When used in construction, the limestone creates carbon-neutral cement
Spotted: The renewable energy-powered process created by Oxford-based startup, Heimdol, captures carbon for an indefinite period of time in a way that is usable in construction. This solves one of the main challenges facing much of the construction industry. Limestone is one of the main ingredients of concrete and a naturally occurring carbon sink. Yet to find and extract the mineral requires significant amounts of energy. As one of the world’s most ubiquitous building materials, concrete has a vast energy footprint.
Heimdol reduces the resource expenditure by using solar energy to power the process of isolating certain minerals found in seawater. When those compounds are removed, the concentration of carbon in the water is much reduced, allowing the water to absorb more carbon when it is returned to the sea. And because the process can be done repeatedly, it has the potential to remove tonnes of carbon from the atmosphere.
The gathered minerals and compounds can be used for carbon-negative limestone, an essential ingredient in green concrete. Heimdol has signed letters of intent with several European businesses and expects to earn more through sales of green hydrogen and desalinated water. With a pilot plant being built in the United States, the startup is also looking for additional locations near desalination plants. Wastewater from the plants is treated with the same process, thereby turning potential pollution into a valuable product. The company plans to begin commercial production in 2023.
Written by: Keely Khoury