A brilliant new building material designed by a recent architecture graduate of TU Delft could solve several pressing environmental challenges at once. Taking what he calls the ‘biomimetic’ approach, Eric Geboers relies on solar energy to separate the salt from water in seawater. The resulting salt is then mixed with a starch derived from algae in seawater to create bricks that have greater compressive strength than earth, and could be used to construct aesthetically-pleasing buildings in arid regions. The desalinated water, meanwhile, would be used to grow food.
“Every minute of every day 23 hectares of arable land are lost to encroaching deserts, leading to a staggering number of 12 million hectares of land lost every year,” Geboers writes on his website The Salt Project. “52% of the world’s land used for agriculture is affected – leading to problems for 1.5 billion people world wide. In the meantime the global population is ever increasing to an expected 9 billion in 2048…meaning higher demand for food and the threat of an even quicker degradation of our soils due to exhaustion.”
Geboers aims to create a closed-loop system that would produce zero waste. Unlike traditional desalination technology, where concentrated brine is often pumped back into the sea in concentrations that are unhealthy to marine ecosystems, the extracted salt could be reused as a sustainable building material. Because it has great compressive strength, but not so much tension, it would be most ideally used in domes and arches, which are common in vernacular desert architecture.
Salt, of course, does not react well when exposed to moisture, so Geboers seals the starchy salt bricks with an epoxy. Since this is a plastic-based material, the architect is currently researching bio-based plastics as a more ecological alternative. Water distilled as a byproduct of the solar desalination process would then be used to grow food in greenhouses – similar to the Sahara Forest Project that is successfully cultivating crops in Qatar.
Geboers has already won a suite of awards for his groundbreaking design, and he’s currently looking to team up with engineers to take The Salt Project to the next level. He’s even developed a masterplan for a salt city in Lusail, just north of Doha, Qatar. Gulf countries are particularly well-suited for this kind of innovative architecture given limited freshwater resources and ubiquitous access to saltwater, severe aridity, and a growing, hungry, wealthy population that relies almost exclusively on imports for food.
We will be watching this promising project very carefully.