Comparing Adsorption and Condensation-Based Atmospheric Water Harvesting Systems

Adsorption-based AWG systems utilize materials with a high affinity for water molecules, known as adsorbents. Common examples include reticular materials such as metal organic frameworks (MOFs) and covalent organic frameworks (COFs), which excel in low humidity water generation by capturing water vapor from the air, even when humidity levels are low. Once the adsorbent is saturated, heat is applied to release the adsorbed water, which is then condensed into liquid form and collected.

 

These atmospheric water generators are particularly effective in arid and semi-arid regions, making them suitable for off-grid water solutions. They can yield clean water even when humidity levels drop below 20%, demonstrating the potential for generating water from air in challenging climates. 

In contrast, condensation-based AWH systems operate by cooling air to the dew point, causing moisture to condense into water droplets, similar to how dew forms on grass. The collected water is then filtered for contaminants and purified for use. This method tends to be most effective in areas with higher humidity levels, where the air contains sufficient moisture to condense. 

  

However, cooling-condensation AWG systems can be energy-intensive, requiring significant cooling power to achieve the necessary temperature drop. Especially in arid environments, their efficiency diminishes substantially, limiting their application in regions facing water scarcity. 

 

The primary distinction between these technologies lies in their mechanisms for extracting water: 

 

• Adsorption: This method uses materials that adsorb water molecules from the air and later releases them, making it ideal for low humidity water generation. 

 

• Condensation: This method cools air to extract moisture by reaching the dew point, making it suitable for on-grid environments of relatively high humidity levels. 

 

These fundamental differences dictate their operational conditions, energy consumption, and overall efficiency. 

 

Efficiency in Water Extraction

 

Adsorption-based systems are generally more effective in low humidity water generation, as they can extract water even when the air is relatively dry. Condensation-based need significant amounts of energy to produce water when moisture levels are low.

 

 

Energy Consumption and Requirements

 

Adsorption-based systems are generally more effective in low humidity water generation, as they can extract water even when the air is relatively dry. Condensation-based need significant amounts of energy to produce water when moisture levels are low.

 

Suitability for Various Operational Conditions

 

Adsorption-based systems are generally more effective in low humidity water generation, as they can extract water even when the air is relatively dry. Condensation-based need significant amounts of energy to produce water when moisture levels are low.

Both adsorption and condensation-based atmospheric water generators present unique advantages and limitations based on environmental conditions. Existing technologies struggle, especially in arid conditions where drinkable water is generally needed the most. 

 

At Atoco, we leverage decades of research in reticular chemistry for our transformational air to water technology. We focus on adsorption systems based on nano-engineered reticular materials that are particularly effective for low humidity water generation, ensuring a reliable and sustainable solution for generating water from air. By developing advanced off-grid water technologies with a minimal carbon footprint, Atoco aims to address global water challenges effectively. For more information on Atoco’s innovative technologies and their impact on sustainable water solutions, please visit Our Technology page.  

Atoco is a leader in climate technology, founded by Professor Omar Yaghi, the pioneer of Reticular Chemistry. Atoco leverages reticular materials such as Metal organic Frameworks (MOFs) and Covalent Organic Frameworks (COFs) to develop breakthrough solutions for carbon capture and atmospheric water harvesting.

These technologies, designed with atomic precision, are engineered to tackle global and most pressing challenges: climate change and water scarcity.