Cement, which is the main ingredient in concrete, accounts for 8% of all global CO2 emission. That makes 3 billion tonnes each year. Seratech offers a solution to reduce it to zero.

The founders of Seratech, PhD students at Imperial College London Sam Draper and Barney Shanks, have discovered a simple way to capture waste CO2 and utilise it in the manufacturing of cement, resulting in carbon-neutral concrete products. For this, they have received the OBEL AWARD 2022.

“It is such an honour to receive the OBEL AWARD. This visibility will help us attract people in industry and scale our technology – and scale it rapidly. Humanity can’t afford to spend 20-50 years scaling the technology to give us sustainable materials. It needs to be now,” says Sam Draper.

“Architects and designers are already working with things such as intelligent design, flexible use, special types of formwork, and repurposing of materials. These are levers they can pull to reduce the carbon associated with buildings. What we’re trying to do is give them another lever,” says Barney Shanks.


Wrapped in a nice bow

The Seratech process is simple and adaptable. Seratech captures industrial CO₂ emissions directly from flues and produces a carbon negative cement replacement material, a silica. When this is used in combination with Portland cement, the carbon capture associated with producing the silica means the concrete products are zero carbon.

“We can use waste CO2 from any industrial emitter. It doesn’t need to be pure or liquid CO2, which a lot of other technologies require. It doesn’t have to be scrubbed; we can use it as it comes out at the back of a factory,” Shanks explains.

Seratech uses emissions from cement kilns, however, in order to focus on the construction sector and take advantage of the existing processes and infrastructure.

“Including the cement kiln in our process wraps everything up in a nice bow. We’re taking a waste product from a cement kiln to produce something that can then go back into the cement industry. It’s a nice, fully integrated loop. Also, there’s transport and other infrastructure that you need to operate at this scale, which we can tap into,” says Shanks.

Many of the existing low-carbon solutions are limited in their size, but Seratech’s process can produce concrete in any size, and while the result is a shade whiter than “normal” concrete, it looks and acts exactly the same, Draper explains, adding:

“To summarise : The Seratech technology is carbon-neutral, it’s scalable, and it’s scalable now. The raw materials are hugely abundant; it doesn’t need complete rewriting of design standards. It works.”


A labour of love

The idea for Seratech originated in the lab at Imperial College London where the two PhD students were working in the same office on their own projects – Barney Shanks within chemistry, and Sam Draper in structural engineering. Draper spotted the silica that Shanks was producing and wondered if it could be used in normal concrete. Turned out it could.

The next big step came when the structural engineering company AKT II got in touch because one of their developers read an article about the technology.

“And so AKT II emailed me and asked: ‘Can we buy some of your concrete to use in our buildings?’ And I laughed because we only had about 15 grams,” says Shanks.

Today, the big concrete blocks and the machines take up more and more space in their academic office.

“This is still what you’d politely call an artisanal-scale project; it’s still done by hand. I have to make all the silica in the lab in big buckets with a repurposed paint mixer, and then we take it downstairs, and Sam churns out these bricks, 8 at a time, with our steel molds. It’s very much a labour-intensive process – but a labour of love,” he says.

Seratech has received a lot of industry body support and is currently working on a pilot plant to model the process at large scale. The company now consists of five members as well as affiliated researchers, graduate students and interns.

“We bring very different backgrounds, and that’s a big advantage for a technology like this, which is so split between the processing of materials and their practical use in concrete. Both of those things have to work as flawlessly as possible for the technology to stand any chance in the industry,” says Draper.


Slipping into the flow

Seratech’s idea is the product of interdisciplinary work within academia – but very much also between academia and industry. Seratech has involved industry actors early on and have listened to their needs and advice.

“Because we worked with industry to begin with, asking them what they needed, our solution just slips into the existing workflow of concrete and infrastructure. It doesn’t inhibit the way we use the material or how we design our buildings. Architects can continue to design beautiful and safe buildings with this material,” says Shanks.

“Cement and concrete are old-school, behemoth industries. They have so much existing infrastructure and a lot of confidence in their material – and rightly so, because it’s been tested again and again and has so rarely failed us. So, they are naturally against any radical change, which is why we position ourselves as an evolution rather than a revolution in terms of our technological development. It’s just a partial replacement, just a new thing to replace your cement with,” he says.

The two of them both believe that in the fight against climate change, more integration of industry and academia is important in whatever form that takes. Industry actors need to listen to academics to stay updated on new ideas and knowledge, but academics also need to listen to the needs of industry in order to produce relevant research and technology, Draper explains:

“The earlier you can get industry engaged, even if very briefly, the earlier you can spot problems and address them or reframe your technology – and it can potentially save years and years of pointless development. We hope to be sequestering meaningful emissions with a few sizeable pilot facilities within a couple of years. But there’s no pathway to that without significant industry involvement.”


Attention from architects

In a very short time, the two PhD students have developed their initial lab idea to a finished, commercial product. Receiving the OBEL AWARD, they say, is an important next step to deliver the idea faster, spreading awareness, interest, and demand for the product. This is crucial to achieving the end goal of significantly reducing global carbon emissions of the construction sector.

“I think it’s a huge honour that the jury see the potential in this technology – the scalability and the impact it will have on the way we design sustainably. I hope that it will transfer to the architects that hear about the award. The recognition is massively important going forward: to have people talking about the technology, wanting to use the concrete in their buildings,” says Draper. Shanks adds:

“We want to highlight the importance of collaboration between academia, industry, and the work of architects. That’s why the OBEL AWARD is great because it’s essentially forcing this collaboration, making us take notice of each other, and getting that interdisciplinary work happening. I can’t wait to see some of the brilliant architects take this material and do some weird and wonderful things with it.”