Journal of Supercritical Fluids, Vol.129, 36-47, 2017
Measurement and modelling of mass transport properties during the supercritical fluid extraction of emulsions
Supercritical fluid extraction of emulsions (SFEE) is a method used for producing aqueous suspensions, containing encapsulated particles in nanometric scale, through the extraction of an organic phase from an emulsion with supercritical CO2. Optimization of SFEE process conditions is complex as they influence several process steps. In this work, ethyl acetate and dichloromethane o/w emulsions were prepared using soybean lecithin and polaxamers as surfactants and contacted with supercritical CO2. Mass transport properties were measured by magnetic suspension balances, which provide an on-line contactless weight measurement method, and a mass transfer model based on the experimental results was developed. Experimental results indicate that the density of supercritical CO2 has a strong influence in mass transfer parameters, while no influence of other conditions such as type or concentration of surfactant was observed. In the case of dichloromethane/water emulsions, emulsion destabilization took place immediately after pressurization of the system. (C) 2017 Elsevier B.V. All rights reserved.
Keywords:supercritical fluid extraction of emulsions;SFEE;magnetic suspension balance;emulsion;supercritical carbon dioxide;mass transfer model;interfacial tension