Investigation of membrane dehumidification by pervaporation

Controlling humidity is essential for a comfortable life and various technologies have developed for the dehumidification devices. Among the systems, we introduce a novel system including a vacuum pump and a membrane (fabricated by Prof. Seo, Young Soo, Sejong Univ.) that separates a feed chamber and a permeate chamber, connected with the vacuum pump.  Both sides of the membrane are faced with the humid part (feed chamber) and the dry part (permeate chamber) at the same time, driving the water vapor, which is referred to as pervaporation. We measure the outlet humidity and the water vapor transport rate, the mass of vapor permeated through the membrane, under the various experimental conditions of different feed flow rates and feed chamber heights. As the flow rate increases, the outlet humidity is decreased, whereas the water vapor transport rate is increased. However, they are independent of the height in our experiment range. Combining mass transport theory and the volume conservation, we have established theories of the outlet humidity and the water vapor transport rate. The experimental data points are entirely consistent with our theory curves. Comparing the experimental results and the theories, we also have derived the membrane coefficient.