Co-production of cyclohexylamine and bis(para-aminocyclohexyl) methane
View Patent ↗Embodiments of the present invention disclose a process for the co-production of bis(para-aminocyclohexyl) methane (PACM). Also disclosed are articles of manufacture made using PACM produced by methods of this invention. The methods of the present invention generally include a first mixture having methylene di-aniline (MDA) and a second aromatic amine. The first mixture has less than 15% polymeric MDA by weight and the second aromatic amine is present in an amount to render the first mixture a liquid. The first mixture is hydrogenated to produce a product mixture comprising PACM and at least one second non-aromatic amine.
1. A process for the co-production of bis(para-aminocyclohexyl) methane which comprises the steps of:
providing a first mixture having methylene di-aniline and at least one second aromatic amine,
wherein the at least one second aromatic amine is present in an amount to render the first mixture a liquid, and
wherein the first mixture has less than 15% polymeric methylene di-aniline by weight based on the total weight of the first mixture; and
hydrogenating the first mixture to produce a product mixture comprising bis(para-aminocyclohexyl) methane and at least one second non-aromatic amine.
2. A process according to claim 1 further comprising separating the product mixture to recover bis(para-aminocyclohexyl) methane from the product mixture.
3. A process according to claim 1 further comprising separating the product mixture to recover the at least one second non-aromatic amine from the product mixture.
4. A process according to claim 1 wherein the first mixture is liquid at ambient temperature.
5. A process according to claim 1 wherein the at least one second aromatic amine comprises aniline.
6. A process according to claim 5 wherein the at least one second non-aromatic amine comprises cyclohexyl amine.
7. A process according to claim 5 wherein the second non-aromatic amine comprises dicyclohexyl amine.
8. A process according to claim 1 wherein the first mixture comprises a stream extracted from an isocyanate plant.
9. A process according to claim 1 wherein the first mixture comprises a recycle stream of aniline and methylene di-aniline.
10. A process according to claim 9 wherein the recycle stream recovers unreacted aniline from a reaction of aniline and formaldehyde to produce methylene di-aniline and polymeric methylene di-aniline.
11. A process according to claim 1 wherein the at least one second aromatic amine is present in an amount of at least about 30% by weight based on the total weight of the first mixture.
12. A process according to claim 1 wherein the at least one second aromatic amine is present in an amount of at least about 50% by weight based on the total weight of the first mixture.
13. A process according to claim 1 wherein the at least one second aromatic amine is present in an amount of at least about 70% by weight based on the total weight of the first mixture.
14. A process according to claim 1 wherein the first mixture has less than about 5% polymeric methylene di-aniline by weight of the first mixture.
15. A process according to claim 1 wherein the first mixture has less than about 1% polymeric methylene di-aniline by weight of the first mixture.
16. A process according to claim 1 wherein the first mixture contains less than about 0.01% polymeric methylene di-aniline by weight of the first mixture.
17. A process according to claim 1 wherein hydrogenating the first mixture comprises using a catalyst, wherein the catalyst is selected from group consisting of: iron, cobalt, nickel, ruthenium, titanium, palladium, rhodium, platinum, iridium and combinations thereof.
18. A process according to claim 17 wherein the catalyst is supported on at least one inert carrier.
19. A process according to claim 1 wherein the at least one second aromatic amine is present in the first mixture in an amount effective to modify the content of bis(para-aminocyclohexyl) methane to have less than 25% by weight of the trans-trans isomer of the bis(para-aminocyclohexyl) methane, based on the total weight of all isomers of bis(para-aminocyclohexyl) methane.
20. A process according to claim 1 , wherein hydrogenating the first mixture occurs at a temperature of about 75° C. to about 200° C.
21. A process according to claim 1 wherein hydrogenating the first mixture occurs at a temperature of about 100° C. to about 130° C.
22. A process for the co-production of bis(para-aminocyclohexyl) methane which comprises the steps of:
providing a first mixture having methylene di-aniline and aniline, wherein the first mixture has less than about 5% polymeric methylene di-aniline by weight based on the total weight of the first mixture and wherein the aniline is present in an amount to render the first mixture a liquid;
hydrogenating the first mixture to produce a product mixture comprising bis(para-aminocyclohexyl) methane and cyclohexyl amine; and
separating the product mixture to recover bis(para-aminocyclohexyl) methane from the product mixture.