CO2 absorption in aqueous solutions of N-(2-hydroxyethyl)piperazine: Experimental characterization using interferometry and modeling

This work deals with the experimental characterization of carbon dioxide (CO2CO2) absorption in an aqueous solution of N  -(2-hydroxyethyl)piperazine, by using of digital holographic interferometry. This method enables visualizing the phenomena taking place in the vicinity of the gas–liquid interface. Thanks to a calibration, the obtained results yield the time evolution of the CO2CO2 loading field in the aqueous solution and the gas–liquid absorption rate for various operating conditions. The processing method and the obtained results are detailed. A phenomenological model, highlighting the limiting steps of the gas–liquid CO2CO2 absorption, is proposed. A set of experiments is realized and the parameters of this model are estimated for various initial amine concentrations and initial loadings. The results are discussed and correlations are proposed for the model parameters.