Journal of the American Chemical Society, Vol.131, No.46, 17009-17013, 2009
High Yield of Liquid Range Olefins Obtained by Converting i-Propanol over Zeolite H-ZSM-5
Methanol, ethanol, and i-propanol were converted under methanol-to-gasoline (MTH)-like conditions (400 degrees C, 1-20 bar) over zeolite H-ZSM-5. For methanol and ethanol, the catalyst lifetimes and conversion capacities are comparable, but when i-propanol is used as the reactant, the catalyst lifetime is increased dramatically. In fact, the total conversion capacity (calculated as the total amount of alcohol converted before deactivation in g(alcohol)/g(zeolite)) is more than 25 times higher for i-propanol compared to the lower alcohols. Furthermore, when i-propanol is used as the reactant, the selectivity toward alkanes and aromatics declines rapidly over time on stream, and at 20 bar of pressure the liquid product mixture consists almost exclusively Of C-4-C-12 alkenes after approximately a third of the full reaction time. This discovery could open a new route to hydrocarbons via i-propanol from syn-gas or biobased feedstocks.