New Amphiphilic Tricationic Imidazolium and Pyridinium Ionic Liquids for Demulsification of Arabic Heavy Crude Oil Brine Emulsions.

Abstract

Preparation of new green oilfield chemicals based on ionic liquids (ILs) having higher demulsification efficiency to solve the heavy crude oil brine water emulsions became a target in the petroleum research studies and industry. In the present work, the combination of pyridinium, imidazolium, and hydrophilic or hydrophobic moieties in the chemical structure of ILs has been investigated to improve the surface properties of ILs in both bulk solution and interfaces. Aminopyridine was quaternized with cetylbromide and condensed with glyoxal and 4-hydroxybenzaldehyde in acetic acid to prepare imidazolium–pyridinium bromide acetate ionic liquid (IPy-IL). The phenol group of IPy-IL was etherified with tetraethylene glycol to alter its amphiphilicity and synthesize new amphiphiles (AIPy-IL). Their chemical structure, thermal characteristics, and stabilities were characterized. Their aqueous solution performance in seawater was evaluated to investigate their surface activity, aggregation particle sizes, and surface charges. The demulsification performances of the prepared Arabic heavy crude oil seawater emulsions in the presence of different concentrations of IPy-IL and AIPy-IL were evaluated and proved by interfacial tension, particle size, and demulsification efficiencies at a temperature of 45 °C. The data concluded that AIPy-IL was an effective demulsifier for different crude oil seawater emulsion compositions at a low injection dose and temperature of 100 ppm and 45 °C, which were not report elsewhere.