Extracting Water from Air and Revolutionizing Cooling: This Material Can Do It and Is Ready for the Pilot Phase
The increasing dryness and rising temperatures, particularly in the Mediterranean basin, are pushing scientific research towards unconventional solutions for water supply.
In this direction goes the study from the Institute of Inorganic Chemistry at the University of Kiel in Germany, focused on the development and scalability of advanced porous materials capable of capturing atmospheric moisture and optimizing cooling systems. The results, published in two separate papers in the scientific journals Journal of Materials Chemistry A and Industrial & Engineering Chemistry Research, describe the overcoming of one of the main bottlenecks of the technology: the transition from laboratory synthesis to industrial-scale production.
The material studied, named CAU-10-H, belongs to the class of Metal-Organic Frameworks, also known by the acronym MOF. These are metal-organic structures characterized by a dense network of interconnected microscopic cavities that act like true sponges on a molecular scale. The fundamental chemistry behind the MOFs earned Omar Yaghi the Nobel Prize in Chemistry in 2025.
Unlike common hygroscopic materials, which require high relative humidity rates to function, CAU-10-H is extraordinarily efficient even under extreme dryness conditions. The process of adsorbing water molecules at room temperature activates as soon as the relative humidity of the air reaches or exceeds the minimum threshold of 18%, a percentage that most traditional systems would consider too low to exploit. Equally efficient is the reverse process of desorption, or the release of previously captured water. To release the trapped moisture, it is sufficient to heat the material to a temperature of about 70 °C. This thermal threshold is so low that it can be easily reached using simple solar heat or waste heat from industrial processes, eliminating the need to resort to expensive electric heaters powered by the grid.
To further accelerate this cycle, the research team led by Professor Norbert Stock combined the material with specific carbon conductive structures. The resulting composite can be heated very quickly and efficiently, allowing the system to complete capture and release cycles in just a few hours. Under dry air conditions, this material is capable of storing up to 0.17 grams of water for every gram of MOF used. On a daily basis, this efficiency translates into a potential yield of about 1.8 liters of drinking water for every kilogram of composite material employed.
Beyond generating drinking water, CAU-10-H has demonstrated enormous potential in the field of eco-friendly air conditioning through adsorption cooling systems. In this type of application, the new compound has recorded performance up to three times higher than silica gel, which represents the historically used industrial standard for this purpose. The real revolution lies in the ability to power these air conditioning systems using exclusively residual heat, such as that constantly generated by data center servers or bakery ovens. Instead of dissipating this heat into the environment, it can be channeled to activate the CAU-10-H cycle, cooling workspaces without burdening the electricity bill and drastically reducing the environmental impact compared to traditional compressor air conditioners.
The true novelty of the work coordinated by Norbert Stock, conducted together with lead author Lasse Wegner and pilot scale manager Kalle Mertin, lies not only in the chemical properties of the material but in its actual commercial feasibility. Often, materials synthesized in the lab struggle to find a real outlet because they are too complex or expensive to produce in large quantities. Thanks to the financial support of the Validation Fund from the University of Kiel, the German team has instead managed to complete the transition to pilot scale, producing an initial batch of about 30 kilograms of CAU-10-H. This is a quantity about 60 times larger than any previous batch synthesized in the lab. At the same time, a careful techno-economic analysis has shown that the production of this material can settle at decidedly competitive costs, ranging between $12 and $14 per kilogram, making large-scale application finally accessible.