Hydrodynamic and mass transfer parameters for CO2 absorption into amine solutions and its blend with nano heavy metal oxides using a bubble column

In this work, hydrodynamic and mass transfer of CO2 absorption into metal oxide nanofluid includes TiO2, ZnO, and ZrO2 nanoparticles at Piperazine (Pz) solution in the bubble column was studied. The novel rigorous correlations were extended based on the variable parameters for the calculation of gas holdup, enhancement factor, and mass transfer coefficients in the reactive absorption processes using the pi-Buckingham method. The correlations were constructed based on dimensionless numbers, including nanoparticle loading, film parameter, CO2 partial pressure ratio to the total pressure, the film thickness of phases, CO2 loading, and ratio of diffusion coefficients of CO2 in the gas and liquid phases. Experimental data were used to calculate the correlations, consisting of Pz concentration, CO2 partial pressure, nanoparticle loading, and stirrer speed in the range of 0.1-0.5 mol/l, 16.0-35.2 kPa, 0.0-0.1 wt%, and 0-300 rpm, respectively. The film parameter was applied to exert the influence of chemical reactions on the performance of absorption. The mean squared error (RMSEP), the average absolute error (%AARD), and the coefficient of correlation of the results (R-2) for the correlations were in the range 0.021-2.604, 3.78-18.14, and 0.861-0.980, respectively, which represents the excellent accuracy of the proposed correlation.