The Californian climate technology company Heirloom unveiled the first commercial facility for direct air capture of CO2 in the United States on Thursday. The new facility, named “Direct Air Capture” (DAC), is located in Tracy, approximately an hour and a half from San Francisco. It comprises hundreds of stacks of limestone shells designed to naturally absorb CO2.
The limestone has been treated to accelerate the absorption process compared to normal weathering processes. Once the rock has captured a sufficient amount of CO2, it is heated using renewable energy to release the greenhouse gas. Subsequently, the stones are reused. Heirloom collaborates with the startup company CarbonCure to permanently store the released CO2 in concrete.
According to the New York Times, the Tracy facility has the capacity to remove around a thousand tons of CO2 from the atmosphere each year, which is equivalent to the emissions of about 200 cars. While the facility’s capacity is relatively modest, Heirloom plans to construct additional CO2 capture facilities to achieve millions of tons per year. By 2035, the company aims to capture and store one billion tons of CO2 from the air.
Expensive Climate Protection: 2000 USD per Ton
The problem is not only that a significant number of such facilities are required, but the cost is also staggering. Experts estimate the cost of capturing one ton of CO2 to be between 600 and 1000 US dollars. In the initial sales of Heirloom for carbon capture and storage in 2021, some prices exceeded 2000 US dollars per ton. The U.S. government aims to reduce this cost to 100 dollars per ton within a decade.
The U.S. Department of Energy allocates billions in grants for the construction of demonstration plants for direct air CO2 capture, with Heirloom being one of the beneficiaries of the largest funding program. “We need to scale up. Only then can we make rapid progress,” stated U.S. Energy Secretary Jennifer Granholm in an interview on Thursday after an on-site visit. The U.S. government intends to achieve its climate protection goals more swiftly with such facilities and offset emissions in other sectors.
No Climate Scenario Without Negative Emissions
Many climate scenarios today are based on the premise that, in addition to reducing emissions, actively removing carbon dioxide from the atmosphere is essential. Global greenhouse gas emissions continue to rise each year, with only a brief hiatus during the pandemic.
The Intergovernmental Panel on Climate Change (IPCC) has explored scenarios that could still achieve the 1.5-degree target, and none of them can do so without the additional storage of CO2. Two years ago, the world’s largest carbon capture facility became operational in Iceland, capable of sequestering 4000 tons of CO2 annually.