Join the discussion
Write your take first — we'll ask for email only when you're ready to publish.
- Hacker News
- How is the viscosity at -60?by yread
- 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.by wronex
- Replacing fossil fuel with biofuel only works if we starve half the planet and use their food for fuel.by padjo
- 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.
by tass - 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.by abyssin
- So we can't have the dark chocolate Bounty bar anymore but we can use coconuts to fuel planes?
This isn't the future I want.
by dofm - They've already got coconut content down to 20% but I'm sure the food scientists are working on the next iteration; A new low calorie environmentally friendly 'fun size', '3-for-1' bounty containing bleached cellulose flakes, synthetic coconut flavor and hydrogenated seed oil.by brikym
- 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.
by splittydev - blended with standard jet fuel, in a small-scale micro jet engineby SoftTalker
- We shouldn't be burning agricultural products for fuels. We should be electrifying and using synthetic fuels made from CO2 and renewable energy where we can't.by breakyerself
- > using synthetic fuels made from CO2 and renewable energy where we can't.
Guess what plants are made of.
by jjk166 - Around one million coconuts required to fly from Tokyo to Los Angeles.
Around 40 million flights per year.
40 trillion coconuts required for all flights, or 1000x current production.
To scale up coconut production we need 12 billion hectares, or 80% of the Earth's surface for coconut trees.
We need 100k cubic km of water per year, or twice the renewable fresh water on this planet.
Ok cool. We will need to terraform Mars before we can fly by coconut.
Finally I understand the mad billionaire's plan.
by chr15m - Hey Alexa, change all paperclip production to coconut production.by euroderf
- The O in "occupy mars" is actually a coconut.by jeffrallen
- 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.
by RcouF1uZ4gsC - 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.
- Part time coconut farmer here.
Adding some numbers for a base line. (Note all of these numbers are almost the upper limit of a well managed farm with very good cultivars)
Best yielding palms yield ~300 nuts per pals at 70 palms/acre.
at 750g a dehusked nut with 20% oil yield
You get ~2.3 tonnes oil/acre.
For reference an a321neo burns around 2,300 kg of fuel per hour when cruising
by parimm - Top comment is a chemist explaining aromatics and seal compatibility. Fourth comment starts with "part time coconut farmer here".
I <3 you HN, never change.
by jeffrallen - 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.)
by pfdietz - 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.
by spaceywilly - 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.
- "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.
by giantg2 - Middle of the road, comparable to Sunflower oil. But they want to utilize waste products and a low energy conversion process.by zweifuss
- > The US created biofuel subsidies a few years ago
A few years ago? Corn ethanol subsidies have been a thing for my entire life.
It's a net-negative fuel. Costs more fuel to produce than it provides. It's literally just a way to waste water, farmland, huge quantities of diesel (burned by engines exempt from any sort of emissions), labor, etc.
What changed is that ethanol has been forced by regulations into more and more use over time. That has driven up demand for corn, and one of the worse side effects is that a major food staple for Mexico has gone up dramatically in price.
> effectively become a wealth transfer to support poor rural American communities,
If you think that's bad, stop and think for a moment about what purpose the US military serves for rural America, both directly through personnel but also indirectly through all the incredibly wasteful equipment, service, and supply contracts.
The US military's primary reason for existence is force projection, but its secondary is keeping rural American's uneployment from skyrocketing.
by KennyBlanken - 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.
by zdragnar - 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.
by qeternity - > 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!
by 317070 - 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.
by mdp2021 - > 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.
by europoorean - 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.
by landl0rd