Absorption of NO x into Nitric Acid Solution in Rotating Packed Bed

Abstract

Absorption of NO x into nitric acid solutions was studied in the presence of ozone by using a rotating packed bed (RPB) contactor. The influences of operating parameters, such as high gravity number, amount of ozone, gas velocity, liquid spray density and inlet concentration of NO x , on the removal efficiency of NO x were investigated, among which the high gravity number and ozone amount are more important. Ozone was introduced to oxidize HNO 2 to HNO 3 to prevent the decomposition of HNO 2 in the liquid phase. The high gravity number presents the effective external force for enhancing the mass transfer of ozone from gas phase to liquid phase. Under the experimental condition, the removal efficiency of NO x is higher than 90% and the concentration of nitric acid product exceeds 45%.