Validation of mass transfer and liquid holdup correlations for CO2 absorption process with methyldiethanolamine Solvent and piperazine as an activator

Abstract

In the present study, 24 data sets regarding CO2 absorption by the piperazine (PZ) activated aqueous methyldiethanolamine (MDEA) solution (30% wt) have been obtained from Khan et al.’s work and have been investigated using rate base model. Hence, mass transfer correlations such as Onda’s, Bravo-Fair’s, Billet-Schultes’ correlations and liquid hold-up correlations of Billet-Schultes and Stichlmair have been studies in the current paper. In addition, important parameters like CO2 absorption (%), liquid temperature and rich solvent’s loading have been compared in different mass transfer and liquid hold-up correlations. The results of using the rate-base model in the mass transfer and liquid hold-up correlations in 24 different experimental conditions indicate that the Bravo-Fair mass transfer correlations have higher accuracy compared to other mass transfer correlations. This comparison has been carried out based on CO2 absorption (%) and the rich solvent’s loading. Moreover, studying mass transfer correlations give the following amounts for the average error of Onda’s, Bravo-Fair’s and Billet-Schultes’ mass transfer correlations respectively for CO2 absorption (%) calculation in 16 different experimental conditions: 23.45, 14.63 and 38.59 (%). In the last part of the paper, rich solvent’s loading is compared with real amounts in 12 different experimental conditions. The comparison shows that the average errors of Onda’s, Bravo-Fair’s and Billet-Schultes’ mass transfer correlations are 14.80, 9.70 and 21.75 (%) respectively. Investigating liquid hold-up correlations indicates that Billet-Schultes’ and Stichlmair’s correlations give the same results regarding rich solvent’s temperature, solvent’s temperature profile along the absorption column, CO2 absorption (%) and rich solvent’s loading.