Method for gasoline yield enhancement in the fixed bed methanol-to-gasoline process

Claim 1

In a process for the conversion of methanol to gasoline boiling range components which comprises passing a methanol feed through a heat exchanger means and a dehydration reactor means for conversion of said methanol feed to a dehydration product comprising methanol, dimethyl ether and water, and passing said dehydration product through a single fixed catalyst bed so as to completely convert said dehydration product to a product rich in gasoline boiling components, the improvement which comprises; dividing said fixed catalyst bed into a plurality of separate fixed catalyst beds comprising a first reactor bed and at least one downstream reactor bed, passing said dehydration product through said first reactor bed to complete conversion of said dehydration product therein and produce an effluent comprising said gasoline-rich product, continuing to complete conversion of dehydration product passing through said first reactor bed and bypassing said downstream reactor beds until such time as there is a predetermined decline of said complete conversion of said dehydration product whereupon said dehydration product is passed through said first reactor bed and said effluent comprising partially converted dehydration product passes from said first reactor bed to said downstream reactor bed to yield said complete conversion, continuing complete conversion and placing subsequent downstream reactor beds in service only upon such time as said predetermined decline of complete conversion in an immediately preceeding downstream reactor bed is detected until the final reactor bed of said plurality of separate catalyst beds is placed in service, whereby gasoline yields and cycle lengths from conversion in said divided fixed catalyst bed is improved over said single fixed catalyst bed at equivalent conversion conditions.