A process for producing olefins comprises providing a vapor product stream from an oxygenate to olefin reaction, the vapor product stream comprising C.sub.2 to C.sub.4 olefins, C.sub.2 to C.sub.6 carbonyl compounds and water. The vapor product stream is cooled to provide a first vapor effluent stream comprising no more than 10 wt. % water, and a liquid water-rich stream. The first vapor effluent stream, and a first wash flash vapor stream, are compressed from a first pressure to a second pressure greater than said first pressure to form a second vapor effluent stream, which is then cooled to form a cooled second effluent stream that is at least partially in the vapor state. At least part of the cooled second effluent stream is washed with a liquid alcohol-containing stream, at a third pressure greater than the first pressure but not greater than the second pressure, to produce a wash liquid stream, which comprises C.sub.3 and C.sub.4 olefins, and a wash vapor stream, which contains less C.sub.2 to C.sub.6 carbonyl compounds than the first vapor effluent stream. The wash liquid stream is exposed to a pressure of at least the first pressure but less than the third pressure to form a first wash flash liquid stream and the first wash flash vapor stream, the first wash flash vapor stream being provided for compression with the first vapor effluent stream.