Study on CO2 bubble absorption and visualization in nanofluids.

In this study, Al2O3 nanoparticles and methanol are combined into Al2O3/methanol nanofluid to enhance the CO2 absorption rate of the base fluid, which is pure methanol. The absorption experiments are performed in a bubble type absorber equipped with mass flow controller and mass flow meter. The parametric analysis on the effect of the particle fraction on CO2 absorption rate is carried out. The Al2O3 nanoparticle concentration is ranges from 0.005-0.1 vol%. The maximum CO2 absorption enhancement compared to the pure methanol found to be 3.1% at 0.01 vol% of Al2O3/methanol nanofluids at 20°C, and 4.5% at 0.01 vol% of Al2O3/methanol nanofluids at -20°C. Furthermore, the CO2 bubble absorption visualization is performed by a high speed camera to analyse the gas absorption enhancement mechanism in nanofluids. It appears that the hydrodynamic effect is the main reason for the mass transfer enhancement in nanofluids. It is concluded that the methanol nanofluids are expected to be a promising absorbent for removing the CO2 gas.