Process for removal of alkynes and/or dienes from an olefin stream
AssigneeExxon Mobil Chemical Patents Inc.
InventorsKeith Holroyd Kuechler, David R. Lumgair, Jr.
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Abstract
The present invention is a process for removing alkynes and/or dienes from an olefin product stream withdrawn from an oxygenate-to-olefins reactor. The process comprises hydrogenating a first olefin stream that has alkynes and/or dienes in the presence of excess hydrogen and a first hydrogenation catalyst. The hydrogenation of the first olefin stream produces a second olefin stream that has unreacted hydrogen. The second olefin stream is contacted with a second hydrogenation catalyst producing a third olefin stream. The third olefin stream has low levels of hydrogen and alkynes and/or dienes.
Claims34
A process for hydrogenating byproducts selected from the group consisting of alkynes, dienes and mixtures thereof in an olefin product stream from an oxygenate-to-olefins reactor, the process comprising the steps of:
- (a) contacting an oxygenate with a molecular sieve catalyst in the oxygenate-to-olefins reactor to provide the olefin product stream;
- (b) isolating from the olefin product stream a first olefin stream containing 25 mol. % or more ethylene or 25 mol. % or more propylene, based upon the composition of the first olefin stream, and 500 mppm or less of the alkyne or diene byproduct;
- (c) hydrogenating the first olefin stream to produce a second olefin stream;
- and
- (d) hydrogenating the second olefin stream in the presence of from 100 mppm to 1000 mppm hydrogen, based upon the weight of the second olefin stream, to produce a third olefin stream containing 20 mppm or less hydrogen, based upon the composition of the third olefin stream.
Dependencies are inferred from the claim text.