Influence of Phosphoric Acid Modification on Catalytic Properties of γ-χ Al2O3 Catalysts for Dehydration of Ethanol to Diethyl Ether

Mutjalin Limlamthong -  Center of Excellence on Catalysis and Catalytic Reaction Engineering, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University , Bangkok 10330, Thailand
Nithinart Chitpong -  Department of Textile Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi , Pathumthani, 12110, Thailand
*Bunjerd Jongsomjit -  Center of Excellence on Catalysis and Catalytic Reaction Engineering, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University , Bangkok 10330, Thailand
Received: 28 Mar 2018; Revised: 7 Aug 2018; Accepted: 15 Aug 2018; Published: 15 Apr 2019; Available online: 25 Jan 2019.
Open Access Copyright (c) 2019 Bulletin of Chemical Reaction Engineering & Catalysis
Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Citation Format:
Cover Image
Abstract

In this present work, diethyl ether, which is currently served as promising alternative fuel for diesel engines, was produced via catalytic dehydration of ethanol over H3PO4-modified g-c Al2O3 catalysts. The impact of H3PO4 addition on catalytic performance and characteristics of catalysts was investigated. While catalytic dehydration of ethanol was performed in a fixed-bed microreactor at the temperature ranging from 200ºC to 400ºC under atmospheric pressure, catalyst characterization was conducted by inductively coupled plasma (ICP), X-ray diffraction (XRD), N2 physisorption, temperature-programmed desorption of ammonia (NH3-TPD) and thermogravimetric (TG) analysis. The results showed that although the H3PO4 addition tended to decrease surface area of catalyst resulting in the reduction of ethanol conversion, the Al2O3 containing 5 wt% of phosphorus (5P/Al2O3) was the most suitable catalyst for the catalytic dehydration of ethanol to diethyl ether since it exhibited the highest catalytic ability regarding diethyl ether yield and the quantity of coke formation as well as it had similar long-term stability to conventional Al2O3 catalyst. The NH3-TPD profiles of catalysts revealed that catalysts containing more weak acidity sites were preferred for dehydration of ethanol into diethyl ether and the adequate promotion of H3PO4 would lower the amount of medium surface acidity with increasing catalyst weak surface acidity. Nevertheless, when the excessive amount of H3PO4 was introduced, it caused the destruction of catalysts structure, which resulted in the catalyst incapability due to the decrease in active surface area and pore enlargement. Copyright © 2019 BCREC Group. All rights reserved

 

 

Keywords
Ethanol Dehydration; Diethyl Ether; Phosphoric Acid; Heterogeneous Catalyst

Article Metrics:

  1. Sun, J., Wang, Y. (2014). Recent Advances in Catalytic Conversion of Ethanol to Chemicals. ACS Catalysis, 4(4): 1078-1090.
  2. Riittonen, T., Toukoniitty, E., Madnani, D.K., Leino, A.-R., Kordas, K., Szabo, M., Sapi, A., Arve, K., Wärnå, J., Mikkola, J.-P. (2012). One-Pot Liquid-Phase Catalytic Conversion of Ethanol to 1-Butanol over Aluminium Oxide-The Effect of the Active Metal on the Selectivity. Catalysts, 2(4): 68-84.
  3. Rass-Hansen, J., Falsig, H., Jørgensen, B., Christensen, C.H. (2007). Bioethanol: fuel or feedstock? Journal of Chemical Technology & Biotechnology, 82(4): 329-333.
  4. Rahmanian, A., Ghaziaskar, H.S. (2013). Continuous dehydration of ethanol to diethyl ether over aluminum phosphate–hydroxyapatite catalyst under sub and supercritical condition. The Journal of Supercritical Fluids, 78: 34-41.
  5. Jothi, N.K.M., Nagarajan, G., Renganarayanan, S. (2007). Experimental studies on homogeneous charge CI engine fueled with LPG using DEE as an ignition enhancer. Renewable Energy, 32(9): 1581-1593.
  6. Alharbi, W., Brown, E., Kozhevnikova, E.F., Kozhevnikov, I.V. 2014). Dehydration of ethanol over heteropoly acid catalysts in the gas phase. Journal of Catalysis, 319: 174-181.
  7. Chen, G., Li, S., Jiao, F., Yuan, Q. (2007). Catalytic dehydration of bioethanol to ethylene over TiO2/g-Al2O3 catalysts in microchannel reactors. Catalysis Today, 125(1-2): 111-119.
  8. Fan, D., Dai, D.J., Wu, H.S. (2012). Ethylene Formation by Catalytic Dehydration of Ethanol with Industrial Considerations. Materials (Basel), 6(1): 101-115.
  9. Golay, S., Kiwi-Minsker, L., Doepper, R., Renken, A. (1999). Influence of the catalyst acid/base properties on the catalytic ethanol dehydration under steady state and dynamic conditions. In situ surface and gas-phase analysis. Chemical Engineering Science, 54: 3593-3598.
  10. Han, Y., Lu, C., Xu, D., Zhang, Y., Hu, Y., Huang, H. (2011). Molybdenum oxide modified HZSM-5 catalyst: Surface acidity and catalytic performance for the dehydration of aqueous ethanol. Applied Catalysis A: General, 396(1-2): 8-13.
  11. Phillips, C.B., Datta, R. (1997). Production of Ethylene from Hydrous Ethanol on H-ZSM-5 under Mild Conditions. Industrial & Engineering Chemistry Research, 36: 4466-4475.
  12. Phung, T.K., Busca, G. (2015). Diethyl ether cracking and ethanol dehydration: Acid catalysis and reaction paths. Chemical Engineering Journal, 272: 92-101.
  13. Ramesh, K., Hui, L.M., Han, Y.-F., Borgna, A. (2009). Structure and reactivity of phosphorous modified H-ZSM-5 catalysts for ethanol dehydration. Catalysis Communications, 10(5): 567-571.
  14. Takahara, I., Saito, M., Inaba, M., Murata, K. (2005). Dehydration of Ethanol into Ethylene over Solid Acid Catalysts. Catalysis Letters, 105(3-4): 249-252.
  15. Varisli, D., Dogu, T., Dogu, G. (2007). Ethylene and diethyl-ether production by dehydration reaction of ethanol over different heteropolyacid catalysts. Chemical Engineering Science, 62(18-20): 5349-5352.
  16. Zaki, T. (2005). Catalytic dehydration of ethanol using transition metal oxide catalysts. J Colloid Interface Sci, 284(2): 606-13.
  17. Zhang, D., Wang, R., Yang, X. (2008). Effect of P Content on the Catalytic Performance of P-modified HZSM-5 catalysts in Dehydration of Ethanol to Ethylene. Catalysis Letters, 124: 384-391.
  18. Zhang, M., Yu, Y. (2013). Dehydration of Ethanol to Ethylene. Industrial & Engineering Chemistry Research, 52(28): 9505-9514.
  19. Ramesh, K., Jie, C., Han, Y.-F., Borgna, A. (2010). Synthesis, Characterization, and Catalytic Activity of Phosphorus Modified H-ZSM-5 Catalysts in Selective Ethanol Dehydration. Industrial & Engineering Chemistry Research, 2010: 4080-4090.
  20. Mao, R.L.V., Nguyen, T.M., Mclaughlin, G.P. (1989). The Bioethanol-to-Ethylene (B.E.T.E.) Process. Applied Catalysis, 48: 265-277.
  21. Phung, T.K., Hernández, L.P., Lagazzo, A., Busca, G. (2015). Dehydration of ethanol over zeolites, silica alumina and alumina: Lewis acidity, Brønsted acidity and confinement effects. Applied Catalysis A: General, 493: 77-89.
  22. Pearson, D.E., Tanner, R.D., Picciotto, I.D., Sawyer, J.S., Cleveland, J.H., Jr. (1981). Phosphoric Acid Systems. 2. Catalytic Conversion of Fermentation Ethanol to Ethylene. Ind. Eng. Chem. Prod. Res. Dev., 20: 734-740.
  23. Janlamool, J., Jongsomjit, B. (2017). Catalytic Ethanol Dehydration to Ethylene over Nanocrystalline chi- and gamma-Al2O3 Catalysts. J Oleo Sci, 66(9): 1029-1039.
  24. Wannaborworn, M., Praserthdam, P., Jongsomjit, B. (2015). A Comparative Study of Solvothermal and Sol-Gel-Derived Nanocrystalline Alumina Catalysts for Ethanol Dehydration. Journal of Nanomaterials, 2015: 1-11.
  25. Sing, K.S.W. (1982). Reporting Physisorption Data for Gas/Solid Systems with Special Reference to the Determination of Surface Area and Porosity. Pure & Appl. Chem., 54(11): 2201-2218.
  26. Khom-in, J., Praserthdam, P., Panpranot, J., Mekasuwandumrong, O. (2008). Dehydration of methanol to dimethyl ether over nanocrystalline Al2O3 with mixed g- and c-crystalline phases. Catalysis Communications, 9(10): 1955-1958.