Still think jet fuel is the wrong thing to be looking at with carbon fuel emissions.
It is technically more feasible on a small scale because jet (and turbine) engines will burn basically anything, with jet fuel being a mixture of kerosene like hydrocarbons.
But iirc both land vehicle and shipping outclass airplanes in total emissions.
Cars & Trucks can be (for much cheaper) replaced by proper mass transit like high speed rail.
And I’m surprised cargo ships still run mostly on novelty sized diesel engines. Would be interesting to throw a small ultra safe nuclear powered engine on one of those or even just enforcing better fuel use instead of spamming low grade MDO.
And I’m surprised cargo ships still run mostly on novelty sized diesel engines. Would be interesting to throw a small ultra safe nuclear powered engine on one of those or even just enforcing better fuel use instead of spamming low grade MDO.
It’s a real shame that NS Savannah was designed as a weird half-passenger, half-cargo hybrid that made it uneconomical to operate. It’s even more of a shame that protesting by hysterical anti-nuclear fearmongerers got it banned from ports and scared off anybody from building more traditional cargo ships with nuclear propulsion.
https://en.m.wikipedia.org/wiki/NS_Savannah
That’s well before my time.
Before mine, too. I just read a lot. 🤷
Aviation is about a fortieth of the world’s total emissions, so while there are certainly bigger sectors to look at it’s still substantial enough that it’d be extremely helpful to fix it
What not fix all?
Research money may be a zero-sum deal. If so, do we want to waste time on essentially this decade’s “vampire power”?
Hear me out: Nuclear airplanes.
It works for the submarines. Think of the pros:
- Full power electric outlets at every seat instead of that bullcrap they have today
- Flight attendants can easily be trained as Nuclear Physicists
- If a meltdown does occur, it might very well recreate the entire plot of Donnie Darko.
As a fun aside, the Americans and Russians both experimented with this idea during the Cold War. Check out YouTube for some info on the designs
Yeahhhh, maybe not…
For military it has been looked into. Issue at the time was weight vs power.
Main issue being such an aircraft cannot become a unaimed bomb in the event of downing somehow. And while air may statically be the safest way to travel. Planes have had many issues. More so during the time of this research.
So only with the nuclear unit contained in a 18000ft drop saft container. Is such an idea considered viable. Subs and ships do not need that level of protection. Or have that much limitation on power to weight.
Yeah, switching to LTA craft with solar panels and batteries is way more feasible
The real question is whether sustainable jet fuel can melt steel beams.
Combustion is the breaking of carbon bonds to bond with oxygen, producing carbon dioxide and monoxide. There is no carbon based fuel that isnt 1:1 for energy released vs GHG emitted. Making fuels from plant mass doesnt change that.
The advantage of making fuels from plants isn’t in them burning cleaner, it’s in the fact that growing the plants takes carbon out of the atmosphere. That means that the carbon released upon burning them was carbon that was already recently in the atmosphere, as opposed to being deep underground like it was with fossil fuels
That doesn’t negate the issues of land use changes and similar, but in terms of plain old net carbon emissions they absolutely are better
The caveat of finding “better” methods is that it excuses continuing or expanding the things we do that are the core problems of rapid growth, consumption, and a throwaway society. And like you said, they have their own issues that might become problematic with growth in that process. Not to say that we shouldn’t try to improve what we can, just a point that being better than the worst way to do things isn’t all that great either.
The word “sustainable” in the title is one of those greenwashing terms to sell a product and keep the status quo of business as usual. As the report shows.
For sure, I’m not disagreeing with the article. The problems raised by this report are not what the comment I was replying to raised, and I think that we should criticise these things for their actual problems.
And I guess not all of the plant is something that can be burned as fuel so done right it should be a net negative
No, under normal circumstances, the part of the plant that isn’t burned eventually also decomposes and the carbon continues in the cycle. You’d have to explicitly do something to prevent it (e.g. sink it in a bog) to make it net negative.
Technically combustion is the breaking of chemical bonds to instead bond with oxygen; carbon need not be involved. (Actually, technically oxygen need not be involved either, but we have an oxygen atmosphere not a chlorine one, so it’s gonna be oxygen.)
Good luck finding a non-carbon-based fuel suitable for commercial air travel though, hydrogen tanks are too heavy, while hydrazine and ammonia are out for obvious reasons
but we have an oxygen atmosphere not a chlorine one, so it’s gonna be oxygen.
Could also be fluorine but there are other good reasons not to use anything involving that as a fuel
“It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively. It can be kept in some of the ordinary structural metals-steel, copper, aluminium, etc.-because of the formation of a thin film of insoluble metal fluoride which protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.” ― John Drury Clark, Ignition!: An informal history of liquid rocket propellants
I think that bit was about Chlorine Trifluoride but I might be misremembering.
That is indeed the chlorine trifluoride quote
I’m in favor of using carbon-free energy sources to power plants that do carbon capture and manufacturer fuel from the captured carbon. This on top of using carbon-free energy sources for our other energy needs would lead to carbon in the atmosphere being reduced, at least temporarily.
That being said, I suspect those have even worse scalability.
One greenhouse gas per energy?
This is the best summary I could come up with:
Hopes that replacement fuels for airplanes will slash carbon pollution are misguided and support for these alternatives could even worsen the climate crisis, a new report has warned.
There is currently “no realistic or scalable alternative” to standard kerosene-based jet fuels, and touted “sustainable aviation fuels” are well off track to replace them in a timeframe needed to avert dangerous climate change, despite public subsidies, the report by the Institute for Policy Studies, a progressive thinktank, found.
Chuck Collins, co-author of the report, said: “To bring these fuels to the scale needed would require massive subsidies, the trade-offs would be unacceptable and would take resources aware from more urgent decarbonization priorities.
But the new Institute for Policy Studies report argues that the airline industry has missed previous goals to ramp up sustainable aviation production and that boosting use of the fuel source may even damage the environment and global climate targets.
“Agricultural land use changes could threaten global food security as well as nature-based carbon sequestration solutions such as the preservation of forests and wetlands,” the report states.
Large commercial airliners cannot be outfitted with batteries, unlike cars, due to their weight, while progress in other fuel forms, such as hydrogen, has been complicated.
The original article contains 692 words, the summary contains 204 words. Saved 71%. I’m a bot and I’m open source!
The report just says not to divert funding from other projects to SAF, that’s pretty reasonable and expected really - At some point it might change but at the moment there are better things to spend the money snd resources on.
When the grid is green snd there is no shortage of demand even with electric cars, boats, and heating factored in then hopefully saf will have matured enough to help complete the final transition from fossil fuel or even better electric planes will take over.
Regardless the big powers will continue to research the chemistry and engineering side of SAF because it’s important for space based infrastructure, no fossils in space to power the return trip.
Except aircraft actually has the easiest inferstructure to change. As it is centered at a limited number of locations compared to any other transportation.
So refusing to invest in research to change that. Has a larger effect in how long harm will continue. As rebuilding there inferstructure is cheaper.
