Heirloom uses limestone to pull CO2 from the air and stores it permanently. It runs a commercial plant in Tracy, California, is developing two direct air capture facilities in Shreveport, Louisiana, and raised a $150 million Series B in December 2024.
At a glance
| Price from | Custom |
| Best for | Buyers of direct air capture removal in the US |
From Heirloom's own website.
What stands out
- Uses cheap, abundant limestone
- Commercial plant already running
Worth knowing
- Louisiana plants not yet operating
- Small capture volumes so far
How it ranks
Heirloom is ranked 9th of 10 in Best Climate Tech Startups (Lister Score 86.6).
#9 in Best Climate Tech Startups · Lister Score 86.6
Heirloom, founded in 2020 in San Francisco, captures carbon dioxide from the air using limestone and stores it permanently. It runs what it calls America's first commercial direct air capture facility, in California's Central Valley, and is developing two plants in Louisiana.
Heirloom's carbon removal buyers include Microsoft, Meta, United Airlines and Shopify..
| Rank | Best Climate Tech Startups | Score |
|---|---|---|
| 1 | Redwood Materials | 96.9 |
| 2 | Octopus Energy | 95.6 |
| 3 | Fervo Energy | 94.4 |
| 4 | Form Energy | 93.1 |
| 5 | Antora Energy | 91.8 |
| 6 | Watershed | 90.5 |
| 7 | Group14 Technologies | 89.2 |
| 8 | Twelve | 87.9 |
| 9 | Heirloom | 86.6 |
| 10 | Rondo Energy | 85.3 |
Frequently asked questions
How does Heirloom rank on Lister?
Heirloom is ranked 9th of 10 in Best Climate Tech Startups (Lister Score 86.6).
Appears in
- #9 in Best Carbon Capture Companies · Deep Tech
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