Researchers at Kiel University have taken an important step towards the commercial production of an advanced porous material capable of harvesting drinking water from the atmosphere while also significantly improving the efficiency of cooling systems.

Developed by the Institute of Inorganic Chemistry, the material belongs to the family of Metal-Organic Frameworks (MOFs), highly porous crystalline materials that can adsorb and release large quantities of water vapour in short cycles. The research addresses growing concerns over water scarcity and rising temperatures, particularly in arid regions such as the Mediterranean, while also offering opportunities to reduce the energy demand of cooling technologies.

Designed for Atmospheric Water Harvesting

The Kiel research team has focused on optimising the MOF known as CAU-10-H, originally discovered at the university around 15 years ago. Thanks to its sponge-like network of microscopic pores, the material captures water molecules from the air at room temperature when relative humidity exceeds 18%, before releasing them again at approximately 70°C.

To improve performance, the researchers combined the MOF with conductive carbon structures, creating a composite material that can be heated efficiently using electricity or solar energy. This accelerates water release, enabling shorter and repeatable operating cycles.

Under dry environmental conditions, the composite achieves a water uptake of up to 0.17 g of water per gram of material. According to the researchers, 1 kg of the material could potentially produce up to 1.8 litres of drinking water per day, making it a promising solution for decentralised water production in regions experiencing increasing water stress.

A More Sustainable Cooling Technology

Beyond water harvesting, CAU-10-H also shows strong potential for adsorption cooling systems. In testing, the material delivered up to three times the cooling performance of conventional silica gel, a widely used desiccant.

Unlike traditional air conditioning, adsorption cooling systems can operate using low-grade waste heat from sources such as data centres, industrial processes or commercial bakeries. By making better use of existing thermal energy, these systems could substantially reduce the electricity consumption associated with cooling buildings and infrastructure, contributing to lower carbon emissions.

Pilot-Scale Production Demonstrates Commercial Potential

A key milestone for the project is the successful transition from laboratory synthesis to pilot-scale manufacturing. Supported by Kiel University’s Validation Fund, the research team produced approximately 30 kg of CAU-10-H, around 60 times the quantity previously manufactured in the laboratory.

Alongside scaling production, the researchers conducted a techno-economic assessment indicating that manufacturing costs of US$12–14 per kilogram are achievable. This suggests the material could become economically viable for industrial applications in both atmospheric water harvesting and energy-efficient cooling.

The work forms part of a broader interdisciplinary collaboration between chemistry and materials science researchers at Kiel University and contributes to ongoing efforts to develop sustainable material solutions for climate adaptation and resource efficiency.

Source: Kiel University
Photo: Roegger