Novel petroleum demulsifiers based on acrylic random copolymers

Although normally the copolymers used to remove water from crude oil have a block structure, two series of random acrylic copolymers were evaluated as petroleum demulsifiers. These acrylic copolymers, with two different butyl acrylate (BuA) and 2-ethylhexyl acrylate (2-EHA) contents, were synthesized by semi-continuous emulsion polymerization. Their weight-average molar mass () was varied by modifying the amount of chain transfer agent relative to the monomers from 0 to 8wt%. FTIR and C-13-NMR spectroscopies confirmed that the conversion of the monomers was complete. The synthesized acrylic copolymers were subsequently evaluated as demulsifier agents in a Mexican heavy crude oil (10.24 degrees API). Copolymers with 70wt% butyl acrylate monomer and a weight-average molar mass above of 11 000g mol(-1) presented the greatest ability to remove emulsified water from the system. The demulsifying capability of the copolymer was evidenced to be strongly dependent on their molecular mass. HighlightsSynthesis of random acrylic copolymers (BuA-co-2-EHA) of different average molar mass ().Evaluation of random acrylic copolymers as demulsifiers of heavy crude oil.Weight-average molar mass () and monomer composition play an important role on the performance of random acrylic copolymers as demulsifiers. [GRAPHICS] .