Adsorption of SOx by oxide materials: A review

• Single oxides to remove SOx from flue gases
• Oxides supported on various supports for the removal of SOx
• Influence of the support on the SOx removal
• Regeneration of the adsorbent by thermal decomposition of the metal sulfate

This paper is an attempt to provide a review — as extensive as feasible — of the literature devoted to the wide variety of sorbent systems that are currently either in use or under laboratory investigation for the removal of the SOx (SO2 + SO3) from flue gases. From an industrial perspective and besides any economic consideration, “the ideal” SOx sorbent candidate must ally four essential qualities some of which may appear contradictory to some extent: a strong affinity of the sorbent towards SOx along with fast kinetics; a large specific surface; a high physical/thermal/chemical stability and the capability for multiple regenerations at a reasonable temperature and with performance recoveries close to 100%.In this paper, the sorbent are classified in four categories which are: (i) single oxides; (ii) mixed oxides (including spinels and alumina supported oxides); (iii) oxides supported on carbonaceous materials and (iv) oxides supported on zeolites and mesoporous materials. A noteworthy outcome of this review lies in the promising prospects offered by porous silica-based materials as desulfurization (“DeSOx”) candidates and the interest of elaborating in this direction.