Technology

Our Atmosphere

CO₂ removal is a necessity

Even if the world stopped emitting CO₂ tomorrow, the planet would continue to warm because of the massive amounts of emissions already blanketing our atmosphere. To keep global temperature rise below 1.5 degrees celsius, we’ll need to remove billions of tons of CO₂ each year – a volume equivalent to 10–20% of today’s annual global emissions. Heirloom’s unique DAC platform is one of the few low-cost carbon removal technologies capable of reaching billion-ton scale.

Our process

Designed for scale, engineered for impact

Our approach is unique; it combines the best of two well-established CO₂ removal technologies – carbon mineralization and Direct Air Capture – to build a truly scalable, low-cost carbon removal solution. We use limestone, one of the world’s most abundant and inexpensive minerals, to capture CO₂ directly from the atmosphere, and then permanently and safely store it underground.

Read our DAC whitepaper

Read our CO₂ STORAGE whitepaper

How our Direct Air Capture system works

Using limestone like a sponge

Limestone is made up of calcium oxide and CO₂. When CO₂ is removed from the limestone, the remaining calcium oxide is hydrated with water to form calcium hydroxide, commonly known as “lime”. Lime is “thirsty” for CO₂ because it wants to return to its natural limestone state and acts like a sponge – pulling CO₂ from the atmosphere. Our technology accelerates this natural property of limestone, reducing the time it takes to absorb CO₂ from years to less than 3 days.

Removing CO₂ from limestone

We heat limestone mineral powder in a renewable-energy powered kiln to remove the CO₂. Our partners then permanently and safely sequester this CO₂ underground or in concrete.

Soaking up CO₂ from the atmosphere

Once the CO₂ is removed, we spread the CO₂-thirsty material onto vertically-stacked trays, add water, and “treat” it to optimize its ability to uptake CO₂ quickly.

Repeating the process

Like repeatedly wringing a sponge, we loop this limestone through our system to continuously suck CO₂ from the atmosphere – a cyclic process that not only lowers costs but also reduces how much limestone must be mined.

Our Technical Advantage

The fastest path to low-cost, permanent carbon removal

Our technology is designed to enable rapid cost reduction through scale, allowing us to meaningfully impact climate change as quickly as possible.

Low-cost inputs

Our technology is powered by limestone – a low-cost and easy-to-source material. By working with abundant and mature supply chains, we have a clear path to driving down costs and scaling quickly.

Modular

Our DAC facilities are carbon-absorbing warehouses – designed to be modular, mass manufacturable and easy to scale rapidly around the world.

Learning from every ton

We collect tens of millions of data points each month to further optimize our CO₂ uptake rate – which further increases our output and reduces cost.

Our facility

America’s first commercial DAC facility

In a world first for Direct Air Capture technology, our facility in Tracy, California, is capturing CO₂ from the atmosphere which is then embedded permanently in concrete. Working with our partner CarbonCure, this CO₂-enriched concrete is laid in the foundations of buildings and structures, with the added benefit of creating stronger concrete.

We’re also proud to be implementing a community governance model, which will gather stakeholder input on financial and programmatic investments into Tracy and San Joaquin County community organizations beginning in Q1 of 2024.