Review of adsorptive desulfurization process: Overview of the non-carbonaceous materials, mechanism and synthesis strategies

Adsorption of pollutants or contaminants remains one of the most promising approaches for environmental and economical cleaning purposes. Whilst the adsorption is a very desirable and attractive method of cleaning and separation based on the cost and ease of operation, the efficiency of adsorptive technology anchors or revolves around the choice of the adsorbent. Carbon and its modified varieties, metal–organic frameworks (MOF), clays, zeolites, silica-based, and supported metal(s) have been employed over decades as adsorbents for different industrial, environmental and biological applications. This review focuses on the milestones achieved over decades regarding different non-carbonaceous adsorbents for adsorptive desulfurization of sulfur compounds in liquid fuels. Synthesis strategies of adsorbents, adsorption mechanisms, competitive effect of aromatic compounds, regenerability, nature of the liquid fuel (medium of liquid fuel), cost effectiveness, efficiency and few characterization techniques, and other parameters that affect the performance and operability of adsorbents will be explored in this review. The maximum adsorption capacity will be compared as a yardstick for chosen adsorbent for a specific sulfur compound in a suitable medium, and future research direction would be suggested. The readers will have a full understanding of adsorbents’ properties and performance in different media of liquid fuels and the chemistry of interaction with the host matrices. The review will also serve as a guide in bridging the gap between the past, present and the future on the adsorptive desulfurization technology.