Research progress on the adsorption of sulfocompounds in flue gas

Sulfocompounds in flue gas emitted by various industries, not only affect the stability of pipelines and subsequent devices but also cause air pollution when discharged into the atmosphere. Due to the advantages of low cost and good recyclability, porous materials are usually applied to adsorb both organic and inorganic sulfocompounds. Inorganic sulfocompounds can easily interact with porous adsorbents by polar interaction, acid-base interactions, or metal coordination adsorption. Organic sulfocompounds with high reaction energy are more likely to be immobilized by physisorption. Among the adsorption materials, carbon materials and molecular sieves have well-developed pores and a huge specific surface area to build different active sites. Metal active sites (–OH, adsorbed oxygen, lattice oxygen) in metal oxides are the main sites for their adsorption effects, and MOFs materials, as metal crystalline materials with periodic structure, have both large specific surface area and abundant metal sites. When the porous material is saturated with adsorption, it is necessary to keep the recycling of the material. Correspondingly, in this work, the desulfurization mechanisms including both physical and chemical interaction were elucidated firstly, based on which the adsorbent materials (i.e., carbon-based materials, molecular sieves, metal oxides, metal organic frameworks) were then summarized from both aspects of their textural properties and their application in desulfurization. The applicability of three ways ((i.e., thermal regeneration, solvent regeneration, and pressure reduction/vacuum regeneration) for regenerating porous materials are summarized. It is expected to provide some advanced guidance for researchers in the adsorption of sulfocompounds in flue gas.