PROCESS FOR PURIFYING AMINOCAPRONITRILE
A process for converting caprolactam to aminocapronitrile (ACN), the process comprising contacting a caprolactam feed stream with ammonia to produce a first crude product stream; separating the first crude product stream to produce an intermediate product stream comprising ACN and caprolactam recovery stream; and purifying the intermediate product stream to produce a purified product stream comprising greater than 95 wt % aminocapronitrile.
1 . A process for converting caprolactam to aminocapronitrile, the process comprising:
contacting a caprolactam feed stream with ammonia to produce a first crude product stream;
separating the first crude product stream via a continuous process to produce an intermediate product stream comprising aminocapronitrile and a recovery stream comprising ammonia, caprolactam, or a combination thereof; and
purifying the intermediate product stream to produce a purified product stream comprising greater than 95 wt % aminocapronitrile.
2 . The process of claim 1 , wherein the continuous process comprises continuous distillation.
3 . The process of claim 1 , wherein the separating is conducted at a pressure ranging from 0.1 kPa to 100 kPa.
4 . The process of claim 1 , wherein the temperature at the bottom of the one or more distillation columns during the separating ranges from 150° C. to 180° C.
5 . The process of claim 1 , wherein the reflux ratio during the separating ranges from 1:1 to 10:1.
6 . The process of claim 1 , wherein the purifying comprises separating the intermediate product stream to produce a first purified product stream and a crude column bottoms.
7 . The process of claim 6 , wherein the first purified product stream comprises greater than 95 wt. % aminocapronitrile and less than 5 wt. % of impurities comprising cyclohexanone, cyclohexenone, n-hexanenitrile, 5-hexenenitrile, aminocaproic acid, caprolactam, caprolactam dimers caprolactam oligomers, or n-phenylacetamide, or combinations thereof.
8 . The process of claim 6 , further comprising separating the first purified product stream to form a second purified product stream comprising greater than 95 wt % aminocapronitrile, preferably greater than 99 wt % aminocapronitrile.
9 . The process of claim 6 , further comprising separating the crude column bottoms to produce a distillate caprolactam recycle stream comprising greater than 95 wt % caprolactam and heavy byproducts stream containing organic impurities and less than 10 wt % caprolactam.
10 . The process of claim 1 , wherein the caprolactam feed stream comprises less than 99 wt. % caprolactam and greater than 1 wt. % impurities.
11 . The process of claim 1 , wherein the contacting is conducted in a reactor, preferably a fixed bed reactor.
12 . A process for converting caprolactam to aminocapronitrile, the process comprising:
contacting a caprolactam feed stream with ammonia to produce a first crude product stream;
separating the first crude product stream via continuous distillation in one or more columns at a pressure less than 100 kPa to produce an intermediate product stream comprising ACN and a caprolactam recovery stream comprising caprolactam; and
purifying the intermediate product stream to produce a purified product stream comprising greater than 98 wt % aminocapronitrile.
13 . The process of claim 12 , wherein the residence time in any one column is less than 450 minutes.
14 . The process of claim 13 , wherein the residence time in any one column is less than 180 minutes.
15 . The process of claim 12 , wherein the reflux ratio during the separating ranges from 1:1 to 10:1.
16 . The process of claim 15 , wherein the reflux ratio during the separating ranges from 1:1 to 3:1.
17 . The process of claim 12 , wherein the temperature at the bottom of the distillation column bottom temperature during the separating ranges from 150° C. to 180° C.
18 . The process of claim 12 , wherein the recovery of aminocapronitrile in the intermediate product stream is greater than 70%.
19 . The process of claim 12 , wherein the recovery of caprolactam in the caprolactam recovery stream is greater than 90%.
20 . The process of claim 12 , wherein the contacting comprises a feed rate ranging from 1 klb/hr to 250 klb/hr.