Ionic Liquids as Crude Oil Demulsifiers: A Mini-Review

Demulsification of crude oil emulsions represents a critical process in the petroleum industry. Identifying effective demulsifiers remains a pivotal research focus in petroleum science. As emerging materials, ionic liquids (ILs) have found extensive applications across various industrial sectors, including their use as demulsifiers for crude oil emulsions. This review systematically examines recent advancements in the molecular design of IL-based demulsifiers, focusing on structure–performance relationships. Key factors influencing demulsification efficacy, including alkyl chain configuration, cation multiplicity, counteranion selection, functional group integration, polymerization strategies, and carrier-loading approaches, are critically analyzed. Furthermore, this work evaluates standard performance characterization methodologies while addressing current challenges and future prospects for IL-based demulsification technologies.