HYDRATION OF BUTENE-1 OVER H.-MORDENITE AND H-MORDENTTE COMPOSITED WITH ZEOLITE-β

• Published in: Petroleum science and technology 1998-01, Vol.16 (1-2), p.41-57
• Main Authors: Faramawy, S., Shaker, N.O., El-Sockary, M.A., Ibrahim, S.H.
• Format: Article
• Language: English
• Subjects: butene-1; hydration; mordenite; zeolite-β
• ISSN: 1091-6466; 1532-2459
• DOI: 10.1080/10916469808949771

The hydration of butene-1 over H-mordenite and H-mordenite composited with different amounts of zeolite-β has been investigated in a batch reactor. The products of the reaction were sec-butanol (SBA), diisobutylether (DIBE) and C 8 -oligmer. The reaction was carried out over H-mordenite at different operational conditions of a reaction temperature and built-up pressure. The maximum activity (46% of the thermodynamic equilibrium) of H-mordenhe was observed at 250°C and 180.27 atm with 88% selectivity of SBA and no formation of C« dimmer by-product. The structural characteristics of a H-form of the composited catalysts, containing 10, 15 and 45 wt% of zeolite-β, were studied by means of an electron dispersion system (EDS) technique in order to determine SiO 2 /Al 2 O 3 ratio and % degree of exchange. It was found that SiO 2 /Al 2 O 3 ratio ranges between 20.2 and 29.61 indicating that all the catalysts could be considered as siliceous zeolites. The acidic properties of the pure mordenites and those composited with zeolite-β were determined potentiometrically in an aqueous medium. From the results obtained, it is obvious that the catalysts, containing mordenite composited with 15 and 45 wt% of zeolite-β, possess stronger acidic -OH's than pure mordenites. Also, the hydration activity of zeolites seemed to be strongly correlated with their protonic acid strength. The activity and selectivity of the composited zeolites for the hydration reaction were studied at the optimum operational conditions and compared with those of pure mordenite. The binary composited zeolites, containing 15 and 45 wt% of zeolite-β were found to be more active and selective for the hydration of butene -1 than those of pure mordenite. It was suggested that the activity and selectivity of the binary zeolite catalyst system may be due to shape selectivity of β-zeolite, high surface acidity and hydrophobic nature exhibited by the two forms of zeolites.