Abstract
A study on the visualization of the absorption process in the vicinity of the gas-liquid interface was performed. The system in which CO_2 was absorbed into amine solvents and diffused toward the interior of liquid phase was visualized. The interferogram pattern obtained by phase shifting interferometer showed that the increasing of concentration field instability in liquid phase was observed as time advanced or pressure of the gas phase was increased. This was caused by the density increase of the amine absorbing CO_2 and the liquid was affected by the negative buoyant force which generated natural convection locally. Therefore, pseudo diffusion coefficient in this system was determined larger than that of the molecular diffusion system. It was considered that the self-generated instability enhanced the mass transfer of CO_2 in the vicinity of interface and liquid phase.