Method of removing dimethyl ether from an olefin stream
AssigneeExxonMobil Chemical Patents Inc.
InventorsMinquan Cheng, Jeffrey J. Phillips, Michael Peter Nicoletti, David Ritchie Lumgair, Jr., John Richard Shutt, Jeffrey Alan Kabin
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Abstract
This invention is directed to a method of removing dimethyl ether from an olefin stream. The method includes distilling the olefin stream so that the dimethyl ether is separated out of the olefin stream with propane. The olefin stream can then be further distilled to provide a polymer grade ethylene stream and a polymer grade propylene stream, with each stream containing not greater than about 10 wppm dimethyl ether.
Claims28
A method of separating dimethyl ether from an olefin stream made from an oxygenate to olefin reaction process, comprising:
- contacting oxygenate with a molecular sieve catalyst to form the olefin stream, wherein the olefin stream comprises water, propylene, propane, and dimethyl ether;
- cooling the olefin stream to a temperature below the condensation temperature of the oxygenate;
- separating the cooled olefin stream into a condensed, water containing stream and an olefin vapor stream;
- drying the olefin vapor stream to form a dried olefin stream;
- and
- distilling the dried olefin stream to separate a dimethyl ether and propane containing stream from the propylene.
A method of removing dimethyl ether from an olefin stream, comprising:
- providing an olefin stream which comprises water, propylene, propane and dimethyl ether;
- drying the olefin stream to form a dried olefin stream containing not greater than 1,000 wppm water;
- and
- distilling the dried olefin stream so as to separate out a propane and dimethyl ether stream from the propylene, wherein the propane and dimethyl ether stream comprises from 60 to 99.5 wt % propane and from 0.05 to 40 wt % dimethyl ether.
Dependencies are inferred from the claim text.