Process for the production of 2-alkylalkanol

Patent metadata

Field	Value
Publication number	US-10717692-B2
Application number	US-201716340830-A
Country	US
Kind code	B2
Filing date	Oct 12, 2017
Priority date	Oct 14, 2016
Publication date	Jul 21, 2020
Grant date	Jul 21, 2020

Abstract

A process for the production of 2-alkylalkanol from an aldehyde is disclosed. The process comprises the steps of: feeding aldehyde to a reactor (42) operated under condensation and dehydration conditions such that reaction occurs and an unsaturated aldehyde is produced; recovering a stream from the reactor (42) comprising the unsaturated aldehyde and feeding said stream to a first hydrogenation reactor (45) operated under conditions such that at least some of the unsaturated aldehyde is converted to 2-alkylalkanol; recovering the stream from the first hydrogenation reactor (45) comprising the 2-alkylalkanol, one or more of unreacted acrolein, alkylalkenol and alkylalkanal and heavies; passing the stream recovered from the first hydrogenation reactor (45) to a first distillation zone (48) where at least some of the heavies are separated from the stream; recovering a stream from the first distillation zone (48) comprising the 2-alkylalkanol, one or more of unreacted acrolein, alkylalkenol and alkylalkanal, said stream having a reduced heavies content when compared to the stream fed to the first distillation zone (48), and feeding said stream to a second hydrogenation reactor (51) operated under conditions such that at least one of the unreacted acrolein, alkylalkenol and alkylalkanal are converted to 2-alkylalkanol; and recovering a stream from the second hydrogenation reactor (51) comprising an increased 2-alkylalkanol content compared to the stream fed to the second hydrogenation reactor (51).

First claim

The invention claimed is:

1. A process for the production of 2-alkylalkanol from an aldehyde comprising the steps of:
(a) feeding aldehyde to a reactor operated under condensation and dehydration conditions such that reaction occurs and an unsaturated aldehyde is produced;
(b) recovering a stream from the reactor of step (a) comprising the unsaturated aldehyde and feeding said stream to a first hydrogenation reactor operated under conditions such that at least some of the unsaturated aldehyde is converted to 2-alkylalkanol;
(c) recovering the stream from the first hydrogenation reactor comprising the 2-alkylalkanol, one or more of unreacted acrolein, alkylalkenol and alkylalkanal and heavies;
(d) passing the stream recovered in step (c) from the first hydrogenation reactor to a first distillation zone where at least some of the heavies are separated from the stream;
(e) recovering a stream from the first distillation zone comprising the 2-alkylalkanol, one or more of unreacted acrolein, alkylalkenol and alkylalkanal, said stream having a reduced heavies content when compared to the stream fed to the first distillation zone, and feeding said stream to a second hydrogenation reactor operated under conditions such that at least one of the unreacted acrolein, alkylalkenol and alkylalkanal are converted to 2-alkylalkanol; and
(f) recovering a stream from the second hydrogenation reactor comprising an increased 2-alkylalkanol content compared to the stream fed to the second hydrogenation reactor.

2. The process according to claim 1 where the stream recovered from the second hydrogenation reactor in step (f) is passed to a second distillation zone where lights are removed, said second distillation zone having no heavies removal.

3. The process according to claim 1 wherein the aldehyde is n-butyraldehyde and the product is 2-ethylhexanol.

4. The process according to claim 1 wherein the aldehyde is n-valeraldehyde and the product is 2-propylheptanol.

5. The process according to claim 1 wherein the first hydrogenation reactor is operated at a temperature of from about 100° C. to about 200° C. and at a pressure of from atmospheric pressure to about 15 MPa.

6. The process according to claim 1 wherein a nickel catalyst is used in the first hydrogenation reactor.

7. The process according to claim 6 wherein the first hydrogenation reactor is operated at a temperature of about 150° C. or below and a pressure of from about 10 to about 30 bara where the reaction is carried out in the liquid phase or at a temperature of from about 100° C. to about 150° C. and a pressure of from atmospheric to about 5 bara where the reaction is carried out in the gas phase.

8. The process according to claim 5 wherein a copper catalyst is used in the first hydrogenation reactor.

9. The process according to claim 8 wherein the first hydrogenation reactor is operated at a temperature of from about 100° C. to about 150° C. and a pressure of from about 15 to about 30 bara where the reaction is carried out in the liquid phase or at a temperature of from about 135° C. to about 170° C. and a pressure of from atmospheric to about 5 bara where the reaction is carried out in the gas phase.

10. The process according to claim 1 wherein the second hydrogenation reactor is operated in the liquid phase.

11. The process according to claim 10 wherein the second hydrogenation reactor is operated at a temperature of from about 80° C. to about 150° C. and at a pressure of from about 10 bara to about 35 bara.

12. The process according to claim 1 wherein the bottoms temperature in the first and second distillation zone is below about 175° C.

13. The process according to claim 1 wherein the pressure at a top of the first distillation zone is in the region of from about 0.05 bara to about 0.5 bara.

14. The process according to claim 2 wherein the pressure at a top of the second distillation zone is in the region of from about 0.1 bara to about 0.8 bara.

Assignees

• Johnson Matthey Davy Technologies Ltd

Inventors

• Lord Adrian
• Smidt Martin

Classifications

• C07C31/125

  containing five to twenty-two carbon atoms · CPC title

• C07C29/80

  by distillation · CPC title

• C07C29/36

  increasing the number of carbon atoms by reactions with formation of hydroxy groups, which may occur via intermediates being derivatives of hydroxy, e.g. O-metal · CPC title

• C07C29/141 Primary

  with hydrogen or hydrogen-containing gases · CPC title

• C07C45/66

  by dehydration · CPC title