Modelling and particle based simulation of electro-coalescence of a water-in-oil emulsion

Abstract

Electrocoalescence is an industrially relevant process, especially in oil exploration and petroleum refining industries, and is the working principle of the process equipment, an electrocoalescer. In this work, electrocoalescence is modelled using dipolar electrostatic forces which bring the droplets together but are resisted by Stokesian drag forces. We demonstrate that hydrodynamic interactions are important to model electrocoalescence. Similarly, a multi box methodology is necessary for getting improved statistics for drop size distribution, since any coagulation/coalescence process, typically results in the loss of droplets. Moreover, the process of chaining can be modelled by assuming a “wait-time” on contact of the interacting drops, and n-mer formation can be predicted. Our results show a reasonable agreement between model predictions and experimental data. The simulations also show that an increase in volume fraction, average droplet size, and polydispersity enhance the dynamics of the coalescence process.