Catalyst recycle methods
The present invention provides novel solutions to the problem of recycling carbonylation catalysts in epoxide carbonylation processes. The inventive methods are characterized in that the catalyst is recovered in a form other than as active catalyst. In some embodiments, catalyst components are removed selectively from the carbonylation product stream in two or more processing steps. One or more of these separated catalyst components are then utilized to regenerate active catalyst which is utilized during another time interval to feed a continuous carbonylation reactor.
1. A method for the continuous reaction of an epoxide and carbon monoxide comprising:
a) feeding a continuous carbonylation reactor during a first interval of time with a catalyst feed stream comprising a carbonylation catalyst, where within the reactor, the epoxide and the carbon monoxide react in the presence of the carbonylation catalyst to provide a reaction product stream comprising an epoxide carbonylation product and carbonylation catalyst
b) treating the reaction product stream;
c) separating at least a portion of the carbonylation catalyst from the reaction product stream, wherein the carbonylation catalyst comprises:
a cationic Lewis acid and
an anionic metal carbonyl;
(d) accumulating the cationic Lewis acid separated in step (c) throughout the first interval of time to obtain a cationic Lewis acid batch, and
(e) feeding a continuous carbonylation reactor during a second interval of time with a catalyst feed stream wherein at least a portion of the catalyst in the catalyst feed stream is derived from the cationic Lewis acid batch accumulated in step (d).
2. The method of claim 1 , wherein the epoxide is ethylene oxide.
3. The method of claim 2 , wherein the epoxide carbonylation product is selected from the group consisting of: beta propiolactone, succinic anhydride, polypropiolactone, 3-hydroxypropionic acid, and a 3-hydroxypropionate ester.
4. The method of claim 2 , wherein the epoxide carbonylation product comprises beta propiolactone.
5. The method of claim 1 , wherein step (c) comprises removing the anionic metal carbonyl from the reaction product stream.
6. The method of claim 1 , wherein the carbonylation catalyst comprises a metal carbonyl compound in combination with one or more other catalyst components.
7. The method of claim 6 , wherein step (c) comprises selectively removing the anionic metal carbonyl to the at least partial exclusion of other catalyst components.
8. The method of claim 1 , wherein step (c) comprises selectively removing at least a portion of the anionic metal carbonyl compound from the reaction product stream using an anion exchanging material.
9. The method of claim 1 , wherein step (c) comprises selectively removing at least a portion of the cationic Lewis acid from the reaction product stream using a cation exchanging material.
10. The method of claim 1 , wherein step (c) comprises treating the reaction product stream using an anion exchanging material to remove the anionic metal carbonyl and separately treating the reaction product stream using a cation exchanging material to remove the cationic Lewis acid; and
wherein the anionic metal carbonyl removed by the anionic exchanging material is accumulated in step (d).
11. The method of claim 1 , comprising a step of regenerating the accumulated carbonylation catalyst from step (d) before feeding the cationic Lewis acid in step (e).
12. The method of claim 11 , wherein the step of regenerating activates the carbonylation catalyst.
13. The method of claim 11 , comprising applying pressure and carbon monoxide to the carbonylation catalyst to regenerate the carbonylation catalyst.
14. The method of claim 11 , wherein the anionic metal carbonyl is regenerated by combining the metal carbonyl with an additional Lewis acid.
15. The method of claim 1 , wherein the epoxide is chosen from a group consisting of ethylene oxide, propylene oxide, 1,2-butylen oxide, 2,3-butylene oxide, epichlorohydrin, cyclohexene oxide, cyclopentene oxide, 3,3,3-Trifluoro-1,2-epoxypropane, styrene oxide, a glycidyl ether, and a glycidyl ester.
16. The method of claim 1 , wherein the anionic metal carbonyl is tetraphenylporphyrinato aluminum carbonyl cobaltate.
17. The method of claim 5 , wherein the anionic metal carbonyl is a cobalt carbonyl compound.
18. The method of claim 1 , wherein the anionic metal carbonyl is carbonyl cobaltate.
19. The method of claim 1 , further comprising:
treating the cationic Lewis acid accumulated in step (d) by swapping a non metal carbonyl anion with the anionic metal carbonyl.
20. The method of claim 10 , further comprising:
treating the cationic Lewis acid accumulated in step (d) by swapping a non metal carbonyl anion with the anionic metal carbonyl.