A new study from Effat University has led to a new model to predict water absorption from air, which could aid future efforts to tackle water scarcity.
The atmosphere contains 3400 trillion gallons of water vapour: an abundant, renewable water supply. But drawing from this reservoir is a challenge, which is why 42 countries in the world still struggle with water scarcity today. Over one billion people are affected.
This new study looked at the potential of “anhydrous salts” — salts with no water already in their structure. Anhydrous salts are inexpensive and readily available, so could represent a potent tool when dealing with water scarcity.
The researchers created a mathematical model that simulated the dehydration mechanism and the subsequent release of water vapour from the salts. Using this model, changes in the thickness, uniformity and porosity (volume of empty space) of the salt samples could be predicted before the practical experiments were actually run.
The absorption demonstrated in this study is a form of “atmospheric water generation” or AWG, a technology that produces water from air that can be used for drinking, irrigation, and other uses.
But if we want to see workable AWG solutions, we must first understand the absorption qualities of the materials being used.
Saudi Arabia, where this study took place, has a water shortage due to several economic and environmental factors. The lack of rainfall in the region restricts replenishing water resources naturally. As a result, many areas are becoming increasingly arid and the potential for drought is growing.
Because of drought conditions, the country relies on desalination — processing saline seawater to make it drinkable. In fact, it is the largest producer of desalinated water in the world.
Despite this, the production of atmospheric water is a new concept here. It needs only a thermal source to produce water, and is more scalable and more environmentally friendly than desalination.
Development of this technology could result in the installation of water harvesting devices in sites across Saudi Arabia, reducing reliance on desalination and combatting the effects of desertification.
Saudi Arabia is just one of the numerous countries in the world that faces water shortages in its future. Therefore, it is easy to see that developments in atmospheric water generation technology could have dramatic impacts across the globe.
This project is a long-term project started at Effat University 2 years ago leaded by Prof. Mohamed El-Amin, Effat College of Engineering and involving serval co-investigators from EU and other universities. This paper is presenting part of the results of this ongoing project and co-authored by Shereen K. Sibie “a master student at the Master of Science in Energy Engineering", and Prof. Shuyu Sun from King Abdullah University of Science and Technology (KAUST).