NO_x removal from the flue gas of oil-fired boiler using a multistage plasma-catalyst hybrid system

摘要

The study on removal of NO_x from the flue gas of oil-fired boiler has been carried out using non-thermal plasma cum catalyst hybrid reactor at 150°C.Propylene(C3H6)was used as a reducing agent.A multistage plasma-catalyst hybrid reactor was newly designed and successfully operated to clean up the flue gas stream having a flow rate of 30 NmVh.TiO2 and Pd/ZrO2 wash-coated on cordierite honeycomb were used as catalysts in the present study.Though the plasma-catalyst hybrid reactor with TiO2 showed good activity on the removal of NO yet it removed only 50-60% of NO_x because a significant portion of NO oxidized to NO2.On the contrary,the plasma-catalyst hybrid reactor with Pd/ZrO2 removed about 50% of inlet NO with a negligible amount of NO oxidation into NO2.The plasma/dual-catalysts hybrid system(front two units of plasma-Pd/ZrO2+rear two units of plasma/TiO2)proved to be very promising in NO_x removal in the presence of C3H6.DeNO_x efficiency of about 74% has been achieved at a space velocity of 3300/h at 150°C.