The tech startup on a mission to decarbonise concrete

Imagine a world where auto buildings around us help us absorb carbon dioxide

instead of pumping more of it into the atmosphere. A world where we use technology to accelerate the processes nature has already mastered

Well, it's already here. This is Pebble, a Rotterdam startup making raw construction material out of CO2

But how does this work? And can it be deployed at scale? The method that we're using, which is actually running nature's chemistry on steroids

So the basic chemistry that we're working with is based on the phenomenon called rock weathering

which is part of the Earth's carbon cycle. And it's actually already today pulling out roughly a billion tons of CO2 out of the air every single year

When rainwater mixes with rock dust, it dissolves carbon dioxide and converts it into minerals that essentially lock it away in solid form

which can last for thousands to millions of years. It's one of Earth's long-term carbon sinks

but as you can imagine, it's a very slow process. We can take that same chemistry

take those same kinds of minerals that you find on all continents

break them up, put them into a chemical reactor, increase the pressure and temperature and add a few catalysts And that gives us a valuable material for the construction industry where you can even use this material to substitute cementitious materials which currently

are causing 68 percent of global greenhouse gas emissions. The core of the problem is that the

raw material for traditional cement is limestone. That's the main component. Limestone is calcium

carbonate and calcium carbonate is calcium oxide and CO2 bound together in a mineral form but they

are dissociated from each other at the high temperature, which causes the emission. Which

also tells you that even if you electrify cement production, you're still going to be left with 40

to 50% of the emissions because of the material you're working with. In contrast, if you make

cementitious materials, and bear in mind, we're not a one-to-one cement replacement, but we have

cementitious properties in our product, you start with two tons of minerals. Again, slightly different

type of mineral, but instead of burning them at a high temperature and losing a lot of CO2

in the air, you add one ton of CO2 to those two tons of rocks, you generate heat, and you're left

with three tons of output product at the end. But how much of this carbon storing material can

really be produced? Since launching in 2020, Bebo has increased their production capacities by 100

from producing around 2 kilograms of material per day to 2 or 300 kilograms in November 2024 Since then we been mostly focusing on scaling up the technology further and the big technical jump that you have to make

is to move from a batch process to a continuous process. So to make that jump, we built a demonstration scale plant

which we opened up in Rotterdam earlier this year. We started it up in March

and that is a plant with a design capacity to process roughly 900 tons of CO2 per year

which then turns into between 2,500 and 4,000 tons of product per year

It's a significant scale-up jump, but it's still very small on the scale of the construction industry

And our next step, of course, is to build a full commercial-scale unit

And we're just in the process of selecting where that will be. The company has already been involved in various projects across Europe

from Kewo-Ankers in Rotterdam to surface-level concrete floors in a Parisian boutique

To be deployed at large scale and compete with traditional concrete, the project will also have to be economically viable

So what we are doing is approaching cost parity with cement and other supplementary cementitious materials with our first commercial scale plants

We may be there or may not quite be there with the first commercial scale plant but once we start building bigger commercial scale plants we are absolutely projecting to be competitive with traditional products in this industry The construction industry isn going anywhere In fact Andres says whether an economy is flourishing or struggling

construction, the largest industry on the planet, is always on the rise

We actually typically build more when the economy is doing worse. And of course, when the economy is doing well

we're also building quite a bit because then people are investing into new projects and so on and so forth

So it's rather so that when the economy is doing really well, the private sector is investing a lot into construction

When the economy is doing not so well, Many governments may invest in construction and infrastructure works to maintain the economic engine

Humans make more concrete than anything else. We produce just about 30 billion tons every single year

And at the same time, we pump out 30 to 50 billion tons of CO2 up into the air

And very importantly, we're not going to stop using concrete. With the current rate of urbanization, we need roughly one Manhattan's worth of concrete every single month

from now on until 2050. And roughly three quarters of all the infrastructure

that we need by that year has yet to be built. And much of it is built or will be built out of concrete

because there are no viable alternatives. So if we could turn concrete from a net emitter

to a net zero or even a net carbon sink, we have a very interesting solution

on a societal level at our hands. Do you think carbon storing construction

can become the new normal? Let us know in the comments