Coconut Oil Jet Fuel Matches Kerosene's Efficiency in Engine Tests
studyfinds.com106 points by mdp2021 5 hours ago
106 points by mdp2021 5 hours ago
This isn't proper SAF, it's basically C8/10 biodiesel. No aromatics which is one of the perennial problems with SAF, due not just to volumetric energy density but nitrile seals not swelling enough. Integral wing tank seals usually expect aromatic exposure also. This is why some of the catalytic routes/CHJ are of greater interest, cycloparaffins/napthenes recover some of this vs a more biodiesel-ish blend, but even 50% cycloparaffin doesn't fully recover swell. These are solvable backwards compatibility issues but not in the short or medium term.
More egregiously FAME is a polar solvent that eats your elastomers, even some fluoroelastomers. It will also attack your polysulfide tank sealant. The remark that it's "technically feasible" to decrease oxygen through hydrogenation is not at all sufficient. Now you're into requiring catalyst beds and a hydrogen plant which makes this much less appealing. Plus ester instability when you sink heat into fuel. Plus freeze point. This is literally a tracked contaminant banned above mg/kg levels that doesn't even have very good properties otherwise they want to run as a major constituent of fuels.
Do coconuts grow particularly efficiently?
Edit: The US created biofuel subsidies a few years ago and it’s led to poor use of land with questionable climate impact. It’s effectively become a wealth transfer to support poor rural American communities, which isn’t necessarily a bad thing but there’re probably more effective ways to do that intentionally.
> a wealth transfer to support poor rural American communities
My immediate reaction to this is: it's probably a wewlth transfer to the few landlords owning the land and probably charging higher rent, not to the communities.
Of course I haven't analysed the data. If I am wrong, hopefully someone will feel compelled to correct me.
My understanding is that it caused the price of corn to go way up, meaning the poor in Mexico found food far more expensive.
International markets and all that...
NAFTA and successive treaties forced Mexico to allow much cheaper corn from the USA to displace many smaller corn farms in Mexico, only larger farms could survive that and farming of corn is declining in Mexico. Also inexpensive processed food displaced traditional diet goods at the same time for the same reasons, probably contributing to obesity epidemic that only started in Mexico after those treaties.
Processed foods are not cheaper than healthier options. People constantly repeat this, but it's flat out wrong.
The best way to apologize for people who, is to say that they don't have enough time to cook between all the jobs they have.
> cheaper than heather options
Due to spoilage concerns grocery stores price food based on shelf stability not just production costs. Processed foods are generally shelf stable enough for this not to be a major concern.
Similarly economies of scale apply in many situations. Slow cooking beans takes more energy the smaller the batch size due to surface area to volume ratios etc.
Combined with the opportunity costs associated with cooking + cleanup means there’s very few healthy options that can compete with highly processed foods.
I bought over a pound of steak the other day for $5. (Yes, it was on sale. But it is frequently on sale.) Along with a potato for 50 cents, that's cheaper than a bag of Doritos.
Oh, and I bought a banana for $.22.
Cooking a steak takes about 10 minutes.
Microwaving a TV dinner ($7.50) takes more time.
Likely, and then... after Mexican farms went out of business, they added biofuels, the price spiked, and Mexico had no domestic corn people could buy.
It's sort of what they want for Canada. They keep trying to attack our protected agricultural sectors, and no sane country doesn't protect their food supply. Amusingly, they want 10% of our dairy market (as a start), and they already have a few percent.
Yet we're 1/10th the size of them. So they make a massive fuss, over 5 additional percent of our market or so, which for their market size is 0.5% of its overall size. The US economy won't even notice, but the Canadian market will 10x as much. It's just petty.
They already grow, they are already harvested, and this process uses discarded parts of the harvest. It is putting in use what we already had but had no use for.
Edit: the article speaks about possibilities that open. It also clearly notices that the a number of problems are unsolved. The infographic is direct: https://studyfinds.com/wp-content/uploads/2026/08/Coconut-Bi...
Note that if some product available in limited amount, say "coconut oil", becomes an asset to improve any context, say "aviation", it does not follow that one should maximize that amount psychotically without a cost-risk-benefit. You can just exploit the available yield through planning.
That infographic says it uses 16-20% more fuel per unit of thrust. That's a significant amount more weight for an aircraft to carry, but because carrying extra fuel also burns fuel, extra fuel use would compound exponentially. This would probably mean significantly more than 20% extra fuel would be required for long-haul flights.
Ouch.
There's one plantation of under 1000 hectares in Papua New Guinea that makes biodiesel from coconut oil to power their own operation and vehicles on the island.[1] But they don't export. On an island with few energy sources, the process makes sense.
This is more like an industrial process that self-powers from its own waste. Sewerage treatment plants do that - the process produces methane, often enough to power the plant. Not enough to put them into the gas business, though.
Amusingly, corn to ethanol plants in the US do not generally self-power. They consume natural gas to produce ethanol.[2] Net energy gain is maybe 1.3. Only subsidies keep this going. About 40% of US corn production goes into this boondoggle.
Sugar cane, though - that's a win for biomass.
[1] https://www.theguardian.com/world/article/2024/may/10/png-co...
[2] https://en.wikipedia.org/wiki/Ethanol_fuel_energy_balance
I presume that the market for coconut oil is far smaller than for jet fuel, so this solution can't scale without wreaking havoc on the environment. These sort of clever uses for exisiting byproducts only work when the market for the main product is much bigger than for the byproduct (e.g. down is a byproduct of duck/goose meat, leather is a byproduct of beef).
The existing solution is actively wreaking havoc on the environment. I don't know the specifics of this crop but generally agricultural products absorb a substantial amount of carbon when growing, so releasing some of that carbon by later burning has the potential to be close to carbon-neutral. Whilst petroleum fuels are 100% carbon negative.
Aviation is a relatively small amount of global carbon dioxide emissions (2.5% or so). However, there is some evidence that their emissions are much worse than they seem on paper due to NOx and water vapour emissions high in the troposphere. Even if coconut oil was a remotely viable alternative it would do nothing to address these other issues.
There's more to the environment than the greenhouse effect. Coconut plantations would compete with rainforest in much the same way palm oil ones do, since they have more or less identical growing climates.
If you want to use biofuels, use a plant that grows in low-value areas like open fields. Something like corn or sugarcane.
Apparently (I’m relying on facts from Claude here), aviation uses about 100 billion gallons of oil a year and coconuts yield about 250 gal/acre, so assuming you can approximately replace them 1:1, you would need to plant about 400 million acres under coconut plantation, an area the size of Mexico.
Edit: you don’t have to plant all of Mexico, every percent of fuel you replace is the equivalent of a percentage of a country under a single crop, displacing what would have been there before (presumably some kind of food).
Yes, but nobody said that it would replace kerosene. Especially at this stage.
To what scale though? Doubtful it's going to be enough for a replacement. Just as GP stated, the corn grown for ethanol is nothing more than an additive and it is quite easy to find fuel without it. It's a boondoggle and not any where close to being a fossil fuel replacement
Isn't that simply a matter of cost? It's pretty difficult to complete with pulling an energy dense material out of the ground.
If we were to globally tax oil extraction proportional to the actual cost of equivalent carbon capture I imagine biofuels would begin to look quite reasonable.
That said it seems to me that tying the energy and food supply together economically in such a direct manner is likely to have some deleterious effects on poor countries.
Oil has its own infrastructure. That infrastructure is producing things for airplanes almost as a byproduct. Both of the oil we pump from the ground goes to cars. If cars switch from using oil, that's going to raise the cost for everything else to get the oil they need because they have to pay for the full refinery output. Or in this case if airplanes quit using kerosene for jet fuel that is going to slightly raise the price of refined oil for everyone because the refineries don't have that one small extra part of their income sheet to help pay for the fixed cost of having a refinery. The whole system needs to work together, of course. If only airplanes get off, the difference is merely insignificant. However, if cars and airplanes both get off using oil, suddenly the other uses of oil become unfeasible.
> it’s led to poor use of land with questionable climate impact.
In the short term, yes, because they were unnecessarily using carbon energy to grow the fuel.
But if we want to de-fossilise society in the long run, we need solutions for flying and long distance travel. Electric flying seems infeasible at the moment, and people are looking for suitable bio-fuels to make flying carbon neutral. Afaik the maximum planes were allowed to handle up to now, was a 50-50 mix kerosene-biofuel. [0]
Coconuts could be a breakthrough!
Just use any carbon monoxide source (e.g., pyrolysis of pretty much anything that'd release carbon dioxide when burned works, followed by some cleaning to get rid of some problematic catalyst poisons (notably sulfur compounds)), add hydrogen, and do Fischer-Tropsch. You get your high quality diesel fuel, often higher quality than what you can easily get from crude oil, btw.
If you don't have anything to pyrolyse, use a sodium or potassium hydroxide wet scrubber to extract it from ambient air and recover it from the solution with burnt lime; it preferentially bonds to the carbonate, becomes nearly insoluble; you take the lime stone powder, heat it with a high temperature blow dryer until the carbon dioxide cooks out (you can use pure carbon dioxide atmosphere for that! Just let out excess buildup of CO2 pressure to your output cooler/storage.), have regenerated the burnt lime, take the resulting CO2 and hydrogen to perform water gas shift to turn the mix into CO and H2O, condense out the H2O, then use the CO + H2 mix for your Fischer-Tropsch synthesis.
You can use incineration facilities to tap off concentrated CO2 and mine landfills until they are empty to keep the incinerators fed to get the CO2 possibly-cheaper than from the direct air capture units.
Start by using more solar cell glass laminate for exterior surfaces of new construction and as roofs over whatever parking lots you do want to keep around longer-term.
Synthetic non-fossil fuel is going to need plenty of electricity and probably much of that "just" to electrolyze water into hydrogen which is reasonable for seasonal energy "storage" (run them during the high-solar 25~50% of the year, use underground caverns (former natural gas wells) or liquify it to store for the winter, run the synthesis plant that consumes it year-round. Don't just burn the hydrogen in power plants, though you can keep existing fossil fuel plants around for a while to run them during the worst week or two of an average winter. But expect the power to be as expensive as each kWh you get today from a small gasoline generator fueled with fully-taxed highway gasoline...
I'm not sure that mass air transit has a place in a post-oil society were we try to leave at peace with the planet. Not just for the carbon impact, but also for the diversity of our species and cultures.
Should every Chinese and Indian visit Venice, even though it destroys the city little by little? Should we send things as futile as watermelons by plane?
Of course, the market wills it so some may think that it must happen, yet I feel that the globalisation and massification of everything made the world a less diverse and interesting place overall.
> I'm not sure that mass air transit has a place in a post-oil society were we try to leave at peace with the planet.
Me neither, but that doesn't stop me from celebrating possible breakthroughs in decarbonisation.
Why not stop other Europeans from going as well?
They live closer by? So less miles travelled, and in many cases travelled by train? Depending on how you generate electricity that works out quite differently.
Went to Venice by night train 15 years ago, would definitely recommend.
Conversely, however, perhaps we should question Europeans massively going to Phuket.
> Should every Chinese and Indian visit Venice, even though it destroys the city little by little? Should we send things as futile as watermelons by plane
Who are you to dictate where Chinese and Indians can and cannot visit or enjoy delicious watermelons?
If someone wants to eat a watermelon like a dirty slave that is their business and you are not going to deny them that right. This is pure insanity.
China and India are the biggest domestic aircraft markets in the world. The manufacturers literally cannot keep up with the demand. If trains were more effective they would have built them already. If California has taught us anything it's that implementation of high speed rail is a joke.
I am appalled at the level of delusion and craziness in these responses, it would take a year to respond to them all.
Air travel is not going anywhere and we are not setting society back 100 years on account of dubious climate histrionics.
Want to save the environment?
Ditch smartphones (future e-waste) and all their useless apps (and resource-sucking infra) we could all live without tomorrow.
Turns out we were as effective in moving goods and services and leisure travel in 2008 as we are today.
We just couldn't post to social media about how uncomfortable the airplane seat was and how the onboard Wi-Fi sucked.
> If trains were more effective
Well they're more convenient by virtue of being faster. The well off will inevitably pay for convenience if allowed.
> If California has taught us anything it's that implementation of high speed rail is a joke.
The only thing California stands as an example of in that regard is political dysfunction. A hypothetical benevolent dictator could have built out high speed rail there on time and on budget.
> I am appalled at the level of delusion and craziness in these responses
Has it not occurred to you that maybe that's a red flag that perhaps your own views or emotional state are a bit off?
> on account of dubious climate histrionics.
An empty dismissal of a vague and poorly defined (on your part) concept. How about engaging with a real position instead of name calling a straw man?
> Ditch smartphones (future e-waste)
And what do you suppose the combined total environmental impact is for those globally compared to other categories?
How many coconuts are on one tree and how many tons of coconuts would be needed to replace kerosene globally?
I am 100% for decarbonization as fast as possible.
BTW Law of Conservation of Energy will be applied to coconut-based energy as well.
Vaclav Smil mentions in his book that we should consume less.
I see so many cheap weekender air tickets… it’s almost impossible to resist the temptation.
Annually 5 billions people travel by plane…
Vaclav Smil so wildly mispredicted the trajectory of renewables that his worldview should be taken with heavy skepticism.
That's true of basically all economists' predictions of technology. But he does a lot more than state predictions, his numbers and breakdowns and decompositioba are valuable in themselves.
The best solution to flying and long distance travel is to reduce it as much as possible. This means no more travelling for hedonistic (touristic) purposes.
I.e. measures like massive taxation (also for private jets of course).
I think that's a bad frame of mind in general. One of the primary ways industry tries to prevent regulation is by putting the burden on the individual. People think the only way we can have a healthy environment is by sacrificing things for the average person. And one of the worst things environmentalists can do is play along with that. In the US there's a push to ban plastic straws, which is annoying to the average consumer, while basically every item you can purchase comes wrapped in tons of plastic packaging. Industry LOVES things like this because it does little to actually reduce plastic consumption, and pits the average person against the environmental movement.
As another example, the amount of greenhouse gas emissions from airplanes is several times less than the amount of methane that leaks out of natural gas pipelines every year (here I'm weighting emissions by their global warming impact). The overwhelming majority of those leaks can be prevented with minimal effort, but industry hasn't been incentivized to do so. Maybe before we start banning tourism, we have some inspectors checking pipelines for pinhole leaks?
Oh we can and should absolutely do both. Travel and tourism has other downsides which make it worth reducing it, like the fast spread of diseases for example.
The difference between removing plastic straws and reducing air travel is that reducing air travel would have an impact.
So no tourist travel for the poor or middle class, just the elite rich? And no tourist income for the poor and middle class? This is a policy only the top .1% will enjoy.
But the purpose of money is exactly to be a currency to be spent on choices. And, I must unfortunately repeat myself with regards to what I wrote nearby, externalities can be charged as a cost - and it is probably the way to handle it. "You pollute, you pay" - then, you acquire money to invest it, especially in activities with downsides.
I don't support the idea as described, but playing devil's advocate presumably it would shift demand towards train and boat travel. That would push tourism closer to home and largely eliminate visiting other continents for those who couldn't either afford the air travel tax or to take several months off of work if going by boat. But it wouldn't eliminate tourism by any means. Even the poor could still easily travel the better part of a given continent.
I didn't say tax everyone the same amount. Make it hurt. Tax the elite a million per flight.
And yes, no tourist income. It's dirty money.
Do you really think that traveling somewhere to experience a natural or historical or cultural landmark is intrinsically immoral? Do you think less of me for traveling to South Africa to go on a Safari? For visiting the Louvre? Why?
Electrified high speed rail solves this, with flying reserved for transoceanic needs. Private jets should not exist outside of scientific, medical, or other non luxury/personal use cases. Travel and tourism will always be with us, and should be imho. Carbon taxes, laws, whatever is needed to accomplish it.
> should not exist outside of
Externalities can be made to bear a cost.
Currently, there is no effective way to put carbon back in the ground, and therefore no way to make the externality bear the cost. This is an excuse to justify high emission, low efficiency use cases. It’s capitalism cope meets buying a Catholic indulgence. “I am wealthy and deserve this and so I will pay a token amount that is meaningless to continue to justify this excessive, unnecessary consumption.”
If the use case does not require fossil fuels, certainly, carry on. Same if your biofuel isn’t going to cause the Amazon to be clear cut and can be economically produced at scale. But until then, have to aggressively impair the consumption of fossil fuels, because it’s only going to keep getting hotter, year after year, long after we reach net zero (which is still a decade or two away). Maybe one day we’ll have a mechanism to sequester carbon, and enough low carbon energy to suck all of the CO2 emitted since the industrial revolution started out of the atmosphere for long term, stable storage to mitigate climate change. But not today, and therefore, these are the facts that must drive policy until the facts change.
Climeworks' capture fails to cover its own emissions - https://news.ycombinator.com/item?id=44017317 - May 2025
> Al Gore gave a TED talk in 2023 where he discussed the carbon capture and disposal industry and specifically mentioned Climeworks. He made fun of the company, calling the capture industry nothing more than a cover for oil and gas companies to keep their businesses afloat.
Even if you don’t like Al Gore, the math remains the math.
> there is no effective way to put carbon back in the ground, and therefore no way to make the externality bear the cost
The cost applied to externalities can be spent to amend the specific damage, which is sometimes impossible, or can be commensurate to the estimate damage in order to create different benefit.
> indulgence
I concour with the analysis, but not necessarily with the moral evaluation. I have already mentioned nearby that money is a token to be spent on freedom in a framework of choice in allocation: Economics, science of Optimization, is the science of the management of Scarcity to some authors - and that scarcity is structural, existential (as evident in the case of Time). The purpose of resources is to invest them according to preference - some choices more loaded, but the computation compares the values of said "load" with the "preference" and the "resource (money etc.)".
The actual rebuttal: if you had to go "black vs white" in preferences, vs the continuous framework I proposed, than heating for example would be a problem - an externality bearing investment that we could not compensate with a reversal of the damage. But should we do without heating? You yourself defend touristic travel. Where can we put a threshold? At that point, it is best to quantify damages and charge the externalities.
Mental model:
Electricity->Batteries, renewables, geothermal, hydro, transmission, cross country interconnectors
HVAC->Heat pumps, low carbon district heating, insulation, sand heat batteries
Mobility->Electric vehicles, bikes, scooters, light rail, heavy duty electric vehicles
Marine traffic->Low carbon produced methanol or ammonia
For air travel that must remain and cannot be replaced with an electrified or low carbon alternative (until low carbon solutions exist), the component that must remain be made as efficient as possible. Regardless of wealth, you fly commercial, just like everyone takes the subway, regardless of wealth or status, in cities with high quality mass transit. Your need is met, just within our collective societal tolerance for the harm incurred for the travel desired (Point A->B).
We may disagree, and that’s fine. I believe the climate data is clear as an input to this decisioning. Whether you’re wealthy should not be a factor in outsized carbon emissions (private jet travel, specifically) simply because the socioeconomic system is defective on this. I assume the appetite for this goes up as climate change consequences become more dire, compelling more appetite for extreme actions to course correct.
Just because there are currently (economically motivated) shams doesn't mean the concept is impossible or the tech not understood. As I see it the primary issue is cost. There's the price tag put forward by the PR shams and then there's the real price tag which at present remains entirely unpalatable.
There's nothing except the political preventing the governments of the world imposing the unpalatable price on the market and policing the capture operations for net effectiveness.
> Electrified high speed rail solves this
Curious -- what speed are you assuming for such a high speed rail?
The last high speed rail I was on was Fuxing Hao series in China, ~200mph. If we can go faster, go faster. Shanghai Maglev can do ~260mph. Japan’s Shinkansen tops out at ~199mph, a bit higher than the TGV in France (~186mph during commercial operations, but has achieved speed records as high as ~360mph).
Within the scope of land travel, it’s clear it can be built. If it isn’t built, of course, that’s a choice. But it’s a lie to say it cannot be done.
Obviously a choice, but also at 200mph it's obviously a vastly slower experience in a lot of way for many of the most-trafficked US domestic routes.
Even at 300mph, which IIRC is much faster than normal operations on existing system, transcontinental travel becomes "too slow." The opposition would be insurmountable to making it take 12+ hours to travel from NYC to LA, for example.
Effectively would split the continent in a way that it hasn't been for generations. Rountes like NYC<->Chicago would get annoyingly slower, but long routes like DC<->Seattle would become an "almost never" trip by train @ 200mph (even assuming direct, as-the-crow-flies). Practically, you're talking "east coast to Asia" durations to cross the continent. Non-starter.
Disclaimer: I love trains. I want high speed trains deployed widely in the US.
> The opposition would be insurmountable to making it take 12+ hours to travel from NYC to LA, for example.
It already takes 6 hours to fly. Add in security, checked bags, getting to and from the airport and it's close to 10 hours. Also you waste a day or ruin a night's sleep on the redeye.
Compared to that an overnight train with a bed sounds delightful. People could do almost-day-trips, coast-to-coast, with no ill effects. Leave LA tonight, shop/sightsee/eat all day in NYC, take in a show, hop on the late train back to LA the following day. This is pretty near impossible today unless you have a private jet.
Is ~400 million to ~4 billions excess deaths over the next ~50 years worth it? How many excess deaths is it worth? Everything is about trade offs. How much mortgaging of the future with are we comfortable with for today’s luxuries? Because this is a debt that will need to be paid back, potentially by someone not even yet born, through no fault of their own.
At least the future can default on sovereign debt, it cannot default on the energy and resources required to repair physical systems required for survival, that debt is the ultimate recourse debt. There is nowhere to run from it.
https://climatechangetracker.org/climate-change-progress/cur...
https://actuaries.org.uk/media/ni4erlna/planetary-solvency.p... (page 32 risk impact matrix)
(day job is risk assessment and management, and the lens through which I see and model this entire system)
Saw a recent post about an electric plane - was pretty sweet let me dig it up. $5 worth of fuel!
> https://www.heartaerospace.com/newsroom/heart-aerospace-comp...
Is it not a bad thing to encourage poor people to continue doing the thing that has apparently made them poor?
It's also very not true that farmers are poor in the US (median household income about 30% greater than general population). This mindset is like a century old.
"It's also very not true that farmers are poor in the US (median household income about 30% greater than general population)."
Most farmers work a "real" job in addition to the farm work.
Then you also have farm workers, who do not own the farm, and they tend to be poor.
The economic landscape of farming is very bimodal. “Most farmers” (by headcount) are subsistence farmers who live in impoverished countries and don’t produce very much food because they are feeding themselves and their immediate community.
The food that people buy at the grocery store in developed countries is primarily produced a relatively small number of industrialized farming operations which are high dollar businesses.
That is both true and not quite true at the same time. The notion of the Yeoman farm family supporting itself off its land is mostly a myth.
Like everything else. it’s been capitalized and farms have consolidated over time. There were lots and lots and lots of farm workers. who are pretty poor and now lack the assets that their grandparents had.
> Is it not a bad thing to encourage poor people to continue doing the thing that has apparently made them poor?
Right, we should tell the farmers to "learn to code"?
Too bad you can't ask Claude to grow potatoes. Though it probably uses the same amount of water and fuel to tell you it can't.
All subsidies are wealth transfers. That's the whole point- to incentivize something that wouldn't otherwise happen at a scale the government deems to be of benefit or necessary.
Biofuels are part of the all-in-one story of renewable energy, especially the transition phase of reducing carbon emissions before we can get to full electrification.
The question of whether or not they are effective in doing so- and whether or not the money for those subsidies would better benefit society elsewhere- is the very same one that skeptics of solar and wind hammer on.
I would much rather see those subsidies go to farmers growing human consumer food, and sending the excess to bioreactors to produce fertilizer and/or methane for power generation. Cheaper groceries make it easier for people to eat more whole foods, after all. Just last week, I found napa cabbage at $3/lb- meaning one head would have been $24. Fresh broccoli and other good veg are also expensive.
The reduction of harm from reduced CO2 by bio-jet-fuel would pale in significance compared to, say, subsidies in regenerative farming practices, or even simply healthy crops.
A lot of food cost is due to food waste and convenience (refrigerated shipping, out of season crops, etc). There's already a lot food waste due to logistics and consumer preference.
Middle of the road, comparable to Sunflower oil. But they want to utilize waste products and a low energy conversion process.
Is Jet Fuel really the best use of coconut oil? I'd imagine it's far better as a lubricant or ingredient in things more directly adjacent to human rather than mechanical use.
"It’s effectively become a wealth transfer to support poor rural American communities"
I'm skeptical that rural community are the primary beneficiaries. Seems more likely that it's benefiting people who own the patents/companies.
Are the people against bioengineered produce also be against us working towards super efficient coconuts or some other plant we designed to fill the same role?
You want a fuel that's chemically identical to current jet fuel, not one burdened with extra oxygen. Yes, this would require more energy, but it would be used more effectively in jets.
A drop-in compatible jet fuel can be made by hydrodeoxygenation of biomass, using Virent's process. The waste cellulose in current US waste streams would be more than enough to displace all current US jet fuel consumption. An extra source of hydrogen would be needed to do this, but hydrogen can be made renewably (and, indeed, that's a good way to provide dispatchable demand to help deal with renewable intermittency, and will have to be done anyway to displace the use of natural gas to make hydrogen.)
I agree, I wish more work was being done on building a hydrogen economy. Hydrogen can be generated sustainably, is a great way to store excess energy from renewable sources, can be transported, and as a bonus can be mixed with hydrocarbon fuels to be used directly as a heating source.
As an example, a house in NH can generate a lot of excess solar power in the summer months when it uses hardly any electricity. If all that energy could be stored as hydrogen, in the winter (when solar power is less due to the far northern latitude and snow covering the panels) it could draw down on the hydrogen to generate electricity and also use it for a backup heat fuel.
I'm in Northern Europe and am in that situation. I have an electric heat pump, so would need around 3 MWh over the winter period. Apparently that would need a tank around 4m3 at 700 bar (typical pressure of hydrogen vehicle tanks). Plus the fuel cell actually generate heat, so that could be used for heating too. Doesn't seem terribly unrealistic.
If it burns more fuel, how is it "about as efficient"? That doesn't seem to make much sense to me.
> New research found that aviation biofuel made from coconut oil can power a small jet engine about as efficiently as traditional jet fuel, with lower unburned hydrocarbon emissions, though the blends burn more fuel and emit slightly more carbon monoxide.
But why? I don't know of a case where biofuels aren't a disaster against the stated environmental purpose. Bailouts for farmers? Sure. A good way to generate green energy? I think engineered algae comes kind of close to making sense as an oil source, but as a fuel would still seem silly to me. Please correct me if I'm wrong.
I think this is awesome. Anything we can do to get away from burning fossil fuel is a win in my book. I don’t know about this particular effort, but it seems to me that aviation could really need some big wins in this direction. Last I looked we still run smaller planes on leaded fuel. Crazy.
This isn’t awesome, it doesn’t work at scale and it only lets idiots ignore what should be done: leave fossil fuels in the ground, and only then do what we can with the energy that’s still available. Aviation is mostly incompatible with a sane global environmental policy.
Leaded is slowly going away, but regulation means these changes take many, many years and dollars to implement and test.
It will be similar (worse?) implementing a new type of fuel for commercial jets, especially when it comes to wide adoption across a majority of countries around the world. Basically you need something which is as least as reliable, clean (I.e., won’t clog/solidify), non corrosive, etc. and remain that way after being mixed with standard jet fuel.
I too want to see alternatives but expect to see more failures than success at this stage.
Replacing fossil fuel with biofuel only works if we starve half the planet and use their food for fuel.
blended with standard jet fuel, in a small-scale micro jet engine
> This study used oil from material the researchers describe as discarded and non-edible, including the large seeds and leftover flesh, so the fuel draws on parts of the crop that would otherwise go to waste.
This statement seems disingenuous. Surely they did not invent a novel way to extract coconut oil as part of this study and not choose to publish it. Surely this is just existing byproduct that already has plenty of commercial use.
If you look at how many coconut plantations you would need to make even a measurable dent in jet fuel demand, this would be an unmitigated environmental disaster.
I want to solve climate change as much as the next guy, but chopping down all our tropical rainforests to make it happen sacrifices exactly what we're trying to save.
Yep, we've seen this sobering reality ignored in previously-hyped "biofuel" aviation stories.
Not to mention another glaring omission here: "By adding acetone to a mixture of alcohol and coconut oil"
How much energy is needed to produce those two ingredients, and the things THEY are made from?
If I were a junior-high teacher, I'd probably give this paper a C.
either wait for bigger batteries, hydrogen or some super efficient material to create the fuselage.
biofuels won't work. they take too much land and are inefficient in terms of producing.
How is the viscosity at -60?
Cue defense industrial base funded influencer campaign to promote the "dangers" of medium chain triglycerides.
Will this produce better smells?
Long life to coconut revolution, in Bougainville island!
Aviation uses around a million metric tons of jet fuel per day.
If you thought habitat destruction from palm oil was bad, that would be nothing compared to coconut oil making up any significant fraction of jet fuel.
The question is which habitat destruction is worse? That which is already happening at scale for oil, versus what would happen if we lean into this in any meaningful way.
I don't think the answer is obvious. And I think many of us are blind or numb to environmental harms of oil outside of carbon exhaust and the occasional spill, simply because we've accepted it as status quo.
An oil well is quite small Area wise compared to the amount of acreage you would need for a coconut plantations to replace the same amount of energy output.
The issue with oil is CO2 and other green house gases and then the occasional oil spill or leak. Land area wise they don’t take up much space
we've been working on biofuel to replace fossils forever, hopefully it leads to something if not jet fuel specifically.
Yeah, but until it matches kerosene in price and availability (how many coconuts per aeronautical mile?) it won't actually be an alternative
Just intuitively I doubt there's nearly enough coconut oil produced to replace any meaningful amount of jet fuel. I scanned the article and didn't see this addressed, but may have missed it.
Various other bio-fuel and synthesized replacements for petroleum-based jet fuel have been tried and are in development. The aviation industry is very slow to approve and adopt changes.
The point isn't to make cheap jet fuel. The point is that to the coconut processor (someone who makes food or whatever) your "coconut tailings" pile is a big liability. The environmentalists could start screeching any day without warning, that's a big risk to your business. Waste that costs you nothing could cost a lot. You might be able to sell it as loam or fertilizer or whatever. But then they'll screech that you need to buy somme compliance solution. Just shipping the damn thing off to the next guy who'll squeeze some jet fuel out of it is real attractive because then the rest of the tailings become his problem. Maybe he's in a better jurisdiction. Maybe it's more inert at that point. In any case it's a liability off your books. The jet fuel just needs to be cheap enough to make this whole process cheaper than whatever way you were dealing with it before. It's like this the world over. Whether you're selling coconut scraps to the people who'll squeeze the oil out of them or strawberry waste to the people who'll make dyes and fragrances it's all the same.
Maybe those cargo cult guys were onto something
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So we just cut down some ancient rainforests to grow them right? Works for Palm oil! Goooo Planet!
