A comprehensive review on desulfurization adsorbents from light sour naphtha

This review highlights the different adsorbents used for desulfurization of light naphtha with regard to regenerability, selectivity, and scalability in industrial processes. The sulfur compounds in the petroleum derivatives should be removed from the products for minimization of their adverse effects on the environment, for enhancing fuel quality, and meeting the international requirements. A systematic review is done of zeolites, metal oxides, activated carbon, and other types of adsorbents. Zeolites, with their porous structure and tunable pore size, exhibit high selectivity for sulfur compounds such as thiophenes and benzothiophenes. Activated carbon, due to its large surface area and customizable properties, is capable of adsorbing a wide variety of sulfur compounds. One of the most important challenges is regenerability and reusability of adsorbents. According to various research, zeolites and some metal oxides regained their functionality after repeated adsorption-desorption cycles, which have advantages in industrial applications. Carbon-based adsorbents also show thermal and chemical stability and, hence, can be used in multiple regeneration cycles. Adsorbents not only have to perform well at an industrial scale but also have to be cost-effective. Metal oxides can be produced at low costs and are thus suitable for large-scale applications. They show promising results in the laboratory, but further research has to be done to evaluate their stability and cost efficiency at larger scales. In this regard, process optimization of operating parameters such as temperature, pressure, and solvent use can strikingly enhance desulfurization efficiency and reduce operating costs.