Physical CO₂ absorption consumes less energy than chemical CO₂ absorption. But physical absorption has a lower efficiency than chemical absorption. Rectisol is the process of physical absorption using methanol as absorbent. In this study, nano-sized oils are added into the methanol to enhance the efficiency of the Rectisol process. The nano-sized oils form the nanoemulsion with the methanol to enhance the heat and mass transfer performance. Heat and mass transfer performance in nanoemulsion increases due to shuttle effect, hydrodynamic effect, and bubble breaking effect. CO₂ absorption rate is affected by heat and mass transfer characteristics in the nanoemulsion. Silicone oil, BrijL-4, and BrijC-10 are used to manufacture the nanoemulsion. Dispersion stability is measured through the experiments such as oil diameter measurement, turbidity, and the Tyndall effect of the nanoemulsion. Through out the experiments of the dispersion stability, the optimal concentration of the oil and the surfactants is measured 0.01 and 0.005 vol%, respectively. In the CO₂ absorption visualization experiment, it is found that the bubble shape of CO₂ becomes more irregular in nanoemulsion than that in methanol.