Mass transfer modeling absorption using nanofluids in porous polymeric membranes

Abstract

The current investigation develops a comprehensive mechanistic model for design and optimization of membrane-based gas absorption process. A mass transfer model was developed based on the well-known convection-diffusion model, and numerically solved using finite element scheme. The studied process is a porous membrane contactor designed to provide proper contact between gas and liquid for the absorption of carbon dioxide. The absorbent was a SiO2-based nanofluid to provide high mass transfer rate in the liquid phase. The results indicated that addition of SiO2 nanoparticles significantly improved the separation efficiency of CO2 from nitrogen due to higher mass transfer and diffusion coefficient in the nanofluid medium. The model's findings were compared with experimental data, and great agreement was achieved with average deviation (AD) of about 6%. The model was further used to evaluate the effect of process parameters and membrane's properties on the separation efficiency of membrane system. It was indicated that increasing the gas flow rate has negative influence on the mass transfer, while membrane porosity and length had positive effects on the CO2 removal. The model has shown to be robust and reliable in design and prediction of membrane-based gas absorption using SiO2 nanofluid.