Exxonmobil Chemical Patents Inc.

Roland Walzl

Helmut Fritz

David R Lumgair, Jr

Minquan Cheng

Josef Kunkel

Wilfried Borgmann

Gerhard Lauermann

Klaus Muller

Jeffrey J Phillips

Wilried Borgmann

Joseph Kunkel

Klaus MÜLLER

A method is described for processing an olefin-containing product stream () that contains, besides ethylene and propylene, longer-chain olefins and compounds of hydrocarbons with oxygen (oxygenates). Such a product stream (I) can occur in particular in olefin synthesis from methanol. The product stream is dewatered in successive process steps, optionally compressed in several steps and dried. Then it is subjected to fractionation. For removal of the undesired oxygenates it is proposed that the oxygenates be washed out of the gaseous product stream after the compression steps and before the drying step in a column () with methanol.

Method for processing an olefin-containing product stream

A method for processing an olefin-containing product stream that contains dimethyl ether as a by-product is described. Such a product stream arises, for example, in the synthesis of olefin from methanol. For separation of the dimethyl ether from the product stream, it is proposed that at least a partial stream chiefly containing Chydrocarbons is separated from the product stream by fractionation, and is sent to a rectification column (Csplitter) () for separation of propylene and propane. The dimethyl ether goes together with the propane into the bottom of the rectification column in the rectification process and can be withdrawn (). A substantially pure propylene product (), which contains at most only traces of dimethyl ether, can be removed from the top of the rectification column.

Method for separating dimethyl ether from an olefin-containing product stream

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Feldafing, Germany

Roland Walzl