HYDRATION OF PROPENE OVER ACIDIC ZEOLITES

A study of the hydration of propene over acidic zeolites shows that the catalytic activities of H-mordenite and stabilised H-(VUS-)Y are determined by their effective Bronsted acidity (i.e. the concentration of acid sites multiplied by their acid strength). For H-ZSM-5 it has been established that the rate of propene hydration is: (i) significantly influenced by competitive adsorption of propene and water, and (ii) limited by intracrystalline diffusion. Water inhibits the rate of hydration, this effect being more pronounced for H-ZSM 5 than for the other two zeolites. During propene hydration the interior of the zeolite becomes rapidly inaccessible due to the formation of carbonaceous compounds resulting from propene oligomerisation.