Interactive Effect for Simultaneous Removal of SO₂, NO, and CO₂ in Flue Gas on Ion Exchanged Zeolites

Abstract

A purification system for simultaneous removal of SO₂, NO, and CO₂ in flue gas was considered in this study. For improving the purification performance of candidate adsorbent NaX zeolite, ion exchange experiments were conducted with cation K⁺, Ca²⁺, Mn²⁺, and Co²⁺, respectively. The texture properties of series zeolites were examined by N₂ porosimetry, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses. Among the sorbents investigated, K–NaX zeolite exhibited the best result to remove SO₂, NO, and CO₂ all together. XPS results revealed that SO₂ has been oxidized to form SO₄^2– on the solid surface; however, species N and C have not been observed. In order to understand the coadsorption effects, pure component, binary, ternary components, and mimic flue gas breakthrough experiments were designed and carried out. It suggested that SO₂ and NO was bonded on the adsorbent surface with degradation of NO. A little competitive effect of CO₂ on SO₂ and NO adsorption system were found. Finally, monitoring of coadsorption venting gas, thermodynamic equilibrium species simulation, TPD experiment, and quantum chemical calculation technology were used to examine the interactive effect