The Uncertain Future of Jet Fuel

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Credits:
Writer/Narrator: Brian McManus

References:
[19] I can’t be arsed to find a reference for this one. I have a masters degree in aeronautical engineering, just trust me.

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Thank you to AP Archive for access to their archival footage.

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[damightymage]

Former US Navy fuel systems engineer here. Well done, this is a fairly comprehensive look at jet fuel production, constraints, and alternatives. I would like to add that the Navy did evaluate a 100% biofuel version of JP-5 back in 2016. Performance-wise it was nearly identical to traditional JP-5, but as you observed, the problem with all biofuels is the cost of production.

Edit based on some of the responses: The Navy's main motivation for investigating biofuels is more to do with diversity of fuel sources (i.e. less dependence on the Middle East) than it is to do with saving the planet. That would be a nice side-benefit, though.

[jonathanm]

Excellent!!

" [19] I can’t be arsed to find a reference for this one. I have a masters degree in aeronautical engineering, just trust me. "

[samschellhase]

"made by someone I actually like" LOL
I think there was a recent Wendover video where he referred to you as "that Irish engineering guy"

[DatPenguin]

The thing about E-fuels as well is that it apparently works with existing ICEs in cars as well, there have been some tests here in Europe.
It could be mixed with normal gasoline in that case as well, so I hope it will catch on in which case there might be more of a chance of it becoming cheaper (?)

[Isopropyl_Alcohol]

"...in this case, no."

The way he says that made me chuckle. :P

[awasaz]

On the freezing point of jet fuel: It's really cold at cruising altitude everywhere in the world. What matters more is the duration of the flight. The fuel takes some time to cool, simply because there is so much of it compared to the fuel tank surface area. Long flights require more careful management of fuel temperature.

[MatthijsvanDuin]

14:40 Something went wrong here, the chart is showing cold hydrogen having a much _lower_ density than room-temperature hydrogen, which is obvious nonsense. Are the labels accidently swapped?

[agoogleuser]

Yet another incredibly well produced documentary. Your channel keeps hitting these home runs and I forecast thousands of people bookmarking your YouTube channel. I've been sharing your most recent aviation videos with most of my pilot friends and the positive feedback has been significant.
Keep up the good work buddy!
Please look into the Embraer Praetor jet. I'm sure there's something interesting to cover in a video with that one.
And your "but" is still my favorite on YouTube!
Cheers!

[neeneko]

Unfortunately, I doubt we will ever see excess energy 'flood the market'. Every time we figure out how to produce more power, esp if it brings the price down, demand goes up. Multiple times over the last hundred years or so people proclaimed that soon power would be too cheap to meter and the market always re-scales to make it expensive again.

[SapereAude]

I love how you drew the different fuels with slightly larger atoms for C and H, indicating they are closer and farther away. Such a nice touch.

[rararou]

21:28 Nice to have a video that's both enthusiastic towards technological solutions, yet acknowledges that some unsustainable practices should probably cost more. It's refreshing to see both approaches combined rather than opposed, kudos for that! And excellent video as usual.

[hltquwb]

Between 1950 and 2018 the efficiency per passenger grew from .4 to 8.2 (a 20+x improvement) RPK per Kg of CO2. The question is what RPK curve was used for the 2050 projection. While I appreciate all the work put into this video it would have even more impact if more time was spent reviewing the study assumption upfront.

[maxsinn]

"We will explore this kind if plane in more detail in a future video" I shall wait paciently for my favorite Video

[ButtKickington]

25% sounds like a big number, but said differently: the other 75% is what used to account for 97%.

[RISCy]

The visuals are incredible in this video on top of the (as always) great explanation of the topic.

[SirNobleIZH]

Petition to get fast food restaurants to sell their used cooking oil to biofuel manufacturers:
1: cooking oil is already super common, and used en masse by fast food industries
2: most fast food restaurants currently just dispose of their cooking oil once used, so it's currently being wasted
3: as mentioned in the video, cooking oil is a great feedstock for biofuel production

[reklessbravo]

I'm hearing pam oil and I'm thinking pam spray and then he goes and shows pictures of palm trees and oh that makes more sense. Accents are fascinating

[swxk]

3:44 "Longer chain hydrocarbons liquify... thanks to their lower boiling point"? A lower boiling would mean that the substance is more likely to stay in gaseous form. Longer carbon chains should have higher boiling points no?

[Tornvongeldern]

Another great video. I love that you look at the matter from different perspectives. Thank you so much for your videos.

[onetrickhorse]

Great video, thanks for posting. I should comment on the hydrogen element since I work in the field researching it, and there are a couple of points I might add. LH2 is volumetrically poor compared to the incumbent, no doubt about it. But what people often don't realise is the immense thermal opportunities it potentially offers, thermal management and advanced engine cycles in particular. Aircraft designs traditionally have been weight constrained, hence the emphasis on MTOW as a fundamental limitation, however with LH2, the challenge shifts as you've rightly identified to a volume constraint. That implies increased drag (larger fuselages to accommodate the fuel for example). What this means is that designs have to change in terms of priority, so blended wing designs, longer fuselages, and potentially drag reduction measures such as boundary layer ingestion become more interesting. Since weight isn't as concerning, engines can become more elaborate too, with the advantages gained being used to mitigate the drag impact.