Supercritical carbon dioxide (SC-CO₂) extraction of palm kernel oil from palm kernel

Extraction of palm kernel oil from dehulled ground palm kernel using supercritical carbon dioxide (SC-CO₂) was studied at conditions of 313.2 and 353.2 K and at pressures from 20.7 to 48.3 MPa. The yield of PKO increased with pressure from 34.5 to 48.3 MPa at 353.2 K and attained a value of 49 g oil/100 g palm kernel at 48.3 MPa and 353.2 K. Lower amounts of shorter chain triglycerides component in terms of fatty acid constituents (C₈-C₁₄) were extracted at lower pressures of 20.7-27.6 MPa, and higher amounts of longer chain fatty acid constituents (C₁₆-C_18:2) were extracted at higher pressures from 34.5 to 48.3 MPa. A simple correlation was developed based on a kinetic mass transfer model. From the correlation, the minimum amount of CO₂ usage for a given yield could be estimated.