Fuel desulfurization using ionic liquids –An updated review

Abstract

Environmental and human safety has become an important subject of research interest in petroleum chemistry and environmental catalysis. The presence of sulfur-containing compounds in fuel oil is an overwhelming problem in the petrochemical industries due to regulations for environmental protection. The emitted toxic gases from the combustion of fossil fuels result in air contamination that can damage the human respiratory system, cause acid rain, and negatively affect refinery equipment. Therefore, fuel desulfurization becomes necessary to remove sulfur and its derivatives from fuel oil. Recently, ionic liquids (ILs) have been identified as good candidates for many industrial applications. They are widely known for their potential as designer solvents due to fascinating properties such as low volatility, high tunability, and high thermal stability. However, their general environmental impact varies significantly depending on their specific chemical compositions with some ILs exhibiting toxicity or poor biodegradability. The present study comprehensively reviews the recent achievements and applications of ILs in fuel oil desulfurization, addressing the mechanisms of the conversion process. The practicality and reusability of ILs for fuel oil desulfurization have been reported, and finally, the conclusion and future research prospects in this exciting area have been suggested. This review is anticipated to provide insights into fuel refinement and purification technologies through the sustainable application of ILs for clean fuel generation.