Macroporous catalyst for the preparation of aliphatic amines
A process for the preparation of aliphatic amines, comprises reacting an aliphatic alcohol with an aminating agent in the presence of a catalyst. The catalyst contains copper oxide on a support made of porous alumina, wherein the porous alumina has a volume, corresponding to pores greater than 500 Å in diameter, of from 10 ml/100 g to 95 ml/100 g.
1. A process, comprising reacting an aliphatic alcohol of formula (I)
R 1 CH 2 OH (I),
wherein R 1 is a linear or branched, saturated or unsaturated aliphatic group having from 3 to 21 carbon atoms, with an aminating agent of formula (II)
wherein R 2 and R 3 , the same or different, are hydrogen or a linear or branched, saturated or unsaturated aliphatic group having from 1 to 24 carbon atoms, for obtaining an aliphatic amine of formula (III), (IV) or (V)
wherein the reaction is carried out in the presence of a catalyst, wherein the catalyst comprises from 5 wt % to 50 wt % of copper oxide; optionally from 0.1 wt % to 20 wt % of a compound of at least one element selected from Fe, Co, Zn, Ni, Cr, Mn, Mg, Ba and rare earth metals; the balance being a support made of porous alumina, weight percentage based on the total weight of the catalyst; wherein the porous alumina has a volume, corresponding to pores greater than 500 Å in diameter, of from greater than 30 ml/100 g to 95 ml/g, as determined by mercury porosimetry.
2. The process according to claim 1 , wherein the porous alumina has a specific surface area of from 10 m 2 /g to 280 m 2 /g.
3. The process according to claim 1 , wherein the porous alumina has a specific surface area of from 50 m 2 /g to 280 m 2 /g.
4. The process according to claim 1 , wherein the aminating agent has the formula (VI)
wherein R 4 and R 5 , the same or different, are a linear or branched, saturated or unsaturated aliphatic group having from 1 to 24 carbon atoms, the aliphatic amine has the formula (VII):
wherein R 1 is a linear or branched, saturated or unsaturated aliphatic group having from 3 to 21 carbon atoms, R 4 and R 5 are as defined in formula (VI).
5. The process according to claim 1 , wherein the aliphatic alcohol and the aminating agent are mixed together with a flow of hydrogen and the mixture is continuously introduced into a reaction zone, wherein the molar ratio of the aliphatic alcohol/the aminating agent/the hydrogen is in the range of from 1:1:5 to 1:2:20.
6. The process according to claim 5 , wherein the molar ratio of the aliphatic alcohol/the aminating agent/the hydrogen is in the range of from 1:1:5 to 1:1.2:15.
7. The process according to claim 1 , wherein the reaction is carried out at a temperature of from 150° C. to 350° C.
8. The process according to claim 1 , wherein the reaction is carried out at a temperature of from 2° C. to 250° C.
9. The process according to claim 1 , wherein the reaction is carried out under a pressure of from 0 to 5 barg.
10. The process according to claim 1 , wherein the reaction is carried out under a pressure of from 0 to 0.5 barg.