Acrylate polymer prepared by dispersion polymerization and its crude oil emulsion demulsification performance

Abstract

AbstractThe development of a new crude oil emulsion demulsifier to replace the block polyether has always attracted attention. In this article, a novel crude oil emulsion demulsifier was prepared by dispersion polymerization using a mixture of ether and water as the dispersion medium and acrylate, methacryloxyethylthrimethyl ammonium chloride (DMC), and acrylamide as the comonomers. Taking the stability and demulsification performance as the index, the effects of acrylate type, ether/water mass ratio, monomer mass ratio, monomer concentration, initiator type, ether type, and reaction temperature on the polymerization results were investigated. The experimental results showed that when the acrylate was butyl acrylate (BA), the mass ratio of BA to DMC was 1:1, and dispersion medium was the mixture of dipropylene glycol methyl ether and water (ether/water mass ratio 1.5:1), monomer concentration was 20 wt%, initiator was V50, reaction temperature was in range of 50 to 55°C, and polymerization reaction was 10 h, the product P (BA‐DMC‐AM) had a good demulsification performance for the crude oil emulsion (crude oil density 0.9625 g/cm3, water content in emulsion 50%). When the dosage of P (BA‐DMC‐AM) was 200 mg/L and the temperature was 75°C, its dehydration was higher than 90% after demulsification for 4 h. This efficiency was similar with the block polyether demulsifier BH133. In addition, interfacial properties showed that P (BA‐DMC‐AM) can adsorb onto the oil–water interface and reduce the strength of W/O interfacial film, thereby achieving demulsification.