New technology is turning demolished concrete – the world’s biggest waste stream – into a carbon sink.
Neustark and Aggregate Industries have partnered on the scheme, with the first site operating in Greenwich, London.
The aim is to permanently store and remove 1,000 tonnes of CO2 (net) per year – the equivalent of the carbon sequestered by over 16,000 tree seedlings grown for 10 years.
It’s the first venture into the UK market for Swiss cleantech start-up neustark, which has already established 19 carbon capture and storage sites around Europe.
The site is one of the first commercially and ecologically viable solutions for permanent, onshore carbon removal in the UK.
Neustark’s technology captures CO2 from biomass sites, liquefies it, then injects it into existing mineral waste streams such as demolished materials to be recycled and used in construction.
This utilises a process of mineralisation that stores the CO2 in the aggregate, permanently removing it from the atmosphere and creating carbonated, recycled building materials such as concrete.
The building and construction industry is estimated to account for 37% of global carbon emissions, with 7% coming from the production of cement alone, according to a 2023 UN report.
While the UK industry has made efforts to decarbonise, the UK Green Building Council warned it was ‘significantly off-track’ on its net zero goals at the end of last year.
By using the carbon removal process of mineralisation, neustark and Aggregate Industries aim to support more decarbonisation in the construction sector by turning 1 billion tons of demolished concrete into a carbon sink every year. Each tonne of demolished concrete can store an average of 10 kg of CO2.
The UK government signalled clear support for carbon capture and storage technology (CCS) by announcing a pledge of £21.7 billion in funding last month. However, the focus of this investment is currently on CCS, a less permanent management approach to carbon emissions, in comparison to neustark’s CO2 removal (CDR) technology. The government initiative is also tasked with building out regional technology ‘clusters’ for the development of the industry.
Valentin Gutknecht, CEO and co-founder, neustark, said: “The UK is an ideal market for us as it has a mature supply chain and the infrastructure we need to remove CO2 at scale.
“The government is supportive of building a competitive carbon market and shifting the industry away from early-stage developments to a competitive commercial set-up. But there is not enough focus on carbon removal, or consideration of how carbon removal can be embedded into existing supply chains and industries beyond oil and gas, rather than always requiring extensive new infrastructure.
“This partnership is proof that collaboration between a cleantech start-up and global leader in building solutions can create tangible climate impact today.”
Lee Sleight, CEO of Aggregate Industries UK, said: “We are excited to get this technology set up in London, where there is direct access to a huge supply of demolished concrete. And this isn’t just carbon removal, it’s a reinforcement of a circular economy enabling the reuse of a major waste stream. Once fully operational, we believe other contractors and specifiers will adopt this technology as well, accelerating their own decarbonisation journeys.”
Unlike other carbon removal technology, neustark is removing CO2 now and has already taken over 2,500 tonnes of CO2 from the earth’s atmosphere since commercial launch in 2023.
