CFD modeling of CO2 capture by water-based nanofluids using hollow fiber membrane contactor

A two-dimensional (2D) model was developed for CO2 removal from a gas mixture using a hollow fiber membrane contactor. Nanofluids of silica and carbon nanotube (CNT) nanoparticles were used as absorbents. The governing equations were solved using computational fluid dynamics technique (CFD). The results of the model were compared with the experimental data and good agreements confirmed the validity of the developed mass transfer model. The results showed that increasing absorbent flowrate enhances the CO2 absorption rate, especially at a low flowrate. The performance of CNT nanofluids is much better than nanosilica. At high liquid flowrate (40 L/h) CNT captures CO2 up to 53.53% while nanosilica captures 37.38%. Also, an increase in the concentration of CNT nanofluid from 0.2 to 0.5 wt.% at a constant flowrate of 20 L/h leads to 20% increase in the CO2 separation while its enhance for nanosilica is 16%.