Investigation on the effect of particle size in dissolution mass transfer inside porous media with micro-tomography

Dissolution mass transfer inside porous media is important in various hydrogeology applications. However, the effect of particle size to the dissolution mass transfer remains an unsolved issue. One of the limitation of studying this phenomenon is the limitation in measurement technology. Direct observation of the trapped phase inside porous media cannot be observed directly. In this work, we utilized micro-tomography measurement technology to observe the trapped phase inside the porous media. The same shape of particle size was used but the size and the distribution was varied to demonstrate the change in particle size characteristics of the porous media. We found that the mass transfer coefficient decrease significantly (about one order of magnitude) at some threshold value of particle size. We believe that the reason behind it is the appearance of the bypassing phenomena during the dissolution process.