Process intensification technologies for oil-water separation

Oil-water mixtures are widely present in various industrial processes. Its properties and enhanced separation technologies are one of the most important research topics in the field of chemical separation. The conventional physical separation technologies, such as sedimentation, cyclone, and electric coalescence, etc are used in combination with chemical agents for demulsification, which have several problems, such as low separation efficiency and secondary pollution. In recent, the development of enhanced separation technology represented by multi-physical field coupling and new separation materials has attracted wide attention. In this study, the separation of the large volume of water-in-oil (W/O) crude oil emulsion and oil-in-water (O/W) oily wastewater emulsion in the petroleum industry is investigated. The formation, classification, and basic physicochemical properties of oil-water mixtures are described. It pointed out that the breaking of emulsion stability is the key to enhance the separation based on the analysis of microscopic interfacial film. Various separation technologies and their characteristics are systematically introduced from the aspects of conventional separation technology, applied field, separation materials, and coupling, etc. Finally, the further research trends of enhanced oil-water separation technology are prospected. © 2020, Chemical Industry Press Co., Ltd. All right reserved.