Domestic researchers have developed a high-efficiency seawater desalination system to address water scarcity issues. They expect it to minimize environmental pollution by using eco-friendly materials while also addressing the expense issues associated with existing technologies.
A research team led by Professor Yoo Jeong-mok from Kyunghee University’s Department of Convergence Bio and New Materials Engineering announced on the 23rd that they have developed a solar thermal evaporator that increases the efficiency of seawater desalination.
According to the 'UN World Water Development Report 2023' released by the United Nations (UN) last year, the number of people facing water scarcity worldwide has reached 2 billion. Unrestricted water consumption, excessive development, and global warming are cited as the main causes of water shortages. As the availability of drinkable water rapidly decreases, seawater desalination technology has recently gained significant attention. However, the issue of massive expenses associated with constructing and operating large-scale facilities for seawater desalination remains unresolved.
The research team successfully reduced desalination expenses significantly by developing a solar thermal evaporator using cellulose. This evaporator applied carbon dioxide (CO₂) laser carbonization processes and ice templating technology to enhance environmental friendliness while increasing water evaporation efficiency.
Cellulose is a material that can be easily obtained from plants such as trees and grasses. It is biodegradable and has a minimal environmental impact. The research team created cellulose nanofibers and aerogels, which increased the speed of water transfer while confirming a high evaporation rate. They also implemented a porous structure using ice templating technology, rapidly freezing the material to create droplet holes. By generating a carbon layer on the surface with carbon dioxide lasers, they improved solar absorption and enhanced water evaporation efficiency. The surface of the evaporator is coated with polydimethylsiloxane (PDMS) to increase buoyancy while reducing heat loss, enabling sustained performance.
The research team conducted experiments to validate the performance of the newly developed seawater desalination system. As a result, they achieved an evaporation rate of 1.9 kg per square meter per hour and an evaporation efficiency of 93.8% with pure water. It was also confirmed that the system operates stably when used in an environment simulating the sea.
The research team expects that the newly developed solar thermal evaporator can significantly reduce desalination expenses in water-scarce areas. It can also be used to purify agricultural water or treat industrial wastewater. By using the eco-friendly material cellulose, they minimized concerns about environmental pollution.
The research team explained, “Based on this achievement, we will promote the commercialization of eco-friendly and economically viable water treatment technologies,” adding that “we plan to continue sustainable technology development to solve the issue of water scarcity.”
The research results were introduced in the international journal 'Advanced Functional Materials' on the 17th of last month.
References
Advanced Functional Materials (2024), DOI: https://doi.org/10.1002/adfm.202414576