Mathematical modeling of extraction of egg yolk oil with supercritical CO2

Extraction of egg yolk oil (EYO) from egg yolk pou der (EYP) with supercrit ical CO2 was performed on a laboratory apparatus. Solubility of EYO in supe rcritical CO2 was measured. The external diffusion and the equilibrium betw een solid and fluid phases were experimentally found to be the controlling steps during the extraction process. Based on this mechanism, a mathematica l model fur this extraction process was developed. The model parameters, ad sorption equilibrium constant (k(p)), EYO concentration in solid controllin g the transition in the equilibrium (x(k)) and the overall volumetric mass transfer coefficient (K(f)a(p)). were obtained av simulation. Ine simulatio n results indicated thar x(k) is 0.56. K(f)a(p) is directly propurlional to CO2 flow rate with an expunrnr of 0.548. and the adsorption heat of EYO is 6-9 kJ mol(-1). The model was verifird by concentration profiles of solid. The extraction process of EYO with supercritical CO2 was conducted on a pi lot plant and the developed model could predict satisfactorily the process. (C) 2001 Elsevier Science B.V. All rights reserved.