Process for converting oxygenates to olefins using molecular sieve catalysts comprising desirable carbonaceous deposits
AssigneeExxon Chemicals Patents Inc.
InventorsJames Richardson Lattner, Hsiang-ning Sun, Stephen Neil Vaughn, Keith H. Kuechler, David C. Skouby
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Abstract
The present invention relates to methods for selectively converting oxygenates to light olefins, preferably ethylene and propylene, in which desirable carbonaceous deposits are maintained on a total reaction volume of catalyst by totally regenerating only a portion of the total reaction volume of catalyst and mixing the regenerated portion with the unregenerated total reaction volume of catalyst.
Claims42
A process for converting an oxygenate feedstock into an olefin product stream comprising:
- (a) contacting the oxygenate feedstock with a molecular sieve catalyst under conditions effective to convert the feedstock into an olefin product stream comprising C.sub.2 -C.sub.3 olefins and to form carbonaceous deposits on the catalyst;
- (b) separating the catalyst having the carbonaceous deposits into a portion and a remainder;
- (c) contacting the portion with a regeneration medium under conditions effective to obtain a regenerated catalyst portion having less than 1.0 wt % carbonaceous deposits;
- (d) mixing the regenerated catalyst portion with the remainder wherein the mix of the regenerated catalyst portion and the remainder comprises 2-30 wt % carbonaceous deposits;
- and
- (e) repeating steps (a)-(d).
A process for converting an oxygenate feedstock into an olefin product stream comprising:
- mixing together a regenerated molecular sieve catalyst and a molecular sieve catalyst having less than 1.0 wt % carbonaceous deposits comprising carbonaceous deposits thereon, wherein the mix comprises 2-30 2 wt % carbonaceous deposits based on the total weight of the mix;
- and
- contacting the catalyst mix with oxygenate feedstock under conditions effective to convert the feedstock into an olefin product stream comprising C.sub.2 -C.sub.3 olefins.
Dependencies are inferred from the claim text.