Experiments and model on viscosity characteristic of emulsion of heavy fuel oil and water for fluidity improvement

The background of this study is to develop a method to improve the fluidity of high viscosity oil left in sunken ships. We focused on emulsification to control the rheological properties of the oil. As a first step towards the goal, experiments and modeling were conducted to understand the viscosity properties of oil-water emulsions. In the experiments, oil-water emulsions were prepared using several surfactants to measure viscosity properties. The results showed a continuous change in viscosity with increasing water content as well as a discontinuous change in viscosity due to phase inversion that occurs at a certain water content. In the theoretical modelling, a new layer-stacking model was developed and applied to the experimental results. This model, though extremely simplifying the structure of the emulsion, was found to be able to well explain the continuous and discontinuous viscosity characteristics of the emulsion.