LAUSR

Abstract Crude oil is one of the most important energy sources in the world and contains a lot of paraffin wax. At higher temperatures, paraffin wax is dissolved in crude oil in an equilibrium state. However, when the temperature is lower than the precipitation temperature of wax, paraffin wax will precipitate, crystallize, and form a three-dimensional network structure, which will have a great impact on the transportation of crude oil. In engineering, waxy crude oil is usually transported by adding pour point depressants. Pour point depressant molecules can significantly improve the crystallization behavior of wax in waxy crude oil. This article reviews the types, preparation methods, and future development prospects of new pour point depressants in recent years. The nucleation mechanism of new NPPD synthesized by different methods and wax crystals in crude oil is summarized and commented. Starting from the microscopic morphology of the wax crystal, a prospect is put forward for the preparation of a new type of high-efficiency NPPD with better performance in the future. Graphical Abstract