# US 11,028,045 B2 · Process for reducing CPI in a dinitrile stream

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,028,045 B2
- Document ID: US11028045B2
- Status: Granted
- Kind: B2
- Application number: 16/095,793
- Filed: 2017-04-27
- Published: 2019-05-09
- Granted: 2021-06-08
- Earliest claimed: 2016-05-02
- Assignees: INV Nylon Chemicals Americas, LLC
- Applicants: INV Nylon Chemicals Americas, LLC
- Inventors: Chengbao Ni
- Web page: https://patentgrep.com/patent/US11028045B2

## CPC

- C07C 253/34: Separation; Purification
- B01D 3/009: {in combination with chemical reactions}
- B01D 3/34: with one or more auxiliary substances
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)

## Abstract

Disclosed is a process for removing 2-cyanocyclopentylideneimine (CPI) from a mixture containing CPI and dinitrile. The process comprises reacting CPI with an amine. The reaction may take place in the presence of water, and optionally, a catalyst. CPI is converted to products with a low volatility compared to the dinitrile.

## Claims

### Claim 1

A process for removing at least a portion of CPI from a mixture comprising CPI and at least one dinitrile, said process comprising reacting CPI in the mixture with an amine, wherein the amine is an aliphatic or aromatic amine.

### Claim 2 (depends on 1)

The process of claim 1 wherein the dinitrile is selected from adiponitrile, methylglutaronitrile, ethylsuccinonitrile, and mixtures thereof.

### Claim 3 (depends on 1)

The process of claim 1 wherein the reaction occurs at a temperature between ≥150 and ≤290° C.

### Claim 4 (depends on 1)

The process of claim 1 wherein a molar ratio of amine groups to CPI is ≥1.0.

### Claim 5 (depends on 1)

The process of claim 1, further comprising separating low volatility reaction products from the dinitrile by distillation.

### Claim 6 (depends on 1)

The process of claim 1 wherein the dinitrile is adiponitrile, 2-methylglutaronitrile, or both.

### Claim 7 (depends on 1)

The process of claim 1 wherein the aliphatic amine is a diamine.

### Claim 8 (depends on 1)

The process of claim 1 wherein the diamine is hexamethylenediamine.

### Claim 9 (depends on 1)

The process of claim 1 wherein CPI is reacted with the amine in the presence of water.

### Claim 10 (depends on 9)

The process of claim 9 wherein a mole ratio of water to CPI is ≥5.0.

### Claim 11

A method for removing CPI from dinitrile, the method comprising:
reacting the CPI with an amine in the presence of a dinitrile, water and a catalyst to form a separable component; and
separating at least a portion of the separable component from the dinitrile.

### Claim 12 (depends on 11)

The method of claim 11 wherein the dinitrile is adiponitrile, methylglutaronitrile, ethylsuccinonitrile, or mixtures thereof.

### Claim 13 (depends on 11)

The method of claim 11 wherein the catalyst is an acid catalyst.

### Claim 14 (depends on 13)

The method of claim 13 wherein the acid catalyst is a solid.

### Claim 15 (depends on 14)

The method of claim 14 wherein the solid is chosen from silica-alumina, crystalline aluminosilicate, boron phosphate, titania-alumina, and mixtures thereof.

### Claim 16 (depends on 13)

The method of claim 13 wherein the acid catalyst is at least one acidic bisulfate salt of sodium, potassium, ammonium, magnesium, iron, manganese, zinc, cobalt, or nickel.

### Claim 17 (depends on 13)

The method of claim 13 wherein the acid catalyst is at least one inorganic acid.

### Claim 18 (depends on 17)

The method of claim 17 wherein the inorganic acid is at least one of H2SO4, H3PO4, and HCl.

### Claim 19 (depends on 13)

The method of claim 13 wherein the acid catalyst is adipic acid, benzoic acid, or a mixture of adipic acid and benzoic acid.

### Claim 20 (depends on 11)

The method of claim 11 wherein the separating further comprises distilling.

### Claim 21 (depends on 20)

The method of claim 20 wherein the distilling recovers the dinitrile from the separable component as a more volatile component than the separable component.