Two climate problems, one cement block: CO2 storage via low-carbon concrete

At AirMyne, we’re working on a technology that removes carbon dioxide from the air through a process called direct air capture – but we also spend a lot of time thinking about the broader climate ecosystem outside of carbon removal. 

Direct air capture (DAC) is inextricably linked to many other technologies within climate – powering DAC requires large amounts of clean energy, and buying DAC removal credits requires corporations to think critically about the opportunity cost of decarbonization vs carbon removals. Perhaps one of the most exciting interdependencies (and one that we often get asked about) has to do with carbon utilization and storage – i.e. after we capture the CO2, what do we do with it? 

Though our primary mission is to permanently lock CO2 underground through a process called geologic sequestration, we recognize that sequestration may not be economically feasible at initial pilot-scale volumes and requires longer timelines for permitting and well construction. That’s where carbon utilization comes into play – using DAC CO2 as a feedstock to create something else, like sustainable aviation fuel, foams and polymers, or refrigerants. 

Within the world of carbon utilization however, there are few pathways that sit at the nexus of both utilization and storage – low carbon concrete is one of them. 

Concrete is the world’s most commonly used construction material. It’s also a heavy-hitter in terms of global CO2 emissions. Cement, the binding agent used to make concrete, is estimated to produce around 8% of CO2 emissions globally. It’s also incredibly difficult to decarbonize. Cement production requires extremely high temperatures, and even if powered by renewable energy, results in process emissions from the decomposition of limestone.

Today, dozens of low-carbon concrete companies are developing solutions to decarbonize the concrete industry. One approach takes captured CO2 and uses it during curing – a process that both reduces the overall emissions profile of the concrete, and stores CO2 safely away from the atmosphere.

We’re really excited about low carbon concrete, among other utilization pathways – which is why in March of this year, we delivered a canister of AirMyne CO2 to CarbonBuilt, an ultra-low carbon concrete producer, for use in their lab testing. We’ve since increased our output and are excited to keep supporting the low carbon concrete ecosystem, as well as many of the other carbon utilization pathways that are developing. 

Image: AirMyne CO2 canister at CarbonBuilt’s Torrance R&D facility (March 2024)

If you want to read about more developments at AirMyne, follow along on our journey on LinkedIn here. Or reach out to us at hello@airmyne.com!