Mathematical modeling and numerical simulation of CO2 capture using MDEA-based nanofluids in nanostructure membranes

Abstract

The current paper reports a numerical simulation as well as mechanistic modeling of gas separation using nanostructured polymeric membranes. To improve the process separation efficiency, nanoparticles of CNT (carbon nanotube) were incorporated into the solvent to prepare a nanofluid solvent for CO2 capture from a CO2+N2 gas mixture. The membrane used was a hollow-fiber module in counter-current separation operation to enhance the removal efficiency. A mechanistic model based on mass transfer was developed and validated through experimental measured data, and a good agreement was obtained. Computational fluid dynamic approach was used for solving the model’s equations and for simulating the process. It was indicated that the addition of nanoparticles to the solvent increases the CO2 separation percentage due to the synergistic effect of nanoparticles. The simulation results revealed that the gas separation efficiency was improved by increasing the solvent concentration, solvent velocity in the module, and membrane porosity. On the other hand, increasing the gas velocity indicated negative influence on the removal efficiency of CO2 using the nanofluid. The results indicated that nanofluid-based membrane gas separation is a promising approach for process intensification for environmental applications.