Ionic liquid alkylation of 1-butene to produce 2,5-dimethylhexane

Patent metadata

Field	Value
Publication number	US-9302951-B2
Application number	US-201414169059-A
Country	US
Kind code	B2
Filing date	Jan 30, 2014
Priority date	Jan 30, 2014
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A process for producing dimethylhexanes (DMH) is provided. The DMH can be used to produce p-xylene. The process involves the alkylation of isobutane and 1-butene using an ionic liquid to produce naphtha that is rich in DMH. The DMH is then converted in high selectivity to xylene, including p-xylene, by dehydrocyclization.

First claim

What is claimed is:

1. A process for producing dimethylhexane comprising:
introducing a stream comprising isobutane and a stream comprising 1-butene or a stream comprising isobutane and 1-butene to an alkylation reaction zone to form a reaction mixture, the stream comprising 1-butene or the stream comprising isobutane and 1-butene containing less than about 50 wt % total of 2-butene and isobutene; and
alkylating the isobutane and the 1-butene in the alkylation reaction zone in the presence of a haloaluminate ionic liquid catalyst wherein the haloaluminate ionic liquid catalyst comprises a cation selected from one or more of

where R 5 , R 6 , R 18-21 are independently selected from C 1 -C 20 hydrocarbons, C 1 -C 20 hydrocarbon derivatives, halogens, and H;
under alkylation conditions to form a stream rich in dimethylhexane, the stream rich in dimethylhexane having a ratio of dimethylhexane to trimethylpentane of at least about 2:1.

2. The process of claim 1 wherein the haloaluminate ionic liquid catalyst comprises a chloroaluminate ionic liquid catalyst, a bromoaluminate ionic liquid catalyst, or combinations thereof.

3. The process of claim 1 wherein the stream rich in dimethylhexane comprises at least about 25 wt % 2,5-dimethylhexane based on a total weight of dimethylhexane, or at least about 25 wt % 2,4-dimethylhexane based on a total weight of dimethylhexane, or both.

4. The process of claim 1 wherein a ratio of isobutane to 1-butene is in a range of about 1:1 to about 50:1.

5. The process of claim 1 wherein the alkylation conditions include a temperature in a range of about −20° C. to about 100° C., and a pressure in a range of about 0.101 MPa to about 8.0 MPa.

6. The process of claim 1 wherein a ratio of catalyst to olefins is in a range of about 0.1:1 to about 10:1.

7. The process of claim 1 further comprising stirring the reaction mixture and the acidic ionic liquid catalyst.

8. The process of claim 1 further comprising dehydrocyclizing the stream rich in dimethylhexane in the presence of a dehydrocyclization catalyst under dehydrocyclization conditions to form a stream rich in xylenes.

9. The process of claim 1 further comprising:
separating the stream rich in dimethylhexane into a stream rich in 2,5-dimethylhexane and a residual stream; and dehydrocyclizing the stream rich in 2,5-dimethylhexane in the presence of a dehydrocyclization catalyst under dehydrocyclization conditions to form a stream rich in p-xylene.

10. The process of claim 1 further comprising:
separating the stream rich in dimethylhexane into a stream rich in 2,4-dimethylhexane and a residual stream; and
dehydrocyclizing the stream rich in 2,4-dimethylhexane in the presence of a dehydrocyclization catalyst under dehydrocyclization conditions to form a stream rich in m-xylene.

11. The process of claim 1 further comprising isomerizing the stream rich in dimethylhexane in the presence of an isomerization catalyst under isomerization conditions to convert a portion of 2,4-dimethylhexane to 2,5-dimethylhexane.

12. A process for producing xylenes comprising:
introducing a stream comprising isobutane and a stream comprising 1-butene or a stream comprising isobutane and 1-butene to an alkylation reaction zone to form a reaction mixture, the stream comprising 1-butene or the stream comprising isobutane and 1-butene containing less than about 50 wt % total of 2-butene and isobutene;
alkylating the isobutane and the 1-butene in the alkylation reaction zone in the presence of a haloaluminate ionic liquid catalyst wherein the haloaluminate ionic liquid catalyst comprises a cation selected from one or more of

where R 5 , R 6 , R 18-21 are independently selected from C 1 -C 20 hydrocarbons, C 1 -C 20 hydrocarbon derivatives, halogens, and H;
under alkylation conditions to form a stream rich in dimethylhexane, the stream rich in dimethylhexane having a ratio of dimethylhexane to trimethylpentane of at least about 2:1; and
dehydrocyclizing the stream rich in dimethylhexane in the presence of a dehydrocyclization catalyst under dehydrocyclization conditions to form a stream rich in xylenes.

13. The process of claim 12 wherein the stream rich in dimethylhexane comprises at least about 25 wt % 2,5-dimethylhexane based on a total weight of dimethylhexane, or at least about 25 wt % 2,4-dimethylhexane based on a total weight of dimethylhexane, or both.

14. The process of claim 12 wherein a ratio of isobutane to 1-butene is in a range of about 1:1 to about 50:1.

15. The process of claim 12 wherein a ratio of catalyst to olefins is in a range of about 0.1:1 to about 10:1.

16. The process of claim 12 further comprising:
separating the stream rich in dimethylhexane into a stream rich in 2,5-dimethylhexane and a residual stream, and wherein dehydrocyclizing the stream rich in dimethylhexane comprises dehydrocyclizing the stream rich in 2,5-dimethylhexane to form a stream rich in p-xylene.

17. The process of claim 12 further comprising:
separating the stream rich in dimethylhexane into a stream rich in 2,4-dimethylhexane and a residual stream; and wherein dehydrocyclizing the stream rich in dimethylhexane comprises dehydrocyclizing the stream rich in 2,4-dimethylhexane to form a stream rich in m-xylene.

18. The process of claim 12 further comprising isomerizing the stream rich in dimethylhexane in the presence of an isomerization catalyst under isomerization conditions to convert a portion of 2,4-dimethylhexane to 2,5-dimethylhexane.

Assignees

• Uop Llc

Inventors

• Stevens Carl J
• Martins Susie C
• Barger Paul T

Classifications

• C07C2/60 Primary

  with halides · CPC title

• C07C2527/125

  Compounds comprising a halogen and scandium, yttrium, aluminium, gallium, indium or thallium · CPC title

• C07C5/2751

  Metal halides; Complexes thereof with organic compounds · CPC title

• C07C9/16

  Branched-chain hydrocarbons · CPC title

• C07C15/08

  Xylenes · CPC title