Performance evaluation of semi-dry flue gas desulfurization and denitration using nonthermal plasma combined process

Abstract

Nitrogen oxides (NO_x) and sulfur oxides (SO_x) are the major components of environmental pollution; therefore they should be removed. NO oxidation process by using ozone gas and NO_x removal process by using Na₂SO₃ solutions combined with semi-dry desulfurization equipment to glass melting furnace have been investigated. Regarding exhaust gas treatment in glass melting furnaces, desulfurization and particulate collection are performed by a semi-dry desulfurizer using caustic soda (NaOH), a dry electrostatic precipitator and a bag filter, respectively. However, it is difficult to use the conventional selective catalytic reduction method for denitration due to the high concentration of SO_x and sticky dust in the exhaust gas. Therefore, development of applicable denitration method is desired. In this study, we aimed to commercialize the plasma combined desulfurization and denitration method combining the semi-dry desulfurization equipment and the plasma combined denitration method. In a laboratory-scale semi-dry plasma combined desulfurization and denitration system, the effects of varying the simulated exhaust gas flow rate, component concentration, NaOH aqueous solution and Na₂SO₃ aqueous solution concentration and spray amount on desulfurization and denitration were investigated. As a result, in a laboratory-scale semi-dry plasma combined desulfurization and denitration system, NO_x removal was confirmed to have a maximum removal efficiency of approximately 80%.