Removal of Carbon Monoxide from Simulated Flue Gas Using Two New Fenton Systems: Mechanism and Kinetics.

Abstract

Two novel removal processes of carbon monoxide using two new Fenton systems (i.e., Cu2+/Fe2+ and Mn2+/Fe2+ coactivated H2O2 systems) were developed. The effect of several process parameters (concentrations of H2O2, Fe2+, Cu2+, and Mn2+, reagent pH value, solution temperature, and simulated flue gas components) on CO removal was studied in a bubbling reactor. The mechanism and kinetics of CO removal were also revealed. Results show that adding Cu2+ or Mn2+ obviously enhances the removal process of CO in new Fenton systems. The measured results of free radical yield demonstrate that the enhancing role is derived from producing more ·OH (they are produced due to the synergistic activation role of Cu2+/Fe2+ or Mn2+/Fe2+ in new Fenton systems. The removal efficiency of CO is raised by increasing concentrations of Fe2+, Cu2+, and Mn2+ and is reduced by raising concentrations of CO, NO, and SO2. Increasing H2O2 concentration, reagent pH, and solution temperature demonstrates a dual impact on CO absorption. Three oxidation pathways are found to be responsible for CO removal in new Fenton systems. Results of mass-transfer reaction kinetics reveal that CO removal processes are located in a fast-speed reaction kinetics region (the CO removal process is controlled by the mass transfer rate).