Startup plans to remove 1 billion tons of CO2 from the air

A new carbon sequestration startup has big plans — to remove one billion tons of excess carbon from the atmosphere by 2035 — and their vital ingredients are common minerals. 

Technologies that draw carbon from the atmosphere are popping up left and right, including genetically modified trees, carbon-sucking balloons, or machine scrubbers.

But Heirloom Carbon Technologies is taking a unique approach to carbon sequestration: enhanced mineral weathering. The process borrows from nature’s own carbon cycle to suck climate-warming gases from the air. The concept has been around for some time, but Heirloom has come out as one of the first commercial companies to use the method, and they have backing from some big names.

How it works: Heirloom plans to harness the power of carbon-hungry minerals. The carbon capture and storage process, described in Nature Communications last year, is a little like soaking a sponge and then drying it out.

It begins by toasting the mineral magnesium carbonate (which weight lifters use to chalk their hands) at very high temperatures. Doing so lets off CO2 gas, which seems counterintuitive for carbon sequestration. But that gas can be piped directly underground for permanent storage.

The oxide minerals left over are now primed and ready to soak up more CO2 gas. Just by spreading them out in the open sun, the reactive minerals will bond with CO2, pulling it from the air. It usually takes about a year, but Heirloom Carbon Technologies is working on technology that will speed up the carbon sequestration process, reports MIT Technology Review.

Heirloom Carbon Technologies isn’t the first to explore using minerals to pull carbon out of the atmosphere. Project Vesta aims to use the mineral olivine to create green sand that facilitates carbon sequestration as it weathers.

Bold goals: A problem faced by the carbon capture market is that direct air capture technologies promise to store carbon for a long time, but they come with a high price tag. On the other hand, nature-based solutions like offshore kelp farms, or genetically modified trees, may be cheaper but less predictable in their carbon storage capacity and longevity.

But who says high quality and low cost can’t go together? In addition to removing one billion tons of carbon by 2035, Heirloom Technologies also expects to cost less than other carbon removal technologies, at just $50 per ton.

For now, until the project can scale up, the price remains high. But, like most new technology, the price will likely come down, and Heirloom’s CEO Shashank Samala is counting on it.

“Deployment is what makes this cheaper, unleashes new markets, and drives down costs further,” he told MIT Technology Review.

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