June 20, 2024
Swedish startup secures €10M to turn waste into cement

Concrete — a mixture of cement, sand, and water — is the second most used material on Earth after water. Ton-for-ton, more of it is laid down every year than steel, wood, plastics, and aluminium combined. Problem is, cement production emits 8% of global CO2 — four times that of air travel.

Swedish startup Cemvision has devised a cement making process that utilises by-products from industries like steel and mining instead of fresh limestone, resulting in a circular, cleaner alternative. 

“We’re on track to producing cement that emits 95% less carbon than traditional methods while remaining just as strong and potentially even faster-drying,” Oscar Hållén, CEO of Cemvision, told TNW. 

When limestone is heated in a kiln, calcium carbonate breaks down into calcium oxide and carbon dioxide. Around 60% of the cement industry’s total emissions are a result of this process. By using certain industrial by-products, like slag from steelmaking, Cemvision sidesteps this chemical reaction entirely.

The other 40% of cement’s emissions come from the energy needed to superheat limestone in a kiln. Today most kilns are powered by coal, oil, and natural gas. In the EU, some even burn rubbish

Cemvision’s demo plant in Poland, which came online in mid-2023, produces 4,000 ton of cement a year and is powered by biofuel. The startup is currently developing a kiln that runs on (mostly renewable) electricity at its lab in Stockholm. Because the industrial waste it uses can be processed at lower temperatures, Cemvision needs much less energy overall to produce its cement.