Industrial sulfur separation and purification: Paving the way to energy applications

Industrial sulfur separation and purification: paving the way to energy applications. • Assesses advanced sulfur desulfurisation and purification methods. • Novel desulfurisation methods achieve ultra-high-purity sulfur. • Ultra-high-purity sulfur is crucial for efficient energy applications. • Highlights pathways for sustainable sulfur use in energy storage. Sulfur, a by-product of industrial processes, presents a unique opportunity for advancing sustainable energy storage systems, particularly in metal-sulfur batteries (MSBs) and thermal energy storage (TES) applications. Both MSBs and TES technologies benefit from sulfur’s abundance, cost-effectiveness, and high energy storage potential. However, the effective utilisation of sulfur in these systems relies on its purification to meet stringent quality standards, as impurities can significantly impact performance. This review examines sulfur’s role as an industrial by-product, detailing conventional and alternative purification methods from sources such as petroleum and coal. Techniques such as hydrodesulfurisation (HDS), adsorptive desulfurisation (ADS), oxidative desulfurisation (ODS), and biodesulfurisation (BDS) as well as extraction and flotation are evaluated for their efficiency, scalability, and environmental impact. Sulfur’s dual application in MSBs and TES positions it as a critical material for sustainable, large-scale energy storage solutions, underscoring this research’s significance and impact implications. The review emphasises the need for continued innovation in sulfur purification methods and integrating green chemistry principles to enhance sustainability. The insights provided here pave the way for broader sulfur utilisation, offering sustainable pathways for its application in industrial processes and energy storage technologies.