Capture and separation of sulphur hexafluoride: the most powerful greenhouse gas

Sulphur hexafluoride (SF 6 ) is a potent greenhouse gas (GHG), possessing the highest global warming potential among commonly monitored GHGs, making its mitigation a critical environmental priority. Numerous porous solid matrices have been developed for SF 6 capture; however, large-scale industrial deployment remains hindered primarily by high production costs. In this study, the adsorption and separation of SF 6 from SF 6 /N 2 mixtures were investigated using four activated carbon materials (ACs), selected for their low cost, ease of fabrication and suitability for industrial applications. The adsorption equilibria of SF 6 and N 2 on the four ACs (designated AC1, AC2, AC3 and ACHM) were measured using a gravimetric method at three temperatures: 283, 303 and 323 K. The experimental data were fitted using the Toth adsorption model, which accurately described the system behaviour across both low and high-pressure regions. Additionally, the selectivity of the SF 6 /N 2 was evaluated using Ideal Adsorption Solution Theory (IAST). Among the tested materials, ACHM exhibited superior selectivity of the SF 6 /N 2 mixture, attributed to its high microporosity. Finally, a comparative analysis with materials reported in the literature under industrially relevant conditions highlighted the strong potential of these ACs, particularly in terms of working capacity, selectivity and regeneration capacity.