Enhancement of gas-liquid mass transfer by nanofluids in a microchannel under Taylor flow regime

Abstract

The gas-liquid two-phase flow and the enhancement of mass transfer by nanoparticles for the process of CO2 absorbed by SiO2 nanofluids were investigated in a microchannel under Taylor flow regime. The influences of the dispersed and continuous phase flow rates and particle concentration in slurry on liquid side volumetric mass transfer coefficient (KLa), mass transfer enhancement factor (E), CO2 absorption efficiency, and pressure drop were studied systematically. The results show that the presence of nanoparticles can effectively enhance the gas-liquid mass transfer. Both KLa and pressure drop increase, while the CO2 absorption efficiency decreases with increasing the gas-liquid flow rate ratio. Differently, KLa, CO2 absorption efficiency and pressure drop increase with the increase of particle concentration in slurry. Considering the energy consumption and mass transfer enhancement effect, the effective mass transfer enhancement efficiency is in the range of 1.2 ~ 2.4, which shows the excellent enhancement performance of nanoparticles on gas-liquid mass transfer.