Process for making phenol and/or cyclohexanone

Patent metadata

Field	Value
Publication number	US-9546121-B2
Application number	US-201415031759-A
Country	US
Kind code	B2
Filing date	Oct 17, 2014
Priority date	Nov 22, 2013
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

A process for making phenol and/or cyclohexanone comprises: (A) oxidizing a cyclohexylbenzene feed to obtain an oxidation product comprising cyclohexylbenzene, cyclohexyl-1-phenyl-1-hydroperoxide and phenol; (B) separating at least a portion of the oxidation product to obtain a first fraction comprising cyclohexyl-1-phenyl-1-hydroperoxide and a second fraction comprising cyclohexylbenzene and phenol; (C) removing at least a portion of the phenol from at least a portion of the second fraction to obtain a third fraction; (D) recycling at least a portion of the cyclohexylbenzene in the third fraction to the oxidizing step (A); and (E) contacting at least a portion of the cyclohexyl-1-phenyl-1-hydroperoxide in the first fraction with an acid catalyst in a cleavage reactor under cleavage conditions to obtain a cleavage product comprising phenol and cyclohexanone.

First claim

The invention claimed is:

1. A process for making phenol and/or cyclohexanone, the process comprising:
(A) oxidizing a cyclohexylbenzene feed to obtain an oxidation product comprising cyclohexylbenzene, cyclohexyl-1-phenyl-1-hydroperoxide and phenol;
(B) separating at least a portion of the oxidation product to obtain a first fraction comprising cyclohexyl-1-phenyl-1-hydroperoxide and a second fraction comprising cyclohexylbenzene and phenol;
(C) removing at least a portion of the phenol from at least a portion of the second fraction to obtain a third fraction;
(D) recycling at least a portion of the cyclohexylbenzene in the third fraction to the oxidizing step (A); and
(E) contacting at least a portion of the cyclohexyl-1-phenyl-1-hydroperoxide in the first fraction with an acid catalyst in a cleavage reactor under cleavage conditions to obtain a cleavage product comprising phenol and cyclohexanone.

2. The process of claim 1 , wherein the separating step (B) comprises:
(B1) subjecting at least a portion of the oxidation product to vacuum evaporation to obtain a vapor phase; and
(B2) condensing the vapor phase to produce the second fraction.

3. The process of claim 2 , wherein the vacuum evaporation is conducted at a temperature of no greater than 130° C. and an absolute pressure in a range from 0.05 to 3 kPa.

4. The process of claim 1 , wherein the removing step (C) comprises:
(C1) contacting at least a portion of the second fraction with an aqueous composition comprising a base to produce an aqueous phase containing at least part of the phenol from the second fraction or a derivative thereof and an organic phase containing cyclohexylbenzene and having a reduced concentration of phenol as compared with the second fraction; and
(C2) recovering at least a portion of the organic phase as the third fraction.

5. The process of claim 4 , wherein the base used in step (C1) has a pK b value less than 3.

6. The process of claim 4 , wherein the pH of the aqueous composition used in step (C1) is at least 8.

7. The process of claim 4 , wherein the molar concentration of the base in the aqueous composition is greater than the molar concentration of phenol in the second fraction.

8. The process of claim 4 , wherein the base comprises a hydroxide of an alkali metal and/or a hydroxide of an alkaline earth metal.

9. The process of claim 4 , wherein the contacting step (C1) comprises contacting the second fraction with the aqueous composition in a liquid-liquid extraction device.

10. The process of claim 9 , wherein the liquid-liquid extraction device comprises at least one of a sieve tray column, a spray column, a packed column, a rotating disc contactor and a mixer-settler.

11. The process of claim 4 , wherein the removing step (C) further comprises:
(C3) washing the organic phase with water before recovering the third fraction.

12. The process of claim 11 , wherein the removing step (C) further comprises:
(C4) subjecting the third fraction to a coalescing step to assist phase separation of the third fraction.

13. The process of claim 1 , wherein:
the oxidation product comprises phenol at a concentration of CPh1 ppm by weight;
the third fraction comprises phenol at a concentration of CPh2 ppm by weight; and
CPh1/CPh2≧2.0.

14. The process of claim 13 , wherein CPh2 is less than 50.

15. The process of claim 1 , wherein the concentration of cyclohexyl-1-phenyl-1-hydroperoxide in the oxidation product is at least 20 wt %, the concentration of cyclohexyl-1-phenyl-1-hydroperoxide in the first fraction is at least 50 wt % and the concentration of cyclohexyl-1-phenyl-1-hydroperoxide in the second fraction is at most 5 wt %.

16. The process of claim 1 , wherein the concentration of cyclohexylbenzene in the oxidation product is at most 65 wt %, the concentration of cyclohexylbenzene in the first fraction is at most 50 wt %, and the concentration of cyclohexylbenzene in the second fraction is at least 95 wt %.

17. The process of claim 1 , wherein the cleavage product comprises cyclohexylbenzene, and the process further comprises:
(F) separating a fourth fraction comprising cyclohexylbenzene and at least some phenol from the cleavage product;
(G) removing at least a portion of the phenol from the fourth fraction to obtain a fifth fraction; and
(H) recycling at least a portion of the cyclohexylbenzene in the fifth fraction to the oxidation step (A).

18. The process of claim 17 , wherein the removing steps (C) and step (G) are combined into a single operation.

19. The process of claim 17 , wherein the removing step (G) comprises:
(G1) contacting at least a portion of the fourth fraction with an aqueous composition comprising a base to produce an aqueous phase containing at least part of the phenol from the fourth fraction or a derivative thereof and an organic phase containing cyclohexylbenzene and having a reduced concentration of phenol as compared with the fourth fraction; and
(G2) recovering at least a portion of the organic phase as the fifth fraction.

20. The process of claim 17 , wherein the removing step (G) comprises hydrogenation of the fourth fraction.

21. The process of claim 1 , wherein in step (A), an oxidation catalyst having a structure of formula (FC-I), (FC-II), or (FC-III) below is used:

where:
A represents an optionally substituted ring;
X represents a hydrogen, an oxygen free radical, a hydroxyl group, or a halogen;
R 1 , the same or different at each occurrence, independently represents a halogen, a N-, S-, or O-containing group, or an optionally substituted linear or branched acyclic alkyl or cyclic alkyl group having 1 to 20 carbon atoms; and
m is 0, 1 or 2.

22. The process of claim 1 , wherein in step (A), an oxidation catalyst having a structure of formula (FC-IV) is used:

where:
R 2 , the same or different at each occurrence, independently represents a halogen, a N-, S-, or O-containing group, or an optionally substituted linear or branched acyclic alkyl or cyclic alkyl group having 1 to 20 carbon atoms; and
n is 0, 1, 2, 3, or 4.

23. The process of claim 1 , wherein in step (A), N-hydroxyl phthalmic imide is used as an oxidation catalyst.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Patel Bryan A
• Dakka Jihad M

Classifications

• C07C49/403

  of a six-membered ring · CPC title

• C07C13/28

  Polycyclic hydrocarbons or acyclic hydrocarbon derivatives thereof · CPC title

• C07C39/04

  Phenol · CPC title

• C07C37/08 Primary

  by decomposition of hydroperoxides, e.g. cumene hydroperoxide · CPC title

• C07C45/53

  of hydroperoxides · CPC title