The effect of cationic unit structure on reverse demulsification and air flotation performance of cationic polyacrylate

Cationic polyacrylates have efficient reverse demulsification performance and air flotation performance, which make them potentially viable for application in offshore oil fields. However, study of the relationship between their structure and performance is still lacking. In this paper, four compounds (benzyl chloride, 3-chloro-1-prop-anol, 3-chloro-1,2-propanediol and 3-chloro-2-hydroxytrimethylammonium chloride) were used to modify the copolymer of acrylate and tertiary amine monomer, and four cationic polyacrylates (CP-1, CP-2, CP-3 and CP-4) with different cationic unit structures were prepared. The hydrophilicity of the cationic units in these four cationic polyacrylates increased successively. The relationship between the cationic unit structure, interface properties and produced water treatment performance of products was studied. The results showed that CP-1 had the highest air flotation efficiency because it had the largest adsorption capacity on the surface of bubble and the strongest attractive force between oil droplets, while CP-2 had the highest reverse demulsification efficiency because it had the largest adsorption capacity on the surface of oil droplet and the strongest ability to reduce the elastic modulus of the O/W interface. The research results can provide a reference for chemical agent selection in the treatment of oilfield produced water.

Automated summary

This paper studied the relationship between the structure and performance of cationic polyacrylates, and prepared polymers with different cationic unit structures. The research results showed that cationic polyacrylates with different unit structures exhibited different air flotation and reverse demulsification efficiencies, providing reference for the selection of chemical agents in oilfield produced water treatment.