Heirloom Carbon Technologies

Heirloom Carbon Technologies is a US company developing direct air capture technology to remove carbon dioxide from the atmosphere. Its process uses limestone, an abundant and inexpensive rock: limestone is heated in a renewable-powered kiln to release its CO2, which partners store permanently underground, and the resulting material is spread out to absorb CO2 from the air again, so it can be reused in a repeated cycle. Heirloom develops carbon removal projects and sells the resulting removal to organisations. The company's stated aim is to remove large volumes of CO2 permanently at lower cost.

• Limestone-based direct air capture of CO2
• Reusable capture cycle
• Captured CO2 directed to permanent storage
• Development of carbon removal projects
• Carbon removal sold to organisations