(601a) Liquid Dissolution: 10 Times Slower Than Blending and 10 Times Faster Than Liquid-Liquid Break-up

Understanding the dissolution kinetics in a miscible liquid-liquid system can give great insights on how the physical properties of the system affect the drop size population. For stirred tanks operated in the turbulent flow regime, integrating the mechanisms determining the drop size distribution can be difficult because they depend on the local turbulence around the drop. A simplified simulation model which adequately captures the inhomogeneity in the stirred tank by using local averages known as ?mixing fields?, and the mechanisms involved in the drop size evolution has been developed. The drop break-up and dissolution processes typical of slightly miscible, low dispersed phase fraction (non-coalescing) liquid-liquid dispersion systems are modeled using established correlations and equations. By using Symmetric Geometric Length Scales (SGLS), very good resolution is given to the smaller drop sizes where mass transfer by dissolution is considerable. This model is a compromise between Computer Fluid Dynamics (CFD) simulations and models that assume perfect isotropy in stirred tanks. It is a good representation of the inhomogeneity observed in stirred tanks and the results match experimental results for both the concentration in the continuous liquid and the mean drop size with no adjustable parameters required.