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 SO2, CO2, NOx, 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 SO2 abatement. The results indicate that H2O2 may be an important alternative for SO2 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 (kga) were calculated and an experimental relationship among kga, 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 H2O2 was carried out to speed up the SO2 removal rate. The results obtained in this condition are similar to those achieved with a solution of 2 g L–1 H2O2.