Process for removal of alkynes and/or dienes from an olefin stream
First Claim
1. 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.
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Accused Products
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The present invention is a process for removing alkynes and/or dienes from an olefin product stream withdrawn from an oxygenate-to-olefins reactor.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.
32 Citations
34 Claims
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1. 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:
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(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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification