In the power generation industry, the integrated gasification cycle is considered an environmentally friendly power generation system using coal. However, Carbon dioxide (CO2) that is created during the gasification process should be removed for performance improvement of the system. There are some acid gas removal processes in large systems with high-pressure conditions such as Selexol, Purisol and Rectisol. Rectisol process is a trade name for an acid gas removal process that uses methanol as a refrigerant to separate acid gases. Methanol can selectively absorb the CO2 gas. However, the Rectisol process needs a very low temperature which is not good for energy saving. Previous research has focused on the enhancement of CO2 absorption rate by adding Al2O3 nanoparticles into methanol refrigerant. The objective of this paper is to visualize the single bubble behavior for CO2 absorption process in nanofluid refrigerants. The surface tension and viscosity are measured to analyze the effect of the nanoparticles on the refrigerant thermophysical properties. It is found that Al2O3 nanoparticles enhance CO2 absorption performance and increase the viscosity as high as14% at 0.01 vol%..