In a paper published in Nature Energy, RepAir Carbon, along with a team of researchers from the University of Delaware, demonstrates peer-reviewed results from its battery design that could unlock electrochemical direct air capture (DAC) at a price below US$100 per tonne of CO2.
This breakthrough would be enabled with a carbon capture cell built on rechargeable battery chemistry that can remove CO2 from ambient air using as little as half of the energy required by the liquid-based systems that dominate DAC today.
Energy consumption and the resulting high operational costs are some of the main obstacles standing in the way of scaling DAC technology. RepAir highlights that most systems running at scale release the captured CO2 from the system filters using heat and consuming 1.5 to 2.5 MWh per tonne of CO2.
The cell technology described in the Nature Energy paper is part of RepAir’s ElectraStack system, and it captures and releases carbon dioxide at high purity as it charges and discharges, using the same nickel hydroxide chemistry found in rechargeable batteries.
The paper confirms the same low energy consumption of RepAir’s technology across three different trials: when assessed independently at the University of Delaware, over time at RepAir and when deployed at a larger scale by RepAir.
What RepAir’s DAC battery tests showed
When tested by University of Delaware researchers, a 25 cm² laboratory cell captured CO2 from ambient air (400 ppm) at an average energy cost of 1.15 MWh per tonne of carbon dioxide.
Used by RepAir over time, a manufacturable single cell ran for more than 5,000 hours on ambient air and reached 0.46 MWh per tonne CO2 by the end of the test, while a larger deployment of a nine-cell stack of 300 cm² cells averaged 0.83 MWh per tonne CO2 with a pressure drop below 300 Pa, meeting the requirements for efficient DAC at scale.
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The paper also outlines a cost pathway from $566 per tonne for the current pilot generation to below $100 per tonne at volume, following learning rates observed in the battery industry.
“Our customers ask which carbon capture technology can prove it will reach the cost target at scale. Operating cost is energy, and this paper settles that with peer-reviewed data,” said Amir Shiner, CEO and co-founder of RepAir Carbon.
“Capital cost is whether the equipment can be built on automated production lines that already exist. That is what we are building now,” he added.
Read more: RepAir Carbon Opens New European Office In Luxembourg
