New composite adsorbent for solar-driven fresh water production from the atmosphere

In this paper, a new highly-efficient water-selective composite adsorbent for solar-driven fresh water production from the atmospheric air is presented. It is synthesized by a patented ultra-large pore crystalline material MCM-41 as host matrices and calcium chloride as a hygroscopic salt. Experimental data demonstrate that adsorption capacity of the new composites is as high as 1.75 kg/kg dry adsorbent, which is higher than composites synthesized by silica-gel and calcium chloride, and the adsorption rate of the new composites is also found attractive. The desorption characteristics of the new composites are also studied, and it demonstrates that it can desorb more than 90% of the adsorbed water at lower heating temperature at about 80°C. A solar-driven water production test unit using the new adsorbent is also presented and tested. The experimental tests of this developed unit demonstrated a feasibility of the fresh water production with the daily water productivity more than 1.2 kg/m2 solar collector area.