What future for synthetic gasoline?

Synthetic gasoline is a fuel that must be “assembled brick by brick,” so to speak. Instead of starting from a crude product, oil, from which we separate the different components and refine it to obtain gasoline, we start from almost nothing: we take CO2 from the atmosphere or in industrial chimneys to retain only the carbon, which is then reacted with hydrogen to obtain synthetic gasoline — since, after all, gasoline molecules are long chains of atoms of carbon in single file, to which hydrogen atoms attach to each other.

Well, I’m simplifying a little here, since there may be other sources of carbon and some synthetic fuels are made from nitrogen, but the basic idea is there. We “create” a fuel that is carbon neutral (assuming that the hydrogen is made with clean electricity) since we must remove carbon from the atmosphere or from renewable sources to make it.

And it can work. At the Trois-Rivières Grand Prix, for example, certain categories which race cars manufactured with “ordinary” engines have been using synthetic gasoline for three years “and it works very well,” testifies the CEO of the event, Dominic Fugère.

“There was a lot of apprehension on the part of the drivers at the beginning, so we did some test benches and it went well. (…) And it’s gasoline drop in : no need to modify the engine or the pipes,” he explains.

Now, it’s not entirely accurate to say that these fuels are booming in Europe. What happened was that the European Union was last year on the verge of completely banning the sale of combustion engine vehicles on its territory from 2035 when, at the last minute, the Germany has added an exception for cars that run on synthetic gasoline, the site reported Politico.

This undoubtedly created the impression that synthetic gasolines were on the rise, but “it would be wrong to say that synthetic fuels will make electric cars obsolete,” warns Patrice Mangin, emeritus researcher at UQTR. who has worked extensively on alternative fuels.

Same story from his colleague Louis Fradette, researcher in chemical engineering at the École Polytechnique de Montréal, “and the reason is very simple,” he says: these fuels cost at least 4 to 5 times more than normal gasoline because there is not much production.

At the Trois-Rivières Grand Prix, confirms Mr. Fugue, “it costs us 5.95 euros per liter, and we have to add transport costs, so in total it comes to around 10 Canadian dollars per liter. But for competition gas, it’s not that expensive.”

These prices are expected to fall significantly as production capacities increase, he believes. And that’s almost always what happens when you “scale,” as engineers say.

Energy losses

But we will probably not be able to reduce costs that much, opines Mr. Fradette. If CO2 extraction costs are relatively low these days — around $50 per ton at the outlet of an industrial chimney — “it takes a lot of hydrogen to make these fuels, and hydrogen is precisely very expensive to produce, both in money and energy. So by definition, synthetic gasoline is always going to be expensive to make,” he says.

Ultimately, we could say that by extending the useful life of gasoline cars, these fuels will delay the manufacture of a certain number of electric vehicles — and at the same time, the pollution associated with them. Some even make it a point of social justice because as battery vehicles are more expensive to purchase than their gasoline equivalents, banning their sale will penalize the most disadvantaged strata of our societies. An English team also argued in this direction recently in Frontiers in Energy Research.

But ultimately, synthetic fuels suffer from the same fundamental problem as green hydrogen. From an energy point of view, their manufacture is not “profitable”: 1 liter of synthetic gasoline contains less energy than what was spent to manufacture it. And it’s even worse in the case of these fuels “because in addition, it takes hydrogen [dont la production n’est pas énergétiquement rentable, elle non plus] to make them,” says Mr. Fradette.

“Energy losses are high during the manufacture and use of synthetic fuels due to the many processes involved [ndlr : il y a beaucoup de conversion d’énergie d’une forme à une autre qui viennent avec des pertes à chaque fois, et les moteurs à combustion sont beaucoup moins efficaces que les moteurs électriques]recently wrote the British Royal Society in a report on this subject.

“However,” the document continued, “this may be justifiable in uses for which electric propulsion is not well suited or when renewable electricity is cheap and abundant.”

For the foreseeable future, therefore, this means that synthetic gasoline will likely be used mainly in certain fairly niche sectors — aviation, for example. But it would be surprising if their use went much beyond that, if only for questions of electricity production capacity.

Already the electrification of transport poses challenges in this area, it would be even worse with synthetic fuels, concluded some reports on this subject, because combustion engines are much less efficient (regardless of the type of gasoline used). ‘we put in) than electric motors: when you count everything from one end of the chain to the other, it takes around four times more electricity to travel 100 km with synthetic gasoline than with a car battery powered.

So to decarbonize transport, except in certain sectors, it is not a practical solution for the moment.

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