HYDRATION OF BUTENE-1 OVER H-MORDENITE AND H-MORDENITE COMPOSITED WITH ZEOLITE-BETA

The hydration of butene-1 over H-mordenite and H-mordenite composited with different amounts of zeolite-beta has been investigated in a batc h reactor. The products of the reaction were sec-butanol (SEA), diisob utylether (DIBE) and C-8-oligmer. The reaction was carried out over H- mordenite at different operational conditions of a reaction temperatur e and built-up pressure. The maximum activity (46% of the thermodynami c equilibrium) of H-mordenite was observed at 250 degrees C and 180.27 atm with 88% selectivity of SEA and no formation of Cg dimmer by-prod uct. The structural characteristics of a II-form of the composited cat alysts, containing 10, 15 and 45 wt% of zeolite-beta, were studied by means of an electron dispersion system (EDS) technique in order to det ermine SiO2/Al2O3 ratio and % degree of exchange. It was found that Si O2/Al1O3 ratio ranges between 20.2 and 29.61 indicating that all the c atalysts could be considered as siliceous zeolites. The acidic propert ies of the pure mordenites and those composited with zeolite-p were de termined potentiometrically in an aqueous medium. From the results obt ained, it is obvious that the catalysts, containing mordenite composit ed with 15 and 45 wt% of zeolite-p, possess stronger acidic -OH's than pure mordenites. Also, the hydration activity of zeolites seemed to b e 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 t hose of pure mordenite. The binary composited zeolites, containing 15 and 45 wt% of zeolite-beta were found to be more active and selective for the hydration of butene -1 than those of pure mordenite. It was su ggested that the activity and selectivity of the binary zeolite cataly st system may be due to shape selectivity of p-zeolite, high surface a cidity and hydrophobic nature exhibited by the two forms of zeolites.