Coals are a bit of a topic of contention. True enough, the industrial world has subsisted on the support of coal energy for decades, and much of the world’s mechanical and innovative advances in technology can be attributed to our consumption of the material. However, we now recognize that our reliance on this resource has damaged the planet; in fact, we’ve inflicted so much damage that the Amazon rainforest, long regarded as the largest forest in the world, now produces more carbon emissions than what its trees can absorb back.
It thus becomes all the more important for scientists of today to figure out ways of supporting our constantly-growing energy needs without placing too much strain on the planet’s resources. One way of doing so is through the use of renewable resources, like solar energy and hydrothermal energy.
Researchers from King Abdullah University of Science and Technology (KAUST), however, decided to think outside the box. While most people looking for ways to reduce our carbon footprint would opt to remove coal from consumption entirely, the KAUST research team led by Associate Professor Andrea Fratalocchi, decided that coal still has its place; they instead thought of a new, carbon-neutral way of using coal as a water filter.
Specifically, the coal in their study functions as a crucial aspect of a water desalination setup, where salt is routinely taken out of seawater as a way to address the planet’s growing need for fresh, potable water. The very study by Fratalocchi and team made use of what they called compressed carbonized powders (CCP), or crushed coal and charcoal pieces that were recompressed into a new, porous structure. Their method of compression also allows the formation of other custom shapes, which can then be tailored specifically to certain setups and applications.
The researchers then combined the CCP with cotton fibers, forming a 20 cm × 20 cm (7.8 in × 7.8 in) block. This block was then placed in the middle of a 34 cm × 34 cm (13.4 in × 13.4 in) container filled with seawater.
The fibers served as attractors to seawater, which then traveled through the block to the top which was exposed to sunlight. The hot surface of the block evaporates the water, leaving the salt in the block and allowing the resulting steam to collect and condense on the pyramid-shaped lid of the setup. The condensing water is then guided into troughs, leading to clean, drinkable water produced from saltwater.
Results from the KAUST study showed their coal-based desalination setup to be two to three times more effective compared to regular solar desalination setups; likewise, a setup of 16 m × 16 m (52.5 ft × 52.5 ft) is expected to desalinate enough water for a family of four, said the research team. The entire technology is expected to be commercialized, with its first pilot plant targeted to be established in Brazil with the help of Netherlands-based PERA Complexity.
Said co-author and Fratalocchi’s lab postdoc Marcella Bonifazi in a KAUST news release: “CCP is abundant in nature and low cost, as well as lightweight, versatile and highly scalable from a fabrication point of view. The device produced fresh water for around one-third the cost of current state-of-the-art solar desalination technologies.”
This study was published in the journal Advanced Sustainable Systems.
(Read more on climate-saving efforts like Iceland’s recent launch of the world’s largest direct air capture plant, or on climate change’s deleterious effects on archaeological artifacts in the Indonesian island of Sulawesi.)
References
- Bonifazi, M., & Mazzone, V. (2021, November 3). Coal product used to create green clean water. KAUST Discovery. https://discovery.kaust.edu.sa/en/article/1181/coal-product-used-to-create-green-clean-water
- Coal energy in the U.S. (n.d.). Statista. Retrieved November 8, 2021, from https://www.statista.com/topics/1206/coal-energy/
- Coal product used to create green clean water. (2021, November 3). KAUST Computer, Electrical and Mathematical Sciences and Engineering. https://cemse.kaust.edu.sa/news/coal-product-used-create-green-clean-water-0
- Coxworth, B. (2021, November 5). Coal could find new use in eco-friendly desalination tech. New Atlas. https://newatlas.com/good-thinking/coal-ccp-desalination/
- Marohl, B. (2021, July 26). In 2020, the United States produced the least CO2 emissions from energy in nearly 40 years. U.S. Energy Information Administration. https://www.eia.gov/todayinenergy/detail.php?id=48856
- Mazzone, V., Bonifazi, M., Aegerter, C. M., Cruz, A. M., & Fratalocchi, A. (2021). Clean carbon cycle via high-performing and low-cost solar-driven production of freshwater. Advanced Sustainable Systems, 5(10), 202100217. https://doi.org/10.1002/adsu.202100217
