Process for producing phenol

• US 8,487,140 B2
• Filed: 07/14/2009
• Issued: 07/16/2013
• Est. Priority Date: 08/29/2008
• Status: Expired due to Fees

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Inventors: Buchanan, John S., Stanat, Jon E., Chen, Tan-Jen, Dakka, Jihad M., Lattner, James R.
• Primary Examiner(s): Davis, Brian J
• Application Number:
  US12/996,219
• Publication Number:
  US 20110105805A1
• Time in Patent Office: 1,463 Days
• Field of Search: None
• US Class Current: 568/799
• CPC Class Codes: C07C 13/28 Polycyclic hydrocarbons or acyclic hydrocarbon derivatives thereof
• CPC Class Codes: C07C 2/74 by addition with simultaneous hydrogenation
• CPC Class Codes: C07C 2601/14 The ring being saturated
• CPC Class Codes: C07C 37/06 by conversion of non-aromatic six-membered rings or of such rings formed in situ into aromatic six-membered rings, e.g. by dehydrogenation
• CPC Class Codes: C07C 37/08 by decomposition of hydroperoxides, e.g. cumene hydroperoxide
• CPC Class Codes: C07C 39/04 Phenol
• CPC Class Codes: C07C 407/00 Preparation of peroxy compounds
• CPC Class Codes: C07C 409/14 the carbon atom belonging to a ring other than a six-membered aromatic ring
• CPC Class Codes: C07C 45/53 of hydroperoxides
• CPC Class Codes: C07C 49/403 of a six-membered ring

Abstract

In a process for producing phenol, cyclohexylbenzene is oxidized to produce cyclohexylbenzene hydroperoxide and then the resultant cyclohexylbenzene hydroperoxide is cleaved to produce an effluent stream comprising phenol and cyclohexanone. At least a portion of the effluent stream is then fed to at least one dehydrogenation reaction zone, where the effluent stream portion is contacted with a dehydrogenation catalyst under conditions effective to convert at least part of the cyclohexanone in the effluent portion into phenol and hydrogen.

Claims

1. A process for producing phenol, the process comprising:

(a) oxidizing cyclohexylbenzene to produce cyclohexylbenzene hydroperoxide;

(b) converting cyclohexylbenzene hydroperoxide from (a) to produce an effluent stream comprising phenol and cyclohexanone;

(c) feeding at least a portion of said effluent stream to at least one dehydrogenation reaction zone; and

(d) contacting said at least a portion of said effluent stream with a dehydrogenation catalyst in said dehydrogenation reaction zone under dehydrogenation conditions including a temperature of 250°

C. to 500°

C. effective to convert at least part of the cyclohexanone in said at least a portion of said effluent stream into phenol and hydrogen.

4. The process of claim 1, wherein said at least a portion of said effluent stream fed to said dehydrogenation reaction zone has the same composition as the effluent stream produced by said converting (b).

5. The process of claim 1, and further including subjecting the effluent stream produced by said converting (b) to at least one separation step such that said at least a portion of said effluent stream fed to said dehydrogenation reaction zone contains less phenol than the effluent stream produced by said converting (b).

6. The process of claim 5, and further including subjecting the effluent stream produced by said converting (b) to at least one separation step such that said at least a portion of said effluent stream fed to said dehydrogenation reaction zone contains less than 50 wt % phenol.

7. The process of claim 1, and further including subjecting the effluent stream produced by said converting (b) to at least one separation step to remove components boiling below 155°

C. (as measured at 101 kPa) prior to feeding said at least a portion of said effluent stream to said dehydrogenation reaction zone.

8. The process of claim 1, and further including subjecting the effluent stream produced by said converting (b) to at least one separation step to remove components boiling above 182°

C. (as measured at 101 kPa) prior to feeding said at least a portion of said effluent stream to said dehydrogenation reaction zone.

9. The process of claim 1, wherein said dehydrogenation conditions comprise a temperature of 300°

C. to 450°

C.

10. The process of claim 1, wherein said dehydrogenation conditions comprise a pressure of 1 kPa to 2000 kPa (0.01 atm to 20 atm).

11. The process of claim 10, wherein the pressure is from 100 kPa to 300 kPa (1 atm to 3 atm).

12. The process of claim 1, wherein in said feeding (c), hydrogen is fed to said dehydrogenation reaction zone together with said at least a portion of said effluent stream.

13. The process of claim 12, wherein at least part of the hydrogen fed to said dehydrogenation reaction zone in said feeding (c) is hydrogen produced in said contacting (d).

14. The process of claim 12, wherein the molar ratio of hydrogen to cyclohexanone in the feed to the dehydrogenation reaction zone is 0:

1 to 4;

1.

15. The process of claim 1, wherein said at least a portion of said effluent stream is fed to a plurality of dehydrogenation reaction zones connected in series.

16. The process of claim 5, further including subjecting the effluent stream produced by said converting (b) to at least one separation step such that said at least a portion of said effluent stream fed to said dehydrogenation reaction zone contains less than 1 wt % phenol.

2. A process for producing phenol from benzene, the process comprising:

(a1) contacting benzene and hydrogen with a catalyst under hydroalkylation conditions to produce cyclohexylbenzene;

(a) oxidizing cyclohexylbenzene from said contacting (a1) to produce cyclohexylbenzene hydroperoxide;

(b) converting cyclohexylbenzene hydroperoxide from said oxidizing (a) to produce an effluent stream comprising phenol and cyclohexanone;

(c) feeding at least a portion of said effluent stream to at least one dehydrogenation reaction zone;

(d) contacting said at least a portion of said effluent stream with a dehydrogenation catalyst in said dehydrogenation reaction zone under dehydrogenation conditions effective to convert at least part of the cyclohexanone in said at least a portion of said effluent into phenol and hydrogen; and

(e) recycling at least part of the hydrogen produced in (d) to said contacting (a1).

3. The process of claim 2, wherein said dehydrogenation conditions include a temperature of 250°

C. to 500°

C.