Published: 9 January 2023| Version 1 | DOI: 10.17632/bk6rj2ms4x.1
DhurjatiPrasad Chakrabarti, Matthew Charles


Water-in-Oil (W/O) Emulsion is deemed as one of the most difficult problems in colloid science. Several modelling studies have been conducted to gain a more thorough understanding of the separation process of emulsion from different configurations. Some of these phenomenological models are based on experimental published data or theoretical estimates of the coalescing process. However, authors have agreed that a general coalescence model that can describe coalescence of liquid-liquid systems that can encapsule all scaling parameters is needed. For that reason, a “simple” one dimensional mechanistic coalescence model is vital, which outlines the key parameters correctly. Unavoidably, these fitting parameters must be established by information derived from experiments. Hence, this improved empirical model, accounts for all the major phenomena of coalescence probability. Using previous works of (Noik, C.; Palmero, T.; Dalmazzone, C., 2013), the model includes droplet polydispersity and the viscosity of a liquid-liquid system, through the adoption of Sauter Mean Diameter (d32) and Einstein’s viscosity equation (𝜂𝑐−𝑐). The methodology first looked at settling of droplets through the existing model, and then introduced this to determine how coalescence behaves in the presence of demulsifiers from various authors. Application of this modified model to experimental research papers was performed and the results were recorded. As expected by enhancing the viscosity of the oil phase, this showed how fast the droplets settle for hindered settling section. The model results are somewhat acceptable for the phase distributions, albeit there were some issues with the units published by the authors which did not derive an exact replication of the stimulated results. This study outlined how considering the impact of rheological properties with droplet coalescence phenomena can be integral. The simulated results of emulsion separation profiles were differentiated with the predefined model, between experiments and tests simulation. The model sensitivity to operational parameter such as oil characteristics were tentatively analyzed. Additionally, recommendations are presented for further work which entails consideration of Population Balance Equations (PBEs) with several velocity groups, as compared to one and its effects of different demulsifiers.



University of the West Indies


Fluid Mechanics