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Regenerable flue gas desulfurization (FGD) is highly attractive because of the transformation of sulfur dioxide (SO2) to high-value products. In this study, selenium-assisted SO2 reduction by carbon monoxide (CO) in the liquid phase [dimethylformamide (DMF) + water (H2O) mixture] is proposed and applied in the FGD process. This process realizes recycle of the elemental sulfur product under room temperature. Moreover, results show that both the selenium catalyst and DMF solvent have good stability and can be well recycled, implying that this process is economically feasible. Furthermore, the mechanism of selenium-assisted SO2 reduction by CO in DMF/H2O is investigated. Results show that the selenium catalyst dissolves in solution and forms Sen2- species, which are the active intermediates and promote formation of the sulfur product. [ABSTRACT FROM AUTHOR]

NO 2 and SO 2 , as valuable chemical feedstock, are worth being recycled from flue gases. The separation of NO 2 and SO 2 is a key process step to enable practical deployment. This work proposes SO 2 separation from NO 2 using chabazite zeolite (SSZ-13) membranes and provides insights into the feasibility and advantages of this process using molecular simulation. Grand canonical ensemble Monte Carlo and equilibrium molecular dynamics methods were respectively adopted to simulate the adsorption equilibria and diffusion of SO 2 , NO 2 , and N 2 O 4 on SSZ-13 at varying Si/Al (1, 5, 11, 71, +∞), temperatures (248-348 K), and pressures (0-100 kPa). The adsorption capacity and affinity (SO 2 > N 2 O 4 > NO 2 ) demonstrated strong competitive adsorption of SO 2 based on dual-site interactions and significant reduction in NO 2 adsorption due to dimerization in the ternary gas mixture. The simulated order of diffusivity (NO 2 > SO 2 > N 2 O 4 ) on SSZ-13 demonstrated rapid transport of NO 2 , strong temperature dependence of SO 2 diffusion, and the impermeability of SSZ-13 to N 2 O 4 . The membrane permeability of each component was simulated, rendering a SO 2 /NO 2 membrane separation factor of 26.34 which is much higher than adsorption equilibrium (6.9) and kinetic (2.2) counterparts. The key role of NO 2 -N 2 O 4 dimerization in molecular sieving of SO 2 from NO 2 was addressed, providing a facile membrane separation strategy at room temperature.