| abstract |
ABSTRACT Zeolite catalyst compositions comprise a crystalline aluminosilicate zeolite having pore windows formed by 8-membered rings of oxygen atoms, e.g., ZSM-34, in combination with magnesium oxide, manganese oxide or magnesium oxide/platinum oxide catalyst modifier, and are especially useful for converting methanol and/or dimethyl ether into an olefin-containing hydrocarbon product enriched in ethylene and propylene with an enhanced catalyst lifetime. |