Oxidation Removal of CO from Flue Gas Using Two Fenton-like Wet Scrubbing Systems

Abstract

Advanced oxidation removal of carbon monoxide (CO) from flue gas using two Fenton-like wet scrubbing systems was studied in a bubbling scrubber for the first time. Influence of several technological parameters (e.g., H2O2 concentration, Fe3+/Cu2+ concentration, temperature, solution pH, CO inlet concentration, and gas flow rate) on the oxidation removal of CO was evaluated. Free radicals, products, and mechanism of CO oxidation removal were also studied. The results demonstrate that pH and temperature of the solution and concentration of H2O2 have double influence on the removal efficiency of CO. The increase of Fe3+/Cu2+ concentration elevates the removal efficiency of CO. The CO removal efficiency is reduced by raising the CO inlet concentration and the gas flow rate. Hydroxyl radical (•OH) oxidation is proved to be responsible for the oxidation removal of CO in the two studied Fenton-like wet scrubbing systems (H2O2/Cu2+ and H2O2/Fe3+). The main products of CO oxidation removal are bicarbonate, carbonate, and CO2 and can be effectively treated using a simple postprocessing strategy. The new removal process will not produce subsequent pollution, and may even provide a new option for green emission reduction of CO from exhaust gas.