総合化学5社。　https://neovisionconsulting.blogspot.com/2024/11/5-20241111.html: Google翻訳。New technology can produce 1.3L of drinking water per day from desert air! Hopes for its use in disaster-stricken areas! 2024.06.29 SATURDAY.

https://nazology.net/archives/155759

For us, it is natural that we can turn the tap handle and water comes out, but this is not the case around the world.

In fact, approximately two-thirds of the world's population suffers from water shortages , and it is estimated that "approximately 40% of the world's annual water demand will not be met by 2030."

Even in Japan, where water facilities are well established, disaster-stricken areas will continue to face difficulties in obtaining sufficient water.

To address these challenges, a research team led by Shanyu Li of the Massachusetts Institute of Technology (MIT) in the United States has developed a new system for harvesting water from the atmosphere .

It is believed to be able to produce two to five times more drinking water than conventional systems, making it ideal for use in extremely dry areas such as deserts.

Details of the research were published in the scientific journal ACS Energy Letters on June 26, 2024 .

Small, absorbent 'fins' collect humidity rather than swim through waterhttps://www.eurekalert.org/news-releases/1048856?Harvesting Drinking Water from Air with Innovative Absorbent Finshttps://scitechdaily.com/harvesting-drinking-water-from-air-with-innovative-absorbent-fins/

Design of a Compact Multicyclic High-Performance Atmospheric Water Harvester for Arid Environmentshttps://doi.org/10.1021/acsenergylett.4c01061

table of contents
How to harvest water from the atmosphere to get drinking water
A new water generation system with copper plates sandwiched between them! 2 to 5 times more efficient than conventional systems
How to harvest water from the atmosphere to get drinking water

How to get water in the desert? / Credit: Canva
There are several ways to obtain drinking water in water scarce
For example, there is technology that can filter dirty, muddy water to make it drinkable, or turn seawater into fresh water.
However, these techniques rely on the presence of some water at the site, whether dirty or salty.
So how can people get drinking water in extremely dry areas, such as deserts, where there are no puddles ?
As one way to do this, scientists have long focused on systems that harvest water from the air .
This method involves using an "adsorbent" to collect water from the air, then heating it with the sun or another heat source to extract the water .

The adsorbent captures water from the air. Image / Credit: Xiangyu Li (MIT) et al., ACS Energy Letters (2024)
Zeolite is a mineral with tiny pores.
Because the size of the pores in zeolite is similar to that of water molecules, zeolite has a very high adsorption power for water molecules and can capture water molecules from humid air .
However, in order to extract water from zeolite, it is necessary to heat it, and conventional methods using sunlight are not very efficient.
So this time, Li and his research team wanted to use waste heat instead of sunlight .
Waste heat is a type of excess energy generated by industrial processes, power plants, etc. that is usually wasted.

(Top) Heating using sunlight, (bottom) Heating using exhaust heat, etc. It is efficient because it has many cycles of adsorption and drainage. / Credit: Xiangyu Li (MIT) et al., ACS Energy Letters (2024)
By integrating the water production system with existing infrastructure that generates waste heat, such as factories and other buildings, and transportation vehicles, it is believed that the adsorption and dehydration cycle in the adsorbent can be accelerated , as shown in the diagram above.
Incidentally, utilizing waste heat will also reduce the environmental impact, making it more valuable as a "sustainable water supply system."
Several substances are used as adsorbents, for example " zeolite ".
A new water generation system with copper plates sandwiched between them! 2 to 5 times more efficient than conventional systems
The research team designed a new system that not only utilized waste heat but also sought to achieve even greater efficiency.
Their new system uses copper-based adsorption fins .

A new water collection system. A copper plate is sandwiched between the fins. / Credit: Xiangyu Li (MIT) et al., ACS Energy Letters (2024)
As usual, the surface of the fins is coated with zeolite as an adsorbent.
By arranging multiple thin fins with a small gap between them, we were able to increase the surface area that comes into contact with the moist air, enabling it to adsorb water efficiently.
In addition, a copper plate is sandwiched inside the fin.
Exhaust heat is used to heat the fins, and copper plates have the advantages of high thermal conductivity and corrosion resistance. By sandwiching a copper plate inside the fins, the cycle of "adsorption" of water and "release by heating" is made more efficient .
In their proof-of-concept experiments, the team used a device with 10 fins spaced about 2mm apart.

A new system that produces drinking water from air is 2 to 5 times more efficient than conventional systems / Credit: Xiangyu Li (MIT)_Small, adsorbent 'fins' collect humidity rather than swim through water (2024 EurekAlert)
In this device, the fins were saturated with water within an hour and the water could be released by heating.
By repeating the collection and release cycle 24 times, it was found that 1.3 liters of drinking water could be produced per liter of adsorbent per day in an environment with 30% humidity .
This is two to five times more efficient than conventional systems .
Furthermore, since it utilizes waste heat, it is also extremely energy efficient.
If this new system develops, it will be possible to supply drinking water even in areas where water shortages are severe.
There are high hopes for this technology, as it may prove particularly useful in arid regions such as deserts .