Computational study of carbon nanotube (CNT)-based nanofluid performance in hollow fiber membrane contactor for H2S separation

In this study, the removal of H₂S was investigated using hollow fiber membrane contactors (HFMCs). The absorbent fluid was a nanofluid containing carbon nanotubes, which was added to the absorbent fluid to enhance H₂S absorption. After the modeling and model validation of the HFMC, the nanofluid effect on the H₂S separation performance was discussed. A 2D HFMC model was considered, and COMSOL software was used for the model’s numerical solution. In the following, gas and nanofluid concentration distribution, velocity development profile in the membrane tube side, pressure drop in the tube side, the effect of gas flow rate on H₂S removal, the effect of hollow fiber number and the effect of liquid flow rate on H₂S removal were investigated. The results showed that adding the nanofluid to the absorbent fluid led to a significant increase in H₂S absorption in all cases. Additionally, the results indicated that increasing the gas flow rate and decreasing the absorbent fluid flow rate could result in a decrease in H₂S removal. The investigation of pressure variations in the absorption process from 1 to 10 bar also showed a slight increase in H₂S removal (approximately 5%). Furthermore, the conversion of the conventional fluid to the nanofluid resulted in an approximately 40% increase in H₂S removal.