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.
Coconut oil jet fuel matches kerosene's efficiency in engine tests
91–100 of 250 posts
Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests
#92Earlier quoted context omitted.
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.
Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests
#93Earlier quoted context omitted.
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.
Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests
#94Do 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.
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Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests
#95Earlier quoted context omitted.
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.
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?
Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests
#96Earlier quoted context omitted.
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…
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.
Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests
#97Aviation 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.
Ah, the modern debacle, shall we choose this kind of shit or that?
Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests
#98Earlier quoted context omitted.
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 ass…
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.
Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests
#99You 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 sou…
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…
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.
Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests
#100This 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…
Maybe it's time to develop new sealing materials?
edit: thanks for the downvote. I should've said "Maybe it's time to _invest into developing_ new sealing materials?" ;)