Carbon removal technology provider Heirloom announced today that it has raised $150 million in Series B funding, with proceeds from the financing aimed at supporting the rapid scaling of commercial Direct Air Capture (DAC) technology.

DAC technology is listed by the IEA as a key carbon removal option in the transition to a net-zero energy system. According to an Intergovernmental Panel on Climate Change (IPCC) climate change mitigation study, scenarios that limit warming to 1.5°C include carbon dioxide removal methods scaling to billions of tons of removal annually over the coming decades, with DAC positioned to potentially account for a significant portion of the total.

Direct air capture (DAC) technologies extract CO2 directly from the atmosphere at any location, unlike carbon capture systems which are generally deployed at the point of emissions. Founded in 2020, California-based Heirloom utilizes limestone – the world’s second most abundant mineral, and also one of the cheapest minerals – to capture CO2 directly from the air. The process starts with natural limestone, nearly 50% of which is CO2. By extracting this CO2 from the limestone and adding water, the process creates a material that rapidly captures additional CO2 from the atmosphere. Once the CO2 is absorbed, it is extracted from the limestone material using a renewable energy-powered kiln and then stored permanently underground.

Heirloom’s carbon removal customers include Microsoft, JP Morgan, McKinsey, Stripe, and Shopify.

The new funding will be used to continue to drive down the cost of its technology, develop additional projects and provide the resources needed to subsequently access infrastructure capital, the company said.

The round was co-led by Future Positive, and Lowercarbon Capital – which also invested in Heirloom’s Series A round. New investors in the round included H&M Group, Japan Airlines, Mitsubishi Corporation, Mitsui & Co., MOL Switch LLC, Quantum Innovation Fund, and Siemens Financial Services, alongside existing investors Ahren Innovation Capital, Breakthrough Energy Ventures, Carbon Direct Capital, and MCJ Collective. Heirloom noted that its new backers include a range of industrial investors across difficult-to-decarbonize sectors, including automotive, shipping, aviation, and advanced manufacturing.

Shashank Samala, CEO of Heirloom, said:

“We believe DAC is all about cost, cost, and cost – and that it will only scale to make a meaningful difference on climate change if it is affordable. This is precisely why people are investing in Heirloom. Through our real-world deployments and continued technological advancements, we are demonstrating not only that Heirloom has a clear trajectory to the lowest-cost DAC solution – but that we are executing on that vision and delivering results.”