A feed vaporization process and apparatus for oxygenate to olefin conversion is provided which uses a vapor-liquid disengaging drum to separate non-volatiles and/or partial non-volatiles from volatiles in the oxygenate feed and produce a vaporized effluent that is reduced in non-volatiles and/or partial non-volatiles while at the same time maintaining the effluent at optimal temperature and pressure as a feed for oxygenate to olefin conversion.