CO₂ absorption enhancement by nanoabsorbents in Taylor-Couette absorber

CO₂ gas is physically absorbed in liquid methanol in bubbly Taylor-Couette absorber. The experiments are performed in the turbulent regime with rotational Reynolds numbers ranging from 1.9 × 10⁴ to 19.2 × 10⁴. The volumetric mass transfer coefficients are obtained for the counter-current operation. Methanol is utilized as the base absorbent. In addition, with the purpose of enhancing CO₂ absorption performance, Al₂O₃ nanoparticles are combined with methanol to produce the absorbent. The results show an increase in the volumetric mass transfer coefficient that reaches a maximum value at 4 × 10⁴ rotational Reynolds number for both pure methanol and the nanoabsorbents, after which the absorption rate declines almost linearly with the rotational speed. The reasons for the reduction in the absorption performance are discussed. The maximum enhancement in the volumetric mass transfer coefficient is estimated at 20% for 4 × 10⁴ rotational Reynolds number and up to 27% for methanol and Al₂O₃ nanoparticles at a concentration of 0.1 vol%.