler metanolün dehidrasyon reaksiyonunda yüksek aktivite göstermiştir. Ayrıca yüksek reaksiyon sıcaklığı da MeOH dönüşümü ile DME seçiciliğini olumlu etkilemiştir. Çalışmadan elde edilen sonuçlar, STA içerikli hBN katalizörlerinin, alternatif yakıt kaynağı olan dimetil eterin üretimi için uygun bir seçenek olabileceğini göstermiştir.

Keywords

• Alternatif yakıt
• Dimetil eter
• Hekzagonal bor nitrür
• Metanol

Dimethyl ether production in the presence of hexagonal boron nitride supported catalysts

Abstract

Hexagonal boron nitride (hBN) has recently attracted attention due to its properties such as high thermal conductivity, electrical insulation, and chemical and mechanical durability. Moreover, thanks to its mesoporous structure, it is also suitable for use as a support material in alternative fuel production reactions. The aim of the study is to investigate the use of Hbn as a catalyst support material in the alternative fuel production reaction and to perform catalytic activity tests in dimethyl ether (DME) production studies by dehydration of methanol (MeOH). For this purpose, silicotungstic acid (STA) was loaded into the structure of hBN at different rates (1, 4, and 8% by mass) by the impregnation method, and the surface acidity of the material was increased. The synthesised catalysts were characterised by X-ray diffraction (XRD), N2 adsorption/desorption (BET), inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscopy - energy dispersive X-ray spectroscopy (SEM-EDS), and diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) techniques of pyridine-adsorbed samples. Activity tests of the catalysts were carried out at different reaction temperatures (200-300 °C) and different weight hourly space velocity (WHSV, 0.25-0.5 and 1.0 h−1). Thus, the effect of reaction temperature and flow rate on DME selectivity and MeOH conversion was examined. As a result of the study, 100% DME selectivity was achieved with the 8STA@hBN catalyst at 275°C. hBN supported catalysts showed high activity in the dehydration reaction of methanol, as the number of Bronsted acid sites increased with the increase in the amount of STA in the structure of the catalysts. In addition, high reaction temperature positively affected MeOH conversion and DME selectivity. The results obtained from the study showed that STA-containing hBN catalysts may be a suitable option to produce dimethyl ether, an alternative fuel source.

Keywords

• Alternative fuel
• Dimethyl ether
• Hexagonal boron nitride
• Methanol

References

1. [1] Zielinska, B., Sagebiel, J., McDonald, J. D., Whitney, K., & Lawson, D. R. (2004). Emission rates and comparative chemical composition from selected in-use diesel and gasoline fueled vehicles. Journal of the Air & Waste Management Association, 54(9), 1138-1150. https://doi. org/10.1080/10473289.2004.10470973
2. [2] Kritsanaviparkporn, E., Baena-Moreno, F. M., & Reina, T. R. (2021). Catalytic converters for vehicle exhaust: Fundamental aspects and technology overview for newcomers to the field. Chemistry, 3(2), 630-646. https://doi.org/10.3390/chemistry3020044
3. [3] Bikis, A., & Pandey, D. (2022). Air quality at public transportation stations/stops: contribution of light rail transit to reduce air pollution. Aerosol Science and Engineering, 6(1), 1-16. https://doi.org/10.1007/ s41810-021-00119-0
4. [4] Dogan, M. Y., Tasdemir, H. M., Arbag, H., Yasyerli, N., & Yasyerli, S. (2024). H2 production via H2S decomposition over activated carbon supported Fe-and W367 catalysts. International Journal of Hydrogen Energy, 75, 483-495. https://doi.org/10.1016/j.ijhydene.2024.02.316
5. [5] Dogan, M. Y., Arbag, H., Tasdemir, H. M., Yasyerli, N., & Yasyerli, S. (2023). Effect of ceria content in Ni-Ce- Al catalyst on catalytic performance and carbon/coke formation in dry reforming of CH4. International Journal of Hydrogen Energy, 48(60), 23013-23030. https://doi. org/10.1016/j.ijhydene.2023.04.011
6. [6] Ozcan, M. C., Karaman, B. P., Oktar, N., &Dogu, T. (2022). Dimethyl ether from syngas and effect of CO2 sorption on product distribution over a new bifunctional catalyst pair containing STA@ SBA-15. Fuel, 330(15), 125607. https://doi.org/10.1016/j.fuel.2022.125607
7. [7] Tokay, K. C., Dogu, T., & Dogu, G. (2012). Dimethyl ether synthesis over alumina based catalysts. Chemical Engineering Journal, 184, 278-285. https://doi. org/10.1016/j.cej.2011.12.034
8. [8] Ciftci, A., Varisli, D., Tokay, K. C., Sezgi, N. A., & Dogu, T. (2012). Dimethyl ether, diethyl ether & ethylene from alcohols over tungstophosphoric acid based mesoporous catalysts. Chemical Engineering Journal, 207, 85-93. https://doi.org/10.1016/j.cej.2012.04.016

9. [9] Pekmezci Karaman, B., Oktar, N., Doğu, G., & Doğu, T. (2020). Bifunctional silicotungstic acid and tungstophosphoric acid impregnated Cu-Zn-Al & Cu- Zn-Zr catalysts for dimethyl ether synthesis from syngas. Catalysis Letters, 150, 2744-2761. https://doi. org/10.1007/s10562-020-03171-6
10. [10] Arya, P. K., Tupkari, S., Satish, K., Thakre, G. D., & Shukla, B. M. (2016). DME blended LPG as a cooking fuel option for Indian household: A review. Renewable and Sustainable Energy Reviews, 53, 1591-1601. https://doi.org/10.1016/j.rser.2015.09.007
11. [11] Dadgar, F., Myrstad, R., Pfeifer, P., Holmen, A., & Venvik, H. J. (2016). Direct dimethyl ether synthesis from synthesis gas: The influence of methanol dehydration on methanol synthesis reaction. Catalysis Today, 270, 76-84. https://doi.org/10.1016/j.cattod.2015.09.024
12. [12] Hosseininejad, S., Afacan, A., & Hayes, R. E. (2012). Catalytic and kinetic study of methanol dehydration to dimethyl ether. Chemical Engineering Research and Design, 90(6), 825-833. https://doi.org/10.1016/j. cherd.2011.10.007
13. [13] Yang, Q., Zhang, H., Kong, M., Bao, X., Fei, J., & Zheng, X. (2013). Hierarchical mesoporous ZSM-5 for the dehydration of methanol to dimethyl ether. Chinese Journal of Catalysis, 34(8), 1576-1582. https://doi. org/10.1016/S1872-2067(12)60621-4
14. [14] Palomo, J., Rodríguez-Cano, M. A., Berruezo-García, J., Rodríguez-Mirasol, J., & Cordero, T. (2022). Efficient methanol dehydration to DME and light hydrocarbons by submicrometric ZrO2-ZSM-5 fibrillar catalysts with a shell-like structure. Fuel, 315, 123283. https://doi. org/10.1016/j.fuel.2022.123283
15. [15] Celik, G., Arinan, A., Bayat, A., Ozbelge, H. O., Dogu, T., & Varisli, D. (2013). Performance of Silicotungstic Acid Incorporated Mesoporous Catalyst in Direct Synthesis of Dimethyl Ether from Syngas in the Presence and Absence of CO2. Topics in Catalysis, 56, 1764-1774. https://doi.org/10.1007/s11244-013-0112-4
16. [16] Bateni, H., & Able, C. (2019). Development of heterogeneous catalysts for dehydration of methanol to dimethyl ether: A Review. Catalysis in Industry, 11, 7-33. https://doi.org/10.1134/S2070050419010045
17. [17] Degirmencioglu, P., & Arbag, H. (2023). Acid treatment to improve total light olefins selectivity of HZSM-5 catalyst in methanol to olefins (MTO) reaction. Arabian Journal for Science and Engineering, 48(12), 16123- 16136. https://doi.org/10.1007/s13369-023-08067-2
18. [18] Bayat, A., & Dogu, T. (2016). Optimization of CO2/CO ratio and temperature for dimethyl ether synthesis from syngas over a new bifunctional catalyst pair containing heteropolyacid impregnated mesoporous alumina. Industrial & Engineering Chemistry Research, 55(44), 11431-11439. https://doi.org/10.1021/acs.iecr.6b03001
19. [19] Karaman, B. P., Oktar, N., Doğu, G., & Dogu, T. (2022). Heteropolyacid incorporated bifunctional core-shell catalysts for dimethyl ether synthesis from carbon dioxide/syngas. Catalysts, 12(10), 1102. https://doi. org/10.3390/catal12101102
20. [20] Karaman, B. P., & Oktar, N. (2020). Tungstophosphoric acid incorporated hierarchical HZSM-5 catalysts for direct synthesis of dimethyl ether. International Journal of Hydrogen Energy, 45(60), 34793-34804. https://doi. org/10.1016/j.ijhydene.2020.07.044
21. [21] Postole, G., Caldararu, M., Ionescu, N. I., Bonnetot, B., Auroux, A., & Guimon, C. (2005). Boron nitride: A high potential support for combustion catalysts. Thermochimica Acta, 434(1-2), 150-157. https://doi. org/10.1016/j.tca.2005.01.007
22. [22] Lin, C., Wu, J. C. S., Pan, J., & Yeh, C., (2002). Characterization of boron-nitride-supported PT catalysts for the deep oxidation of benzene. Journal of Catalysis, 210(1), 39-45. https://doi.org/10.1006/ jcat.2002.3638
23. [23] Özkurt, J., & Ay, N. (2023). Lüminesans özellik gösteren hekzagonal bor nitrür üretiminin araştırılması. Journal of Boron, 8(special issue), 12-18. https://doi. org/10.30728/boron.1266900
24. [24] Elmusa, B., & Ay, N. (2022). Lityum iyon pilleri ayırıcılarında hekzagonal bor nitrür kullanımı ve gelişmeler. Journal of Boron, 7(1), 440-452. https://doi. org/10.30728/boron.1008704
25. [25] Guvenc, C., Alan, E., Degirmencioglu, P., Ozcan, M. C., Karaman, B. P., & Oktar, N. (2023). Catalytic upgrading of bio-oil model mixtures in the presence of microporous HZSM-5 and γ-Al2O3 based Ni, Ta and Zr catalysts. Fuel, 350, 128870. https://doi.org/10.1016/j. fuel.2023.128870
26. [26] Ibrahim, S. A., Ekinci, E. K., Karaman, B. P., & Oktar, N. (2021). Coke-resistance enhancement of mesoporous γ-Al2O3 and MgO-supported Ni-based catalysts for sustainable hydrogen generation via steam reforming of acetic acid. International Journal of Hydrogen Energy, 46(77), 38281-38298. https://doi.org/10.1016/j. ijhydene.2021.09.084
27. [27] Zhu, L., Lian, G., Tan, M., Wang, Q., Zhao, X., Cui, D., & Tao, X. (2008). Reaction of hexagonal boron nitride nano-crystals under mild hydrothermal conditions. Zeitschrift für Naturforschung B, 63(6), 742-746. https:// doi.org/10.1515/znb-2008-0623
28. [28] Varışlı, D., Tokay, K. C., Çiftçi, A., Doğu, T., & Doğu, G. (2009). Methanol dehydration reaction to produce clean diesel alternative dimethylether over mesoporous aluminosilicate-based catalysts. Turkish Journal of Chemistry, 33(3), 355-366. https://doi.org/10.3906/ kim-0809-31
29. [29] Yaripour, F., Baghaei, F., Schmidt, I. B., & Perregaard, J. (2005). Catalytic dehydration of methanol to dimethyl ether (DME) over solid-acid catalysts. Catalysis Communications, 6(2), 147-152. https://doi. org/10.1016/j.catcom.2004.11.012
30. [30] Fu, Y., Hong, T., Chen, J., Auroux, A., & Shen, J. (2005). Surface acidity and the dehydration of methanol to dimethyl ether. Thermochimica Acta, 434(1-2), 22-26. https://doi.org/10.1016/j.tca.2004.12.02