Interfacial energy during the emulsification of water-in-heavy crude oil emulsions

Abstract

The aim of this study was to investigate the interfacial energy involved in the production of water-in-oil (W/O) emulsions composed of water and a Brazilian heavy crude oil. For such purpose an experimental set-up was developed to measure the different energy terms involved in the emulsification process. W/O emulsions containing different water volume fractions (0.1, 0.25 and 0.4) were prepared in a batch calorimeter by using a high-shear rotating homogenizer at two distinct rotation speeds (14000 and 22000 rpm). The results showed that the energy dissipated as heat represented around 80% of the energy transferred to the emulsion, while around 20% contributed to the internal energy. Only a very small fraction of the energy (0.02-0.06%) was stored in the water-oil interface. The results demonstrated that the high energy dissipation contributes to the kinetic stability of the W/O emulsions.