Pilot-Plant Molecular Distillation of Seal Oil Fatty Acids

Abstract

Seal oil fatty acids are the important natural source of some functional fatty acids, for example, DPA, EPA and DHA. The three kinds of effective components (DPA, EPA and DHA) in the rough finished product of seal oil account for about 20% of the total content. However, the healthcare applications using seal oil fatty acids require products with higher purity. To meet this requirement, it is necessary to selectively enrich the content of the effective components in the crude product. A pilot plant VTA wiped film molecular distillation unit is used to give a product (residue). The seal oil fatty acids in residue have a higher content of the effective components (about 26%) than the undistilled material with a content of about 20%. Feed flow rates and evaporator temperatures are varied to observe the resultant of the purity and yield of DPA, EPA and DHA in the residue and the residue to distillate split mass ratio. The maximum values of the purity in the residue fraction are 0.269 (301 °C), 0.263 (310 °C), and 0.266 (317 °C), and the maximum values of the split ratios and yields occur at 294 °C (1.392, 0.694), 299 °C (1.588, 0.727), and 309 °C (1.380, 0.685). Therefore, there is a trade-off between the yield and purity of DPA, EPA and DHA in the residue. The higher the temperature is, the higher the purity but the lower yield. In conclusion, seal oil fatty acids can be successfully purified for healthcare applications using a pilot plant wiped film molecular distillation unit and high vacuum.