Hydrogen as an aircraft fuel source ?
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Hydrogen as an aircraft fuel source ?
Been a couple of hydrogen posts about so thought I'd start a thread...
Possible problems:
- The weight of the fuel tank may be the limitation.
- Corrosive nature of the fuel.
- Why bother. When natural oil runs out we can still make avgas/jet out of coal or methane hydrates or even out of the air with solar panel power.
- ?
.
Possible problems:
- The weight of the fuel tank may be the limitation.
- Corrosive nature of the fuel.
- Why bother. When natural oil runs out we can still make avgas/jet out of coal or methane hydrates or even out of the air with solar panel power.
- ?
.
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Okaaay Binghi I'll bite.
ARE WE USING THE WRONG GAS ?
1. Wouldn’t it be wonderful if Australian scientists unlocked a product that would earn huge export dollars and create tens of thousands of Australian jobs? Better still if this product could provide cheap sustainable clean energy forever? (i)
2. But wait there’s more. What if it could prevent the closure of the Curtis Island LNG plants, keep many power stations economically operational, utilise megatons of flood waters, and re-invigorate towns hit hard as coal mines close? Just a dream? Not at all.
3. Just as science is telling us of the devastating damage that coal and gas burning is wreaking on our biosphere, science has made a breakthrough which if developed will allow us to affordably use the cleanest fuel known to man.
4. Hydrogen (H2) is often described as the ultimate clean fuel. The only emission arising from the use of Hydrogen is water. You can also manufacture H2 completely renewably. (ii)
5. The major problem with H2 is storage and transportation. It has very small molecules which leak out of hoses and containers, as well as making metals brittle and thereby weakening them. H2 requires a lot of energy to compress or to liquefy it down to a useful energy-dense volume.
6. Chemical engineers have long known that Ammonia (NH3) contains a high density of H2. It actually has greater H2 density by volume than liquid H2. Ammonia becomes a liquid at -33⁰C at normal atmospheric pressure. Compare that with LNG at -160⁰C, and liquid H2 at -253⁰C. So comparatively ammonia is easy to liquefy and store. (iii)
7. Ammonia is the second most manufactured chemical in the world, after sulphuric acid, with some 200 million tons being manufactured each year. Obviously world-wide its storage and transportation is well understood. Internal combustion engines with modification can use ammonia directly as a fuel, and indeed it was used with liquid oxygen to power the X15, the fastest aircraft ever built at 7,274 kph. (iv)
8. However, it is the ability to transport hydrogen economically in the form of liquid ammonia, by road, rail, sea, or pipeline, that has long held the interest of scientists. Separating H2 from NH3 economically has been a difficult problem until a recent discovery by Australia’s CSIRO scientists. (v) They have developed a metal mesh so fine that once ammonia disassociates at about 430⁰C it allows the tiny H2 molecules through but not the larger Nitrogen ones. The N2 can be released or retained as desired, and the H2 used as a fuel. The separation could be done at the point of H2 sale, or as technology improves, on board the vehicle using the H2.
9. The most efficient way of using the H2 to power a vehicle would be in a fuel cell, resulting in more than double the efficiency of internal combustion engines. However, with little modification current internal combustion engines can use ammonia as a fuel without separating it into its components. This would allow today’s vehicles to continue in use until new fuel cell vehicles become readily available. (vi)
SO HOW WOULD IT WORK IN PRACTICE IN GLADSTONE OR THE REST OF AUSTRALIA? (vii)
10. Clean energy (e.g. wave, wind, hydro, photovoltaic, fusion) would make electricity to supply normal daily needs. Any excess electricity would be sent to a plant to manufacture ammonia. This field is rapidly evolving and would involve scientists selecting the most cost-effective way of making NH3. The Haber Bosch method appears to have been replaced by solid state electrochemical synthesis of ammonia. (viii) Part of this new technology is already in use on Curtis island to extract Nitrogen from air.
11. The ammonia would then be piped to Curtis Is LNG plant (probably standing idle due to gas shortage and world-wide court action (ix)). Here it is liquefied at an easy -33⁰C reducing its volume to 1/850. From Curtis Is the ammonia would be piped or trucked to wherever it is needed in Australia. It would be used to fire gas-powered base load power stations in small towns where it is not economical to connect to the grid.
Major previously coal powered stations could be converted to ammonia or H2. All the electrical distribution system could then stay in place. The only emissions from this process are water and nitrogen.
12. Ships previously built to carry LNG could transport surplus ammonia to overseas countries not as blessed as Australia with sun and wind.
13. If we move rapidly to an ammonia economy we could be world leaders in clean energy supply and technology. Australia more than most countries has abundant sunshine and wind. In producing ammonia we would have an endless supply of a sought-after product. With ammonia as an energy carrier we would be selling our wind and sunshine to the world.
14. All that is required now is for the politicians to publicly acknowledge the dangerous nature of burning fossil fuels (i) (ii), and to explain to the public that there is a way we can produce unlimited clean energy while at the same time boosting jobs and overseas exports.
15. As a forward-thinking person are you willing to consider new ideas?
The current Federal Government is considering spending billions on a new coal-fired power station which at best will still put out more than half the CO2 of current coal-fired power stations.
16. Why not put that money into a clean, reliable, renewable, affordable job rich energy future?
ARE WE USING THE WRONG GAS ?
1. Wouldn’t it be wonderful if Australian scientists unlocked a product that would earn huge export dollars and create tens of thousands of Australian jobs? Better still if this product could provide cheap sustainable clean energy forever? (i)
2. But wait there’s more. What if it could prevent the closure of the Curtis Island LNG plants, keep many power stations economically operational, utilise megatons of flood waters, and re-invigorate towns hit hard as coal mines close? Just a dream? Not at all.
3. Just as science is telling us of the devastating damage that coal and gas burning is wreaking on our biosphere, science has made a breakthrough which if developed will allow us to affordably use the cleanest fuel known to man.
4. Hydrogen (H2) is often described as the ultimate clean fuel. The only emission arising from the use of Hydrogen is water. You can also manufacture H2 completely renewably. (ii)
5. The major problem with H2 is storage and transportation. It has very small molecules which leak out of hoses and containers, as well as making metals brittle and thereby weakening them. H2 requires a lot of energy to compress or to liquefy it down to a useful energy-dense volume.
6. Chemical engineers have long known that Ammonia (NH3) contains a high density of H2. It actually has greater H2 density by volume than liquid H2. Ammonia becomes a liquid at -33⁰C at normal atmospheric pressure. Compare that with LNG at -160⁰C, and liquid H2 at -253⁰C. So comparatively ammonia is easy to liquefy and store. (iii)
7. Ammonia is the second most manufactured chemical in the world, after sulphuric acid, with some 200 million tons being manufactured each year. Obviously world-wide its storage and transportation is well understood. Internal combustion engines with modification can use ammonia directly as a fuel, and indeed it was used with liquid oxygen to power the X15, the fastest aircraft ever built at 7,274 kph. (iv)
8. However, it is the ability to transport hydrogen economically in the form of liquid ammonia, by road, rail, sea, or pipeline, that has long held the interest of scientists. Separating H2 from NH3 economically has been a difficult problem until a recent discovery by Australia’s CSIRO scientists. (v) They have developed a metal mesh so fine that once ammonia disassociates at about 430⁰C it allows the tiny H2 molecules through but not the larger Nitrogen ones. The N2 can be released or retained as desired, and the H2 used as a fuel. The separation could be done at the point of H2 sale, or as technology improves, on board the vehicle using the H2.
9. The most efficient way of using the H2 to power a vehicle would be in a fuel cell, resulting in more than double the efficiency of internal combustion engines. However, with little modification current internal combustion engines can use ammonia as a fuel without separating it into its components. This would allow today’s vehicles to continue in use until new fuel cell vehicles become readily available. (vi)
SO HOW WOULD IT WORK IN PRACTICE IN GLADSTONE OR THE REST OF AUSTRALIA? (vii)
10. Clean energy (e.g. wave, wind, hydro, photovoltaic, fusion) would make electricity to supply normal daily needs. Any excess electricity would be sent to a plant to manufacture ammonia. This field is rapidly evolving and would involve scientists selecting the most cost-effective way of making NH3. The Haber Bosch method appears to have been replaced by solid state electrochemical synthesis of ammonia. (viii) Part of this new technology is already in use on Curtis island to extract Nitrogen from air.
11. The ammonia would then be piped to Curtis Is LNG plant (probably standing idle due to gas shortage and world-wide court action (ix)). Here it is liquefied at an easy -33⁰C reducing its volume to 1/850. From Curtis Is the ammonia would be piped or trucked to wherever it is needed in Australia. It would be used to fire gas-powered base load power stations in small towns where it is not economical to connect to the grid.
Major previously coal powered stations could be converted to ammonia or H2. All the electrical distribution system could then stay in place. The only emissions from this process are water and nitrogen.
12. Ships previously built to carry LNG could transport surplus ammonia to overseas countries not as blessed as Australia with sun and wind.
13. If we move rapidly to an ammonia economy we could be world leaders in clean energy supply and technology. Australia more than most countries has abundant sunshine and wind. In producing ammonia we would have an endless supply of a sought-after product. With ammonia as an energy carrier we would be selling our wind and sunshine to the world.
14. All that is required now is for the politicians to publicly acknowledge the dangerous nature of burning fossil fuels (i) (ii), and to explain to the public that there is a way we can produce unlimited clean energy while at the same time boosting jobs and overseas exports.
15. As a forward-thinking person are you willing to consider new ideas?
The current Federal Government is considering spending billions on a new coal-fired power station which at best will still put out more than half the CO2 of current coal-fired power stations.
16. Why not put that money into a clean, reliable, renewable, affordable job rich energy future?
Moderator
https://en.wikipedia.org/wiki/Hydrogen-powered_aircraft
I vaguely recall a Lockheed (?) hydrogen powered aircraft design concept maybe 40 years ago, that never got beyond the design stage.
I vaguely recall a Lockheed (?) hydrogen powered aircraft design concept maybe 40 years ago, that never got beyond the design stage.
Hydrogen is not a fuel source as such - although it can be used as an energy storage medium (basically a very good battery). So for starters you'll still need an energy source to create the H2. Today, the cheapest and most efficient way - by far - to create H2 is to take natural gas and strip off the carbon. So much for being carbon neutral (with current technology).
If we assume that we have a large source of environmentally friendly energy - windmills, solar, pixie dust, whatever - we still need an efficient method of creating H2 from that energy source. Electrolysis works, but with current technology is very inefficient - so either we need a breakthrough that makes large scale electrolysis efficient and viable, or a new technology to turn energy into H2.
OK, so we've solved that and we have large sources of H2 available. While H2 has great energy density per unit weight, it's horrible per unit volume. So we either need to compress it to a thousands of PSI, or cool it to cryogenic temperatures so it's a liquid, and even then it's density per volume is a small fraction of Jet A. So to give an aircraft reasonable range, we need a massive fuel tank that has to be able to handle very high pressures and/or very low temperatures (read HEAVY and EXPENSIVE) Such a fuel tank isn't going to fit in the wing like what we do today with Jet A - to be even remotely efficient it needs to be round or cylindrical - the obvious answer being to put in the fuselage (you know, the same place where the payload goes today).
So, what we have is an aircraft that is expensive to build, expensive to fuel, can't fly very far, and can't carry very much, and isn't remotely viable given current technology.
OR, you can grow algae and use it to make biofuel Jet A which done properly is basically carbon neutral, using technology that exists today, works in today's aircraft and is already being used on a small scale, and is already approaching being cost effective compared to fossil fuels.
If we assume that we have a large source of environmentally friendly energy - windmills, solar, pixie dust, whatever - we still need an efficient method of creating H2 from that energy source. Electrolysis works, but with current technology is very inefficient - so either we need a breakthrough that makes large scale electrolysis efficient and viable, or a new technology to turn energy into H2.
OK, so we've solved that and we have large sources of H2 available. While H2 has great energy density per unit weight, it's horrible per unit volume. So we either need to compress it to a thousands of PSI, or cool it to cryogenic temperatures so it's a liquid, and even then it's density per volume is a small fraction of Jet A. So to give an aircraft reasonable range, we need a massive fuel tank that has to be able to handle very high pressures and/or very low temperatures (read HEAVY and EXPENSIVE) Such a fuel tank isn't going to fit in the wing like what we do today with Jet A - to be even remotely efficient it needs to be round or cylindrical - the obvious answer being to put in the fuselage (you know, the same place where the payload goes today).
So, what we have is an aircraft that is expensive to build, expensive to fuel, can't fly very far, and can't carry very much, and isn't remotely viable given current technology.
OR, you can grow algae and use it to make biofuel Jet A which done properly is basically carbon neutral, using technology that exists today, works in today's aircraft and is already being used on a small scale, and is already approaching being cost effective compared to fossil fuels.
rutan, the only problem with ammonia is that it is classified in some jurisdictions as an extremely hazardous substance, and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities. It's dangerous stuff.
That was the Lockheed CL-400 Suntan Tailwheel. A study which lead to the SR-71.
That was the Lockheed CL-400 Suntan Tailwheel. A study which lead to the SR-71.
But I agree that the stuff is still too bulky and problematic to be a practicable alternative to AvTur [etc].
PDR
lethally stupid debate until an efficient way of storing hydrogen is discovered. energy density in terms of kw/cm3 is the defining metric. on that basis liquid petroleum based fuels win hands down. Ammonia? toxic.
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Why would we use ammonia which is highly toxic and liable to produce NOx when burnt at high temperature, when we could produce methane using the same excess electricity?
(iii) https://nh3fuelassociation.org/comparisons/
Methane WTF? The whole idea of going to a Hydrogen / Ammonia economy is to stop putting greenhouse gasses into the atmosphere.
Ammonia is toxic but is not carcinogenic like gasoline and is much harder to ignite than either gasoline or methane. 200 million tons of it are made worldwide per year with a good safety record. Don't confuse it with ammonium nitrate.
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energy density in terms of kw/cm3 is the defining metric. on that basis liquid petroleum based fuels win hands down. Ammonia? toxic.
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and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities. It's dangerous stuff.
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Storage and safety of those in close proximity of both hydrogen and ammonia are serious issues. How do you protect the driver and pax if something goes wrong?
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Storage and safety of those in close proximity of both hydrogen and ammonia are serious issues. How do you protect the driver and pax if something goes wrong?
rutan is hopelessly ignorant of the logistics (distribution) of new energy media. they aren't easy to employ. care to think for example of driving an electric car outside major cities?
The Skunk Works investigated a Hydrogen-fuelled aircraft decades ago and came to the conclusion the thing would be mostly a vast flying fuel-tank if it were to have any decent range or capability. They abandoned it.
The technology today is the same as it was then as far as liquifying and storing Hydrogen is concerned. Apart from the size of the "flying fuel-tank" needed to carry it, the fuel itself is still just too damn dangerous and too dam hard to distribute and handle in any significant quantity for it to be feasible or economical.
If the Skunk Works says it's a dud - trust me, it's a dud. Read "Skunk Works" by Ben Rich and Leo Janos for the full story.
The technology today is the same as it was then as far as liquifying and storing Hydrogen is concerned. Apart from the size of the "flying fuel-tank" needed to carry it, the fuel itself is still just too damn dangerous and too dam hard to distribute and handle in any significant quantity for it to be feasible or economical.
If the Skunk Works says it's a dud - trust me, it's a dud. Read "Skunk Works" by Ben Rich and Leo Janos for the full story.
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rutan is hopelessly ignorant of the logistics (distribution) of new energy media.
1 Recognize and accept that there is a problem. (man made climate change)
2 Stop heading in the wrong direction. No NEW fossil fuel plants.
3 Engage the best and brightest scientific minds across all disciplines to determine the best way forward. ( Note it's scientific minds - not political or fact free shock jocks)
4 Immediately commence infrastructure work on the best pollution free solution or mix of solutions the scientists recommend.
5 Be flexible in adopting new and better energy plans if new discoveries are made and recognize that changing to a new energy source cannot happen overnight.
6 Any new system should be as much as possible fungible with the old one.
These are some reasons I'm advocating a hydrogen / ammonia economy. I would happily throw my support behind a better system if anyone has one.
Requirements for an ideal form of energy.
Must be:
1. Non-polluting
2. Storable, transportable, available on demand
3. Sustainable forever, or at least until a superior replacement is found.
4. Reasonably energy dense
Problems with our current energy sources:
1. Carbon based fuels are finite but long before they run out their pollution will have rendered the earth unfit for human and other life
2. Electrical energy from any source including renewables is difficult to store and not ideal for transporting or use in transport vehicles.
3. Hydrogen, sometimes referred to as the ultimate clean fuel, is difficult to store and to transport in its pure form.
A Promising solution to the above requirements and problems.
AMMONIA NH3
8 things I’ve learned about ammonia.
1. It is the second most manufactured chemical in the world – 200 million tons per annum.
2. It liquifies at a surprisingly high temperature, at -33⁰C. The lowest ever Antarctic temperature recorded was -94.7⁰C.
3. By volume, liquid ammonia is more hydrogen dense than liquid hydrogen, thereby making it an excellent transport and storage medium for H2.
4. Internal combustion engines can run on NH3 and were in WW2 in some places eg Belgium. Emissions are pure water and Nitrogen. Prototype NH3 cars have recently been built in South Korea and Japan.
5. Australia’s CSIRO recently invented a metal mesh so fine that it can economically separate H2 molecules from N2 molecules, thus making fuel cell hydrogen cars more viable.
6. Numerous parts of the world already have large distribution systems for ammonia.
7. Burnt NH3 produces no greenhouse gases.
8. Internal combustion engines can use up to 50:1 compression ratio when using ammonia.
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Burning carbon based fuels isn't a problem if you're synthesizing it from atmospheric sources. Carbon neutral.
rutan, the "scientific minds" you posit are a waste of time and money. i speak from experience.
consider the logistics of designing and constructing distribution centres and fuelling stations capable of allowing mother to refuel her car with liquid ammonia (with a baby in the back seat). then think about the safety precautions necessary for fire brigades to handle a car crash. Gaseous Ammonia is effing toxic! liquid ammonia more so.
consider first the logistics of electric car recharging at service stations on the hume highway when current recharge times are of the order of 45 minutes minimum. then consider the electricity grid feeding that network of service stations.
to put it another way; someone tell i'm e's dreaming.
consider the logistics of designing and constructing distribution centres and fuelling stations capable of allowing mother to refuel her car with liquid ammonia (with a baby in the back seat). then think about the safety precautions necessary for fire brigades to handle a car crash. Gaseous Ammonia is effing toxic! liquid ammonia more so.
consider first the logistics of electric car recharging at service stations on the hume highway when current recharge times are of the order of 45 minutes minimum. then consider the electricity grid feeding that network of service stations.
to put it another way; someone tell i'm e's dreaming.
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https://www.google.com.au/search?q=h...w=1336&bih=580
If they can do explosive hydrogen safely why not ammonia? The lass in the photo didn't look too stressed.
If they can do explosive hydrogen safely why not ammonia? The lass in the photo didn't look too stressed.