Aqueous salt solution liquid membranes, supported by nanoparticles, for water extraction from the atmosphere via air dehumidification

Abstract

AbstractBACKGROUNDMembrane technology is a promising solution for the development of a sustainable air dehumidifier because it is, in general, considered a cost‐effective technology and, moreover, water recovered from the air via membrane‐based dehumidification process can be recycled.RESULTSThe efficiency of aqueous salt solution liquid membranes that were prepared by a nano‐sized additive supporting method and applied for the dehumidification of air, was evaluated in terms of the water permeability and condensed water recovery rate. It was found that not only the nature of the selective membrane material but also the type of membrane supporting material has an impact on the overall liquid membrane performance. Membranes supported by surface treated carbon black nanoparticles showed a water recovery rate of 12 g h−1 at 75–80%RH and average water permeability of 9 × 10−12 kmol m/(m2 s kPa). The most selective liquid membranes were LiBr and CaCl2, supported by surface treated carbon black, with water vapor/air separation factor of 34 300 and 21 700, respectively.CONCLUSIONSThis work for the first time demonstrates the applicability of aqueous inorganic salt solutions in liquid membranes for dehumidification applications. Prepared liquid membranes showed moderate condensed water recovery rates and membrane stability over 1 month. © 2018 Society of Chemical Industry