Effect of temperature on SO2 absorption into sulphuric acid solutions containing hydrogen peroxide

A mathematical model previously developed for the absorption at 20 °C of sulphur dioxide into sulphuric acid solutions containing hydrogen peroxide was adapted to take the effect of the temperature into account. This model was exploited to determine at 35 and 50 °C the overall kinetic parameter relative to the absorption–oxidation of SO2, for increasing H2SO4 molarities (from 1 to 6.4 M) and in the presence of a variable concentration of H2O2 (1.2–4.4 M) from absorption test runs performed in a cables-bundle laboratory scrubber. It was clearly observed that an increase in temperature enhances the global process of SO2 absorption (solubility + diffusion + reaction), whereas at a given temperature, an increase in the sulphuric acid content slows down the process.