Stripping of Ammonia from Aqueous Solutions in the Presence of Carbon Dioxide

The stripping of ammonia from aqueous solutions in the presence of carbon dioxide in the low concentration region is studied experimentally and theoretically. The phase equilibria method of Edwards et al. (1978) is selected by comparison of different methods with newer experimental data. The differential two adjacent films model enabling component fluxes calculations is used in a stripper model. In the experimental part the systems NH3-water-air and CO2-water-air are used in order to select the best physical mass transfer coefficients correlations. The system NH3-CO2-water-air modified with strong acids or bases is used for experimental verification of the process model in a wide range of process variables. Model predictions in conditions of negative enhancement of mass transfer are presented. The influence of this effect on ammonia stripping efficiency in the presence of carbon dioxide is analysed.