Study on mass transfer and kinetics of CO2 absorption into aqueous ammonia and piperazine blended solutions

A small wetted wall column (WWC) was used to study the kinetics of CO2 absorbed in PZ and NH3/PZ blended solution. The experiments of CO2 absorption into 0.1–0.4M PZ and 0.53–4M NH3/0.1–0.4M PZ mixed solution at 10–40°C have been done in wetted wall column under the driving force of 8–25kPa in this paper. The ‘interface concentration corrected-pseudo first order’ mass transfer model and ‘Ternary-termolecular’ reaction mechanism were proposed to describe the CO2 absorption into NH3/PZ system for the high driving force and low PZ concentration condition. Both of the models in this study used for CO2 with NH3/PZ blended solution were in a good agreement with the experimental results. ►Kinetics of CO2 absorption into PZ and NH3/PZ blends were measured at 10–40°C. ► The ‘interface concentration corrected-pseudo first order’ model was proposed. ► The ‘Ternary-termolecular’ reaction mechanism was proposed. ► The models can be used for high driving force and low PZ concentration condition.