Water recovery from waste gaseous streams using membrane condensers

Hydrophobic microporous PVDF commercial membranes were used for recovery of water contained in gaseous streams simulating the ones coming out from industrial processes. Hydrophobicity of these membranes and the difference temperature between fiber and feed stream gives possible the condensation of the water vapor on the membrane surface[1]. The results obtained were expressed in terms of quantity and quality of recovered water. In particular, the recovered water was defined as mass of liquid water retained in the retentate side with respect to the total water contained as vapour in the gaseous feed stream. The experiments were carried out by varying the module and gas temperatures and the feed flow rate as well. The best results achieved indicate that 50% of water can be recovered operating with a temperature difference of ca. 19°C feeding 222 mL min-1 of air 100% humidified. Further studies aimed to evaluate the ability of these membranes in decreasing the contaminant concentrations in the feed stream, showed a contaminant reduction at ca. 2% owing to the higher volatility of contaminant species[2]. A large part (ca.98%) of the contaminants was removed and ca. 50% of the water fed was recovered and it can be used for other purposes. Thus membrane condensers could be a right solution for the pre-treatment of the exhaust gases of power plants. References 1. Macedonio F.; Brunetti A.; Barbieri G.; Drioli E.; "Membrane condenser as a new technology for water recovery from humidified waste gaseous streams", Ind. Eng. Chem. Res. 2013, dx.doi.org/10.1021/ie203031b. 2. Macedonio F.; Cersosimo M.; Brunetti A.; Barbieri G.; Drioli E.; "Water recovery from humidified waste gas streams: Quality control using membrane condenser technology", Chem. Eng. Proc.: Process Intensification, 2014, dx.doi.org/10.1016/j.cep.2014.08.008.