Vapour transport mechanism in osmotic distillation process

Osmotic distillation experiments were carried out using pure water as feed in order to investigate the mass transfer mechanism in the membrane. In the experiment, the hollow fibre modules with packing density of 30.6 and 61.2% were employed. The Dusty gas model was used to estimate the transport of vapour through the membrane. The results revealed that the water vapour transport in the membrane pores in this study followed the Knudsen-molecular diffusion transition model. The value of membrane mass transfer coefficient evaluated by the transition model was found to be 0.863 kg/m2.h.Pa which was in good agreement with the experimental value. The packing density of the module did not affect the membrane mass transfer coefficient. On the other hand, the membrane mass transfer coefficient depended on the temperature.