Novel petroleum demulsifiers based on acrylic random copolymers

AbstractAlthough 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 (Mw¯) was varied by modifying the amount of chain transfer agent relative to the monomers from 0 to 8 wt%. FTIR and 13C-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°API). Copolymers with 70 wt% butyl acrylate monomer and a weight-average molar mass above of 11 000 g 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...