Influence of fluid properties and solid surface energy on efficiency of bed coalescence

Emulsion separation is important in industry due to economic, safety, and ecological reasons. It can be applied in liquid-liquid extraction, effluent treatment, heat exchange, and fuel and chemical purification. In case of both oil-in-water and water-in-oil emulsions, regardless of their quantity and phase concentration, bed coalescence is a good and economical solution for separation. Due to the complexity of the bed coalescence phenomenon, the coalescer design relies on the base of the experimental test. The design strategy of a coalescer to separate oils of different quality in time is additionally complicated This paper presents a literature review on the current understanding of the influence of properties of both liquids and surface phenomena of filter media on emulsion separation efficiency using steady-state bed coalescence. The influence of oil viscosity, interfacial tension, density, molecular weight, emulsivity and dielectric constant of mineral oil is presented. The effect of solid surface roughness and wettability on separation efficiency is also elaborated.