Kinetic Studies on NO2 Absorption into Ammonium Sulfite Solutions

The absorption reactions of NO₂ into (NH₄)₂SO₃ solution were investigated in a stirred tank reactor. The kinetic regime of the absorption reaction was identified and the effects of various experimental parameters were studied. The experimental results indicated that the absorption of NO₂ into (NH₄)₂SO₃ solution is accompanied by a fast pseudo-first-order reaction. It was found that the NO₂ absorption rates were enhanced by the increasing concentration of (NH₄)₂SO₃ but nearly remained constant if the concentration is greater than 0.1 mol/L. The absorption rates also increased with increasing the reaction temperature and the concentration of NO₂ in inlet gas, but decreased as the oxygen concentration increased.