Phenol resin treatment improvement

1. A method for purifying phenol, comprising:

contacting a feed comprising phenol and an aldehyde containing compound with a first ion exchange material to produce a first treated product, wherein the first treated product has a pH that is less than a pH of the feed, and wherein the first treated product contains less of the aldehyde containing compound than the feed; and

contacting the first treated product with a second ion exchange material to produce a second treated product, wherein the second treated product has a pH that is greater than the pH of the first treated product, and wherein each of the first ion exchange material and the second ion exchange material is a solid, a semi-solid, or a combination thereof.

2. The method of claim 1 , further comprising separating acetophenone, cumylphenol, dimethylbenzyl alcohol, alpha methylstyrene dimer, dicumylphenol, or any combination thereof from a crude phenol to produce the feed.

3. The method of claim 1 , further comprising distilling the second treated product to produce a purified phenol product that contains less than 40 ppm of impurities on a dry basis.

4. The method of claim 1 , wherein the first ion exchange material comprises a cation exchange resin and the second ion exchange material comprises an anion exchange resin.

5. The method of claim 4 , wherein the cation exchange resin comprises sulfuric acid and HSO 4 − functional groups.

6. The method of claim 4 , wherein the cation exchange resin comprises a polymer based on a cross-linked styrene divinylbenzene copolymer containing sulfuric acid and HSO 4 − functional groups.

7. The method of claim 4 , wherein the anion exchange resin comprises one or more functional groups selected from the group consisting of: primary amine groups, secondary amine groups, and tertiary amine groups, wherein the resin is in a free base, OH − , form.

8. The method of claim 4 , wherein the anion exchange resin comprises a polymer based on a cross-linked styrene divinylbenzene copolymer containing quaternary ammonium groups.

9. The method of claim 1 , wherein the first treated product has a pH of about 2 to about 5, and wherein the second treated product has a pH of about 4 to about 8.

10. The method of claim 1 , wherein the first treated product comprises about 2 ppm to about 50 ppm sulfonic acid, and wherein the second treated product comprises less than 5 ppm sulfonic acid.

11. The method of claim 1 , wherein the second ion exchange material has an average pore diameter of about 200 Å to about 500 Å, a pore volume of about 0.1 mL/g to about 0.4 mL/g, and a surface area of about 10 m 2 /g to about 50 m 2 /g.

12. The method of claim 1 , wherein the first treated product is contacted with the second ion exchange material at a rate of about 0.5 m 3 reaction product per 1 m 3 ion exchange material per hour to about 5 m 3 reaction product per 1 m 3 ion exchange material per hour.

13. A method for producing phenol, comprising:

reacting cumene with an oxidant to produce a reaction product comprising cumene hydroperoxide, dimethylbenzyl alcohol, acetophenone, and dicumyl peroxide;

separating at least a portion of the dimethylbenzyl alcohol, the acetophenone, the dicumyl peroxide, or any combination thereof from the reaction product to produce a concentrated cumene hydroperoxide product;

cleaving the concentrated cumene hydroperoxide product to produce a cleaved product comprising phenol, acetone, alpha methylstyrene, and an aldehyde containing compound;

separating at least a portion of the acetone from the cleaved product to produce a first crude phenol product comprising a mixture of phenol, a compound having a boiling point greater than phenol, and aldehyde containing compound;

distilling the crude phenol product to produce a first heavy byproduct comprising the compound having a boiling point greater than phenol and a second crude phenol product comprising the phenol and the aldehyde containing compound;

contacting the second crude phenol product with a cation exchange material at a temperature of about 45° C. to about 125° C. to produce a first treated product, wherein the first treated product has a pH that is less than a pH of the second crude phenol product, and wherein the first treated product contains less of the aldehyde containing compound than the second crude phenol product;

contacting the first treated product with an anion exchange material at a temperature of about 45° C. to about 80° C. to produce a second treated product, wherein the second treated product has a pH that is greater than the pH of the first treated product, and wherein each of the cation exchange material and the anion exchange material is a solid, a semi-solid, or a combination thereof; and

distilling the second treated product to produce a purified phenol product and a second heavy byproduct.

14. The method of claim 13 , wherein the cation exchange material is a resin comprising sulfuric acid and HSO 4 − functional groups.

15. The method of claim 13 , wherein the anion exchange material is a resin comprising one or more functional groups selected from the group consisting of: primary amine groups, secondary amine groups, and tertiary amine groups, and wherein the resin is in a free base, OH − , form.

16. The method of claim 13 , wherein the first treated product has a pH of about 2 to about 5 and the second treated product has a pH of about 4 to about 8.

17. The method of claim 13 , wherein the first treated product comprises about 2 ppm to about 50 ppm sulfonic acid, and wherein the second treated product comprises less than 5 ppm sulfonic acid.