Crude oil extracted from oil wells is a kind of water-in-oil fluid, which must be demulsified before refining. Crude oil demulsification mainly adopts high-voltage electrostatic field method and chemical demulsification method. The most effective method for chemical demulsification and dehydration is non-ionic surfactant demulsification.
In the production of petroleum products, various additives must be added to improve the performance of the products. According to the functions, additives can be classified into the anti-wear agent, detergent, dispersant, viscosity modifier, pour point depressant, rust inhibitor, fuel energy-saving agents, etc., most of which are non-ionic surfactants. Sorbitan esters and Polysorbates are non-ionic surfactants that can be used to achieve micro-emulsification or solubilization of water in fuels, which can play a significant energy-saving role. Sorbitan esters and polysorbates and commonly formulated in oil additive to create an additive with multiple functions.