Method for the production of polyether carbonate polyols and device therefor

Patent metadata

Field	Value
Publication number	US-10208162-B2
Application number	US-201515323686-A
Country	US
Kind code	B2
Filing date	Jun 30, 2015
Priority date	Jul 3, 2014
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

The present invention relates to a method for producing polyether carbonate polyols by addition of one or more alkylene oxides and carbon dioxide to one or more H-functional starter substances in the presence of at least one DMC catalyst, in which the reaction is conducted in a main reactor (8) and a tubular reactor (11, 17) connected as a post reactor downstream thereof, wherein the method is characterized in that at the outlet (13) of the tubular reactor (11, 17) a temperature is set that is at least 10° C. above the temperature in the inside of the main reactor (8). The invention further relates to a device for carrying out said method.

First claim

The invention claimed is:

1. A process for preparing polyether carbonate polyols by adding one or more alkylene oxides and carbon dioxide onto one or more H-functional starter substances in the presence of at least one DMC catalyst, wherein the reaction is conducted in a main reactor and in a tubular reactor, wherein the tubular reactor is positioned downstream of the main reactor as a postreactor, wherein a reaction product flows from the main reactor into the tubular reactor, and wherein a temperature at the exit of the tubular reactor is set at least 10° C. above the temperature within the main reactor.

2. The process as claimed in claim 1 , wherein a temperature at the exit of the tubular reactor is set at 10° C. to 40° C. above the temperature within the main reactor.

3. The process as claimed in claim 1 , wherein the temperature at the exit of the tubular reactor is a function of a % by weight of unreacted alkylene oxide, based on the total weight of reaction mixture, measured at the entrance to the tubular reactor, and wherein the temperature at the exit of the tubular reactor is set at 2.5° C. to 12° C. per % by weight of unreacted alkylene oxide measured at the entrance to the tubular reactor above the temperature within the main reactor.

4. The process as claimed in claim 1 , wherein the temperature at the exit of the tubular reactor is set by a heating unit.

5. The process as claimed in claim 1 , wherein the reaction mixture is fed from the main reactor into the tubular reactor, and wherein the reaction mixture at the entrance to the tubular reactor has a content of unconverted alkylene oxides of 1% to 10% by weight, based on the total weight of reaction mixture.

6. The process as claimed in claim 1 , wherein:
(i) the DMC catalyst is suspended in one or more H-functional starter substances;
(ii) the suspension from (i) is combined with one or more alkylene oxides and with 10 to 200 bar of carbon dioxide; and
(iii) the mixture resulting from (ii) is reacted in the main reactor at a temperature of 80 to 150° C.,
wherein the pressures set in the tubular reactor are essentially the same pressures as in the main reactor, and wherein:
(iv) the suspension from (i) is first combined in a first mixer with one or more alkylene oxides and then in a second mixer with 10 to 200 bar of carbon dioxide.

7. The process as claimed in claim 1 , wherein the DMC catalyst, the H-functional starter substance, the alkylene oxide, and the carbon dioxide are fed directly to the main reactor and reacted therein at a temperature of 90 to 135° C. and a reaction pressure of 20 to 180 bar, wherein the DMC catalyst is fed directly to the main reactor as a dispersion in the H-functional starter substance, the alkylene oxide, and the carbon dioxide.

8. The process as claimed in claim 1 , wherein the internal diameter of at least a section of the tubular reactor is 1.1 mm to 900 mm.

9. The process as claimed in claim 1 , wherein the tubular reactor is formed from a continuous piece of tube.

10. The process as claimed in claim 1 , wherein the tubular reactor comprises a first subsection that extends over 20% to 60% of a total length of the tubular reactor, wherein the first subsection has an internal diameter of 1.1 mm to <100 mm, wherein the tubular reactor comprises a second subsection that follows downstream of the first subsection, wherein the second subsection extends over 80% to 40% of the total length of the tubular reactor, and wherein the second subsection has an internal diameter of 100 mm to 500 mm.

11. The process as claimed in claim 1 , wherein the tubular reactor has a ratio of tube length L to internal tube diameter d R of L/d R >50.

12. The process as claimed in claim 1 , wherein the main reactor is a continuously operated stirred reactor.

13. The process as claimed in claim 1 , wherein the H-functional starter substance is selected from the group consisting of: polyether polyol, polyester polyol, polyether carbonate polyol, water, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, propane-1,3-diol, butane-1,4-diol, butene-1,4-diol, butyne-1,4-diol, neopentyl glycol, pentane- 1,5-diol, 3-methylpentane-1,5-diol, hexane-1,6-diol, octane-1,8-diol, decane-1,10-diol, dodecane-1,12-diol, 1,4-bis(hydroxymethyl)cyclohexane, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, dibutylene glycol, trimethylolpropane, glycerol, trishydroxyethyl isocyanurate, castor oil, pentaerythritol, sorbitol, hexitol, sucrose, starch, starch hydrolyzate, cellulose, cellulose hydrolyzate, hydroxy-functionalized fats, hydroxy-functionalized oils, and combinations of any thereof.

14. An apparatus for preparing polyether carbonate polyols by adding one or more alkylene oxides and carbon dioxide onto one or more H-functional starter substances in the presence of at least one DMC catalyst, wherein the apparatus comprises a main reactor and a tubular reactor, wherein the tubular reactor is positioned downstream of the main reactor as a postreactor, wherein a reaction product flows from the main reactor into the tubular reactor, wherein a temperature at the exit of the tubular reactor is set at least 10° C. above the temperature within the main reactor, and wherein the temperature at the exit of the tubular reactor is set via a heating unit.

15. The apparatus as claimed in claim 14 , wherein the exit of the tubular reactor comprises a temperature sensor, and wherein the temperature sensor is coupled to the heating unit for controlling the heating unit of the tubular reactor.

16. The process as claimed in claim 1 , wherein the temperature at the exit of the tubular reactor is a function of a % by weight of unreacted alkylene oxide, based on the total weight of reaction mixture, measured at the entrance to the tubular reactor, and wherein the temperature at the exit of the tubular reactor is set 3° C. to 7° C. per % by weight of unreacted alkylene oxide measured at the entrance to the tubular reactor above the temperature within the main reactor.

17. The process as claimed in claim 1 , wherein the temperature at the exit of the tubular reactor is set by an insulation of the tubular reactor.

18. The process as claimed in claim 1 , wherein the reaction mixture is fed from the main reactor into the tubular reactor, and wherein the reaction mixture at the entrance to the tubular reactor has a content of unconverted alkylene oxides of 3% to 4% by weight, based on the total weight of reaction mixture.

19. The process as claimed in claim 1 , wherein:
(i) the DMC catalyst is suspended in one or more H-functional starter substances;
(ii) the suspension from (i) is combined with one or more alkylene oxides and with 10 to 200 bar of carbon dioxide; and
(iii) the mixture resulting from (ii) is reacted in the main reactor at a temperature of 80 to 150° C.,
wherein the pressures set in the tubular reactor are essentially the same pressures as in the main reactor, and wherein:
(iv) the suspension from (i) is first combined in a first mixer with 10 to 200 bar of carbon dioxide and then in a second mixer with one or more alkylene oxides.

20. An apparatus for preparing polyether carbonate polyols by adding one or more alkylene oxides and carbon dioxide onto one or more H-functional starter substances in the presence of at least one DMC catalyst, wherein the apparatus comprises a main reactor and a tubular reactor, wherein the tubular reactor is positioned downstream of the main reactor as a postreactor, wherein a reaction product f

Assignees

• Covestro Deutschland Ag

Inventors

• Braun Stefanie
• Zwick Horst
• Wohak Matthias
• Hofmann Jörg
• Wolf Aurel
• Traving Michael
• Bachmann Rolf

Classifications

• B01J19/242

  in series · CPC title

• B01J19/0013

  Controlling the temperature of the process · CPC title

• C08G65/2663

  Metal cyanide catalysts, i.e. DMC's · CPC title

• B01J2219/00058

  Temperature measurement · CPC title

• C08G64/205 Primary

  characterised by the apparatus used · CPC title