Decarbonizing concrete with Ureaka's Philip Salter

Philip Salter is the founder of Ureaka, a climate tech company developing carbon-negative cement replacement materials using waste streams and circular chemistry.

What's your background and what led you to found Ureaka?

I studied geology at undergraduate level and was always drawn to the geochemistry side of things. At the same time I was working in a lab developing cosmetic products, scaling up from making things at a bench to producing them at five tons a job. I kept moving toward more applied science and engineering, so I started my PhD in civil engineering at the University of Strathclyde in Scotland, where I'm originally from. The research focused on using bacteria and enzymes to form alternative mineral binders, with an emphasis on how those processes could translate to industrial systems.

During my PhD, we identified a new pathway that connected carbon capture, waste materials, and mineral formation into a repeatable industrial system. The key insight was that CO₂ did not need to be treated as a waste to manage, but as a feedstock that could be permanently locked into construction materials while remaining cost-competitive at scale. That moment shifted our thinking away from isolated lab materials toward full systems design.

Academia is excellent at generating insights, but many promising ideas struggle to translate beyond the lab. We wanted to build something that could move faster and make a measurable dent in emissions. Ureaka exists to replace as much cement as possible with materials that are genuinely carbon-negative, using waste streams and circular chemistry rather than offsets or accounting mechanisms.

How is the construction industry currently tackling cement emissions and where is it falling short?

Cement and concrete are responsible for around 8 percent of global CO₂ emissions. The industry does have some solutions it has been using for decades. There are drop-in replacements for cement that are typically byproducts of other industries: blast furnace slag, steel slag, fly ash from coal power plants and, more recently, clays. Those solutions have been adopted over the past 20 to 30 years.

Over the past year, our team has spoken extensively with contractors, material suppliers, precast manufacturers, and regulators. One message comes through very clearly: the future of low-carbon concrete will be driven by solutions that fit within existing industrial reality. When low-carbon alternatives fail to scale, it usually comes down to three things.

First is cost. If a solution is meaningfully more expensive than cement, adoption will not happen at scale. Second is supply chain fit. Concrete is produced in enormous volumes with tight margins and highly optimized logistics. Third is disruption. If a technology requires rebuilding factories, retraining the workforce, or replacing infrastructure, uptake will be slow, regardless of future regulation.

Historically the solutions that have scaled are the ones that slot into existing plants as drop-in replacements. Encouragingly, standards are shifting toward performance-based requirements, meaning materials are judged on strength and durability rather than their exact chemistry. That shift lowers risk for adopters, because it allows new materials to be evaluated on how they perform in real structures, rather than how closely they resemble existing formulations.

How does Ureaka's approach differ from others in the space?

Ureaka was always designed around mineral binders; we have now prioritized drop-in cement replacement materials because they offer the fastest route to global scale. Around 70 percent of concrete globally is ready-mix, with the remainder precast. By supplying a powder that replaces a portion of cement, we can integrate directly into existing concrete production. For example, replacing 30–50 percent of cement in a standard mix delivers a material reduction in embodied CO₂ immediately, with higher substitution levels possible as standards evolve.

What sets Ureaka apart is that, based on detailed process and cost modeling, the business does not rely on carbon credits to be viable. Many carbon sequestration technologies depend on carbon pricing, which introduces political and regulatory risk. Ureaka instead combines CO₂ utilisation with waste-derived feedstocks, creating multiple value streams. Our analysis shows a credible path to profitability at cement-competitive pricing, driven by low energy intensity and circular material flows.

At its core, the innovation lies in controlling a closed-loop chemical system that enables CO₂ mineralisation at significantly lower energy demand than many competing approaches. We have been working closely with chemical engineers to model what this looks like at industrial throughput, rather than at lab scale. Using waste-derived feedstocks also reduces exposure to volatile raw material markets, which is increasingly important for an industry facing both carbon constraints and supply risk.

The complexity lies not in any single step, but in integrating multiple unit operations into a system that remains low-energy, scalable, and economically competitive.

The cement and concrete space is incredibly competitive. How do you think about differentiation as an early-stage company?

It is highly competitive. There are hundreds of companies addressing cement emissions, some of which have raised significant capital and are already operating at scale. However, very few approaches offer a credible route to being genuinely carbon-negative without relying on offsets or subsidies.

Our focus on system-level modeling, energy minimization, and supply-chain compatibility helps partners and investors evaluate scalability early. This is not a laboratory curiosity; it is designed for industrial deployment.

We also see a strong role for biocementation in repair and retrofit applications. Because the fluids used are very low viscosity, they can penetrate cracks and voids that traditional cement grouts cannot reach. Extending the lifespan of existing infrastructure is one of the fastest ways to reduce construction-related emissions.

What does the roadmap look like for Ureaka over the next few years?

Ureaka is supported by a multidisciplinary team spanning civil engineering, chemistry, and process engineering, alongside experienced commercial leadership. We are currently working with Scottish Enterprise and industry partners to deliver a pilot-scale system at the University of Strathclyde.

Over the next 12 to 18 months, the focus is on integration and validation at meaningful throughput. Using modular pilot infrastructure designed to inform both licensing and deployment decisions. The long-term deployment model is flexible: Ureaka can license the technology into existing cement and materials producers or support dedicated facilities where appropriate, without requiring the industry to rebuild its core infrastructure.

Letters of intent from partners reflect the industry’s need for demonstrated solutions rather than concepts. Rigor, data, and demonstration are essential. The focus at this stage is not speed for its own sake, but proving repeatability, reliability, and economics at pilot scale before scaling deployment.

If Ureaka succeeds, how does the world look different?

If technologies like ours replace a meaningful fraction of cement globally, the impact is measured in hundreds of millions of tonnes of permanently stored CO₂. In Ureaka’s process, CO₂ is chemically transformed into a solid mineral form – effectively turned into rock – and locked into construction materials. 

Once mineralised in this way, the carbon cannot escape back into the atmosphere under normal conditions. That level of permanence makes construction materials one of the largest engineered carbon sinks available. Because the process both avoids conventional cement emissions and permanently mineralises captured CO₂, the net effect is carbon-negative rather than simply lower-carbon.

I should also mention that we were a global finalist in Tencent's CarbonX program from over 660 applicants. That gave us a lot of exposure and I was struck by the quality of the other technologies that were there. Competing alongside companies such as Heirloom, a successful direct air capture company, provided valuable independent technical scrutiny and reinforced confidence in the fundamentals of the approach.

How do you define deep tech?

Deep tech should not be defined by novelty alone. Ultimately, the economics have to work. Whether a solution is based on biology, chemistry, or physics is secondary to whether it performs reliably, scales to industrial volumes, and competes on cost.

There is sometimes a tendency, particularly in Western markets, to treat deep tech as something fundamentally different from “regular” technology,  as if technical sophistication alone justifies adoption. In reality, industry tends to be much more pragmatic. The questions are simple: does it work, can it scale, and can it be integrated without breaking existing systems?

That perspective is especially important in sectors like construction, where margins are tight and supply chains are highly optimized. If a technology cannot slot into existing markets at competitive pricing, it will remain a niche, no matter how elegant the science behind it.

For climate technology to have real impact, it has to meet both tests. It must be scientifically robust, but it must also make sense commercially. The future of deep tech will be defined not just by ingenuity in the lab, but by the ability to translate that ingenuity into solutions that industry is actually willing to adopt. In climate and infrastructure, impact only happens when deep technology becomes normal technology.

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