Methyl-substituted biphenyl compounds, their production and their use in the manufacture of plasticizers

Patent metadata

Field	Value
Publication number	US-9328053-B2
Application number	US-201414201226-A
Country	US
Kind code	B2
Filing date	Mar 7, 2014
Priority date	Mar 14, 2013
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

In a process for producing a methyl-substituted biphenyl compound, at least one methyl-substituted cyclohexylbenzene compound of the formula:

is contacted with a dehydrogenation catalyst under conditions effective to produce a dehydrogenation reaction product comprising at least one methyl-substituted biphenyl compound, wherein each of m and n is independently an integer from 1 to 3 and wherein the dehydrogenation catalyst comprises (i) an element or compound thereof from Group 10 of the Periodic Table of Elements and (ii) tin or a compound thereof.

First claim

The invention claimed is:

1. A process for producing a methyl-substituted biphenyl compound, the process comprising:
(a) contacting at least one methyl-substituted cyclohexylbenzene compound of the formula:

with a dehydrogenation catalyst under conditions effective to produce a dehydrogenation reaction product comprising at least one methyl-substituted biphenyl compound wherein each of m and n is independently an integer from 1 to 3 and wherein the dehydrogenation catalyst comprises (i) platinum and (ii) tin or a compound thereof wherein the hydrogenation product contains less than 10 wt % of methyl biphenyl compounds and less than 5 wt % of fluorene and methyl fluorenes combined.

2. The process of claim 1 , wherein each of m and n is 1.

3. The process of claim 2 , wherein the dehydrogenation reaction product comprises less than 10 wt % of monomethyl-substituted biphenyl compounds.

4. A process for producing methyl-substituted biphenyl compounds, the process comprising:
(a) contacting a feed comprising at least one aromatic hydrocarbon selected from the group consisting of toluene, xylene and mixtures thereof with hydrogen in the presence of a hydroalkylation catalyst under conditions effective to produce a hydroalkylation reaction product comprising (methylcyclohexyl)toluenes and/or (dimethylcyclohexyl)xylenes; and
(b) dehydrogenating at least part of the hydroalkylation reaction product in the presence of a dehydrogenation catalyst under conditions effective to produce a dehydrogenation reaction product comprising a mixture of methyl-substituted biphenyl compounds, wherein the dehydrogenation catalyst comprises (i) an element or compound thereof from Group 10 of the Periodic Table of Elements and (ii) tin or a compound thereof, wherein the hydroalkylation reaction product comprises at least 60 wt % of the 3,3, 3,4, 4,3 and 4,4-isomers of (methylcyclohexyl)toluene based on the total weight of all the (methylcyclohexyl)toluene isomers and less than 30 wt % of methylcyclohexane.

5. The process of claim 4 , wherein the hydroalkylation catalyst comprises an acidic component and a hydrogenation component.

6. The process of claim 5 , wherein the acidic component of the hydroalkylation catalyst comprises a molecular sieve.

7. The process of claim 6 , wherein the molecular sieve is selected from the group consisting of BEA, FAU and MTW structure type molecular sieves, molecular sieves of the MCM-22 family and mixtures thereof.

8. The process of claim 6 , wherein the molecular sieve comprises a molecular sieve of the MCM-22 family.

9. The process of claim 5 , wherein the hydrogenation component of the hydroalkylation catalyst selected from the group consisting of palladium, ruthenium, nickel, zinc, tin, cobalt and compounds and mixtures thereof.

10. The process of claim 4 , wherein the hydroalkylation conditions in the contacting (a) include a temperature from about 100° C. to about 400° C. and a pressure from about 100 to about 7,000 kPa.

11. The process of claim 4 , wherein the molar ratio of hydrogen to aromatic feed supplied to the contacting (a) is from about 0.15:1 to about 15:1.

12. The process of claim 4 , wherein the aromatic hydrocarbon is toluene and the hydroalkylation reaction product comprises and less than 2% of dimethylbicyclohexane compounds.

13. The process of claim 4 , wherein the aromatic hydrocarbon is toluene and the hydroalkylation reaction product comprises less than 1 wt % of compounds containing in excess of 14 carbon atoms.

14. The process of claim 4 , wherein the feed to step (a) further comprises benzene and/or at least one alkylbenzene different from toluene and xylene.

15. The process of claim 4 , wherein the aromatic hydrocarbon is toluene and the dehydrogenation reaction product comprises less than 10 wt % of monomethyl-substituted biphenyl compounds.

16. The process of claim 4 , wherein the aromatic hydrocarbon is toluene and the dehydrogenation reaction product comprises less than 5 wt % of fluorene and methylfluorenes combined.

17. The process of claim 4 , wherein the dehydrogenation conditions in (b) include a temperature from about 200° C. to about 600° C. and a pressure from about 100 kPa to about 3550 kPa.

18. A process for producing biphenyl esters, the process comprising:
(a) contacting a feed comprising at least one aromatic hydrocarbon selected from the group consisting of toluene, xylene and mixtures thereof with hydrogen in the presence of a hydroalkylation catalyst under conditions effective to produce a hydroalkylation reaction product comprising (methylcyclohexyl)toluenes and/or (dimethylcyclohexyl)xylenes;
(b) dehydrogenating at least part of the hydroalkylation reaction product in the presence of a dehydrogenation catalyst under conditions effective to produce a dehydrogenation reaction product comprising a mixture of methyl-substituted biphenyl compounds, wherein the dehydrogenation catalyst comprises (i) an element or compound thereof from Group 10 of the Periodic Table of Elements and (ii) tin or a compound thereof;
(c) contacting at least part of the dehydrogenation reaction product with an oxygen source under conditions effective to convert at least part of the methyl-substituted biphenyl compounds to biphenyl carboxylic acids; and
(d) reacting the biphenyl carboxylic acids with one or more C 4 to C 14 alcohols under conditions effective to produce biphenyl esters.

19. The process of claim 18 , wherein the hydroalkylation catalyst comprises an acidic component and a hydrogenation component.

20. The process of claim 19 , wherein the acidic component of the hydroalkylation catalyst comprises a molecular sieve.

21. The process of claim 20 , wherein the molecular sieve is selected from the group consisting of BEA, FAU and MTW structure type molecular sieves, molecular sieves of the MCM-22 family and mixtures thereof.

22. The process of claim 20 , wherein the molecular sieve comprises a molecular sieve of the MCM-22 family.

23. The process of claim 18 , wherein the hydroalkylation conditions in (a) include a temperature from about 100° C. to about 400° C. and a pressure from about 100 to about 7,000 kPa.

24. The process of claim 18 , wherein the feed to step (a) further comprises benzene and/or at least one alkylbenzene different from toluene and xylene.

25. The process of claim 18 , wherein the dehydrogenation conditions in (b) include a temperature from about 200° C. to about 600° C. and a pressure from about 100 kPa to about 3550 kPa.

26. The process of claim 4 , wherein unreacted aromatic feed is removed from the hydroalkylation reaction product of step a) and recycled back to the hydroalkylation of step a).

27. The process of claim 4 , wherein toluene and or xylene feed is removed from the hydroalkylation reaction product of step a) and recycled back to the hydroalkylation of step a).

28. The process of claim 4 wherein fully saturated single ring by-products in the hydroalkylation reaction product of step a) are dehydrogenated to produce recyclable feed that is recycled back to the hydroalkylation of step a).

29. The process of claim 4 wherein methylcyclohexane and dimethylcyclohexane in the hydroalkylation reaction product of step a) are dehydrogenated to produce recyclable feed th

Assignees

• Exxonmobil Chem Patents Inc

Inventors

• Bai Chuansheng
• Dakka Jihad M
• Decaul Lorenzo C

Classifications

• C07C2523/42

  Platinum · CPC title

• C07C2529/74

  Noble metals · CPC title

• C07C15/14

  all phenyl groups being directly linked · CPC title

• C07C2/76

  by condensation of hydrocarbons with partial elimination of hydrogen · CPC title

• C07C5/367

  Formation of an aromatic six-membered ring from an existing six-membered ring, e.g. dehydrogenation of ethylcyclohexane to ethylbenzene · CPC title