6 ms·

I've not heard of sustainable aviation fuel. Is it snake oil? Why wouldn't it just be "sustainable fuel" suitable for trains and automobiles? And if we simply

I've not heard of sustainable aviation fuel. Is it snake oil? Why wouldn't it just be "sustainable fuel" suitable for trains and automobiles? And if we simply slowed the world down a little bit I wonder if blimps could take over for a majority of ocean-crossing journeys. Not that it will ever happen.

denimnerd42 3y ago
They are developing these fuels for Formula1 and the like. Probably won't see them in road vehicles due to cost. But never know. It's likely normal fuels in hybrids or pure electric vehicles will be better (cheaper and lower carbon). For trains overhead electrification would be better. I'm not sure the fuel itself is that low carbon but the cycle of producing it may be. I'm sure a quick search would reveal they produce slightly less CO2 or something in a suitable engine.
- handy2000 3y ago
  Do you mean synthetic fuel? Haven't heard of Formula1 being interested in biofuel.
  - rswskg 3y ago
    It's a huge part of the 2026 rule changes.
    - handy2000 3y ago
      E-fuel is different from SAF that is described in this article. E-fuel is carbon-neutral and SAF is low-carbon (made from tallow, algae, etc).
  - denimnerd42 3y ago
    There's no mention of biofuel in the article. But yes any technology designed to reduce the impact of the fuel production/use cycle. In F1 it's branded as synthetic fuel right? It's like a natural gas derived fuel but could be derived from anything the scientists engineers can make work. Jet fuel is heavier so starting with an oil derived from bio matter might make more sense. Either way something designed with less impact than drilling for fuel.
    - handy2000 3y ago
      The fuel mentioned in the article — "sustainable aviation fuels, or SAF" — is biofuel I believe, not synthetic fuel.
      - denimnerd42 3y ago
        oh gotcha. To me it's all in the same. Some engineered alternative that produces less carbon. it's terribly semantic though because every fuel today is engineered to produce less emissions.
        handy2000 3y ago
        Right, agreed - it's an improvement over what we currently use! From what I read E-fuel is very expensive to produce, so I was surprised by the possibility of airplanes switching to it.
        denimnerd42 3y ago
        Sounds more feasible than electric planes though. That never made viable sense to me. At least they could build a 737 sized alternative fuel plane today.
handy2000 3y ago
> Is it snake oil? It's biofuel made from palm oil, algae, tallow, etc.
alkonaut 3y ago
It's just the same as the non-fossil versions of diesel like HVO100 and similar. Whether this fuel is "sustainable" or "emission free" of course depends on how you see it. It will depend on what the source of the fats used is, and how those were produced, how much and what energy was used in the processing and so on. But at least it's significantly better than regular fossil fuel. An interesting thing about this is that there has been quite a lot of infrastructure built to create these fuels for road transport in the last decades. So if road transport is electrified but flight isn't, then all those resources could quite easily be redirected to make aircraft fuel instead. If I recall the interview correctly that I heard regarding the flight mentioned below, I think there are some countries that have enough biofuel production (currently for road transport) already, to replace all the aircraft fuel used domestically. The first commercial transatlantic flight with this type of fuel was just two days ago: https://apnews.com/article/transatlantic-flight-sustainable-aviation-fuel-e25e6a6c7f78e3cadb6c4dca29a37fc8 https://apnews.com/article/transatlantic-flight-sustainable-... > Is it snake oil? While renewable, the worlds entire production of snake oil would only make a small dent in the fuel needs of the airline industry.
rswskg 3y ago
It's a hydrocarbon chain produced from corn and waste fats. Fairly similar to bio fuel for cars. Sustainable trains are nuclear powered. Blimps are either too slow or can't carry enough cargo. Solving the use of heavy tanker fuel is quietly a massive priority, the naive answer is nuclear, the real world answer isn't clear.
camgunz 3y ago
The way it's "sustainable" is that it's not a fossil fuel (well, currently it's 50% fossil fuel, they hope it can be 100% fossil fuel free by 2030), so it's just part of the normal carbon cycle like forest fires and breathing. IMO it's probably just a stand-in until hydrogen really works.
fcantournet 3y ago
It's snake oil. It's renewable is the same sense that cow farts are renewable : if you dedicated the entire arable surface of the planet you could make fuel with it for 5% of our consumption. Don't get me started on the oil USED to produce this wonderful green fuel.
- robertlagrant 3y ago
  Snake oil is at least renewable. Just grow more snakes.
micromacrofoot 3y ago
not really "sustainable" but "more sustainable"
- Ekaros 3y ago
  It probably will not be sustainable... But it might be carbon-neutral... Which might not or might be part of sustainability...
graphe 3y ago
Hydrogen could be the fuel of the future. Go for the moonshot, a space elevator.
tialaramex 3y ago
Trains are, by their nature, very suitable for electrification. As with renewable energy the expense is almost all capital, it's cheaper to run electric trains it's just expensive to build electric railway lines they run on. Planes are not well suited to electrification. Trainers can reasonably be made electric, as might certain commercial purpose aircraft, but if there will be electric New York to LA passenger flights it won't happen any time soon. Although the fuel in a Cessna would be AvGas which is basically leaded gasoline, essentially anything you'd pay to fly on has turbine engines running on JetA which is basically kerosene instead. Small local planes, especially in Europe might look like just the Cessna only bigger, but the propellers are spun by a jet turbine, they don't have internal combustion engines.
- AshleyGrant 3y ago
  A jet turbine is an internal combustion engine. It isn't a "reciprocating" engine, though.
  - cherryteastain 3y ago
    Well, unless it has an afterburner like Concorde's engines
    - dredmorbius 3y ago
      That's still considered "internal" combustion, as the combustion is occurring within the context of the engine itself. The traditional contrast to the I.C.E. is the external combustion of a steam engine, where the combustion occurs in a boiler, which then directs steam to the actual reciprocating engine (in a traditional steam engine). Steam turbines actually could be a case of an external-combustion turbine, as these are powered by steam which is heated externally to the turbine itself (e.g., there is no internal combustion chamber). Not all steam turbines are combustion engines, however. A nuclear power plant's steam turbines are fed by steam created from nuclear fission rather than chemical combustion. Some solar thermal power systems runs steam turbines based on solar power, and I believe that most geothermal power involves steam and turbines. Functionally, the steam turbine bits of these systems are identical to a coal-fired steam turbine, but the heat cycle differs.
dboreham 3y ago
> I've not heard of sustainable aviation fuel. Is it snake oil? Why wouldn't it just be "sustainable fuel" suitable for trains and automobiles? Planes don't run on the same fuel as trains and automobiles. The basic idea is pretty simple: it's all hydrocarbons. We traditionally use hydrocarbons grown as plants millions of years ago and stashed in the ground until we dig them up/pump out the ground. We don't put the carbon back in the ground -- it goes into the atmosphere mostly. "Sustainable" fuels are the same thing except you grow the plants today. Since plants growing today use carbon from the atmosphere, even when the fuel is burned like traditional fuel, you're not adding much net carbon to the atmosphere. Everything else is mere details, such as: growing plants today is much more costly than digging up plant material from the Cambrian; the fuel has to have the same energy density as traditional fuels; it has to not gunge up the engine; etc.

denimnerd42 3y ago

They are developing these fuels for Formula1 and the like. Probably won't see them in road vehicles due to cost. But never know. It's likely normal fuels in hybrids or pure electric vehicles will be better (cheaper and lower carbon). For trains overhead electrification would be better. I'm not sure the fuel itself is that low carbon but the cycle of producing it may be. I'm sure a quick search would reveal they produce slightly less CO2 or something in a suitable engine.

handy2000 3y ago
Do you mean synthetic fuel? Haven't heard of Formula1 being interested in biofuel.
- rswskg 3y ago
  It's a huge part of the 2026 rule changes.
  - handy2000 3y ago
    E-fuel is different from SAF that is described in this article. E-fuel is carbon-neutral and SAF is low-carbon (made from tallow, algae, etc).
- denimnerd42 3y ago
  There's no mention of biofuel in the article. But yes any technology designed to reduce the impact of the fuel production/use cycle. In F1 it's branded as synthetic fuel right? It's like a natural gas derived fuel but could be derived from anything the scientists engineers can make work. Jet fuel is heavier so starting with an oil derived from bio matter might make more sense. Either way something designed with less impact than drilling for fuel.
  - handy2000 3y ago
    The fuel mentioned in the article — "sustainable aviation fuels, or SAF" — is biofuel I believe, not synthetic fuel.
    - denimnerd42 3y ago
      oh gotcha. To me it's all in the same. Some engineered alternative that produces less carbon. it's terribly semantic though because every fuel today is engineered to produce less emissions.
      - handy2000 3y ago
        Right, agreed - it's an improvement over what we currently use! From what I read E-fuel is very expensive to produce, so I was surprised by the possibility of airplanes switching to it.
        denimnerd42 3y ago
        Sounds more feasible than electric planes though. That never made viable sense to me. At least they could build a 737 sized alternative fuel plane today.

handy2000 3y ago

> Is it snake oil? It's biofuel made from palm oil, algae, tallow, etc.

alkonaut 3y ago

It's just the same as the non-fossil versions of diesel like HVO100 and similar. Whether this fuel is "sustainable" or "emission free" of course depends on how you see it. It will depend on what the source of the fats used is, and how those were produced, how much and what energy was used in the processing and so on. But at least it's significantly better than regular fossil fuel. An interesting thing about this is that there has been quite a lot of infrastructure built to create these fuels for road transport in the last decades. So if road transport is electrified but flight isn't, then all those resources could quite easily be redirected to make aircraft fuel instead. If I recall the interview correctly that I heard regarding the flight mentioned below, I think there are some countries that have enough biofuel production (currently for road transport) already, to replace all the aircraft fuel used domestically. The first commercial transatlantic flight with this type of fuel was just two days ago: https://apnews.com/article/transatlantic-flight-sustainable-aviation-fuel-e25e6a6c7f78e3cadb6c4dca29a37fc8 https://apnews.com/article/transatlantic-flight-sustainable-... > Is it snake oil? While renewable, the worlds entire production of snake oil would only make a small dent in the fuel needs of the airline industry.

rswskg 3y ago

It's a hydrocarbon chain produced from corn and waste fats. Fairly similar to bio fuel for cars. Sustainable trains are nuclear powered. Blimps are either too slow or can't carry enough cargo. Solving the use of heavy tanker fuel is quietly a massive priority, the naive answer is nuclear, the real world answer isn't clear.

camgunz 3y ago

The way it's "sustainable" is that it's not a fossil fuel (well, currently it's 50% fossil fuel, they hope it can be 100% fossil fuel free by 2030), so it's just part of the normal carbon cycle like forest fires and breathing. IMO it's probably just a stand-in until hydrogen really works.

fcantournet 3y ago

It's snake oil. It's renewable is the same sense that cow farts are renewable : if you dedicated the entire arable surface of the planet you could make fuel with it for 5% of our consumption. Don't get me started on the oil USED to produce this wonderful green fuel.

robertlagrant 3y ago
Snake oil is at least renewable. Just grow more snakes.

micromacrofoot 3y ago

not really "sustainable" but "more sustainable"

Ekaros 3y ago
It probably will not be sustainable... But it might be carbon-neutral... Which might not or might be part of sustainability...

graphe 3y ago

Hydrogen could be the fuel of the future. Go for the moonshot, a space elevator.

tialaramex 3y ago

Trains are, by their nature, very suitable for electrification. As with renewable energy the expense is almost all capital, it's cheaper to run electric trains it's just expensive to build electric railway lines they run on. Planes are not well suited to electrification. Trainers can reasonably be made electric, as might certain commercial purpose aircraft, but if there will be electric New York to LA passenger flights it won't happen any time soon. Although the fuel in a Cessna would be AvGas which is basically leaded gasoline, essentially anything you'd pay to fly on has turbine engines running on JetA which is basically kerosene instead. Small local planes, especially in Europe might look like just the Cessna only bigger, but the propellers are spun by a jet turbine, they don't have internal combustion engines.

AshleyGrant 3y ago
A jet turbine is an internal combustion engine. It isn't a "reciprocating" engine, though.
- cherryteastain 3y ago
  Well, unless it has an afterburner like Concorde's engines
  - dredmorbius 3y ago
    That's still considered "internal" combustion, as the combustion is occurring within the context of the engine itself. The traditional contrast to the I.C.E. is the external combustion of a steam engine, where the combustion occurs in a boiler, which then directs steam to the actual reciprocating engine (in a traditional steam engine). Steam turbines actually could be a case of an external-combustion turbine, as these are powered by steam which is heated externally to the turbine itself (e.g., there is no internal combustion chamber). Not all steam turbines are combustion engines, however. A nuclear power plant's steam turbines are fed by steam created from nuclear fission rather than chemical combustion. Some solar thermal power systems runs steam turbines based on solar power, and I believe that most geothermal power involves steam and turbines. Functionally, the steam turbine bits of these systems are identical to a coal-fired steam turbine, but the heat cycle differs.

dboreham 3y ago

> I've not heard of sustainable aviation fuel. Is it snake oil? Why wouldn't it just be "sustainable fuel" suitable for trains and automobiles? Planes don't run on the same fuel as trains and automobiles. The basic idea is pretty simple: it's all hydrocarbons. We traditionally use hydrocarbons grown as plants millions of years ago and stashed in the ground until we dig them up/pump out the ground. We don't put the carbon back in the ground -- it goes into the atmosphere mostly. "Sustainable" fuels are the same thing except you grow the plants today. Since plants growing today use carbon from the atmosphere, even when the fuel is burned like traditional fuel, you're not adding much net carbon to the atmosphere. Everything else is mere details, such as: growing plants today is much more costly than digging up plant material from the Cambrian; the fuel has to have the same energy density as traditional fuels; it has to not gunge up the engine; etc.