Modelling of orange flower concrete fractionation by supercritical CO2

Supercritical CO2 extraction was used to post-process a semi-solid orange f lower extract produced by liquid solvent extraction. The optimum process co nditions to separate volatile oil were 90 bar and 40 degrees C. At these co nditions no undesired compounds were co-extracted except waxes. Adopting a stage-wise separation procedure, consisting of two separators operated in s eries, these latter compounds were eliminated. The volatile oil yield was 53.6% by weight of the charged material. The vol atile oil was considered to be a mixture of four different compound familie s (pseudo-components). A model based on the formation of 'shock concentrati on waves' was proposed and integrated with a numerical method. The results of modelling confirm that the hypothesis of volatile oil as formed by pseud o-components is sufficient to describe the behavior of monoterpenes (hydroc arbon and oxygenated), whereas a multi-pseudo-component simulation is requi red to describe the extraction kinetics of sesqui- and diterpenes. (C) 1999 Elsevier Science B.V. All rights reserved.