[Stones and Stories] Drinking Water from Seawater Using a Sugar Cube Solar Evaporator

Solar Thermal Evaporator-Based Seawater Desalination System

[Asia Economy Reporter Junho Hwang] Domestic researchers have developed a solar-powered photothermal evaporator for seawater desalination with high evaporation performance using readily available sugar cubes in daily life. It is expected to open a path to continuously obtain large amounts of drinking water easily from seawater or brine.

The National Research Foundation of Korea announced on the 30th that Professor Lee Sang-jun's research team at Pohang University of Science and Technology developed a solar-powered photothermal evaporator for seawater desalination with 99% evaporation efficiency and desalination technology using it. Seawater desalination is a water treatment process that removes dissolved substances including salt from seawater to obtain drinking water. A photothermal evaporator is a device that converts light energy into heat energy to evaporate water.

The research team developed a photothermal evaporation membrane with the highest evaporation efficiency ever and self-cleaning function using a porous silicon structure made from inexpensive sugar cubes. This photothermal membrane exhibited 99% evaporation efficiency due to its superhydrophilic and thermal localization properties. The team stated that self-cleaning activity occurs through flow activation inside the porous medium, enabling stable drinking water production over a long period.

Using this membrane, the research team reported desalinating seawater with an extremely high efficiency of 99.997%. They desalinated 30 liters of water per square meter daily for three months. The desalinated water met the drinking water standards of the World Health Organization (WHO) and the United States Environmental Protection Agency (EPA).

The research team said, "We confirmed for the first time in the world that strong flow is generated inside the membrane by optimally combining the membrane's surface and structural characteristics," adding, "Based on this porous medium internal flow phenomenon, we developed membrane self-cleaning technology that allowed stable long-term seawater evaporation."

They continued, "If this technology is commercialized, it can be used for desalination of seawater and brine using solar energy as well as water treatment processes for polluted water," and "It can also be utilized as an indoor evaporative humidifier using the remarkably high evaporation rate."

This content was produced with the assistance of AI translation services.