Phase separation process by inversion of the direction of dispersion

Patent metadata

Field	Value
Publication number	US-10207201-B2
Application number	US-201313937428-A
Country	US
Kind code	B2
Filing date	Jul 9, 2013
Priority date	Jul 11, 2012
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

The present invention relates to a process for separating a phase (A) from a phase (B), phase (A) having a higher viscosity than phase (B), by inverting the direction of dispersion from phase (B) in phase (A) to phase (A) in phase (B) by recycling a stream comprising phase (B) in excess.

First claim

The invention claimed is:

1. A process for separating a phase (A) from a phase (B), phase (A) having a higher viscosity than phase (B), wherein phase (A) comprises at least one ionic liquid and phase (B) comprises at least one hydrocarbon, comprising the following steps:
a) providing a stream (S 1 ) comprising a dispersion (D 1 ) in which phase (B) is dispersed in phase (A),
b) introducing a stream (S 2 ) comprising at least 70% by weight of phase (B), into stream (S 1 ), stream (S 2 ) being recycled from step f),
c) to form a stream (S 3 ) comprising a dispersion (D 2 ) in which phase (A) is dispersed in phase (B),
d) introducing stream (S 3 ) into a phase separator,
e) separating stream (S 3 ) in the phase separator into a stream (S 5 ) comprising at least 70% by weight of phase (B), and into a stream (S 4 ) comprising at least 70% by weight of phase (A),
f) removing a portion of stream (S 5 ) as stream (S 2 ) and recycling stream (S 2 ) to step b).

2. The process according to claim 1 , wherein in step b) the stream (S 2 ) comprises at least 90% by weight of phase (B) or in step e) the stream (S 5 ) comprises at least 90% by weight of phase (B) or in step e) the stream (S 4 ) comprises at least 90% by weight of phase (A).

3. The process according to claim 1 , wherein the viscosity of phase (A) is at least 0.1 mPas higher than that of phase (B).

4. The process according to claim 1 , wherein the ionic liquid present in phase (A) comprises, as a cation, an at least partly alkylated ammonium ion or a heterocyclic cation or, as an anion, a chloroaluminate ion having the composition AlnCl(3n+1) where 1<n<2.5.

5. The process according to claim 1 , wherein phase (B) comprises, as the hydrocarbon, cyclohexane or a mixture of cyclohexane with at least one further hydrocarbon selected from methylcyclopentane (MCP), n-hexane, isohexane, n-heptane, isoheptane or dimethylcyclopentane.

6. The process according to claim 1 , wherein, in step b), stream (S 2 ) is introduced into stream (S 1 ) in a stirred vessel or static mixer in which stream (S 3 ) according to step c) is formed.

7. The process according to claim 1 , wherein the phase ratio of phase (A) to phase (B) in dispersion (D 2 ) present in stream (S 3 ) is ≤3 kg/kg.

8. The process according to claim 7 , wherein the phase ratio is ≤0.9 kg/kg.

9. The process according to claim 1 , wherein the phase ratio of phase (A) to phase (B) in dispersion (D 2 ) present in stream (S 3 ) is <2.5 kg/kg, stream (S 3 ) being formed in a stirring apparatus by introducing stream (S 2 ) into stream (S 1 ).

10. The process according to claim 1 , wherein stream (S 1 ) is obtained from an isomerisation.

11. The process according to claim 10 , wherein the isomerisation is an isomerization of methylcyclopentane (MCP) to cyclohexane in the presence of an ionic liquid.

12. The process according to claim 1 , wherein stream (S 5 ) obtained according to step e) comprises not more than 10% by weight of phase (A) (based on the amount present in (S 3 )).

13. The process according to claim 1 , wherein stream (S 4 ) obtained from the phase separator according to step e) comprises not more than 15% by weight of phase (B) (based on the amount present in (S 3 )) or stream (S 4 ) is recycled into an isomerization.

14. The process according to claim 1 , wherein the phase ratio of phase (A) to phase (B) in dispersion (D 1 ) present in stream (S 1 ) is >3 kg/kg.

15. The process according to claim 14 , wherein the phase ratio is >4 kg/kg.

16. The process according to claim 1 wherein removal of stream (S 2 ) is followed by passing stream (S 5 ) through a coalescing filter or a downstream separator in order to remove residual amounts of phase (A) remaining in stream (S 5 ).

17. The process according to claim 16 , wherein a coalescing filter is used, or the downstream separator comprises a knit.

18. The process according to claim 17 , wherein the coalescing filter is made from glass fiber or acrylic/phenolic resin or the knit is a glass fiber knit.

19. The process according to claim 1 , wherein cyclohexane is isolated from stream (S 5 ).

20. A process for separating a phase (A) from a phase (B), phase (A) having a higher viscosity than phase (B), wherein phase (A) comprises at least one ionic liquid and phase (B) comprises at least one hydrocarbon, comprising the following steps:
a) providing a stream (S 1 ) comprising a dispersion (D 1 ) in which phase (B) is dispersed in phase (A),
b) introducing a stream (S 2 ) comprising at least 70% by weight of phase (B), into stream (S 1 ), stream (S 2 ) being recycled from step f),
c) to form a stream (S 3 ) comprising a dispersion (D 2 ) in which phase (A) is dispersed in phase (B),
d) introducing stream (S 3 ) into a horizontal, glass phase separator, which is operated in flooded mode resulting,
e) separating stream (S 3 ) in the phase separator based on viscosity difference in the phases into a stream (S 5 ) comprising at least 70% by weight of phase (B), and into a stream (S 4 ) comprising at least 70% by weight of phase (A),
f) removing a portion of stream (S 5 ) as stream (S 2 ) and recycling stream (S 2 ) to step b).

Assignees

• Basf Se

Inventors

• Pfeiffer Daniel
• Bitterlich Stefan

Classifications

• B01D17/02 Primary

  Separation of non-miscible liquids · CPC title

• B01D17/0214 Primary

  with removal of one of the phases · CPC title