CO2 absorption enhancement by nanoabsorbents in Taylor–Couette absorber

Abstract

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 0.1vol%.