Not a plant to be seen，the desert ground is too dry．But the air contains water，and research scientists have found a (51) of obtaining drinking water from air humidity．
“The process we have developed is based exclusively on renewable energy sources (52) thermal solar collectors and photovoltaic(光电的)cells， (53) makes this method completely energy autonomous．It will (54) function in regions where there is no electrical infrastructure(基础设施)，”says Siegfried Egner，head of the research team．The principle of the (55) is as follows：hygroscopic(吸湿的)brine(盐水)，-saline(含盐的)solution which absorbs moisture-runs down a tower shaped unit and absorbs water from the air．It is then ed (56) a tank a few meters off the ground in which a vacuum prevails．Energy from solar collectors (57) up the brine，which is diluted by the water it has (58) ．
Because of the vacuum，the boiling point of the liquid is lower than it would be under (59) atmospheric pressure．The evaporated(蒸发的)，non-saline water is condensed and runs down through a completely filled tube in a controlled manner．The gravity of this water column (60) produces the vacuum and SO a vacuum pump is not needed．The reconcentrated brine (61) down the tower suce again to absorb moisture from the air．
“The concept is suitable for various water (62) ．Single-person units and plants supplying water to entire hotels are conceivable，”says Egner．Prototypes have been built for (63) system components-air moisture absorption and vacuum evaporation-and the research scientists have already () their interplay on a laboratory scale．In a further (65) the researchers intend to develop a demonstration facility．
Obtaining Drinking Water from Air Humidity