Harvesting water from air using adsorption material - Prototype and experimental results

Drinking water resources have always been limited in the gulf region of the Middle East and other desert regions around the world. In attempt to provide viable supplement, a device that harvests clean drinking water from air is designed, built and tested. The operation of the device is based on harvesting water naturally from air using adsorption materials. The prototype of this device consists of sorbent (silica gel is used in this study) exposed to radiant flux, water sorbent unit, condenser and reflector. Experimental studies of production of fresh water from air in controlled indoor environment have been carried out using the prototype. Several experimental tests were conducted under the conditions of 22 degrees C ambient temperature, a range of relative humidity (RH) from 30 to 60%, a range of silica gel thickness from 25 to 35 mm, surface area to volume ratio from 0.29 to 0.4 and radiant heat flux range from 509 to 556 W/m(2). The prototype was able to produce up to 159 g of water per 1 kg of silica gel in a 12 h cycle when exposed to 556 W/m(2) radiant flux. In terms of per one day (24 h), the harvester can produce 800 mL of water with an overall efficiency of 50% for 25 mm silica layer thickness. Increasing the relative humidity speeds up the adsorption cycle and increases the water capture, release and collection rates. The system can be improved by adding multiple layers of sorbent stacked on top of each other and by using sorbents with improved adsorption and desorption properties.

Automated summary

In regions with limited drinking water resources like the Middle East, a device has been developed to harvest clean drinking water from air using adsorption materials. Experimental studies have shown that the device can produce a significant amount of water under specific conditions, and increasing the relative humidity can improve water capture rates and overall efficiency. Further improvements can be made by incorporating multiple layers of sorbent and using sorbents with enhanced adsorption and desorption properties.