Simulation of water recovery in membrane condenser dehumidification process

Abstract

Abstract The high humidity gas dehumidification process and water recovery characteristics in the membrane condenser (MC) were investigated with numerical simulation method in this paper. Different from the traditional condensation process, the hydrophobic porous membrane was utilized for water gases separation. The transmembrane pressure difference was considered as a supplement to the driving force of temperature difference. Results indicate that the porous surface has a positive effect on the high humidity gas dehumidification. It is important to note that water recovery tends to increase and then decrease with inlet feed flow rate increasing from 0.12 L/min to 0.6 L/min. The sweep flow rate ranging from 0.094 L/min to 0.885 L/min were considered. The optimal flow rate ratio between sweep side and feed side is 0.281 for the single-pipe model. It is found that increasing the inlet feed flow temperature from 315 K to 335 K can improve the water recovery over 20%. Additionally, water recovery reduces significantly with the increase of transmembrane flux, for the transmembrane gas reduces the transmembrane temperature difference while increasing the perturbation. These findings would provide important references in using hollow fiber MC for water recovery from high humidity gas.