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Startup Spotlight: Heirloom

The future of Direct Air Capture is rocky. In a good way.
Meghan Proulx
Oct 2, 2022 8 min read
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Take a break from your climate change-induced stress sweats for a moment. There might just be some (renewable energy-powered) light at the end of this tunnel.

Carbon sequestration - trees do it, the ocean does, even some particular carbonate rocks do it. Our planet is generously sprinkled with these carbon sinks that naturally absorb and store CO2. So since we seem to have an excess of the stuff, why not just plant a bunch of carbon-loving redwoods and go back to driving our Hummers to the mall?

As it turns out, these natural carbon sinks aren’t equipped to take on all the CO2 we spew into the atmosphere with reckless abandon. But thankfully, what nature can do, humans can imitate. And maybe even do it a little faster. Which is exactly what the team at Heirloom is working on.

Heirloom is building a Direct Air Capture technology that permanently removes carbon from the atmosphere using limestone, a superabundant mineral found everywhere from the Cliffs of Dover to the gravel walkway outside your house.

Limestone naturally absorbs and holds onto CO2, but this process takes years to occur in nature. Heirloom’s process speeds things up to just a matter of days.

How it works:

Limestone is crushed and heated up using an electric kiln powered by renewable energy. When the limestone reaches about 900 ºC, that CO2 it was holding onto for dear life is released. The released CO2 then gets pumped into special geological underground structures that are approved by the EPA to be safe, secure, and to not leak.

Currently, a majority (but not all) of the underground structures that are approved for the safe storage of sequestered carbon are created through enhanced oil recovery –– a process where the desired result is to push as much crude oil out of the ground as possible by pumping captured CO2 in. This process is one of the first ways that capturing carbon became profitable for companies intending to bury it. This sounds like a good thing until you realize many companies are only capturing CO2 so they can draw out more crude oil and put that captured CO2 right back into the atmosphere.

But Heirloom, like many of the other new Direct Air Capture companies, is doing things differently. Heirloom’s goal is to capture CO2, bury it in the ground, and keep it there.

A perk to Heirloom’s process is that the same limestone can be reused within the system over and over, repeatedly absorbing and releasing CO2 like a reusable kitchen sponge. This is a circular process that minimizes the mining intensity of acquiring more limestone.

By sharpening their process, Heirloom aims to permanently sequester 1 billion tonnes of carbon dioxide from the atmosphere by 2035 –– a climate goal that is refreshingly not that far in the future.

“The IPCC recommends 6-10 billion tonnes [of CO2 from the atmosphere] be removed every year by 2050. It will take a range of technologies to make this happen” says Heirloom’s Head of Marketing and Communications, Alexa Dennett. So while Heirloom’s tech is exciting, it’s not a magic wand. “It's not just us, but an ecosystem of carbon removal technologies that are removing CO2 from the atmosphere. It will take a portfolio of solutions,” says Dennett. “We will need massive net-new renewable energy and more geological storage for CO2.”

As different carbon dioxide removal methods continue to pop up, more renewable energy and permanent storage ecosystems will also need to grow over the next decade to keep up. Though there are several permitted Class VI wells due to be approved in the next few years, there are currently not enough wells in the US to store all the carbon dioxide that needs to be sequestered over the next decade. There isn’t even enough space for the carbon that Heirloom alone hopes to safely store.

Heirloom is planning to launch its direct air capture facility next year. In the meantime, they’re also prioritizing how they can better serve communities that will feel the effect of climate change the most. This includes siting their facilities in the communities impacted by job loss in the oil and gas sector and focusing on climate equity. “This type of tech has the opportunity to be a great equalizer,” says Dennett. “Large-scale deployment will hopefully result in better-served communities, preserved ecosystems, and cleaner air for all.

An EPA report from last year showed that the effects of climate change will be disproportionately felt by communities that are “unable to prepare for, and recover from heat waves, poor air quality, flooding, and other impacts.” Heirloom’s CEO Shashank Samala adds that while growing up in India, he saw firsthand how vulnerable people are being impacted by climate change. Not just in the future, but today.

How to get involved:

The passion and urgency at Heirloom is real and infectious. If you’re excited by their work, check out their careers page where you’ll see they’re hiring for over 30 different roles. And Alexa has some great advice for anyone feeling hesitant to make the jump to work in climate tech: “this is a new space, this tech has just started to be commercialized. So if you’re interested in this space but hesitant to make the jump because you don’t feel like you have enough experience, don’t be, because very few people do. There aren’t that many people with knowledge in this space. If you care and you think you have something to offer, go for it.”

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The Author

Meghan Proulx