______________________________________________________________________________________________ Carbon Sourcing
elsewhere who are looking to export to the EU, are now solely chasing biogenic CO 2
, primarily from ethanol plants due to their scale and purity, though pulp and paper, sugar and biogas plants are also being considered. Whilst it is of course good to try and use all the carbon from biomass, all these sources clearly bind PtL to the same land-constrained carbon cycle that their mother plants contend with.
This approach completely excludes countries rich in renewables but poor in biomass, such as nations in the Middle East, from playing any role in low carbon aviation fuel. These countries could be ideal locations for producing low-carbon PtL fuels, but the rules close that door.
DAC dilemmas
Direct air capture( DAC) is an option, but all chemical engineers know this is an eye wateringly expensive and incredibly energyintensive one due to the thermodynamics which will never change. Extracting CO 2 from air requires vast energy inputs, due to the extreme dilution of CO 2 in the atmosphere. While DAC may play a role in the long term, it is not yet a scalable or affordable primary feedstock and in the short term, it is likely to be a reckless use of energy in most locations, particularly given the current size of global emissions. Also, philosophically what distance from a flue gas is air capture considered DAC anyway? As clearly it would be preferred to place your DAC machine with a tiny air gap from a flue gas pipe as the CO 2 concentration would be higher? The pragmatic answer is to remain open on CO 2 sourcing in the near term. What matters is doing what we can to reduce the carbon intensity of aviation fuels now and being open to a variety of sources with different carbon intensities and trade-offs. Not every pathway will be perfect but insisting on narrow definitions too early risks slowing progress. In aviation, where emissions are hard to abate, pragmatism is essential.
Naturally, PtL developers will favor CO 2 sources that offer long-term security, such as cement, steel plants, and natural gas processing, rather than coal power stations that are likely to close. The market will selfcorrect. But we must give it the flexibility to do so.
The goal in sight
The world emits 38 billion tons of CO 2 every year. Only a small fraction would be required to decarbonize aviation. With demand for flying set to rise, we cannot afford to block viable pathways out of misplaced rigidity.
If we force PtL fuels back into the land use debate, we risk losing one of the few scalable tools to reduce aviation’ s carbon intensity. Europe’ s policymakers must keep their eyes on the goal. Delivering cleaner aviation fuels is hard enough. Let us not make it harder than it needs to be. ■
Andrew Symes www. oxccu. com
Andrew is the Co-Founder and CEO of OXCCU, a spinout from Oxford University, specializing in converting waste carbon into fuels, chemicals, and plastics via novel catalysis. OXCCU’ s mission is to develop the world’ s lowest cost, lowest emission pathways to make SAF, enabling people to continue to fly and use hydrocarbon products but with a reduced climate impact.
newenergy-today. com 27