This invention is directed to a process for converting oxygenate to olefin
product at an increased prime olefin selectivity (i.e., increased
ethylene and/or propylene content) compared to conventional systems. The
increase in ethylene and/or propylene content of the produced olefin
product is accomplished using a reaction system that has at least two
stages. Any number of stages can used in the entire process, as long as
there are at least two stages in series and the temperature of any
subsequent stage in series is lower than that of the preceding stage.