Continuous method for the production of neopentyl glycol
View Patent ↗A continuous method for preparing neopentyl glycol by addition of isobutyraldehyde and formaldehyde in the presence of a tertiary alkylamine as catalyst to give hydroxypivaldehyde with subsequent hydrogenation in the gas phase at a temperature of 125 to 180° C., is characterized in that the hydrogenation is carried out in the presence of a copper chromite catalyst comprising the activators barium and manganese and at a superatmospheric pressure of 30 to 120 kPa.
1. Continuous method for preparing neopentyl glycol by addition of isobutyraldehyde and formaldehyde in the presence of a tertiary alkylamine as catalyst to give hydroxypivaldehyde with subsequent hydrogenation in the gas phase at a temperature of 125 to 180° C., characterized in that the hydrogenation is carried out in the presence of a copper chromite catalyst comprising the activators barium and manganese and at a superatmospheric pressure of 30 to 120 kPa.
2. Method according to claim 1 , characterized in that the hydrogenation is carried out in the presence of water in an amount of 15 to 25% by weight based on the total amount of the hydrogenation starting mixture used.
3. Method according to claim 1 , characterized in that the hydrogenation is carried out at a temperature of 140 to 180° C. and a superatmospheric pressure of 60 to 100 kPa.
4. Method according to claim 1 , characterized in that the tertiary alkylamines used are symmetrical tertiary alkylamines.
5. Method according to claim 4 , characterized in that the symmetrical tertiary alkylamines used are trimethylamine, triethylamine, tri-n-propylamine or tri-n-butylamine.
6. Method according to claim 1 , characterized in that the tertiary alkylamines used are asymmetrical tertiary alkylamines.
7. Method according to claim 1 , characterized in that the copper chromite catalyst comprises barium in an amount of 0.5 to 8% by weight and manganese in an amount of 0.5 to 8% by weight, in each case based on the total content of copper, chromium, barium and manganese.
8. Method according to claim 7 , characterized in that the copper chromite catalyst comprises barium in an amount of 1 to 4% by weight and manganese in an amount of 3 to 5% by weight, in each case based on the total content of copper, chromium, barium and manganese.
9. Method according to claim 1 , characterized in that the continuous gas phase hydrogenation is carried out in a cycle gas mode with a cycle gas stream and a fresh gas stream at a ratio of cycle gas stream to fresh gas stream of 40 to 70.
10. Copper chromite catalyst comprising barium in an amount of 0.5 to 0.8% by weight and manganese in an amount of 0.5 to 8% by weight, in each case based on the total content of copper, chromium, barium and manganese.
11. Method according to claim 1 , characterized in that the hydrogenation is carried out in the presence of water in an amount of 18 to 25% by weight, based on the total amount of the hydrogenation starting mixture used.
12. Method according to claim 2 , characterized in that the hydrogenation is carried out at a temperature of 140 to 180° C. and a superatmospheric pressure of 60 to 100 kPa.
13. Method according to claim 2 , characterized in that the tertiary alkylamines used are symmetrical tertiary alkylamines.
14. Method according to claim 3 , characterized in that the tertiary alkylamines used are symmetrical tertiary alkylamines.
15. Method according to claim 13 , characterized in that the symmetrical tertiary alkylamines used are trimethylamine, triethylamine, tri-n-propylamine or tri-n-butylamine.
16. Method according to claim 14 , characterized in that the symmetrical tertiary alkylamines used are trimethylamine, triethylamine, tri-n-propylamine or tri-n-butylamine.
17. Method according to claim 2 , characterized in that the tertiary alkylamines used are asymmetrical tertiary alkylamines.
18. Method according to claim 3 , characterized in that the tertiary alkylamines used are asymmetrical tertiary alkylamines.
19. Method according to claim 2 , characterized in that the copper chromite catalyst comprises barium in an amount of 0.5 to 8% by weight and manganese in an amount of 0.5 to 8% by weight, in each case based on the total content of copper, chromium, barium and manganese.
20. Method according to claim 3 , characterized in that the copper chromite catalyst comprises barium in an amount of 0.5 to 8% by weight and manganese in an amount of 0.5 to 8% by weight, in each case based on the total content of copper, chromium, barium and manganese.