Performance of a UV‐assisted Hydrogen‐peroxide‐fed Spray Tower for Sulfur Dioxide Abatement

Spray towers are widely used for controlling air pollution by gases such as SO 2 , CO 2 , NO x , and HCl. Results of sulfur dioxide absorption in a spray tower using solutions of 1 g L –1 and 2 g L –1 of hydrogen peroxide are reported. For comparison, a water and sodium hydroxide solution was also used for SO 2 abatement. The results indicate that H 2 O 2 may be an important alternative for SO 2 removal in spray towers. A set of experimental removal efficiency data was obtained as a function of gas and liquid flow rates. Volumetric mass transfer coefficients ( k g a) were calculated and an experimental relationship among k g a , gas, and liquid flow rates was proposed. As a final experiment, an oxidation process assisted by UV radiation using a 1 g L –1 solution of H 2 O 2 was carried out to speed up the SO 2 removal rate. The results obtained in this condition are similar to those achieved with a solution of 2 g L –1 H 2 O 2 .