Continuous operation of commercial-scale plasma-chemical aftertreatment system of smoke tube boiler emission with oxidation reduction potential and pH control

摘要

NO_x removal from an actual boiler flue gas is investigated using an indirect plasma and chemical hybrid system comprising a commercial ozonizer and an Na_2SO_3 chemical scrubber. A high NO_x removal efficiency in the continuous operation of a commercial-scale apparatus is achieved by controlling pH and oxidation reduction potential (ORP) and injecting additional Na_2SO_3 and NaOH aqueous solutions into the scrubber sump when required. Ozone injection is demonstrated to be extremely effective for NO oxidation. The relation between the ORP and NO_x removal efficiency, which is essential for the optimal operation of this system, is obtained.