Method for stabilizing a cation exchange resin prior to use as an acid catalyst and use of said stabilized cation exchange resin in a chemical process
View Patent ↗A method for preventing the degradation of a catalyst during storage of the catalyst and prior to using the catalyst in a chemical process comprising treating the catalyst with an antioxidant and storing the treated catalyst until further use. The stabilized treated catalyst may be used in a process for producing organic chemicals such as in a process for producing bisphenol A.
1. A process for producing bisphenol A using a cation-exchange resin catalyst comprising:
(a) providing a cation-exchange resin catalyst for catalyzing the condensation of phenol with acetone;
(b) treating the cation-exchange resin catalyst with an antioxidant for preventing the degradation of the treated cation-exchange resin catalyst during storage, handling, processing and/or drying of the treated cation-exchange resin catalyst prior to using the treated cation-exchange resin catalyst in the process; and
(c) condensing phenol and acetone in a reaction zone at a temperature range of from 20° C. to 200° C., in the presence of the treated cation-exchange resin catalyst.
2. The process of claim 1 including washing the treated cation-exchange resin catalyst with deionized water after the treatment step (b).
3. The process of claim 1 wherein the cation-exchange resin catalyst is a sulfonic acid-type cation-exchange resin catalyst.
4. The process of claim 3 wherein the cation-exchange resin catalyst is a sulfonated styrene-divinyl benzene copolymer.
5. The process of claim 1 wherein the antioxidant is a monocyclic or polycyclic phenol, an amine, a diamine, a thioester, a phosphate, a quinoline, or a mixture thereof.
6. The process of claim 1 wherein the antioxidant is 2,6-di-t-butyl-α-dimethylamino-p-cresol.
7. The process of claim 1 wherein the amount of antioxidant incorporated into the cation-exchange resin catalyst is from 0.001 to 10 percent by weight.
8. The process of claim 1 wherein the cation-exchange resin catalyst is stable when stored for three months or more.
9. The process of claim 1 wherein the color increase of water when contacted with the treated cation-exchange resin catalyst is less than 500 APHA during a seven day accelerated aging test.
10. The process of claim 1 wherein the increase in the TOC levels of water when contacted with the treated cation-exchange resin catalyst is less than 500 ppm during a seven day accelerated aging test.
11. The process of claim 1 further comprising preventing oxygen from contacting the catalyst so as to prevent the degradation of an ion-exchange resin catalyst during storage prior to using the treated catalyst in the process.
12. The process of claim 11 wherein oxygen is prevented from contacting the treated cation-exchange resin catalyst by storing the treated cation-exchange resin catalyst in the absence of oxygen by using oxygen barrier packaging, inert gas blanketing or vacuum packaging.
13. The process of claim 1 wherein the antioxidant treatment step (b) comprises dissolving the antioxidant in the water retained in the cation-exchange resin catalyst prior to use.
14. The process of claim 1 wherein the antioxidant treatment step (b) comprises partially neutralizing the acid functionality of the cation-exchange resin catalyst with the antioxidant.
15. The process of claim 1 wherein the antioxidant treatment step (b) of the cation-exchange resin catalyst comprises copolymerizing a monomer with antioxidant properties with other monomers to form the cation-exchange resin copolymer.
16. The process of claim 1 wherein the catalyst is treated with an antioxidant by polymerizing the antioxidant into a polymer resin.