Process for the separation of alkyl branched fatty acids from a fatty acid mixture
View Patent ↗A process for the separation of alkyl branched C 12 to C 24 fatty acids from a fatty acid mixture comprising linear and alkyl branched C 12 to C 24 fatty acids comprises; (i) optionally hydrogenating the fatty acid mixture, (ii) cooling the mixture to form crystals, and (iii) separating the alkyl branched C 12 to C 24 fatty acids from the mixture by dry fractionation.
1. A process for the separation of alkyl branched C 12 to C 24 fatty acids from a fatty acid mixture comprising 15 to 65% by weight of linear C 12 to C 24 fatty acids and 35 to 85% by weight of alkyl branched C 12 to C 24 fatty acids, relative to the total weight of the fatty acid mixture, wherein the process comprises:
(i) optionally hydrogenating the fatty acid mixture,
(ii) cooling the mixture to form crystals, and
(iii) separating the alkyl branched C 12 to C 24 fatty acids from the mixture by dry fractionation.
2. A process according to claim 1 wherein the fatty acid mixture comprises greater than 95% by weight of saturated fatty acids, and less than 5% by weight of unsaturated fatty acids.
3. A process according to claim 1 wherein the fatty acid mixture comprises 40 to 65% by weight of alkyl branched C 12 to C 24 fatty acids, and in the range from 35 to 60% by weight of linear C 12 to C 24 fatty acids.
4. A process according to claim 1 wherein the fatty acid mixture comprises
(i) less than 4% by weight of C 14 fatty acids, and/or
(ii) in the range from 10 to 35% by weight C 16 fatty acids, and/or
(iii) in the range from 50 to 75% by weight of C 18 fatty acids, and/or
(iv) in the range from 3 to 15% by weight C 20 fatty acids, and/or
(v) in the range from 2 to 10% by weight of C 22 fatty acids.
5. A process according to claim 1 wherein the fatty acid mixture comprises in the range from 15 to 30%, by weight C 16 fatty acids.
6. A process according to claim 1 wherein the fatty acid mixture comprises in the range from 55 to 65%, by weight of C 18 fatty acids.
7. A process according to claim 1 wherein the weight ratio of C 18 to C 16 saturated linear fatty acids present in the fatty acid mixture is in the range from 0.4 to 1.5:1.
8. A process according to claim 1 wherein the separated alkyl branched C 12 to C 24 fatty acids comprise in the range from 73 to 95% by weight of branched fatty acids, and in the range from 5 to 27% by weight of linear fatty acids.
9. A process according to claim 1 wherein the separated alkyl branched C 12 to C 24 fatty acids comprise
(i) less than 3% by weight of branched C 14 fatty acids, and/or
(ii) in the range from 2 to 12% by weight of branched C 16 fatty acids, and/or
(iii) in the range from 55 to 85% by weight of branched C 18 fatty acids, and/or
(iv) in the range from 2 to 12% by weight of branched C 20 acids, and/or
(v) in the range from 1 to 8% by weight of branched C 22 fatty acids.
10. A process according to claim 1 wherein the separated alkyl branched C 12 to C 24 fatty acids comprise in the range from 4 to 10% by weight of branched C 16 fatty acids.
11. A process according to claim 1 wherein the separated alkyl branched C 12 to C 24 fatty acids comprise in the range from 60 to 80%, by weight of branched C 18 fatty acids.
12. A process according to claim 1 wherein the separated alkyl branched C 12 to C 24 fatty acids comprise
(i) in the range from 3 to 14% by weight of linear C 16 fatty acids, and/or
(ii) in the range from 0.5 to 6% by weight of linear C 18 fatty acids.
13. A process according to claim 1 wherein the separated alkyl branched C 12 to C 24 fatty acids comprise C 18 to C 16 saturated linear fatty acids present at a weight ratio in the range from 0.1 to 0.7:1.
14. A process according to claim 1 wherein the separated alkyl branched C 12 -C 24 fatty acids comprise greater than 90% by weight of saturated fatty acids, and in the range from 0 to 10% by weight of unsaturated fatty acids.
15. A process according to claim 1 wherein the separated alkyl branched C 12 -C 24 fatty acids have
(i) an acid value in the range from 175 to 205 mgKOH.g −1 , and/or
(ii) a saponification value in the range from 175 to 210 mgKOH.g −1 , and/or
(iii) an unsaponifiable value of less than 7 g.100 g −1 , and/or
(iv) an iodine value of less than 6 g.100 g −1 , and/or
(v) a cloud point in the range from 0 to 10° C., and/or
(vi) a colour value of less than 150 Hazen units.
16. A process according to claim 1 wherein the separated alkyl branched C 12 to C 24 fatty acids have a cloud point in the range from 0 to 80° C.
17. A process according to claim 1 wherein plate-like crystals are formed during cooling.
18. A process according to claim 17 wherein the plate-like crystals have a mean aspect ratio in the range from 1 to 2:1.
19. A process according to claim 17 wherein the plate-like crystals have a mean crystal diameter in the range from 250 to 500 μm.
20. A process according to claim 1 wherein the fatty acid mixture is initially heated to a temperature in the range from 48 to 80° C.
21. A process according to claim 1 wherein the fatty acid mixture is cooled to a temperature in the range from 7 to 16° C.
22. A process according to claim 1 wherein the alkyl branched C 12 to C 24 fatty acids are separated by filtration.
23. A process according to claim 1 wherein the weight ratio of C 18 to C 16 saturated linear fatty acids present in the fatty acid mixture is adjusted prior to or during the cooling stage, preferably by the addition of palmitic acid.
24. A process according to claim 23 wherein in the range from 0.5 to 15 g of palmitic acid is added per 100 g of fatty acid mixture.