United Airlines announced that its United Airlines Ventures (UAV) Sustainable Flight Fund has made an investment in Direct Air Capture (DAC) company Heirloom, alongside an agreement for the right to purchase up to 500,000 tons of carbon dioxide removal to make sustainable aviation fuel.

Launched in 2023, the UAV Sustainable Flight Fund invests in and supports startups focused on sustainable aviation fuel (SAF) research, technology and production, aimed at supporting the scaling of SAF supply. The fund comprises more than $200 million in investment commitments from United and corporate partners including, among others, Embraer, GE Aerospace, Google, and numerous airlines.

United has set a goal to fully reduce greenhouse gas emissions by 2050 without relying on carbon offsets. The announcement marks the company’s third carbon capture investment, and its first in DAC. DAC technology, listed by the IEA as a key carbon removal option in the transition to a net-zero energy system, extracts CO2 directly from the atmosphere for use as a raw material or permanently removed when combined with storage.

Andrew Chang, head of United Airlines Ventures, said:

“Carbon capture is one of our country’s fastest growing, energy enabling pathways. At UAV, our primary focus is finding solutions for decarbonization that are profitable. Heirloom’s technology aligns directly with this objective, offering a scalable and commercially viable approach and complements United’s commitment to net zero by 2050.”

Founded in 2020, California-based Heirloom utilizes limestone – the world’s second most abundant mineral, – 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 said that this is potentially one of the lowest cost pathways for removing carbon dioxide from the air.

In December, Heirloom announced that it raised $150 million in Series B funding. In 2023, Heirloom began operating North America’s first commercial DAC facility in Tracy, California, and the company is part of a team building Project Cypress, a Department of Energy supported DAC Hub in Louisiana.

Shashank Samala, CEO of Heirloom, said:

“We are incredibly proud to welcome the United Sustainable Flight Fund as an investor and to work with them to scale our DAC technology. By utilizing DAC as a dual-pronged tool that can both greatly reduce CO2 emission from aviation fuel and remove residual emissions, we are charting a true path to Net Zero aviation.”