Advances in low-temperature flow performance improvement materials for conventional diesel and biodiesel: a mini review

Diesel fuel, as the core fuel for global transportation, agricultural machinery and industry, its poor low-temperature fluidity has long been a constraint to the stable operation of machinery and equipment. With the application of renewable energy sources such as biodiesel, although its low carbon emission characteristics contribute to the energy structure transition, the fatty acid methyl ester (FAME)-dominated composition of the components also leads to the reduction of the energy barrier for wax crystal formation. Biodiesel has different crystallization characteristics compared to conventional diesel in terms of low-temperature flow improvement technology. While the improvement of conventional diesel mainly targets wax crystals, biodiesel addresses the crystallization of saturated fatty acid methyl esters. By inhibiting the growth of wax crystals or altering the crystallization morphology, low-temperature flow improvers can effectively enhance the low-temperature performance of diesel fuel, leading to a significant reduction in the cold filter plugging point (CFPP) and pour point (PP). This article focuses on the research progress of low-temperature flow improvers for conventional diesel and biodiesel, systematically reviewing the mechanisms and applications of surfactants, polymers, and nanomaterials, while also exploring future research directions to provide a foundation for the development of highly efficient diesel flow improvement materials.