Process for the co-production of fatty alcohols showing different carbon chain lengths

1. A process for the co-production of a stream of a fatty alcohol having first carbon chain lengths and a stream of a fatty alcohol having a second carbon chain lengths, said second carbon chain lengths being longer than said first carbon chain lengths, said process comprising the steps of:

(a) supplying a stream comprising lower alkyl esters of fatty acids having chain lengths comprising the first and second chain lengths to a first vaporisation zone and contacting said stream with an amount of hydrogen which is sufficient to vaporise the lower alkyl esters of the fatty acids having the first carbon chain lengths into the hydrogen;

(b) supplying the hydrogen and the vaporised lower alkyl esters of fatty acids having the first carbon chain lengths to a first reaction zone comprising catalyst and operating under reaction conditions to allow hydrogenation to the desired alcohol having first carbon chain lengths;

(c) recovering from the first reaction zone an alcohol product stream having first carbon chain lengths and hydrogen;

(d) separating the stream of fatty alcohol having the first carbon chain lengths from hydrogen;

(e) supplying the unvaporised lower alkyl esters of the fatty acids having second carbon chain lengths remaining from step (a) to a second vaporisation zone;

(f) contacting the unvaporised lower alkyl esters having second carbon chain lengths in the second vaporisation zone with hydrogen recovered in step (d) and an additional amount of hydrogen such that the total amount of hydrogen is sufficient to vaporise the lower alkyl esters having fatty acids of the second carbon chain lengths into the hydrogen;

(g) supplying the hydrogen and the vaporised lower alkyl esters of fatty acids having second carbon chain lengths to a second reaction zone comprising catalyst and operating under reaction conditions to allow hydrogenation to the desired alcohol having second carbon chain lengths; and

(h) recovering from the second reaction zone an alcohol product stream having second carbon chain lengths and hydrogen.

2. A process for the co-production of a stream of a C 12 /C 14 fatty alcohol and a stream of a C 16 /C 18 fatty alcohol comprising the steps of:

(a) supplying a stream comprising lower alkyl esters of C 12 /C 18 fatty acids to a first vaporisation zone and contacting said stream with an amount of hydrogen which is sufficient to vaporise the lower alkyl esters of C 12 /C 14 fatty acids into the hydrogen;

(b) supplying the hydrogen and the vaporised lower alkyl esters of C 12 /C 14 fatty acids to a first reaction zone comprising catalyst and operating under reaction conditions to allow hydrogenation to the desired C 12 /C 14 fatty alcohol;

(c) recovering from the first reaction zone a C 12 /C 14 fatty alcohol product stream and hydrogen;

(d) separating the stream of C 12 /C 14 fatty alcohol from hydrogen;

(e) supplying the unvaporised lower alkyl esters of C 16 /C 18 fatty acids remaining from step (a) to a second vaporisation zone;

(f) contacting the unvaporised lower alkyl esters of C 16 /C 18 fatty acids in the second vaporisation zone with hydrogen separated in step (d) and an additional amount of hydrogen such that the total amount of hydrogen is sufficient to vaporise the lower alkyl esters of C 16 /C 18 fatty acids into the hydrogen;

(g) supplying the hydrogen and the vaporised lower alkyl esters of C 16 /C 18 fatty acids to a second reaction zone comprising catalyst and operating under reaction conditions to allow hydrogenation to the desired C 16 /C 18 fatty alcohol; and

(h) recovering from the second reaction zone a C 16 /C 18 fatty alcohol product stream and hydrogen.

3. A process according to claim 2 wherein the amount of hydrogen provided to the first vaporisation zone is a stoichiometric amount required for the amount of lower alkyl esters of the C 12 /C 14 fatty acids supplied to the first vaporisation zone.

4. A process according to claim 2 wherein the hydrogen separated in step (d)is combined with the additional hydrogen in the second vaporisation zone.

5. A process according to claim 2 wherein the hydrogen separated in step (d)is combined with the additional hydrogen prior to the second vaporisation zone such that a single hydrogen stream is supplied to the second vaporisation zone.

6. A process according to claim 2 wherein the amount of hydrogen provided may be the stoichiometric amount required for the amount of lower alkyl esters of the C 16 /C 18 fatty acids supplied to the second vaporisation zone.

7. A process according to claim 1 wherein the hydrogen recovered in step (h) is recycled for use in the process.

8. A process according to claim 7 wherein make-up hydrogen is added as required to maintain the total amount of hydrogen in the system.

9. A process according to claim 8 wherein a purge is taken to prevent the build-up of undesirable material in the system.

10. A process according to claim 1 wherein the first and second vaporisation zones are separate zones in the same vaporiser.

11. A process according to claim 1 wherein the first and second vaporisation zones are separate vaporisers.

12. A process according to claim 1 wherein the first and second reaction zones are separate zones in the same reactor.

13. A process according to claim 1 wherein the first and second reaction zones are in separate reactors.