Tricyanohexane purification methods

Patent metadata

Field	Value
Publication number	US-12404235-B2
Application number	US-202318462780-A
Country	US
Kind code	B2
Filing date	Sep 7, 2023
Priority date	May 24, 2019
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

Provided herein are processes for purifying TCH in a feed stream, such as an adiponitrile process stream. The processes include a first separating step of separating the adiponitrile process stream to form a first overhead stream comprising low-boiling components and high-boiling components and a first bottoms stream comprising high-boiling components. The processes also include a second separating step of separating the first overhead stream in one or more distillation columns to form a lights stream comprising low-boiling components, a heavies stream comprising high-boiling components, and a TCH stream.

First claim

We claim:

1. A process for purifying TCH, the process comprising:
a first separating step of flashing an adiponitrile process stream to form a first overhead stream comprising low-boiling components and high-boiling components, and a first bottoms stream comprising high-boiling components and solid impurities;
a second separating step of distilling the first overhead stream to form a second overhead stream comprising low-boiling components, and a second bottoms stream comprising TCH and heavies;
a third separating step of distilling the second bottoms stream to form a third distillate comprising TCH and less than 5 wt. % impurities, the impurities comprising the following:
from 0 wt. % to 0.05 wt. % adiponitrile,
from 0 wt. % to 0.1 wt. % di(2-cyanoethyl) amine,
from 0 wt. % to 0.05 wt. % cyanovaleramide, and
from 0 wt. % to 0.05 wt. % tri (2-cyanoethyl) amine, and

a third bottoms stream comprising heavies;
wherein the residence time in the second or third separating step is less than 8 hours.

2. The process of claim 1 , wherein at least a portion of third bottoms stream and/or the second bottoms stream is recycled.

3. The process of claim 2 , wherein the recycled stream comprises from 0 wt. % to 40 wt. % heavies.

4. A process for purifying TCH, the process comprising
a first separating step of flashing an adiponitrile process stream to form a first overhead stream comprising low-boiling components and high-boiling components, and a first bottoms stream comprising high-boiling components;
a second separating step of distilling the first overhead stream to form a second overhead stream comprising low-boiling components, a second bottoms stream comprising heavies, and a side draw comprising TCH and lights;
a third separating step of flashing the side draw in a second flash vessel to form a third bottoms stream comprising TCH and less than 5 wt % impurities, the impurities comprising the following:
from 0 wt. % to 0.05 wt. % adiponitrile,
from 0 wt. % to 0.1 wt. % di(2-cyanoethyl) amine,
from 0 wt. % to 0.05 wt. % cyanovaleramide, and
from 0 wt. % to 0.05 wt. % tri (2-cyanoethyl) amine; and

wherein the residence time in the second or third separating step is less than 8 hours.

5. The process of claim 4 , wherein at least a portion of the second bottoms stream is recycled.

6. The process of claim 5 , wherein the recycled stream comprises from 0 wt % to 40 wt % heavies.

7. A process for purifying TCH, the process comprising:
a first separating step of flashing an adiponitrile process stream to form a first overhead stream comprising low-boiling components and high-boiling components, and a first bottoms stream comprising high-boiling components;
a second separating step of distilling the first overhead stream to form a second overhead stream comprising low-boiling components, and a second bottoms stream comprising TCH and heavies;
a third separating step of distilling the second bottoms stream to form a third distillate comprising TCH and impurities, and a third bottoms stream comprising heavies; and
a fourth separating step of distilling the third distillate to form a fourth overhead stream comprising low-boiling components, and a fourth bottoms stream comprising TCH and less than 5 wt. % impurities, the impurities comprising the following:
from 0 wt. % to 0.05 wt. % adiponitrile,
from 0 wt. % to 0.1 wt. % di(2-cyanoethyl) amine,
from 0 wt. % to 0.05 wt. % cyanovaleramide, and
from 0 wt. % to 0.05 wt. % tri (2-cyanoethyl) amine; and

wherein the residence time in the second, third, or fourth separating step is less than 8 hours.

8. The process of claim 7 , wherein the fourth overhead stream comprises low-boiling components formed by the decomposition of high-boiling components during the second separating step.

9. The process of claim 7 , wherein at least a portion of the second, third, or fourth bottoms stream is recycled.

10. The process of claim 9 , wherein the recycled stream comprises from 0 wt % to 40 wt % heavies.

11. A process for purifying TCH, the process comprising:
a first separating step of separating an adiponitrile process stream to form a first overhead stream comprising low-boiling components and high-boiling components, and a first bottoms stream comprising high-boiling components;
a second separating step of distilling the first overhead stream to form a second overhead stream comprising low-boiling components, and a second bottoms stream comprising TCH and heavies;
third separating step of distilling the second bottoms stream to form a third distillate comprising TCH and impurities, and a third bottoms stream comprising heavies; and
a fourth separating step of flashing the third distillate in a second flash vessel to form a fourth overhead stream comprising low-boiling components, and a fourth bottoms stream comprising TCH and less than 5 wt. % impurities, the impurities comprising the following:
from 0 wt. % to 0.05 wt. % adiponitrile,
from 0 wt. % to 0.1 wt. % di(2-cyanoethyl) amine,
from 0 wt. % to 0.05 wt. % cyanovaleramide, and
from 0 wt. % to 0.05 wt. % tri (2-cyanoethyl) amine;

wherein the residence time in the second or third separating step is less than 8 hours.

12. The process of claim 11 , wherein the fourth overhead stream comprises low-boiling components formed by the decomposition of high-boiling components during the second and/or third separating step.

13. The process of claim 11 , wherein at least a portion of the second or third bottoms stream is recycled.

14. The process of claim 13 , wherein the recycled stream comprises from 0 wt. % to 40 wt. % heavies.

15. The process of claim 1 , further comprising a treating step of treating the TCH stream to form a purified TCH stream comprising less than 0.1 wt. % impurities, less than 20 ppm water, and/or less than 5 ppm metals.

16. The process of claim 4 , further comprising a treating step of treating the TCH stream to form a purified TCH stream comprising less than 0.1 wt. % impurities, less than 20 ppm water, and/or less than 5 ppm metals.

17. The process of claim 7 , further comprising a treating step of treating the TCH stream to form a purified TCH stream comprising less than 0.1 wt. % impurities, less than 20 ppm water, and/or less than 5 ppm metals.

18. The process of claim 11 , further comprising a treating step of treating the TCH stream to form a purified TCH stream comprising less than 0.1 wt. % impurities, less than 20 ppm water, and/or less than 5 ppm metals.

Assignees

• Ascend Performance Mat Operations Llc

Inventors

• Dube Sanjay
• Elmore Darrick

Classifications

• C07C255/05

  containing at least three cyano groups bound to the carbon skeleton · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• C07C253/34 Primary

  Separation; Purification · CPC title