Enhancement of CO2 desorption from MEA-based nanofluids in membrane contactor: Simulation study

Abstract

As there is no study focusing on the effect of the presence of nanoparticles on enhancing mass transfer in gas desorption systems. In this study, a two-dimensional mathematical model was developed to investigate the effect of the presence of SiO2 nanoparticles on the desorption of carbon dioxide from a monoethanolamine (MEA) solution in a hollow fiber membrane contactor (HFMC). The developed model was validated by experimental data obtained from the literature for a similar system over a range of operating conditions, liquid and gas velocity, and MEA concentration. The numerical data agree well with the experimental results with an average deviation (AD) of about 5%. The numerical data also showed that the major mass transfer resistance in the system was in the liquid phase. The CO2 desorption flux increased dramatically with the increase in the liquid velocity. Meanwhile, the gas velocity showed little effect on the desorption flux. The addition of nanoparticles with loading 0.6 g / L SiO2 to 3M MEA solution greatly improved the mass transfer rate in the liquid phase. The CO2 desorption flux was improved by 33 % at liquid and gas velocities of 1.4 cm s−1 and 10.0 cm s−1, respectively. The desorption flux improved significantly when the MEA concentration in nanofluid was increased. According to the results of the current study, the use of nanoparticles greatly improves the desorption rate of CO2 and can contribute to reducing energy consumption.