• absorption;
  • (NH4)2SO3 solution;
  • NO2;
  • gas–liquid reaction

Absorption experiments of NO2 from simulated flue gas into aqueous (NH4)2SO3 solution were performed in a stirred tank reactor under atmosphere pressure. As can be seen from the experimental results, the absorption rate of NO2 into (NH4)2SO3 solution increases as the (NH4)2SO3 concentration increases from 0.01 to 0.06 mol/L. As the concentration of (NH4)2SO3 solution exceeds 0.06 mol/L, the absorption process becomes gas-film controlled. And the absorption rate increases with increasing NO2 inlet concentration but decreases with increasing reaction temperature. Compared with Na2SO3 solution, (NH4)2SO3 solution has higher NO2 absorption rate. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 465–469, 2013