CO2 absorption enhancement by methanol-based Al2O3 and SiO2 nanofluids in a tray column absorber

In the present study, suspensions of Al2O3 and SiO2 nanoparticles in methanol (nanofluid) are produced and analyzed for the application of CO2 absorption in a tray column absorber. The absorber is an acrylic tray column with twelve plates. The column is a sieve tray type which has flat perforated plates where the vapor velocity keeps the liquid from flowing down through the holes and the CO2 gas and methanol liquid are brought in contact in a counter-current flow. The test section is equipped with two mass flow meters to measure the absorption rate. The results show maximum enhanced absorption rates of 9.4% and 9.7% for Al2O3 and SiO2 particles (compared to pure methanol), respectively. It is also found that SiO2 nanoparticle is a better candidate than Al2O3 nanoparticle and 0.05 vol% of nanoparticles is an optimum condition for CO2 absorption enhancement for the present experimental conditions.

► The use of Al2O3 and SiO2 in methanol promotes the detachment of the bubbles from the orifice.
► CO2 absorption rate is enhanced up to 9.7% by the use of SiO2 nanoparticles.
► Methanol-based nanofluids are promising candidates for CO2 absorption application.