NOx scrubbing with H2O2/HNO3 solutions achieved with a laboratory bubble contactor

In this work, the removal of dilute nitrogen oxides NO x from the gaseous effluents of Tunisian nitric acid plant by absorption into aqueous hydrogen peroxide solutions containing or not nitric acid was studied. All semi-continuous absorption tests were carried out at ambient conditions and at 40 Pa as NO x partial pressure. The effects of the gas flow rate, the initial H 2 O 2 concentration and the presence of HNO 3 on the NO x absorption efficiency (A NO x ) were studied. The tests results revealed that A NO x increases with an increase in initial H 2 O 2 concentration in the scrubbing liquid, but decreases with an increase of gas flow rate. Furthermore, the presence of nitric acid in the aqueous hydrogen peroxide solution has a positive effect on A NO x . These results confirmed that the removal of NO x liberated from the plants of the Tunisian Chemical Group (TCG) by absorption into H 2 O 2 solution is a feasible and an effective solution.