Abstract: Process for the preparation of an olefin comprising contacting a diluted olefinic hydrocarbon feed, containing an oxygenate feed, an olefinic co-feed and one or more diluents, with a solid zeolite catalyst to obtain a reaction product containing one or more olefins, and wherein the diluted feed is contacted with the solid zeolite catalyst at a Gas Hourly Space Velocity, as measured at standard temperature and pressure, of at least 10,000 ml diluted olefinic hydrocarbon feed/gram zeolite catalyst/hour.

Abstract: Process for the preparation of an olefin comprising a) reacting a combination of an oxygenate feed selected from the group consisting of alcohols and ethers, and an olefinic co-feed in a reactor in the presence of a one-dimensional zeolite having 10-membered ring channels to prepare an olefinic reaction mixture; b) separating the olefinic reaction mixture into at least a first olefinic product fraction and a second olefinic fraction containing olefins with 4 or more carbon atoms; and c) recycling at least part of the second olefinic fraction obtained in step b) to step a) as olefinic co-feed.

Abstract: Process for the preparation of propylene, wherein a diluted olefinic hydrocarbon feed, comprising in the range of 1 to 99 vol % of olefinic hydrocarbon feed and 1-99 vol % of one or more diluents, is contacted with a solid zeolite catalyst at a Gas Hourly Space Velocity, as measured at standard temperature and pressure of 23° C. and 1 bar, of at least 15,000 ml diluted olefinic hydrocarbon feed/gram zeolite catalyst/hour.

Abstract: Process for the preparation of an olefin comprising reacting an oxygenate feed and an olefinic co-feed in a reactor in the presence of a zeolite to obtain a reaction product containing one or more olefins; wherein the olefinic co-feed is at least partially obtained ex-situ during a first phase and at least partially obtained in-situ during a subsequent second phase.