Reza Azin

Mass diffusivity of CO2 in different nanofluids was estimated by a designed measurement set up. For conducting diffusion tests, water-based nanofluids, including silicon oxide (SiO2), aluminum oxide (Al2O3), and titanium oxide (TiO2) with concentrations of 0.05, 0.1, and 0.2?wt% were prepared and characterized by dynamic light scattering analysis. The Effects of operational parameters, namely, the temperature, weight percentage of nanoparticles, and size of nanoparticles on CO2 diffusivity, were investigated by pressure decay measurement in a diffusion cell. According to the results of experiments, the most diffusivity improvement was related to TiO2 nanofluid (25?nm) at 0.1?wt% and 35?°C that CO2 diffusivity reached 14.7?×?10?9?m2s?1 which is about four times higher than that of pure water. In this study, a new correlation was developed for the effective diffusivity of CO2 in water-based nanofluid according to the nanoparticles Reynolds number, nanofluids Schmidt number, and nanofluids concentration. The correlation predicted CO2 diffusivity with an average relative error percent of 9.58 % and a correlation coefficient (R2) of 0.945.