No abstract

The technical and economic feasibility of producing docosahexaenoic acid (DHA)-and eicosapentaenoic acid (EPA)-ethyl ester concentrates from transesterified tuna oil using supercritical fluid chromatography (SFC) was studied. A systematic experimental procedure was used to find the optimal values for process parameters and the maximal production rate. DHA ester concentrates up to 95 wt% purity were obtained in one chromatographic step with SFC, using CO 2 as the mobile phase at 65°C and 145 bar and octadecyl silane-type reversed-phase silica as the stationary phase. DHA ester, 0.85 g/(kg stationary phase · h) and 0.23 g EPA ester/(kg stationary phase · h) can be simultaneously produced at the respective purities of 90 and 50 wt%. The process for producing 1,000 kg DHA concentrate and 410 kg EPA concentrate per year requires 160 kg stationary phase and 2.6 tons/h carbon dioxide eluant recycle. The SFC operating cost is U.S. $550/kg DHA and EPA ethyl ester concentrate.

Solubility of 6-caprolactam in supercritical carbon dioxide was measured at temperatures from 307 K to 324 K and pressures from 100 bar to 230 bar. The mole fraction solubilities ranged from 0.02 to 0.07. A static variable volume view cell apparatus was used for the measurements. The solubility data were modeled using the Peng−Robinson equation of state with two adjustable mixture parameters.