CO2 absorption/regeneration performance enhancement by nanoabsorbents

Experiments on CO2 absorption were carried out in Taylor-Couette type absorber at low rotational speeds. The base absorbent used is methanol. Al2O3 and SiO2 nanoparticles are combined with methanol to produce nanoabsorbents with the purpose of enhancing the absorption of the CO2 gas. The system is equipped with a mass flow controller at the inlet and a mass flow meter at the outlet to obtain the absorption rate. The Taylor-Couette absorber performance is compared to a modified version in which trays were added to enhance the absorption rate by increasing the residence time of the gas phase. Experiments in co-current and counter-current flow modes are carried out. It is found that the CO2 absorption rate enhances up to 6% and 8%, respectively, by using SiO2 and Al2O3 nanoparticles. In addition, the two-phase flow pattern of the CO2 gas bubbles and the liquid methanol in the Taylor-Couette absorber and the modified version is analysed with the high-speed camera pictures. Nanoemulsion absorbent is also developed for CO2 absorption performance enhancement. Nanoemulsion absorbent with nanoscale oil droplets has higher dispersion stability than nanofluids. Dispersion stability for both nanofluid and nanoemulsion absorbents is evaluated and compared.