Hydrogen should take priority over biofuel in aviation

Flight Global ^ | 11/30/2010 | Kerry Reals

[ErnstStavroBlofeld]

The aviation industry should focus research and development programmes on liquid hydrogen rather than third-generation biofuels in the quest to reduce carbon dioxide emissions, according to World Wildlife Fund director for global energy policy Stephan Singer.

Speaking at a roundtable on environmental issues at the European Parliament in Brussels today - part of the Aerospace and Defence Industries Association of Europe's (ASD) Aeroweek conference - Singer said liquid hydrogen and algae-derived biofuels should be the focus of investment over other alternative fuels because they are less likely to interfere with land used for food producti

[ErnstStavroBlofeld]

Ping

[pallis]

The aviation industry should concentrate on abundance, efficiency and progress, and forget the quest to reduce carbon dioxide. Lunacy is never a good plan for the future.

[ErnstStavroBlofeld]

I agree.But its not the aviation industry that is pursuing it. Both the USAF and USN is looking into this.

[ErnstStavroBlofeld]

At Edwards AFB they are testing planes with 50/50 blends.

[InABunkerUnderSF]

First law of cryogenics: Hydrogen leaks.

Second law of cryogenics: Helium leaks worse than Hydrogen.

Personally I’d prefer to fly on something fueled by a propellant at or near room temperature.

[babygene]

What a bunch of crap... H2 is at best an energy storage system, and a poor one at that.

[jonrick46]

Hydrogen takes more energy to extract from natural sources than bio fuels. I would concentrate on finding an efficient way to extract bio diesel from algae.

[Myrddin]

Hydrogen is a STORE of energy. It must be generated from a SOURCE of energy. Typically electrolysis of water or scavenged from natural gas. It is inefficient to produce and transport. The only reason to bother with hydrogen is where the combustion products should not be toxic e.g. in a space craft. It makes no sense for a car or airplane.

[Slings and Arrows]

Why not - it worked out so well for the Hindenburg.

[Strk321]

Hydrogen is a powerful, but extremely inefficient fuel. Not only does it have to be cooled to _very_ low temperatures (colder than oxygen) to become a liquid, but its low molecular density requires large storage tanks.

As an example of the technical difficulties involved, the American space program was using LH-fueled rockets in the ‘60s, but the less advanced Soviet program didn’t attempt it until the ‘80s.

One would think too that the extreme flammability of hydrogen would make it a tad dangerous for use outside of rockets. Hindenburg disaster, anyone?

[Skepolitic]

I cannot believe this is a serious proposal. Hydrogen storage would be far to heavy to be practical on an aircraft. Onboard hydrogen generation from hydrocarbons would also be heavy, and it would be difficult for it to achieve the reliability required for air transportation.

[Myrddin]

I think the Hindenburg disaster was as much about the paint on the skin as the use of hydrogen. Hydrogen certainly contributed to the problem. Helium would have been safer. Mythbusters did a nice show on the issue of the paint with finely divided metal particles contributing to the big, flashy flare up. Hydrogen ordinarily burns with a colorless or pale blue flame. Finely divided iron, aluminum or magnesium burns very hot.

The storage problem for hydrogen is a big deal. High pressure and leaks are a problem that has yet to be solved in a satisfactory fashion.

[rdcbn]

Hydrogen simply does not have the energy density to act a fuel for air breathing engine powered airplane

[Arthur McGowan]

I’d feel safe on an airplane powered with helium.

[Strk321]

“Hydrogen ordinarily burns with a colorless or pale blue flame.”

As anyone can see by looking at pictures or video of a space shuttle launch.

Aside from the Hindenburg disaster, another example of hydrogen’s explosive properties was the 1965 Atlas-Centaur launch that fell back onto the pad, producing a quite huge mushroom cloud that put the launch facility out of commission for months. This was the biggest pad explosion to ever happen at Cape Canaveral.

The Challenger disaster of course also involved liquid hydrogen. Most of the explosion there was really a huge cloud of water vapor caused by the LH and liquid oxygen mixing after the external fuel tank broke up.

It takes very high pressure to ignite a LH-LO mixture. If the pressure is too low, you just get water vapor and no combustion. The shuttle main engines posed a serious development challenge since they were designed to be reusable, unlike the earlier Saturn and Centaur engines.

[DuncanWaring]

Those are so safe they don’t even need wings.

[steelyourfaith]

 

Beam me to Planet Gore !

[FreedomPoster]

A-MEN! to that.

CO2 in current atmospheric concentrations is a plant growth stimulant, not a pollutant. The “reducing pollution” argument we get from the AGW Greenies is just absurd.

[wastoute]

It worked so well for the Hindenburg...