US 12,404,235 B2
Tricyanohexane purification methods
Sanjay Dube, Houston, TX (US); and Darrick Elmore, Houston, TX (US)
Assigned to Ascend Performance Materials Operations LLC, Houston, TX (US)
Filed by Ascend Performance Materials Operations LLC, Houston, TX (US)
Filed on Sep. 7, 2023, as Appl. No. 18/462,780.
Application 18/462,780 is a division of application No. 16/880,717, filed on May 21, 2020, granted, now 11,780,804.
Claims priority of provisional application 62/852,604, filed on May 24, 2019.
Prior Publication US 2023/0416192 A1, Dec. 28, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C07C 253/34 (2006.01)
CPC C07C 253/34 (2013.01) 18 Claims
OG exemplary drawing
 
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.