Examining the Effectiveness of Deep Eutectic Solvents in Removal of Sulfur from Fuel Oil: A Mini Review

Abstract

Abstract The global demand for cleaner and more sustainable energy sources has stimulated extensive research into advanced technologies for sulfur removal from fossil fuels. Sulphur compounds in fuels contribute to air pollution, acid rain, and environmental degradation, underscoring the urgency of efficient desulfurisation methods. Deep eutectic solvents (DESs) have emerged as environmentally friendly candidates for sulphur removal from fuels. This review provides an overview of recent advancements in utilising DESs for desulfurisation processes, highlighting their sustainable and economically viable features. The manuscript begins with an introduction to the pressing need for clean fuels. It also emphasises the unique properties of DESs, such as low toxicity, biodegradability, and tunability, making them well-suited for sulphur extraction. A brief discussion on the classification and synthesis of DESs contextualises the review. Additionally, an overview of the effects of sulphur on the environment is presented. This review systematically categorises DESs used for desulfurisation into five distinct groups: DESs containing transition metal salts, sulfones, glycols, aromatic compounds, and organic acids. Each category is thoroughly discussed, examining their respective applications and effectiveness in desulfurisation processes. Towards the end, the review addresses current challenges and prospects in the field, including scaling up DES-based processes and enhancing efficiency through catalysts and synergistic approaches. Graphical Abstract