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

Abstract

BACKGROUND Membrane 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. RESULTS The 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. CONCLUSIONS This 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

Energy performance and climate dependency of technologies for fresh water production from atmospheric water vapour

“…10 A liquid membrane with hygroscopic salts on a carbon black nanoparticle support has been reported effective in this application. 61 Polymer electrolyte membranes are used for electrochemical based air dehumidification, an alternative to the pressure driven membrane dehumidification process. In this process a net water flux over the membrane is created by splitting water electrochemically into oxygen gas and protons at the anode side of the membrane and combining these protons again with the oxygen gas at the cathode side to make water.…”

“…70 Aqueous desiccants would have advantages over solid desiccants when solar heating is used for regeneration because the regeneration temperature of liquid desiccants is generally lower than for solid adsorbents. 61,70,91 Other authors claim solid adsorbents to be the best choice. 64,73 The regeneration requirements of liquid and solid desiccants are relatively similar.…”