Substantial technological advancements will be needed to fully realise the potential of direct air capture, writes Pamela Machado
The EU has outlined ambitious plans for e-fuel production, which will require not only ample renewable hydrogen production but also lots of carbon feedstock. But the bloc's ambitions will hinge crucially on the availability of carbon captured from the atmosphere through direct air capture (DAC), a technology that is in its infancy.
The EU's recent Industrial Carbon Management Strategy envisages that around 280mn t/yr of CO2 would need to be captured by 2040. This would increase to 450mn t/yr by 2050, when approximately 150mn t/yr of CO2 could be used for e-fuels production. In order to maximise climate benefits, EU e-fuels production would only be allowed to use CO2 from biogenic sources or captured from the atmosphere from 2041 onwards. Industrial CO2 will no longer be permissible then, based on the commission's delegated act on renewable fuels of non-biological origin (RFNBOs) from February 2023.
Biogenic CO2 availability is limited in the EU, with some forecasts predicting that it could fall short of what will be needed for e-fuels production alone by the 2040s, meaning DAC will be central to realising the bloc's ambitions.
This will require significant technological advances in the coming years given that DAC is still nascent, although climate group E3G argues that this is the case for most carbon capture and utilisation or storage technologies, saying that these largely "remain concepts more than a reality in Europe".
Several companies have set out to turn DAC ambitions into a reality. Among these is US e-fuels producer HIF Global, which — in partnership with German carmakers Porsche and Volkswagen — is set to start operating a DAC facility at its Haru Oni project in southern Chile this year. The unit is slated to filter up to 600 t/yr of CO2, and HIF "hopes to escalate the technology in the near future", chief executive Cesar Norton says. Porsche sees DAC "as a viable technology for the future" and the company is "working on bringing the technology to a higher degree of maturity", according to its research and development executive board member Michael Steiner. Haru Oni currently operates with biogenic CO2, with DAC to act as "a supplementary solution".
DAC to the future
Maturing and scaling up DAC will be key to making its commercial case. Paris-based energy watchdog the IEA says DAC is "the most expensive application of carbon capture" because it is highly energy consuming, as carbon in the atmosphere "is much more dilute" than in processes such as flue gas from point sources such as a power station or cement plant.
Research gathered by EU industry body the eFuel Alliance shows that DAC would currently cost around €730-815/t ($792-884/t) of CO2 compared with current CO2 allowance prices of less than €60/t under the EU's emissions trading system and historic peaks of just over €100/t under the mechanism. As DAC matures and commercialisation grows, costs could be lowered to €79-89/t by 2050, the eFuel Alliance says. Incentive mechanisms for products made using DAC technology could help accelerate cost reductions, it says.
Given that DAC is an energy-intensive process, it will crucially have to be powered by renewable energy to deliver environmental benefits. Widespread use could then raise questions around the availability of renewable power supply, especially if this is needed near to where renewable hydrogen is produced to make e-fuels.
In any event, the eFuel Alliance expects a sharp rise in DAC from the early 2030s onwards. By 2036, global DAC volumes used for e-fuels production could exceed the amount of carbon captured from point sources and this could grow into a fourfold lead by 2050, the group says.
