Absorption of SO2 by aqueous NaOH solutions in the presence of a surfactant

A report is presented on the influence of liquid flow rate, NaOH concentration, column length and presence of 5 × 10‐3 wt‐% of the surfactant SLS on the rate of absorption of pure SO2 by aqueous NaOH solution in a sphere‐and‐cylinder column. The presence of sodium lauryl sulphate (SLS) prevented axial turbulence which increased mass transfer in longer columns and was almost independent of the flow rate. The enhancement factor due to the reaction between SO2 and NaOH with respect to the process of physical absorption was analyzed for the systems with excess OH‐ in the outflow. The results obtained in the presence of a surfactant are satisfactorily explained by film theory with a single reaction plane model. Those obtained in the absence of surfactant are best described by a two‐plane model using renewal theory.