Investigation of the influence of temperature on absorption with chemical reaction

The aim of this work is to investigate the influence of temperature on the gas-phase mass transfer coefficient in a falling film absorption. Therefore sulfur dioxid (SO2) was absorbed into a dilute sodium hydroxid solution (NaOH) in a falling film column with concentric glass tubes. This system was selected because sulfur dioxid reacts instantaneously at the interface in case of a high concentration of NaOH. Therefore the resistance to mass transfer lies exclusively in the gaseous boundary layer. The temperature of the absorption process was varied from 20 to 50°C in steps of 10°C to investigate the influence of temperature. Therefore the streams of air and liquid were warmed up and the column was additionally heated by a heater band. The stream of air was moistened to minimize the influence of counter diffusion of water in the column. By means of the measured absorption rates gas-phase mass transfer coefficients were thus calculated from HTU-NTU concept. The gas velocity was varied from 0,8 - 3,2 [m/s] and the flow of liquid from 20 to 60 [L/h]. In comparison with published Sherwood correlations experimental data deviates +/- 10%.