Method for separation of a polymer from a polymer solution or dispersion

Patent metadata

Field	Value
Publication number	US-9688782-B2
Application number	US-201414781973-A
Country	US
Kind code	B2
Filing date	Mar 24, 2014
Priority date	Apr 4, 2013
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

The present invention relates to a method for separation of a polymer from a polymer solution or dispersion, wherein (i) a solution or dispersion of a polymer in an organic solvent is atomized by being brought into contact with water vapor in an atomizer container; (ii) the mixture obtained in the atomizer container is routed into a polymer degasification container and flows through same, wherein the organic solvent present in the polymer particles is driven at least partially out of the polymer particles due to the thermal contact between the polymer particles and the water vapor and transitions into the gas phase (iii) the mixture exiting from the polymer degasification container is routed into a phase separator ( 1 ) and the organic solvent present in the gas phase is separated from the polymer particles and the condensed water vapor; and (iv) the polymer particles and the condensed water vapor are routed into a phase separator ( 2 ) in order to separate the polymer particles from the condensed water vapor.

First claim

The invention claimed is:

1. A process for separating a polymer from a polymer solution or a polymer dispersion comprising the following steps:
(i) a solution or dispersion of a polymer in an organic solvent is sprayed in a vaporizer by bringing it into contact with water vapor, wherein a part of the organic solvent is converted into gas phase, a part of the water vapor condenses in the form of droplets and polymer particles are obtained which still contain organic solvent,
(ii) the mixture obtained in the vaporizer is transferred into a polymer degassing container and flows through the polymer degassing container, where by thermal contact of the polymer particles and the water vapor the organic solvent contained in the polymer particles is at least partially removed from the polymer particles and converted into gas phase,
(iii) the mixture leaving the polymer degassing container is transferred into a phase separator 1 where the organic solvent contained in the gas phase and any remaining water vapor, are separated from the polymer particles and the condensed water vapor,
(iv) the separated polymer particles and the separated condensed water vapor from step (iii) are transferred into a phase separator 2 where the polymer particles are separated from the condensed water vapor.

2. The process according to claim 1 , wherein the polymer solution is brought into contact with the water vapor in a multiple fluid nozzle.

3. The process according to claim 1 , wherein the polymer solution enters the vaporizer at an angle of 45-100° compared to the entering of the water vapor into the vaporizer.

4. The process according to claim 1 , wherein the water vapor introduced in the vaporizer has a pressure in the range of from 3-25 bar; and/or the mass ratio of the water vapor to the polymer solution in step (i) is in the range of 0.2-3.

5. The process according to claim 1 , wherein the average diameter of the polymer particles formed in the vaporizer is in the range of 0.01-5 mm.

6. The process according to claim 1 , wherein the polymer degassing container comprises a tubular section; and/or the mixture obtained in the vaporizer of step (i) flows through the polymer degassing container continuously and the condensed water vapor is in the form of droplets.

7. The process according to claim 1 , wherein the average dwell time in the polymer degassing container is 0.1-10 seconds.

8. The process according to claim 1 , wherein the separation of the organic solvent contained in the gas phase and any remaining water vapor from the polymer particles and the condensed water vapor is accomplished via centrifugal force separation in the phase separator 1 .

9. The process according to claim 1 , wherein the average dwell time in the phase separator 1 is less than 100 seconds.

10. The process according to claim 1 , wherein in step (iv) the separation of the polymer particles from the condensed water vapor is accomplished by compressing the polymer particles; and/or wherein the phase separator 2 comprises a polymer collecting unit and a polymer compressing unit which comprises a multiple shaft compression area and a single shaft compression area.

11. A system or facility for separating a polymer from a polymer solution or polymer dispersion, comprising
(a) a vaporizer,
(b) a polymer degassing container,
(c) a first phase separator for separating a gaseous phase from a liquid phase and a solid phase,
(d) a second phase separator for separating a liquid phase from a solid phase, wherein the second phase separator (d) comprises a polymer compression unit, which comprises a multiple shaft compression area and a single shaft compression area.

12. The system according to claim 11 , wherein the vaporizer comprises elements for introducing polymer solution and water vapor and said elements are arranged such that the polymer solution enters the vaporizer at an angle of 45-100° compared to the entering of the water vapor into the vaporizer.

13. The system according to claim 11 , wherein the polymer degassing container comprises a tubular section.

14. The system according to one of claim 11 , wherein the first phase separator (c) is a centrifugal force separator.

15. The system according to claim 11 , wherein the second phase separator (d) comprises a polymer collecting unit, and the polymer collecting unit and the polymer compression unit are arranged to each other such that charging the polymer compression unit with a polymer can be accomplished in the multiple shaft compression area.

Assignees

• Fraunhofer Ges Forschung

Inventors

• Wendler Ulrich
• Vater Marcus
• Gehrhardt Carsten
• Herzig Frank

Classifications

• C08F6/003

  from polymer solutions, suspensions, dispersions or emulsions without recovery of the polymer therefrom · CPC title

• C08F6/14

  Treatment of polymer emulsions {(C08F6/001, C08F6/006, C08F6/008, C08F6/02, C08F6/04 take precedence)} · CPC title

• C08F6/12 Primary

  Separation of polymers from solutions · CPC title

• C08C2/06 Primary

  Winning of rubber from solutions · CPC title

• C08F6/10

  Removal of volatile materials, e.g. solvents {(C08F6/001, C08F6/003, C08F6/005, C08F6/006, C08F6/008, C08F6/02, C08F6/04 take precedence)} · CPC title