Heirloom, a direct air capture (DAC) company permanently removing carbon dioxide (CO₂) from the atmosphere, and Leilac, a decarbonisation technology partner, have signed licence and collaboration agreements to deploy renewably-powered electric kilns at future Heirloom DAC facilities.

Heirloom will employ Leilac’s electric kiln technology to heat limestone to produce high purity CO₂, which will go for permanent storage, and calcium oxide, which is looped through Heirloom’s process to remove CO₂ from the atmosphere.

In welcoming the announcement, Leilac CEO, Daniel Rennie said, “These agreements establish the collaborative foundation for a partnership that combines two complementary technologies and a shared ambitious and purpose-driven culture.”

“Our rapid progress is testament to the dedication and ingenuity of both the Leilac and Heirloom teams. Together, we have the potential to deliver a significant impact on removing legacy emissions while also creating an accelerated pathway for the electrification of hard-to-abate industries, such as cement and lime.”

Heirloom CEO, Shashank Samala agreed, “Heirloom is committed to having our DAC facilities run on renewable energy and we’re excited to further a partnership with Leilac to achieve low-cost carbon removal at future facilities on the way to achieving gigaton scale.”

Following the signing of a memorandum of understanding in February 2023, Leilac and Heirloom have progressed the integration of Leilac’s electric calcination and CO₂ capture technology into Heirloom’s DAC plants through an extensive research and development campaign. This work is informing the design of new commercial DAC facilities.

Prevent, reduce, remove: a shared approach to CO₂ mitigation

Leilac and Heirloom’s partnership is designed to support a range of CO₂ mitigation efforts.

The electrification of mineral processing, including cement, lime, iron and steel and critical minerals, can enable a transition from carbon-intensive to renewable energy inputs, preventing future emissions and improving air quality for local communities.

Some hard-to-abate industries, such as cement and lime, produce CO₂ as an unavoidable by-product of raw material processing. For these industries, effective and low-cost carbon capture and storage is essential to reduce emissions.

But decarbonising alone will not be enough to achieve global climate goals. The Intergovernmental Panel on Climate Change projects that carbon dioxide removal in the order of 1–10 billion tonnes of CO₂ per year could mitigate residual emissions and, in most scenarios, achieve net negative emissions to return global warming to 1.5 °C, following a peak.

Leilac and Heirloom’s collaboration seeks to actively develop and support solutions across the three priorities to prevent, reduce and remove carbon dioxide emissions.

Heirloom and Leilac’s combined DAC approach

Heirloom’s DAC technology uses lime in a novel carbonation process to directly capture CO₂ from the air and form limestone. This process accelerates the natural binding of CO₂ and lime from a period of years to just three days.

After binding and removing CO₂ from the air, the reformed limestone is fed back into the renewably powered Leilac kiln, where the CO₂ is separated and captured, and the cycle begins again.

The CO₂ removed from the air will be mineralised, where it is bound to rocks or other materials, or injected underground into existing natural geological structures, where it remains safely and permanently stored.

The integrated Heirloom and Leilac DAC solution will be 100% renewably powered to deliver the maximum net reduction of atmospheric CO₂.

Mutual benefits for decarbonisation and DAC

Applying Leilac’s technology to Heirloom’s DAC process enables the DAC industry to leverage many years of technology investment and development from Leilac and its parent company Calix, the European Union and partners across the cement and lime industries.

With double the current combined capture capacity of all DAC facilities globally, Leilac’s pilot plant is the largest operating carbon capture facility for cement in the world, outside China. A Leilac demonstration plant, with a designed capture capacity of 100,000 tonnes of CO₂ per year, is due for construction in 2024. Cement is responsible for ~8% of global CO₂ emissions, with most of these emissions being directly and unavoidably released from the raw material processing.

Mr Rennie continued, “Leilac is excited to apply our core technology, developed for and with the cement and lime industries, to DAC. In turn, we expect our partnership with Heirloom will accelerate the development of electric calcination, as we work with all our partners in support of a just-transition towards an industrially sustainable low-carbon society. It’s a win-win arrangement that aims to maximise the scale and speed at which we can reduce industrial and atmospheric CO₂.”

Supporting sustainable local industry

A just transition to net zero requires solutions that balance social, economic and environmental sustainability.

Low-cost and scalable CO₂ mitigation solutions can help maintain the competitiveness of industry in a low-carbon economy. Scaling decarbonisation solutions for essential industries like cement and lime will also help support and maintain sustainable local industrial manufacturing bases.

Heirloom is developing the fastest path to low-cost, permanent CO₂ removal by harnessing limestone. With a cost of approximately US$10-$50/tonne, limestone is inexpensive and easy to source. Combined with highly-modular, easy-to-manufacture facilities, Heirloom’s solution is built to scale quickly to meet the urgency of climate action.

Ultimately, Leilac and Heirloom’s projects are designed to be delivered through local firms using local resources, supporting local jobs in a just transition to sustainable industry.