abstract |
A process for production of alkyl tertiary alkyl ethers in C4+ hydrocarbon streams rich in isoolefins, typically containing catalyst deactivating amounts of dienes and/or compounds containing heteroatoms. The process is especially advantageous in extending the cycle length for the zeolite catalyzed etherification of isoolefins in C4+ FCC gasoline by reducing catalyst aging. It has been discovered that if hydrogen is cofed with the alkanol and C4+ isoolefin rich feedstreams to an etherification reaction catalyzed by acidic zeolite wherein the zeolite has been impregnated with a noble metal the rate of catalyst aging or deactivation is substantially lowered. The process is especially effective, i.e., catalyst aging is particularly reduced, when hydrogen is cofed to an etherification reaction using acidic zeolite Beta catalyst containing palladium. |