Low-temperature demulsification of pectinate alternating copolymer and its mechanism

Abstract

In this work, an amphipathic pectinate alternating copolymer “PEGLA” with alkyl side chain and PEG backbone was developed as demulsifier through a simple one pot epoxy-amine click chemical reaction method. The properties of demulsifier were evaluated by bottle test and the results showed that PEGLA had good demulsification efficiency at low temperature and low concentration. The demulsification efficiency reached 94.1 % with 100 mg/L at 40 °C for 150 min. Moreover, PEGLA has obvious advantages over commercial demulsifiers and reported work. The demulsification mechanism of PEGLA was elucidated through a detailed investigation of its interfacial properties. These results revealed that PEGLA rapidly aggregates at the oil–water interface and replaces or destroys the original asphaltenes interfacial film, thus forming an unstable discontinuous mixed film, lowering the stability of emulsified water droplets, resulting in demulsification.