If the concrete industry were a country, it would be the third largest emitter in the world. It produces around four times as much CO2 as all global air traffic. The start-up Neustark , a spin-off from the Swiss Federal Institute of Technology in Zurich ( ETH ), is countering this with its concept: the mineralization of carbon dioxide from the air to obtain limestone.
Neustark binds CO2 in the pores and on the surface of concrete granulate. This upgraded granulate can then be mixed in fresh concrete as a substitute for sand and gravel. Thanks to these granules, less cement is required while the properties remain the same. This emerges from a communication from the ETH.
“What appealed to me was that the solution would not be available for five or ten years, but already now,” says business economist Valentin Gutknecht, who is responsible for the operational aspects of the business in the ever-growing Neustark team. Together with Johannes Tiefenthaler, he wants to turn this climate-positive business idea into reality. Tiefenthaler is doing his doctorate at the Department of Mechanical and Process Engineering ( MAVT ) on the next generation of technology for the mineralization of carbon dioxide.
There is a lot of research going on in the construction sector, but so far the industry has only achieved small reductions in emissions, so Tiefenthaler. The advantage of the concrete granulate is that it is highly reactive and the broken concrete forms a very stable chemical compound even without climate-damaging pre-treatment with carbon dioxide.
Your pilot plant for recycling concrete is funded by the Federal Office for the Environment ( FOEN ) and the Swiss Climate Foundation. The project is now intended to demonstrate the added value along the entire value chain. Neustark's goal: negative emissions for which there are only "very few technical approaches". The start-up wants to show "that negative emissions can not only bring costs but even economic benefits".
