eFuel for thought

For 2024, Porsche announced that Supercup cars would be powered not by petrol, but exclusively by its own near-carbon-neutral, fully synthetic eFuel.
 
Not to be confused with biofuels like ethanol (alcohol) which are blended with pump fuel in the UK and Europe, or rapeseed oil-derived biofuels and suchlike, synthetic eFuel is a hydrocarbon fuel like the real thing. It contains carbon and carbon dioxide (CO₂) is still emitted from the exhaust but, because CO₂ is used to make the fuel in the first place, it’s carbon-neutral. Since 2021, the series has been fuelled by a second-generation, bio-based and partially synthetic fuel and the switch to fully synthetic came with the first round of the race of the 2024 championship at Imola. 
 
Porsche began talking about eFuel a few years ago. Then, in 2022, it announced that it had taken a £59 million stake in HIF Global (the HIF standing for ‘Highly Innovative Fuels’) and that the pair were establishing a dedicated eFuel manufacturing plant together with partner Siemens. Intriguingly, the choice of location is in a remote area of southern Chile, a few miles from the coast on the Strait of Magellan and about 25 miles north of the city of Punta Arenas – ‘The Gateway to Antarctica’. The plant is called Haru Oni, which translates to ‘land of wind’, giving a clue as to why Porsche and partners chose that particular spot. Quite simply, it’s one of the most consistently windy places on Earth and Porsche estimates that a wind turbine can work at maximum capacity there for 270 days a year. 


 
A 3.4GW Siemens Gamesa wind turbine at the site generates the electricity needed to make the synthetic fuel and provides its carbon-neutral credentials. The renewable energy powers a Siemens Energy electrolyser, which extracts hydrogen from de-salinated water, leaving only oxygen and waste heat as a byproduct. Three litres of water are needed to produce one litre of synthetic fuel and the heat is captured and used elsewhere in the process. The other component needed to make synthetic fuel is CO₂ which, for now, is being produced from biomass. 
 
With the basic ingredients in place using sustainably produced hydrogen extracted from water, heat and CO₂, the next step is to create methanol from which to synthesise the final product. Heating the hydrogen and CO₂ together at high pressure produces raw methanol, which is distilled to reduce the water content from 36 per cent to four per cent. The methanol is fed into a reactor which bonds the carbon atoms in the methanol together to form the long hydrocarbon chains that form the raw synthetic petrol. This in turn is further processed to produce 93 octane synthetic petrol, which is blended with additives to raise the octane rating to 98.
 
The final stage of the process will be to move away from the relatively lengthy method of producing CO₂ from biomass to Direct Air Capture (DAC). While the biomass method is more or less carbon-neutral (plants used to make CO₂ absorbed it from the atmosphere in the first place) DAC effectively cleans the atmosphere of existing CO₂.

 
From a logistical point of view, a DAC plant can be established anywhere and it can be scaled up to produce large quantities of synthetic fuel. In the case of Haru Oni, a DAC plant will use the same wind-generated electricity and waste heat from the electrolysis process used to make the hydrogen can also be used for CO₂ extraction.  
 
To extract CO₂ from the atmosphere, the air is cleaned to remove any large particles of dirt and then passed through a filter material which adsorbs (traps) the CO₂. Finally, the CO₂ is extracted from the filter by heating it, leaving water as a byproduct. Work on DAC was started several years ago by the Volkswagen Group working with HIF Global and MAN Energy Solutions. It’s still at the proof-of-concept stage but, once up and running, it would be a neat final twist in making sustainable synthetic fuel truly sustainable.

How much can Haru Oni produce? The annual maximum was initially around 130,000 litres and it’s expected that the 32 Cup cars running in the series this year will consume around 50,000 litres. That may not sound like much, but the plan is to ramp up production so that, by the end of the decade, the plant is producing 550 million litres a year. It’s on course to be a major achievement, although the quantities barely represent a drop in the ocean compared to the global consumption of fossil fuels. According to the RAC Foundation, petrol consumption in the UK alone reached a colossal 1,563 million litres during the month of June 2024.


 
Given that backdrop, it’s hard to imagine synthetic fuel production reversing the trend away from EVs. However, it could make a significant difference to the mix if adopted on a massive scale and it’s important to remember legacy vehicle fleets too. As many an expert has said, the quickest way to clean up the emissions in an existing fleet of vehicles is to change the fuel and that doesn’t just apply to cars either. Synthetic fuel can be produced as diesel or aviation fuel as well as petrol, so there’s scope for improving emissions in other areas of transport beyond cars.
 
In the meantime, though, what’s happening in the wild and windy wastes of southern Chile will bring a whole different perspective to standing trackside and watching a posse of GT3 Cup cars hurtle by.