Equilibrium and Rate Data for the Extraction of Lipids Using Compressed Carbon Dioxide

Abstract

Equilibrium data are given for the solubilities in compressed C0₂ of the lipid components in freshly ground rape seed and of glycerol trioleate (a typical constituent of rape oil) at pressures up to 200 bar and temperatures 25 to 75C. Continuous flow tests in which a bed of ground rape seed was contacted with a stream of liquid CO₂ at 25C and varied flow conditions are also reported. The results are collated in terms of an empirical mass transfer coefficient. A sharp change took place in the lipid concentration in the extractant stream leaving the bed when about 65% of the available oil had been extracted. This, and changes in the composition of the extract, are discussed, together with the use of this type of data for design purposes.