Discovery of a phosphonium ionic liquid phase from the reaction of trialkylphosphines and epichlorohydrin carbonate and application as a CO2-based triphasic demulsifier of crude oil

Abstract

In the search for a cyclic carbonate-based compound with amphiphilic properties, we combined highly polar epichlorohydrin carbonate with a long chain trialkylphosphine (P(Octyl)3). Under prolonged stirring, these mutually insoluble reagents led to the formation of a single phase containing several phosphonium salts whose composition and mechanism of formation has been systematically investigated by a combination of NMR techniques. Importantly, the obtained phase was immiscible with both water and hydrocarbons and had an intermediate density between such phases thus enabling its application as a unique triphasic demulsifier for water in oil (W/O) mixtures using actual crude oil. This work led to a new insight into the chemistry of CO2-made cyclic carbonates and to their application as intermediates and components of CO2-dervied demulsifiers.