Method for the purification of ethoxyquin

Patent metadata

Field	Value
Publication number	US-10889547-B2
Application number	US-201716311206-A
Country	US
Kind code	B2
Filing date	Jun 22, 2017
Priority date	Jun 29, 2016
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

The present invention relates to a process for purifying ethoxyquin by distillation, to high-purity ethoxyquin obtainable by means of distillative purification and to the use thereof, particularly as additive in foodstuffs and feedstuffs.

First claim

The invention claimed is:

1. A process for purifying ethoxyquin comprising p-phenetidine, comprising at least one step of continuous distillation using at least one dividing wall column, wherein ethoxyquin is obtained comprising less than 100 ppm p-phenetidine, wherein
A) the at least one dividing wall column has a number of separation stages of 10 to 100;
B) the at least one dividing wall column is operated at 1 to 100 mbar;
C) the bottom temperature of the at least one dividing wall column is set to values of 80 to 200° C.;
D) the amount of bottoms liquid (the volume) is from 1 to 30% of the total volume of the amount of substance to be separated in the at least one dividing wall column;
E) a ratio of bottoms takeoff volume to the amount of feed is from 0.01 to 0.3;
F) packed columns with structured packings of a specific surface area of 100 to 1000 m 2 /m 3 are used; and
G) a ratio of amount of reflux to amount of feed has a factor of from 0.5:1 to 5:1.

2. The process according to claim 1 , wherein the at least one dividing wall column has a dividing wall (T) in the longitudinal direction of the column forming an upper ( 1 ) and lower ( 6 ) common column region, an inflow section (A) and an offtake section (B), and the mixture to be separated is fed to the inflow region and the product ethoxyquin is removed from a side offtake;
wherein the upper common column region is situated above the dividing wall(T) and contains 5 to 50% and the lower common column region is situated below the dividing wall (T) and contains 5 to 50% of the total number of theoretical plates in the column.

3. The process according to claim 2 , wherein the dividing wall column (TK) has a dividing wall (T) in the longitudinal direction of the column forming an upper common column region, a lower common column region, an inflow section with rectifying section and stripping section, and an offtake section with rectifying section and stripping section, wherein the mixture to be separated (feed) is fed to the inflow section, a first fraction is removed via the bottom (bottom takeoff C), a second fraction is removed via the overhead (top takeoff A) and a third fraction is removed from the offtake section (side takeoff B).

4. The process according to claim 3 , wherein the upper common column region of the at least one dividing wall column (TK) has 5 to 50%, the rectifying section of the inflow section of the column has 5 to 50%, the stripping section of the inflow section of the column has 5 to 50%, the rectifying section of the offtake section of the column has 5 to 50%, the stripping section of the offtake section of the column has 5 to 50%, and the lower common lower region of the column has 5 to 50%, of the total number of theoretical plates (nth) of the column.

5. The process according to claim 3 , wherein in the at least one dividing wall column (TK), in each case the sum of the number of theoretical plates of the inflow section is 80 to 110% of the total of the number of plates of the subsections (3) and (5) in the offtake section.

6. The process according to claim 2 , wherein the upper common column region (1) of the at least one dividing wall column (TK) has 5 to 50%, the rectifying section (2) of the inflow section (2, 4) of the column has 5 to 50%, the stripping section (4) of the inflow section of the column has 5 to 50%, the rectifying section (3) of the offtake section (3, 5) of the column has 5 to 50%, the stripping section (5) of the offtake section of the column has 5 to 50%, and the lower common column region ( 6 ) of the column has region (6) of the column has 5 to 50%, of the total number of theoretical plates (nth) of the column, and wherein the subsection of the dividing wall column(s) (TK) divided by the dividing wall (T) consisting of subsections 2, 3, 4 and 5 or parts thereof is loaded with ordered packings or random packings, and the column(s) is filled at least partially with random packings or ordered packings.

7. The process according to claim 1 , wherein only one column, and said column in the form of a dividing wall column, is used.

8. The process according to claim 1 , wherein the at least one dividing wall column has 30 to 100 theoretical plates.

9. The process according to claim 1 , wherein the dividing wall section has 40 to 80%, the upper common column region has 5 to 50%, the lower common column region has 5 to 50%, of the total number of theoretical plates of the dividing wall column.

10. The process according to claim 1 , wherein a fraction is removed from via the bottom, wherein the residence time of the fraction in the bottoms is less than 10 hours.

11. A process for producing an ethoyquin-containing foodstuff or feedstuff, wherein in step
1 ) a crude ethoxyquin product is subjected to at least one step of continuous distillation using at least one dividing wall column or at least two thermally coupled columns, wherein at least one of the at least two coupled columns is a dividing wall column, wherein
A) the at least one column has a number of separation stages of 10 to 100; B) the at least one column is operated at 1 to 100 mbar; C) the bottom temperature of the at least one column is set to values of 80 to 200° C.; D) the amount of bottoms liquid (the volume) is from 1 to 30% of the total volume of the amount of substance to be separated in the at least one column; E) the ratio of bottoms takeoff volume to the amount of feed is from 0.01 to 0.3; F) packed columns with ordered packings of a specific surface area of 100 to 1000 m 2 /m 3 are used; and G) the ratio of amount of reflux to amount of feed has a factor of from 0.5:1 to 5:1, and H) a fraction is removed from via the bottom, wherein the residence time of the fraction in the bottoms is less than 5 hours;
wherein the process according to step 1 does not comprise any subsequent ethoxyquin purification steps;
2) from the process of step 1, ethoxyquin having a p-phenetidine content of less than 50 ppm is obtained, and
3) the ethoxyquin obtained in step 2 is incorporated in a foodstuff or feedstuff.

Assignees

• Basf Se

Inventors

• Roy Sumana
• Keller Andreas
• Siegel Wolfgang
• Joedecke Michael
• Haubner Martin

Classifications

• A23B2/762

  Organic compounds containing nitrogen · CPC title

• B01D3/14

  Fractional distillation {or use of a fractionation or rectification column} · CPC title

• A23V2002/00

  Food compositions, function of food ingredients or processes for food or foodstuffs · CPC title

• B01D3/141

  where at least one distillation column contains at least one dividing wall · CPC title

• C07D215/20 Primary

  Oxygen atoms · CPC title