No abstract

An iron-based catalyst with excellent performance and low price was used for simultaneous removal of SO2 and NO x in a typical Fenton system. The catalyst was developed from fly ash of pulverized coal furnace by alkali-magnetic modification process. In other words, the raw fly ash was first modified by Ca­(OH)2, which destroyed the vitreous shell and made the internal substances such as Al2O3, SiO2, and Fe2O3 dissolve out gradually, and then separated magnetically and roasted, and the high magnetic Fe2O3 content of high reactivity was obtained. In the fixed bed experimental system, an ultrasonic nebulizer was adopted to atomize hydrogen peroxide which can reduce the particle size of hydrogen peroxide and shorten the gasification time greatly. Effects of the concentration of hydrogen peroxide, reaction temperature, iron oxide content, and initial concentration of SO2 and NO x on the collaborative removal efficiencies were investigated. Under low hydrogen peroxide concentration (1 mol/L) and flow rate (0.03 mL/min), 100% desulfurization efficiency and 90% denitrification efficiency can be achieved using hydrogen peroxide catalyzed by the modified fly ash. The catalytic mechanism and reaction mechanism were analyzed by XRF, XRD, ESR, SEM, BET, and XPS.

NO removal from flue gas was conducted on a self-made bubbling reactor with ClO 2 . Results indicated that ClO 2 has excellent oxidizing power to NO, and its actual reaction molar ratio is close to the theoretical molar ratio. At the temperature of 80 °C and ClO 2 /NO = 0.6, the NO removal efficiency can reach 96.7%. The electron spin resonance and inhibitor (sodium formate and isopropanol) addition experiments indicated that the ClO 2 and •OH radical in the solution played an important role in NO oxidation. The mechanism of NO removal by ClO 2 was proposed through the analysis of oxidation products and relative references.

No abstract