Experimental results of NO removal by the MBGLS

Abstract

Existing oxidation–absorption denitration processes have some disadvantages such as high cost, equipment corrosion and low oxidant utilisation ratio. In this work, a novel denitration process with a microbubble gas–liquid dispersion system (MBGLS) was proposed. The nitric oxide (NO) removal effects of MBGLS based on the various absorbents containing hydrogen peroxide (H2O2), salinity and metal ions were investigated. The results showed that the MBGLS had an excellent NO removal performance because of hydroxyl radicals (·OH) released by the MBs. H2O2, NaCl, Fe2+ and Mn2+ could enhance the removal properties of MBGLS, but excessive NaCl was not conducive to the removal of NO. Under the optimal reaction conditions (absorbent pH = 8, 330 K, 0.4 mol/l H2O2 and 800 ppm NO), the NO removal efficiency reached 87.7%. This new process is highly cost-effective and environment friendly and shows a good commercial application prospect in flue gas denitration.