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

Patent metadata

Field	Value
Publication number	US-9556087-B2
Application number	US-201414201173-A
Country	US
Kind code	B2
Filing date	Mar 7, 2014
Priority date	Mar 14, 2013
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

In a process for producing methyl-substituted biphenyl compounds, a feed comprising at least one aromatic hydrocarbon selected from the group consisting of toluene, xylene and mixtures thereof is contacted 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 together with dialkylated C 21 + compounds. At least part of the dialkylated C 21 + compounds is then removed from the hydroalkylation reaction product to produce a dehydrogenation feed; and at least part of the dehydrogenation feed is dehydrogenated in the presence of a dehydrogenation catalyst under conditions effective to produce a dehydrogenation reaction product comprising a mixture of methyl-substituted biphenyl compounds.

First claim

The invention claimed is:

1. 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 comprising a molecular sieve of the MCM-22 family under conditions effective to produce a hydroalkylation reaction product comprising (methylcyclohexyl)toluenes and/or (dimethylcyclohexyl)xylenes together with dialkylated C 21 + compounds, 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;
(b) removing at least part of the dialkylated C 21 + compounds from the hydroalkylation reaction product to produce a dehydrogenation feed; and
(c) dehydrogenating at least part of the dehydrogenation feed in the presence of a dehydrogenation catalyst under conditions effective to produce a dehydrogenation reaction product comprising a mixture of methyl-substituted biphenyl compounds.

2. The process of claim 1 , wherein the dehydrogenation feed produced in (b) comprises less than 0.5 wt % of said dialkylated C 21 + compounds.

3. The process of claim 1 , wherein the removing (b) comprises a distillation step.

4. The process of claim 1 , wherein the dehydrogenation catalyst comprises an element or compound thereof from Group 10 of the Periodic Table of Elements.

5. The process of claim 4 , wherein the dehydrogenation catalyst further comprises tin or a compound thereof.

6. The process of claim 1 , wherein the dehydrogenation conditions in (c) include a temperature from about 200° C. to about 600° C. and a pressure from about 100 kPa to about 3550 kPa.

7. The process of claim 1 , wherein the hydroalkylation catalyst comprises a hydrogenation component selected from the group consisting of palladium, ruthenium, nickel, zinc, tin, cobalt and compounds and mixtures thereof.

8. The process of claim 1 , 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.

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

10. The process of claim 1 , wherein the aromatic hydrocarbon comprises toluene.

11. The process of claim 1 , wherein the feed to step (a) further comprises benzene and/or at least one alkylbenzene different from toluene and xylene.

12. 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 comprising a molecular sieve of the MCM-22 family under conditions effective to produce a hydroalkylation reaction product comprising (methylcyclohexyl)toluenes and/or (dimethylcyclohexyl)xylenes together with dialkylated C 21 + compounds, 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;
(b) removing at least part of the dialkylated C 21 + compounds from the hydroalkylation reaction product to produce a dehydrogenation feed;
(c) dehydrogenating at least part of the dehydrogenation feed in the presence of a dehydrogenation catalyst under conditions effective to produce a dehydrogenation reaction product comprising a mixture of methyl-substituted biphenyl compounds;
(d) 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
(e) reacting the biphenyl carboxylic acids with one or more C 4 to C 14 alcohols under conditions effective to produce biphenyl esters.

13. The process of claim 12 , wherein dehydrogenation feed produced in (b) comprises less than 0.5 wt % of said dialkylated C 21 + compounds.

14. The process of claim 12 , wherein the removing (b) comprises a distillation step.

15. The process of claim 12 , wherein the dehydrogenation catalyst comprises an element or compound thereof from Group 10 of the Periodic Table of Elements.

16. The process of claim 15 , wherein the dehydrogenation catalyst further comprises tin or a compound thereof.

17. The process of claim 12 , wherein the dehydrogenation conditions in (c) include a temperature from about 200° C. to about 600° C. and a pressure from about 100 kPa to about 3550 kPa (atmospheric to about 500 psig).

18. The process of claim 12 , wherein the feed to step (a) further comprises benzene and/or at least one alkylbenzene different from toluene and xylene.

19. The process of claim 12 , wherein the aromatic hydrocarbon comprises toluene.

20. The process of claim 1 , wherein the hydroalkylation catalyst comprises a hydrogenation component comprising platinum.

21. The process of claim 1 , wherein the hydroalkylation catalyst comprises a hydrogenation component comprising platinum and tin.

22. 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 comprising MCM-22 under conditions effective to produce a hydroalkylation reaction product comprising (methylcyclohexyl)toluenes and/or (dimethylcyclohexyl)xylenes together with dialkylated C 21 + compounds;
(b) removing at least part of the dialkylated C 21 + compounds from the hydroalkylation reaction product to produce a dehydrogenation feed; and
(c) dehydrogenating at least part of the dehydrogenation feed in the presence of a dehydrogenation catalyst comprising platinum and tin under conditions effective to produce a dehydrogenation reaction product comprising a mixture of methyl-substituted biphenyl compounds.

23. The process of claim 1 , wherein the hydroalkylation reaction product comprises less than 2% of dimethylbicyclohexane compounds and less than 1 wt % of dialkylated C 21 + compounds.

24. The process of claim 1 , wherein unreacted feed is removed from the hydroalkylation reaction effluent and recycled to the hydroalkylation reactor.

25. The process of claim 11 , wherein unreacted feed is removed from the hydroalkylation reaction effluent and recycled to the hydroalkylation reactor.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Dakka Jihad M
• Decaul Lorenzo C
• Deflorio Victor

Classifications

• C07C2101/14

  Chemistry & Metallurgy · mapped topic

• C07C67/08

  by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds · CPC title

• C07C5/367 Primary

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

• B01J29/14

  Iron group metals or copper · CPC title

• C07C13/28

  Polycyclic hydrocarbons or acyclic hydrocarbon derivatives thereof · CPC title