Last year, scientists at the Massachusetts Institute of Technology proposed the concept of using metal-organic scaffolds (MOFs) to extract moisture from the air. And now they are ready to show a prototype of such an installation in action, although its effectiveness is still far from the desired one. But the system is completely passive and needs only good weather to work.
MOF - metal-organic framework structures, they are also organometallic polymers, a hybrid substance with a complex three-dimensional structure. Here, clusters of reactive metals are integrated into a lattice of organic polymers, and the architecture and composition of the framework can vary widely. MIT has chosen such a configuration that allows keeping the maximum volume of water vapor inside the frame.
With the onset of twilight and a sharp change in air temperature in a desert climate, a movement of air masses heated during the day arises. They pass through the IOC trap, the substances react, water is released and concentrated inside. With dawn, the temperature rises, the sun's rays heat the IOC to the level of evaporation of water, which evaporates from the grate, then condenses and collects in a container. No moving parts, it only depends on the availability of sunlight.
The prototype, tested in the Arizona desert, produced 0.25 liters of clean water per kg of IOC mass. Given the cost of the IOC, this is not enough for economic gain in the short term, so scientists will continue to optimize the system. For example, it can already operate at an air humidity of only 10% versus the minimum 50% required by traditional technologies for obtaining water from air.