CAJ | 학술논문

The influence of nano-particles on CO2 absorption was studied experimentally in a stirred thermostatic reactor. Nano-Al2O3 and carbon nanotube (CNT) particles which showed different hydrophobic properties were chosen for the investigation. The experimental results were compared with that of micron-size activated carbon (AC) and Al2O3 particles. From the results, no enhancement by micron-size Al2O3 was found, and with the increase of Al2O3 concentration, the enhancement factor decreased. However, nano-Al2O3 showed a weak enhancement for the CO2 absorption. AC and CNT particles all intensified the gas-liquid mass transfer effectively, yet the trend of the enhancement factor with stirring speed for the two particles was different. With increasing stirring speed, the en-hancement factor of AC particles was decreased, whereas in CNT suspensions it was increased. The experimental phenomena demonstrated a difference in enhancement mechanism for different size particles. For nano-particles, besides the influence of adsorbability and hydrophobicity, the micro-convection caused by Brownian motion should be also taken into account. Considering the micro-convection effect, a theoretical model was developed to shed light on the absorption enhancement by nano-particles.