Ammonia escape mass transfer and heat transfer characteristics of CO2 absorption in packed absorbing column

Ammonia escape is one of the main barriers to CO2 capture by aqueous ammonia solution, so it is of benefit to the practical CO2 capture engineering to clarify the effects of running parameters on the mass transfer of ammonia escape and heat transfer performance in packed absorbing column. Based on the representative elementary volume approach and pseudo-single-liquid model, a computational model of heat and mass transfer for the CO2 capture by aqueous ammonia solution in an industrial packed column is developed, by which the ammonia and CO2 volume fractions and temperatures, ammonia escape mass transfer coefficient and heat transfer per unit volume are obtained. The results show that the ammonia escape volumetric mass transfer coefficient is mainly influenced by the liquid inlet temperature and flow rate, inlet CO2 volume fraction and flow rate. What's more, the ammonia concentration plays a key role in the ammonia escape amount, and the heat transfer per unit volume is greatly dominated by the gas flow rate and liquid inlet temperature. This work can contribute to the ammonia escape inhibition and high CO2 removal efficiency for the industrial application of CO2 capture by ammonia solution in packed columns.