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US Army Pursues Hydrogen Fuel Concepts
securitas writes "According to GlobeTechnology/AP, the US Army is excited about the potential of hydrogen-powered tanks. The interest is the result of a technology demonstration that took place at Auburn University in December. Scientists have invented a process that removes the carbon and sulfur from hydrocarbon fuels like oil and gasoline. Hydrogen-powered vehicles could go three times farther than diesel-powered counterparts. DoD officials say 'it costs about $40 to move one gallon of diesel fuel from Kuwait to Baghdad.' The new process could let them take advantage of the existing oil industry infrastructure. Auburn University scientists 'realized there is already a lot of hydrogen in hydrocarbon fuel' and 'took jet fuel, which is very similar to diesel, and catalytically converted it, separating out the sulfur, carbon dioxide and carbon monoxide, and the fuel cell ran.' The Auburn team is now pursuing military funding."
they're not USING oil, the article states that a development such as this, whereas the military is actually investing in fuel-cell, would give it more hope and better results that it will take over the industry, in the long run
I guess one of the biggest prblems in H powered engines is how to store the hygrogen ... they are using oil here as the storage medium.
However I would have thought it rather defeats the point of switching to Hydrogen...
The giant barrier for fuel cells is, and has been, transportation and distribution of fuel. Pure hydrogen is enormously expensive to transport and store since it "leaks" out of most containers (the molecules fit through the walls or something equally frustrating). Strides were made with that (boron?) chemical storage, but it's still pretty labor intensive and would require a vastly different infrastructure. This, however, manages to use the existing system (for diesel fuel) for hydrogen cells. That's a giant breakthrough.
The article describes the technology as being "a four or a five" on a scale where 10 is production-level, so the whole thing is, to an extent, still vapourware. BUT, the transition path to hydrogren is so advantageous, I wouldn't be surprised if we were to see production examples of fuel-cell diesel trucks (apparently the tech works better with diesel...) in a few years domestically. First a transition for trucks, then a gradual increase in diesel/hydrogen fuel availability for the rest of America's car fleet, and finally a total switch to hydrogen tech. All without having to significantly rework the fossil fuel distribution network. This is the stuff of the future and I, for one, look forwards to it eagerly.
They're using a catalytic converter to draw the hydrogen out of readily available, pre-processed fuel -- probably still in the form of hydrocarbons instead of pure hydrogen. This is cheap. Seperating salt water into Hydrogen, Oxygen, Salt, and extraneous junk is expensive.
From the article:
Between this and Thermal Depolymerization, which can turn any organic material into oil, we're going to be in hog heaven. Who needs to import oil anymore? :)
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What releases energy in chemical combustion is making new chemical bonds which are lower energy (i.e. stronger) than the ones you have to break to start the reaction. In hydrocarbon burning you break the C-H bonds and form much stronger H-O and C=O bonds, releasing energy. So yes, the C does contribute energy, its just that the byproduct is CO2, a greenhouse gas.
To split any kind of water into H2 and O2 actually takes more energy than their recombination (burning H2 to produce H2O) provides. This is the principle of conservation of energy.
What this method has created is a cheap (energy-wise, and apparently, money-wise too) way of producing hydrogen, which can then combine with oxygen in the energy-producing burning reaction to produce water.
I claim first use of "Error No. 0B" - or "No. 0B error." It'll be the new ID 10T!
Any diesel car will happily run on kerosene without modification. You can even use a mixture of petrol and diesel in a diesel car. IANAC either but that would make me suspect that diesel, kerosene and petrol are all fairly close. IIRC kerosene is very close to jet fuel too.
Devices like this, known generally as "reformers", have beeen in use for a decade at least. They universally share the problem of leaking contaminents into the hydrogen output, where these stray molecules stick to the catalyst inside the fuel cell and slowly degrade it.
If this team has invented a new type of reformer, great, but as it stands the article is a joke.
Does it seem kind of backwards to be using Oil in the fuel cell process?
No that is the usual way of getting hydrogen. The other way involves getting it from water but that requires a great deal of energy - in fact, the same amount of energy that you get back when you turn it back into water in the fuel cell (really a fair bit more due to inefficiencies).
This is the problem with many alternative energy sources - they all sound good but there are always downsides that don't get much press. People talk about hydrogen like it's magic energy for free - but you have to GET the hydrogen from somewhere, either from oil, in which case we're back were we started. Or from water which takes more energy to process than you get from the fuel cell. At that point you can simply think of fuel cells as a type of battery. It's a way to store energy which must be produced in some other way.
You may be right about tanks, but there's no worry about regular cars, which normally use gasoline. If you try your little experiment with gasoline, you could well be headed for the hospital if you're not careful. And people drive around with enormous amounts of this stuff stored in their vehicles. Hydrogen is much less dangerous.
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Unfortunately, into the atmosphere it goes. The point of this process is not to reduce greenhouse gases or improve overall fuel efficiency. The point is that since tanks have a limited fuel space, they need to be able to stuff as much power as possible into themselves before leaving for a mission. H2 (apparently) has a 3:1 advantage over hydrocarbons in that regard.
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A hydrogen-powered military tank wouldn't make any more of a bang than a diesel powered tank. Heck, the Hindenberg, with an incredibly large volume of hydrogen held in an unsafe container, didn't even make a huge bang - it simply burned quickly, and there were may survivors. If you ever see the pictures, note that the metal tower next to the air ship wasn't even knocked down by the so-called "explosion".
Then again, hollywood often makes things "more exciting" than physical reality. I've seen lots of cars "blow up" in the movies. But for all the car fires I've seen, I've never seen a car explode. Or even heard of one exploding. Except in the movies and Grand Theft Auto.
Remember, most of Hollywood is based on entertainment, not science.
sulfur is good to use as organic fertiliser and for making low-grade explosives. It can also be used in some plastics and various chemical weapons.
Carbon can be used as fuel, in pencils, tennis raquets and as an additive to some metal alloys.
Actually, yes it did. The flame burned upwards, rather than out and down, napalm-like, as gasoline does. The heat was flaring away from the passenger compartment. Most of the people died from jumping from the airship when it was still too high from the ground. Those who kept their heads waited for the ship to drift to the ground, then hopped off and ran. They survived for the most part.
And, oh yes, the bright searing flame you see in the picture? It's the paint. It was basically thermite. Powdered metal. The company wanted pretty silver shiny skin. One electrical arc, and WHOOMP - hydrogen gets the blame.
And fuel cells fueled by gasoline or diesel are in no way more dangerous than a straight IC design! As a matter of fact, since you get more MPG, you can have a smaller tank of what is essentially napalm.
Hydrogen is not "dangerous" in the sense that gasoline is. Gasoline is heavy, adhears to surfaces, ignites easily when vaporized, burns outward in a mushrooming effect, and also is every vehicle in America - and is dispensed from gas pumps like it is as safe as water!
The process actually has many advantages for the Military and for civilians. But first people have to quit viewing hydrogen as a fuel and see it more like a battery that they charge up. It is not a Energy Source. It is an Energy Storage Media.
Working on such research myself for the USAF *yes military* I have learned a lot about what is going on. The process and demand for such changes is not exactly like what the media tend to report.
The reason we burn gasoline etc is to provide the Heat Catalyzed Hydrogen for conversion to Steam when reacted with Oxygen. While the carbon provides some energy it is really for running a Steam Engine. This cycle is limited thermally to about 38% efficient of the original energy in the steam. This is functionally further limited by other factors leaving current petrol engines about 25% to 28% efficient thermally.
The process for Cracking Hydrogen from fuel uses about 25% of the gross energy entering the process. Then the process of running a fuel cell drive eats another 15% (more or less) This leaves a potential thermal efficiency of a drive train at something close to 60%! This is more than double the current efficiency. Curiously this is not the military reason for doing this. It is but one fairly lessor factor. The military reasons for doing this have to do with issues of "Readiness" and "Dual Use."
If you have a tank that runs this way and you have no longer use for the tank if it runs on standard engines you have a very expensive item to leave just sitting around doing nothing. But if you drive the tank using Hydrogen and produce Electric energy to drive it, the tank can just plug in and become a "Generator" for many uses after battle is done. The savings to the military here by going to such systems is about a 4 to 1 ratio in machinery that they don't have to haul around. This coupled with increased milage etc makes the process very attractive
In Iraq this would have allowed us to just "Plug In" and have the electrical grid up and running. But this is hardly all. There are very big issues here on the weight of drive trains and also in issues such as stealth. Current engines would allow an enemy to hear the Soldiers coming for many miles.(often 20 or more miles) This system is very quiet.
This will spin off into civilian use. The technology is going to do many things. It will make cars which are profoundly less noisy. The technology also has pollution control issues. It is essentially a clean burn for the fuel.
There are other issues here that many people could hardly imagine. The storage of Hydrogen as a liquified gas, or compressed gas is essentially impossible for use in normal conditions. The losses of Hydrogen alone would kill the use. The natural solution is to store the Hydrogen as a Hydride. Much experimentation has been done with Hydrides. All solutions come back to the natural solution that Carbon Hydrides and essentially about 6 to 20 carbon Alcane chains (Gasoline Jet fuel etc) are just about the optimal solution.
What is going to develop will probably be that Gasoline or similar fuel will be made using either Coal for the Carbon or by Hydration of poor quality vegitable oils or vegitable mass like Hydrilla or Algea. This will provide the store for the Hydrogen that may in fact be made from the same process fairly directly. This can be SOLAR in energy source.
There are other features here that are most desirable. This provides a stable store which works with current technology. It is energy optimal. It is fairly clean and allows the addition of regenerative braking and other mechanisms.
This is more or less what is going on. Sorry for those who thought that gasoline was going away, it looks as though it is here to stay for a long time to come. Fuel Reformers (Crackers for Hydrogen) will just make you have a 50 Kg Primary Energy Converter insted of a 500 Kg one. You will no longer have brakes or a transmission. Your controls will be as simple as computer joysticks. The
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Don't worry nobody is violating the laws of thermodynamics. The difference comes from efficiency. Gasoline reciprocal engines are really not very efficient. Plus depending on the transmission you can loose 75% of your power output from the engine through the differential. Move the engine to the wheels and engine output == force at wheel plus you no longer need brakes as the engine can now be used as a brake. I have been tinkering for a while with a turbine generator driving the rear wheel of a 3 wheeled vehicle based exactly on this process, Currently I use diesel fuel but the idea could be done with hydrogen by changing the injection system and converting the blades to a ceramic rather than metal , and thats still using combustion! Diverting the hydrogen through a fuel cell should be even more efficient.
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Not at all. The technology to strip hydrogen atoms off of common hydrocarbons is really the big missing link in the idea of a hydrogen-based economy because it solves the the big problems:
1. How do we get hydrogen in the first place (without wasting energy)?
2.If our cars are hydrogen-powered, how do we distribute the hydrogen to them without rebuilding our infrastructure?
3. How do we store hydrogen in a way that doesn't take up a lot of space or weigh a lot.
How well the Auburn students' solution can address these problems depends on how small and cheap they can make the equipment that does the hydrocarbon->hydrogen conversion. The "holy grail" is to have a system so small that it will fit onboard a car so we won't have to make any modifications to the current fuel distribution infrastructure.
Using the hydrogen from hydrocarbons to directly make electricity will undoubtedly be much more efficient both because it eliminates all the wastefulness inherent in combustion and internal combustion engines, and because electricity can be used much more efficiently than mechanical energy, ie. you don't have to have your motor running continuously, you can use regenerative braking to recover some lost energy.
Finally, electrical engines are much cheaper to buy and maintain than internal combustion engines because they don't have to withstand the stress of thousands of explosions per minute that force dozens of parts to move at high speed.
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Likewise, you need to get energy from some source to drive the hydrogen production process. Hopefully you don't plan on getting that from fossil fuel sources, since they you have the power generation inefficiencies, plus the hydrogen production inefficiencies. Given how hard and expensive to transport the resulting product (hydrogen) is, if you're going to go through all the effort of transforming your energy source into something, you'd think you might want to make ethanol (which can be relatively efficiently produced from cellulose, which we really do have in renewable, limitless supply) that is cheap and easy to transport and adapt to our existing infrastructure.
We *should* be looking into efficient industrial-sized water electrolysis, or maybe some kind of thermolytic or photolytic process.
That's a great plan, except that the energy to do those things has to come from somewhere. It can't be hydrogen, because it would take more hydrogen than you are making to do it.
Um, the energy will come from heat or light, hence the terms "thermolytic" and "photolytic" in the post you replied to.
Moron.
Anyone who knows anything understands that water vapor is indeed a greenhouse gas and contributes more to the natural greenhouse effect than carbon dioxide does.
However, the concentration of water vapor in the atmosphere is very close to its saturation value, so excess water vapor will precipitate out quickly.
The saturation vapor pressure of carbon dioxide in the atmosphere is about 1000 PSI, so excess carbon dioxide introduced into the atmosphere will not precipitate. It must be removed by other processes (e.g., photosynthesis), which run a lot more slowly. Current estimates of the residence time of anthropogenic carbon in the atmosphere are around 60 years.
Other than this, your criticisms of hydrogen as fuel is right on target. I would only add that nuclear power looks like a very good source of power for industrial-scale electrolysis. This still wouldn't address the question of transporting hydrogen, though.
If you're lucky, you can use chemical catalysts to perform chemical changes on a substance while expending virtually no energy. That's what a catalytic converter does in a normal unleaded-fuel automobile.
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Since there are no wells of molecular hydrogen anywhere on the planet, hydrogen will *always* be only a storage medium, *never* a direct energy source
Err, well unless you count nuclear fussion. I suppose that's a little ways off though!
But the extraction-from-hydrocarbon method has got to go.
Have you got any other suggestions? There are only two widely available sources of hydrogen. The first is water, which is all well and good except that you only ever get out less energy than you put in (ie it's purely an energy transport mechanism, you still need a power plant to provide the electricity in the first place). The second widely available source of hydrogen is in hydrocarbons.
Of course, there are some advantages to getting power from hydrocarbons the fuel cell way instead of internal combustion engines. First off, the real big problem with current energy production is that burning hydrocarbons produces all kinds of sulpher dioxide, nitrogen monoxide/dioxide, etc. By separating out the hydrogen using a membrane you shouldn't get nearly as many of these emissions. Also, if the claim of 3x the efficiency is accurate than it would be a BIG bonus, though most numbers I've heard place the efficiency as being much lower. Finally, a fuel cell powered car would probably work better with regenerative breaking than what you get in current hybrid cars, since you would now just have an all-electrical system instead of a gas motor and an electrical motor. At the very least it should make things easier/cheaper than hybrids.
The nice thing about hydrogen is that you can make it from many different energy-producing processes and ship it fairly easily
Err, actually it's not all that easy to ship hydrogen. It's a gas, and a VERY light gas at that. You really need to compress it a whole lot before you can get any meaningful quantity. You also then have the problem of shipping a lot of highly compressed and highly combustable gas. In short, it's not easy at all. Storing is extremely troublesome for the same reasons. Shipping and storing fossil fuels is MUCH easier.
The wind, wave, and solar power installations that some think will save the world can easily drive an electrolytic converter, for example, and the only byproduct is oxygen
I love wind, solar, wave, etc. energy as much as the enxt guy, but lets face it, they aren't anywhere near capable of providing us with our CURRENT energy needs, let alone the SIGNIFICANTLY higher energy needs if we started doing electrolytic converters for all of our cars!
A 100% efficient solar panel gives you about 500-1000KW/km^2 during the day, and nothing at night. In North America we consume about 2KW of energy on average throughout the day.
So, let's take a near best-case scenario of putting solar panels on the equator, getting full-intensity (ie noon hour) sun for 12 hours a day, we're still talking about only being able to provide power to 500 people per km^2. For the United State's 270 million people, that works out to 540,000km^2, or about halfway between the size of California and Texas.
Of course, if we were to use real numbers, even with 100% effective solar panels you would need an area MUCH larger than the size of Texas to support out current energy needs.
Note that this isn't even starting to consider the HUGE extra burder to the power grid if we were to try and power all our cars by it like you're suggesting. Our total energy consumption is up around 7 or 8KW/person when you add in non-electrical energy sources (mainly internal combustion engines for vehicles, heating, etc.).
We know how to get hydrogen out of a lot of things (water, for instance, through electrolosys). Compressed hydrogen is a common commodity (you can buy a cylinder of it at your local welding supply, I believe). The hydrogen that filled the blimps, like the Hindenburg, was likely from compressed tankage on the ground for the main fill, then from smaller, more portable tanks while in flight.
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So, no, that tank won't go three times farther on H2 than on diesel. It will actually have only 1/3 the range.
As usual, distorted facts are reported on Slashdot as gospel.
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The problem with this approach is that it still gives off carbon dioxide. On the other hand, since it's three times more efficient than simply burning the fuel, it only gives off a third as much CO2 for a given amount of work. It may also reduce other unwanted by-products of burning, like carbon monoxide.
As other posters have pointed out, the alternative hydrogen storage methods currently available also have problems, such as high volume, high weight, high complexity, and so on.
Here is an excellent presentation I found on the subject of hydrogen storage:
(PDF:) Hydrogen. Fueling a Cleaner Future.
One of the most interesting alternatives mentioned in the paper was the use of carbon nanotubes to provide high-density hydrogen storage. Here is another article on that subject:
Singapore Physicists Report High Hydrogen Storage Capacities in Alkali-Doped Carbon Nanotubes