A process and apparatus are provided for converting oxygenate to olefins
which comprises: contacting a feedstock comprising oxygenate with a
catalyst comprising a molecular sieve under conditions effective to
produce a vaporous product comprising the olefins, water and unreacted
oxygenate; condensing the vaporous product to provide a liquid stream
rich in the water and unreacted oxygenate, and an olefins-rich vapor
stream; introducing at least part of the liquid stream to a feed tray in
a fractionation tower which provides an oxygenate-rich overhead product
and a water-rich liquid bottoms product; providing a liquid,
oxygenate-rich stream comprising at least about 20 wt % oxygenate above
the feed tray; and passing the olefins-rich vapor stream through a
recovery train to recover at least some of the olefins.