A technology to remove carbon from the atmosphere and lock it into recycled concrete has been put on the UK market.
Building materials supplier Aggregate Industries, which is part of Holcim Group, has partnered with neustark to set up a mineralisation plant in London – the first venture into the UK market for the Swiss cleantech start-up, which has 19 sites in Europe.
Demolished concrete is the world’s largest waste stream but neustark technology helps turn this into a carbon sink, locking carbon removed from the atmosphere into processed concrete.
Concrete from demolished buildings is crushed and screened at an Aggregate Industries UK recycling site. It then undergoes a procedure in which CO2, captured from biogas plants, is liquified and injected into the concrete granules.
This triggers a mineralisation process that locks the captured carbon into the granules and can then be used to make new concrete with the recycled content inside or other building materials, the company said.
It added that neustark has removed more than 2,500 tonnes of carbon since it launched commercially in 2023, with an aim of removing one million tonnes by 2030.
Holcim invested in neustark last year and is collaborating with it to deploy its innovative solution at its sites worldwide, scaling up low-carbon and circular construction to multiple sites.
A first small-scale mobile plant is now operational in Greenwich and will start removing ‘hundreds of tonnes’ of CO2 in the coming months. A large-scale site is set to be installed in the first half of 2025, capable of removing 1,000 tonnes a year (net).
Aggregate Industries UK CEO Lee Sleight said: ‘This takes the battle to reduce carbon emissions to the next level through carbonation. The technology is available now and works - it can make a difference now not in five years' time.
'We have London – as one of the world’s largest urban mines – with direct access to demolished concrete from building projects and we have the neustark technology. Together we can remove carbon from the atmosphere and permanently lock it into recycled concrete which can then go on to be used again in new building projects.'
He added: ‘This isn’t just a great carbon removal innovation but a great circular economy innovation where we are taking what was once a waste stream and reusing it, saving us from digging up virgin materials in the first place.’
Valentin Gutknecht, co-founder and CEO of neustark, said: 'Neustark and Holcim have been working together almost since the founding of neustark five years ago. In that short timeframe, we tested and trialled the solution at lab and pilot scale, launched our first site in Switzerland, and are now our first in the UK.
‘One million tonnes of CO2 durably removed from the atmosphere in 2030 – that’s our ambition. We’re already well underway towards the megaton goal. Our strategic partnership with Holcim represents a significant part of this roadmap.
‘It will be a true catalyst to further scale up the permanent carbon removal impact that we generate in the next few years.’
