Dehydrogenation process

• US 9,580,368 B2
• Filed: 12/02/2011
• Issued: 02/28/2017
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Inventors: Chen, Tan-Jen, Dakka, Jihad Mohammed, Helton, Terry Eugene, Benitez, Francisco Manuel, Smith, Charles Morris, DeCaul, Lorenzo Cophard
• Primary Examiner(s): Pregler, Sharon
• Application Number:
  US14/006,338
• Publication Number:
  US 20140323782A1
• Time in Patent Office: 1,915 Days
• Field of Search: 585/320, 585/315, 585/318, 585/316, 585/314, 585/319, 585/323, 585/431
• US Class Current: 1/1
• CPC Class Codes: C07C 13/20 with a cyclohexene ring
• CPC Class Codes: C07C 2523/14 of germanium, tin or lead
• CPC Class Codes: C07C 2523/42 Platinum
• CPC Class Codes: C07C 2523/62 with gallium, indium, thallium, germanium, tin or lead
• CPC Class Codes: C07C 5/325 of the platinum group
• CPC Class Codes: C07C 5/367 Formation of an aromatic six-membered ring from an existing six-membered ring, e.g. dehydrogenation of ethylcyclohexane to ethylbenzene

Abstract

Disclosed herein is a process for dehydrogenating a saturated cyclic hydrocarbon and/or 5-membered ring compound with a dehydrogenation catalyst. The dehydrogenation catalyst comprises: (i) 0.05 wt % to 5 wt % of a metal selected from Group 14 of the Periodic Table of Elements; and (ii) 0.1 wt % to 10 wt % of a metal selected from Groups 6 to 10 of the Periodic Table of Elements. The process is conducted under dehydrogenation conditions effective to dehydrogenate at least a portion saturated cyclic hydrocarbon and/or 5-membered ring compound.

Claims

1. A dehydrogenation process comprising:

contacting a composition comprising at least 50 wt % of benzene and at least 0.1 wt % of cyclohexane, the wt % s based upon total weight of the composition, with a dehydrogenation catalyst having oxygen chemisorption value of greater than 30%, said dehydrogenation catalyst comprising;

(i) 0.05 to 0.5 wt % of tin;

(ii) 0.1 to 2 wt % of a metal selected from Groups 6 to 10 of the Periodic Table of the Elements, and (iii) a support, the wt % s based upon total weight of the dehydrogenation catalyst, wherein the dehydrogenation catalyst is prepared by sequential impregnation with the tin being applied to the support before the metal selected from Groups 6 to 10 of the Periodic Table of the Elements, and further wherein the dehydrogenation catalyst contains no cobalt.

2. The process of claim 1, wherein the composition comprises at least 1 wt % of cyclohexane, the wt % based upon total weight of the composition.

3. The process of claim 1, wherein the dehydrogenation catalyst converts at least 70% of the cyclohexane to benzene.

4. The process of claim 1, wherein the dehydrogenation catalyst comprises 0.1 to 0.5 wt % of the metal selected from Groups 6 to 10 of the Periodic Table of Elements, based upon total weight of the dehydrogenation catalyst.

5. The process of claim 1, wherein the metal selected from Groups 6 to 10 of the Periodic Table of Elements is platinum or palladium.

6. The process of claim 1, wherein the dehydrogenation process is conducted under dehydrogenation conditions comprising a temperature between 200°

C. and 550°

C. and a pressure between 100 kPa and 7,000 kPa.

7. The process of claim 1, wherein the composition further comprises at least 0.01 wt % methylcyclopentane, based upon total weight of the composition.

8. The process of claim 1, wherein the dehydrogenation catalyst comprises a support containing one or more of silica, alumina, a silicate, an aluminosilicate, zirconia or carbon.

9. The process of claim 1, wherein the dehydrogenation catalyst comprises a support containing an inorganic oxide selected from silicon dioxide, titanium dioxide and zirconium oxide.

10. A dehydrogenation process comprising:

(a) providing a composition comprising at least 0.1 wt % of cyclohexane and at least 0.05 wt % of methylcyclopentane; and

(b) producing a dehydrogenation reaction product by contacting at least a portion of the composition with a dehydrogenation catalyst under conditions effective to convert;

(i) at least a portion of the cyclohexane to benzene; and

(ii) at least a portion of the methylcyclopentane to at least one paraffin,

wherein the dehydrogenation catalyst has oxygen chemisorption value of greater than 30%, and comprises;

(i) 0.05 wt % to 0.5 wt % of tin;

(ii) 0.1 wt % to 2 wt % of a metal selected from Groups 6 to 10 of the Periodic Table of the Elements, and (iii) a support, the wt % s based upon total weight of the dehydrogenation catalyst, further wherein the dehydrogenation catalyst contains no cobalt, and further wherein the dehydrogenation catalyst is produced by a method comprising

(i) treating the support with the Group 14 metal to form a treated support;

(ii) calcining the treated support at a temperature of 100°

C. to 700°

C.;

(iii) impregnating the support with the Group 6 to 10 metal to form an impregnated support; and

(iv) calcining the impregnated support at a temperature of 100°

C. to 700°

C.,

wherein the impregnating step (iii) is effected after the treating step (i).

11. The process of claim 10, wherein the metal selected from Groups 6 to 10 of the Periodic Table of Elements is platinum or palladium.

12. The process of claim 10, wherein the impregnating step (iii) is effected after the calcining step (ii).

13. The process of claim 10, wherein the calcining step (iv) is conducted in an oxygen-containing atmosphere at a temperature of 200°

C. to 500°

C. for a time of 1 to 10 hours.

14. The process of claim 10, wherein the cyclohexane is present in an amount of at least 5 wt % , based upon total weight of the composition.

15. The process of claim 10, wherein the methylcyclopentane is present in an amount of at least 0.1 wt % , based upon total weight of the composition.

17. The process of claim 10, wherein the impregnating step (iii) is effected prior to or at the same time as the calcining step (ii).

16. A process for producing cyclohexylbenzene, the process comprising:

(a) contacting benzene and hydrogen in the presence of a hydroalkylation catalyst under hydroalkylation conditions effective to form a hydroalkylation reaction product comprising cyclohexylbenzene, cyclohexane, methylcyclopentane, and benzene;

(b) separating at least a portion of the hydroalkylation reaction product into (i) a first composition that is rich in at least one of benzene, cyclohexane, and methylcyclopentane; and

(ii) a second composition that is rich in cyclohexylbenzene;

(c) contacting at least a portion of the first composition with a dehydrogenation catalyst under conditions effective to convert at least a portion of the cyclohexane to benzene,

wherein the dehydrogenation catalyst has oxygen chemisorption value of greater than 30% , and comprises;

(i) 0.05 to 0.5 wt % of tin;

(ii) 0.1 to 2 wt % of a metal selected from Groups 6 to 10 of the Periodic Table of the Elements;

(iii) a support; and

(iv) no cobalt, the wt % s based upon total weight of the dehydrogenation catalyst, further wherein the dehydrogenation catalyst is prepared by sequential impregnation with the tin being applied to the support before the metal selected from Groups 6 to 10 of the Periodic Table of the Elements; and

(d) recycling at least a portion of the benzene formed in step (c) to the contacting step (a).