Monitoring and Modeling of Creaming in Oil-in-Water Emulsions

Abstract

This work combines experimental and modeling investigations to monitor the dynamics of creaming in oil-in-water emulsions. Turbidity and Raman spectroscopy methods were compared for the experimental monitoring of creaming of nhexadecane droplets in water. A creaming model is developed based on the convection-diffusion equation. The model accounts for the full droplet size distribution. The experimental data were used to identify the diffusion coefficient of the oil droplets and the Richardson−Zaki coefficient correcting the effect of the local volume fraction. The droplets' size and concentration are varied to evaluate their effect on the creaming rate. The developed model could accurately predict the kinetics of creaming in the different considered cases. It can be used for emulsion stability studies, for instance, in food/pharmaceutical industries and/or for gravity separator design and monitoring.