Process for producing phenol and cyclohexanone

Patent metadata

Field	Value
Publication number	US-9181165-B2
Application number	US-201314394455-A
Country	US
Kind code	B2
Filing date	Apr 9, 2013
Priority date	May 2, 2012
Publication date	Nov 10, 2015
Grant date	Nov 10, 2015

Abstract

In a process for separating a mixture comprising cyclohexanone and phenol, at least a portion of the mixture is distilled in the presence of a solvent including at least two alcoholic hydroxyl groups attached to non-adjacent saturated carbon atoms, water, and in the presence or absence of a hemiketal defined by the formula (I) or the formula (II):

wherein R 1 , the same or different at each occurrence, is independently an alkylene group having from 2 to 10 carbon atoms, R 2 is an alkylene group having from 4 to 10 carbon atoms and/or R 3 is hydrogen or the following group:

and in the presence or absence of an enol-ether derived from the hemiketal defined by the formula (I) or the formula (II), wherein the total concentration of the hemiketal and enol-ether, expressed in term of weight percentage of the total weight of the feed to the distilling step, is at most 0.01%.

First claim

The invention claimed is:

1. A process for separating a mixture comprising cyclohexanone and phenol, the process comprising:
(a) continuously distilling at least a portion of the mixture in the presence of water and a solvent including at least two alcoholic hydroxyl groups attached to non-adjacent saturated carbon atoms, and in the presence or absence of a hemiketal defined by the formula (I) or the formula (II):

wherein R 1 , the same or different at each occurrence, is independently an alkylene group having from 2 to 10 carbon atoms, R 2 is an alkylene group having from 4 to 10 carbon atoms and R 3 is hydrogen or the following group:

and in the presence or absence of an enol-ether derived from the hemiketal defined by the formula (I) or the formula (II), wherein the total concentration of the hemiketal and the enol-ether, expressed in terms of weight percentage of the total weight of the feed to the distilling step (a), is at most 0.01%;
wherein the distilling (a) includes at least one vapor and at least one liquid phase, and further includes a feed point, such that at least a portion of the amount of water is in the at least one liquid phase at or below the feed point.

2. The process of claim 1 , wherein the total concentration of the hemiketal and the enol-ether is at most 0.005%.

3. The process of claim 1 , wherein water is present in an amount of in the range from at least 0.1 wt % to no greater than 20 wt %, based on the total weight of feed to the distilling step (a).

4. The process of claim 3 , wherein water is present in an amount in the range from at least 1.0 wt % and no greater than 8.0 wt %.

5. The process of claim 1 , wherein said solvent is diethylene glycol and R 1 is an ethylene group.

6. The process of claim 5 , wherein said hemiketal is defined by the formula:

and said enol-ether thereof is defined by the formula:

7. The process of claim 5 , wherein said hemiketal is defined by the formula:

and said enol-ether thereof is defined by the formula:

or by the formula:

8. The process of claim 1 , wherein said solvent is 1,4-butanediol and R 2 is an alkylene group having 4 carbon atoms.

9. The process of claim 8 , wherein said hemiketal is defined by the formula:

and said enol-ether thereof is defined by the formula:

10. The process of claim 9 , wherein said hemiketal is defined by the formula

and said enol-ether thereof is defined by the formula:

or by the formula:

11. The process of claim 1 , wherein at least a portion of the water is included into the mixture of phenol and cyclohexanone before the distilling step (a) starts.

12. The process of claim 1 , wherein the weight ratio of phenol to cyclohexanone in the mixture to be separated is at least 2.57.

13. A process for making cyclohexanone and phenol, the process comprising:
(A) contacting benzene and hydrogen with a catalyst under hydroalkylation conditions to produce a first effluent comprising cyclohexylbenzene;
(B) oxidizing at least part of the cyclohexylbenzene in the first effluent to produce a second effluent comprising cyclohexylbenzene peroxide;
(C) cleaving at least part of the cyclohexylbenzene peroxide in the second effluent stream to obtain a product mixture comprising phenol and cyclohexanone;
(D) separating the product mixture by (a) continuously distilling at least a portion of the product mixture in the presence of a solvent including at least two alcoholic hydroxyl groups attached to non-adjacent saturated carbon atoms and water, and in the presence or absence of a hemiketal defined by the formula (I) or the formula (II):

wherein R 1 , the same or different at each occurrence, is independently an alkylene group having from 2 to 10 carbon atoms, R 2 is an alkylene group having from 4 to 10 carbon atoms and R 3 is hydrogen or the following group:

and in the presence or absence of an enol-ether derived from the hemiketal defined by the formula (I) or the formula (II), wherein the total concentration of the hemiketal and enol-ether, expressed in terms of weight percentage based on the total weight of the feed to the distilling step (a), is at most 0.01%;
wherein the distilling (a) in step (D) includes at least one vapor and at least one liquid phase, and further includes a feed point, such that at least a portion of the amount of water is in the at least one liquid phase at or below the feed point.

14. The process of claim 13 , wherein the total concentration of the hemiketal and enol-ether is at most 0.005% in the distilling step (a) of the separating step (D).

15. The process of claim 13 , wherein water is present in an amount in the range of at least 0.1 wt % to no greater than 20 wt %, based on the total weight of the feed to the distilling step (a).

16. The process of claim 15 , wherein the water is present in an amount in the range from at least 1.0 wt % to no greater than 8.0 wt %.

17. The process of claim 13 , wherein at least a portion of said water is introduced below a lowest feed point at a location from 1 to 10 trays above a reboiler.

18. The process of claim 13 , wherein R 1 is an ethylene group or a 1,4-butylene group.

19. The process of claim 13 , wherein at least a portion of said water is included into the product mixture to be separated before the distilling step (a) in (D).

20. The process any claim 13 , wherein the weight ratio of phenol to cyclohexanone in the product mixture to be separated is at least 2.57.

Assignees

• Exxonmobil Chem Patents Inc

Inventors

• Kuechler Keith H
• Benitez Francisco M
• Emanuele Krystle J
• Becker Christopher L
• Heidman Jr John L

Classifications

• B01D3/40

  Extractive distillation · CPC title

• C07C2101/14

  Chemistry & Metallurgy · mapped topic

• C07C37/80 Primary

  by extractive distillation · CPC title

• C07C49/403 Primary

  of a six-membered ring · CPC title

• C07C39/04

  Phenol · CPC title