SUPERCRITICAL-FLUID EXTRACTION OF EVENING PRIMROSE OIL KINETIC AND MASS-TRANSFER EFFECTS

For processing utilization, supercritical fluid extraction requires a thorough understanding of the relevant phase equilibria, mass balance, and kinetic factors that impact on the successful recovery of extract s. In this study, we have determined the factors contributing to the k inetics and mass transfer of evening primrose oil (EPO) from its groun d seed matrix, to supplement previously determined solubility data and chemical characterization of this oil moiety, The effect of ex-tracti on pressure, temperature, fluid density, and flow rate (over a threefo ld range) have been ascertained; the flow rate effect being correlated in terms of the extracted seed mass and similar data from the literat ure performed on a pilot and production plant scale, Using a dual mass transfer model, we have correlated the theory with extraction experim ents conducted over a pressure range from 20-70 MPa, temperatures from 40 degrees-60 degrees C, and carbon dioxide now rates in the interval from 9-27 g/min. The agreement between the model calculations and exp erimental data is excellent allowing potential use of the data in proc ess design.