Air Travel is a Gas
May. 16th, 2008 08:15 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
webfarmerAs we now know, travel by air generates a massive carbon footprint for individuals using it these days. Here are two folks (one responding to the other) talking about how hydrogen might or might not fit into this equation. Serial eco-troublemaker George Monbiot starts things up and Mike Koefman, secretary of the Campaign for a Hydrogen Economy,makes counterpoints.
My own guess is that we'll see more biodiesel being converted to jet fuel use before we see much in the way of hydrogen airships or aircraft.
If There is a God, He's Not Green. Otherwise Airships Would Take Off - Guardian (UK) - 06 May 08
"Hydrogen's great advantage - that it produces only water when it burns - turns into a major liability: in the stratosphere, water vapour is a powerful greenhouse gas. The commission estimates that hydrogen planes would exert a climate-changing effect 'some 13 times larger than for a standard kerosene-fuelled subsonic aircraft'. But there is another use for this gas, though I am aware that it will go down like a lead balloon with most of my readers. The word airship elicits a fixed reaction in almost everyone who hears it: 'What about the Hindenburg?'."
Airships Might Not Work, But Hydrogen Planes Could - Guardian (UK) - 16 May 08
"There is no question of a hydrogen-powered aircraft being 'filled with gas': it would carry its fuel in the ultra-cold liquid form. Monbiot is almost correct to observe that 'hydrogen contains just a quarter of the energy as the same volume of jet fuel', but is mistaken to declare that this is a 'prohibitive issue'. Hydrogen does indeed demand more onboard tankage than kerosene, but it also embodies a huge aeronautical advantage - it contains three times as much energy per unit of weight as kerosene. In other words, the weight saved in stored fuel can contribute to an increased passenger capacity.
Moreover, hydrogen-powered planes would not 'need much wider bodies than ordinary jetliners'. The basic configuration of such a machine has already been fixed through thousands of design hours spent - independently - over the last 30 years by Tupolev/DASA, Lockheed, Dornier and others."
My own guess is that we'll see more biodiesel being converted to jet fuel use before we see much in the way of hydrogen airships or aircraft.
If There is a God, He's Not Green. Otherwise Airships Would Take Off - Guardian (UK) - 06 May 08
"Hydrogen's great advantage - that it produces only water when it burns - turns into a major liability: in the stratosphere, water vapour is a powerful greenhouse gas. The commission estimates that hydrogen planes would exert a climate-changing effect 'some 13 times larger than for a standard kerosene-fuelled subsonic aircraft'. But there is another use for this gas, though I am aware that it will go down like a lead balloon with most of my readers. The word airship elicits a fixed reaction in almost everyone who hears it: 'What about the Hindenburg?'."
Airships Might Not Work, But Hydrogen Planes Could - Guardian (UK) - 16 May 08
"There is no question of a hydrogen-powered aircraft being 'filled with gas': it would carry its fuel in the ultra-cold liquid form. Monbiot is almost correct to observe that 'hydrogen contains just a quarter of the energy as the same volume of jet fuel', but is mistaken to declare that this is a 'prohibitive issue'. Hydrogen does indeed demand more onboard tankage than kerosene, but it also embodies a huge aeronautical advantage - it contains three times as much energy per unit of weight as kerosene. In other words, the weight saved in stored fuel can contribute to an increased passenger capacity.
Moreover, hydrogen-powered planes would not 'need much wider bodies than ordinary jetliners'. The basic configuration of such a machine has already been fixed through thousands of design hours spent - independently - over the last 30 years by Tupolev/DASA, Lockheed, Dornier and others."
