New device to extract water from air developed for all geographical locations

Tribune News Service

Vijay Mohan

Chandigarh, September 5

In the backdrop of depleting fresh water resources worldwide, Indian scientists have developed a portable device that can extract water from the air. This has employability not only for sustainable agriculture, but also for the armed forces deployed in remote areas and civilians residing in water-stressed areas.

Called the Indoor Atmospheric Water Harvester (IAWH), the prototype uses a material called metal-organic framework (MOF) nano-composites, which consists of empty pores like a sponge for absorbing water molecules.

According to the Ministry of Science and Technology, the technology and size of existing gadgets for harvesting water, primarily operational through interfacial solar heating and generally used in arid or desert regions, greatly restricts their employability. Most available commercial atmospheric harvesters function when relative humidity is above 60-70 percent and also suffer from issues like water condensation and regeneration.

About two-thirds of the world’s populace lives under a modest water crisis and by 2050 half of the global population is expected to face severe water shortage. The answer to this impending crisis is atmospheric water generation as the air holds about 13,000 trillion litres of water in the form of vapor and droplets at any given time. Hence a device was required that could be used anywhere and anytime under a wide range of humidity conditions.

The new portable device can be used in indoor conditions assisted by conventional electric power under any humidity condition with low regeneration temperature. The water collection dynamics can be adjusted by varying the ambient humidity, release temperature and on-demand absorption and release cycle without solar irradiation.

The technology relies on a copper-based material connected through organic linkers, resulting in a cage-like framework. Additional templates made of graphene oxide magnesium phyllosilicate provide additional openings for water molecules and improve hydrothermal resilience.

Water molecules initially enter the pore that acts as a ‘seed water’ to attract the next water molecules leading to high-water storage capacity under extremely humid conditions. Besides being more durable and efficient, the material used is cheap to prepare and shows distinguishable colour reversal.

The portable, stand-alone and globally viable device can be used in all geographical locations. The research team is aiming to modify the device for contemporary usage like dehumidification, adsorptive heating and cooling technologies, the ministry’s statement said.