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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."
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? :)
I claim first use of "Error No. 0B" - or "No. 0B error." It'll be the new ID 10T!
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.
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
Never Politically Correct ~ I prefer the facts If you don't like what I say, get a life, or comment yourself.
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.