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Interesting, but when did hydrogen become a "biofuel"?
Wednesday 22 June 2011
ZEHST
Interesting, but when did hydrogen become a "biofuel"?
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Interesting, but when did hydrogen become a "biofuel"?
7 comments:
The problem with supersonic transport isn't the technology. The problem are the airports. They already now operate at the top limits of their capacities.
That is why I usually rather take ship or train.
I'd be wary of any aircraft design that relies on THREE different types of engines, and stops and restarts 2 of them in flight.
Plus, I can see big problems with trim control - it's not very practical to subdivide the cryotankage, so you'd have to shift the hydrocarbon fuel around pretty quick.
On balance, I think I prefer the look of the Reaction engines LAPCAT proposal, even if that doesn't have any windows...
Obama's most recent speech to the DNC mentions "biothermal" energy. According to the technical encyclopedias, this means methane derived from "decaying biomass"- a nice term for compost heaps and/or rubbish tips. Since methane is mostly hydrogen, this probably explains the classification of LH2 as a "biofuel".
It does not, however, explain why a President obsessed with reducing greenhouse gases is excited about creating more of them, and by a tried-and-true method, at that. Of course, his usual ignorance of actual science may simply be in play here.
Either that, or he and the people who propose projects like this have now reached the point of full cognitive dissonance where reality is concerned.
cheers
eon
eon: Barry Husseinovich's method of making speeches is to put up a series of words that polled well for emotional response on the teleprompter, and then read them. And then flash the toothy smile (another thing Obama's got in common with Carter, by the way). I'll bet I could put an Obama speech through a Dissociated Press program, and get another Obama speech out. Hell, I'll bet his own culties won't be able to tell the difference.
Technology... I agree with Daniel. Three times as many engines to go wrong. No clue what the plan might be if the second-stage engine breaks while the craft is in the third stage of its flight. Does everyone put on a pressure suit and a parachute and jump out, or do we just reduce the burden on the resources of Gaia by one plane-load of travelers? (Or, you know, is there a way to get subsonic and land in such a case? Making a test plan for this thing does not seem like an enjoyable job.)
As an aside, this hobby horse of lower carbon emissions has to be close to ready for the glue factory. Supersonic transport! (and Lower Carbon Emissions). New espresso machine! (with Reduced Carbon Emissions). Sailboat! (best thing about it:... you get the point, though I suppose, for something like petroleum transport, a fleet of sailing ships would work as well as oil-burning tankers). As pointed out, it's about carbon dioxide these days, not even greenhouse gasses. Aren't people starting to get tired of having this one thought stuck in their heads yet? Do we have a precedent? Something that intruded so much into so much of life? How long did that take to jump the shark? Or did it only die out when its generation of granola-munchers grew the hell up? In the second case, this kind of thing has the nature of worry beads, which bring comfort rather than novelty when touched, and is going to be with us as part of the flavor of the times. In the next life, maybe, we'll meet our ancestors from the Middle Ages and they'll tell us about their favorite amulets against devils or the evil eye. And we'll tell them about the demon of global warming (may Algore save us from our folly!). 1000 years of history well spent.
Sergej;
All excellent points. I'm also wondering about the practical economics of an aircraft that will have a flyaway cost somewhere north of a B-2 stealth bomber per copy, that only carries 100 passengers.
Unlike air forces, airlines generally have to show a profit, or at least stay out of the red, to stay in business. On that basis alone, I'd expect the per-passenger ticket price on this bird to be high enough to give even the Hollywood crowd and AlGore sticker shock. (Well, maybe not Al.)
Like the Concorde, or the "Airbus 2050" flying cruise monster David posted a few days ago, I'd strongly suspect that this beastie would lose money every time it left the ground.
cheers
eon
after digging through various articles, it appears the the "Biofuel" part refers to the turbofans used for take of and landing - these are supposedly going to be fueled on algae-derived hydrocarbon fuel, while the ramjets and rocket engine will be fuelled by cryo hydrogen (and in the case of the rocket, cryo oxygen too)
because of course, burning hydrogen produces totally harmless water, and cryogenic hydrogen is just lying around waiting to be picked up at no energy cost...
Daniel: well, if you only use hydrocarbon fuels in rare instances, as for takeoff and landing, even making them inefficiently isn't that much of a problem. As for liquid hydrogen, that's a means of concentrating and transporting energy. I can see it being made at a place where there's abundant hydroelectric power or (shudder) a nuclear powerplant. You can't drag Hoover Dam up in an airplane (the people in Colorado might miss it, for one thing), but you can use it to make fuel.
Or else, you know, you aren't looking broadly enough. On other planets, liquid hydrogen is actually just lying around. Given that the people who came up with the idea appear to be proper space cadets, perhaps this is what they're thinking about.
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