Cement is one of the most widely used materials on the planet, and one of the most damaging to the climate. Responsible for around 8% of global CO2 emissions, the industry has long been regarded as one of the hardest sectors to decarbonise. Now, a prospective spinout from the University of Strathclyde is developing a process that could fundamentally change that picture, turning low-value mineral waste into carbon-negative materials capable of replacing a significant portion of cement in everyday construction.
The company is called Ureaka, and it was founded by scientist Dr Philip Salter. Working at the intersection of circular chemistry and mineral processing, Ureaka has developed a method to create supplementary cementitious materials (SCMs), powdered additives that can be blended into standard concrete mixes in place of traditional cement, from waste streams such as demolished concrete. Critically, the process does not require manufacturers to overhaul their existing production methods, meaning the technology is designed to slot directly into current supply chains.
Why Cement Is So Difficult to Clean Up
The scale of the challenge facing the construction industry should not be underestimated. Cement and concrete production collectively account for roughly 8% of global CO2 emissions, a figure that is nearly double the contribution of the entire aviation sector. Unlike many other industries, the problem is not solved simply by switching to renewable energy. A substantial proportion of cement’s emissions arise not from burning fossil fuels but from the chemical reactions inherent in the manufacturing process itself, reactions that release CO2 as limestone is converted into clinker.
Dr Philip Salter explained: “Cement is one of the hardest industries to decarbonise because, even if you electrify production, a large share of emissions still comes from the chemical reactions involved. Ureaka is taking a fundamentally different approach: starting with the mineral value already present in waste concrete, reacting it with captured CO2, and turning it into a cement-replacement material that can work within existing supply chains.”
The Global Cement and Concrete Association reported in November 2025 that the sector had reduced its CO2 intensity by 25% since 1990 — progress that is real but insufficient given the pace of decarbonisation required to meet net zero targets by 2050. New approaches that can permanently remove carbon, rather than simply reduce emissions, are urgently needed.
How Ureaka’s Process Works
Ureaka’s approach centres on recovering valuable mineral components, particularly calcium and silica, from waste concrete streams that would otherwise be landfilled or left to degrade. These elements are then reacted with captured CO2 in a process that forms stable carbonate minerals, effectively locking the carbon into a solid, durable form. The resulting SCM, branded as Carbonis, is produced as a drop-in powder suitable for standard concrete manufacturing.
The environmental credentials are striking. According to the company, Carbonis captures between 0.2 and 0.4 tonnes of CO2 per tonne of product manufactured during its biological mineralisation process. Ureaka estimates that if all UK concrete were produced using Carbonis, it could avoid the production of 14.8 megatonnes of CO2 whilst sequestering a further 6.7 megatonnes, the equivalent of removing more than five million petrol cars from the road for a year.
The CO2 used in the process is sourced from industrial point sources such as distilleries and biogas plants, creating a closed-loop approach that draws on existing waste gas streams rather than relying on large-scale direct air capture. Beyond cement replacement, the company’s earlier work in biocementation also points to potential applications in soil stabilisation for construction projects and the repair of existing concrete structures through mineral formation.
From Lab to Market
Supported by the Industrial Biotechnology Innovation Centre (IBioIC) Spin Out Fund and developed in collaboration with researchers at the University of Strathclyde, Ureaka has now moved beyond laboratory-scale experimentation. The project is progressing through factory-scale modelling and is preparing for third-party product testing and validation in a live manufacturing environment — a significant milestone on the road to commercial readiness.
The company is also seeking additional grant funding and preparing for a seed investment round to support team growth. It has already attracted international recognition, having been named one of 50 global finalists in CarbonX Program 2.0, a climate solutions competition run by technology company Tencent.
Caroline Kewney, senior impact manager at IBioIC, added: “Construction materials are a significant contributor to global emissions, so there is a clear need for scalable alternatives that can support decarbonisation across the sector. This project demonstrates how industrial biotechnology can turn waste streams into valuable new materials, while also supporting carbon capture and more circular approaches to manufacturing. We’re excited to see what’s next for Ureaka as it progresses towards commercialisation.”
A Broader Shift in Construction Materials
Ureaka is not operating in isolation. Across the globe, researchers and start-ups are racing to develop viable low-carbon cement alternatives. Academic research published in late 2025 found that SCMs derived from industrial and agricultural waste have the potential to reduce the global warming impact of cement by 50 to 90% compared to ordinary Portland cement, depending on the material used. Fly ash, slag, and calcined clay have emerged as leading candidates, but supplies of many traditional SCMs are expected to tighten as coal-fired power generation — a key source of fly ash — declines.
What distinguishes Ureaka’s approach is its ability to generate a new SCM from waste streams that would otherwise offer no value, whilst simultaneously sequestering carbon in a permanent mineral form. Rather than simply reducing the carbon intensity of construction, the process actively removes CO2 from the atmosphere and binds it into the built environment.
With the UK government committed to net zero by 2050 and construction remaining one of the economy’s most emissions-intensive sectors, the timing could hardly be more pressing. If Ureaka can successfully scale its technology and navigate the path to commercialisation, it may offer the construction industry something it has long needed: a genuine route to becoming part of the climate solution rather than part of the problem.
