Prediction of the Interaction between Crude Oil Wax-Crystal Fractions and Acrylate Polymers by Monte Carlo Simulation

Abstract

The interaction between n-alkanes and pour point depressants with different structures was investigated. Using n-hexadecane as the representative component of crude oil n-alkanes, molecular simulation was employed to study the interaction between polyacrylate pour point depressants with different side chain length and n-hexadecane, and the interaction between polyacrylate pour point depressants with different polar building blocks and n-hexadecane. It was shown that during wax precipitation process, the mixed energy is low when the side chain length of acrylate is compatible with n-hexadecane. It is easier for polyacrylate to go into wax-crystal lattice, thus lowering crude oil pour point. The simulation for pour point depressants consisting of acrylate and other different polar building blocks demonstrated that the stronger the polarity of polar building block, the lower the interaction energy between polymer pour point depressant and n-hexadecane. At the same time, it is easier for polymers with polar building blocks to interact with n-alkanes. The polar building block can effectively inhibit wax-crystal growth and thus improve crude oil low-temperature fluidity.