# Heirloom Carbon

> Heirloom Carbon Technologies is a San Francisco-based direct air capture company that uses limestone's natural CO2-absorbing properties to pull carbon dioxide permanently out of the atmosphere. Their process accelerates a geological phenomenon that normally takes thousands of years into a 3-day cycle: calcium oxide powder absorbs CO2 from ambient air, becomes limestone, gets heated in a renewable-energy-powered electric kiln to release the captured CO2, and repeats. The captured CO2 is then stored permanently underground or embedded in concrete. Founded in 2020, Heirloom opened America's first commercial DAC facility in Tracy, California in November 2023 and has raised over $354 million to expand capacity toward their goal of removing 1 billion tons of CO2 by 2035.

- **Founded:** 2020
- **Headquarters:** San Francisco, California, United States
- **Founders:** Shashank Samala (CEO & Co-Founder), Noah McQueen (Co-Founder & Head of Research), Zack Bloom (Co-Founder)
- **Team size:** ~210 employees
- **Products:** Limestone-Based Direct Air Capture, Carbon Removal Credits, Permanent CO2 Storage
- **Notable:** Opened America's first commercial Direct Air Capture facility in Tracy, California (November 2023), First facility in the US to capture, permanently sequester, and fulfill commercial CO2 removal purchases, First-ever demonstration of atmospheric CO2 permanently embedded in concrete via CarbonCure partnership (February 2024)

## Products & services

- **Limestone-Based Direct Air Capture** — Proprietary DAC technology using calcium oxide trays to absorb ambient CO2 over 3 days. The resulting limestone is heated in a renewable-powered electric kiln to release concentrated CO2, which is then permanently sequestered. The process repeats in a continuous closed loop.
- **Carbon Removal Credits** — Verified, permanent carbon removal credits sold to corporations (Microsoft, JP Morgan, Stripe, Meta, Shopify) seeking high-quality, durable CO2 offsets. Each removal is third-party monitored and verifiable.
- **Permanent CO2 Storage** — Captured CO2 is stored permanently either underground via geological sequestration or embedded into concrete through partnership with CarbonCure Technologies, the first-ever atmospheric CO2 storage in building materials.

## Achievements

- Opened America's first commercial Direct Air Capture facility in Tracy, California (November 2023)
- First facility in the US to capture, permanently sequester, and fulfill commercial CO2 removal purchases
- First-ever demonstration of atmospheric CO2 permanently embedded in concrete via CarbonCure partnership (February 2024)
- Selected for U.S. Department of Energy's Project Cypress DAC Hub program
- Named to Fast Company's Most Innovative Companies 2024
- Named to TIME's America's Top GreenTech Companies
- Raised $354M+ in total funding backed by Breakthrough Energy Ventures and Lowercarbon Capital
- Secured $475M Louisiana investment for North America's second DAC facility
- Secured partnerships with Microsoft, JP Morgan, Stripe, and United Airlines
- Built with union labor - UA Plumbers & Pipefitters Local 442 and IBEW 595

## Latest updates

- **2025-02** — United Airlines Ventures Sustainable Flight Fund announces 500,000-ton CO2 removal purchase and strategic investment in Heirloom.
- **2024-12** — Closes $150 million Series B led by Future Positive and Lowercarbon Capital, with Japanese corporate investors including Japan Airlines, Mitsubishi, and Mitsui.
- **2024-12** — Announces two Louisiana DAC facilities at Port of Caddo-Bossier (Shreveport) and near Vinton (Calcasieu Parish) with combined capacity of nearly 320,000 tons annually.
- **2024-02** — Achieves world's first permanent storage of atmospheric CO2 in concrete via CarbonCure partnership at Central Concrete facility.
- **2023-11** — Opens Tracy, California facility - America's first commercial Direct Air Capture plant with 1,000 tons annual CO2 removal capacity.

## Links

- Website: https://heirloomcarbon.com
- LinkedIn: http://www.linkedin.com/company/heirloom-carbon
- Twitter/X: https://twitter.com/HeirloomTech

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Profile page: https://yespress.io/heirloom
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Last updated: 2026-05-29