Hydrogen Fuel Cells instead of gas in the military.

[munky99999]

http://www.defenselink.mil/news/Mar2006/20060324_4605.html
What I am wondering is what is the position the Canadian forces are taking on this idea. It could definitely help save a good amount of money on the gas costs of our operations.

The question of the whole situation is if the fuel tanks were hit with a bullet, they would essentially explode like a bomb. Testing however had shown that the bullet enters into the tank and the hydrogen then simply evacuates out with no harm to the people or equipment.

The bigger question I have is “What if the bullet is an incendiary bullet?” Wouldn’t it then create an explosion?

Also I believe all the results are actually all classified.
http://www.highbeam.com/'s massive url.

The compressed hydrogen fuel is stored in Quantum's TriShield Type IV impact-resistant, 100% composite and carbon fiber storage tanks coupled with the company's in-tank regulators and sensors and shut-off valve to create the Fuel Storage Module (FSM). The FSM holds approximately 4.4 lb. of hydrogen at 5000 psig. The TriShield is designed so the external carbon fiber wrappings form a tough and very durable shell that should provide protection against bullets and shrapnel.

One of the standard tests performed on this type of fuel tanks is the bullet test to determine how the tank will perform should it be punctured. The goal is a tank that does not explode or shred, but releases its contents slowly. The TriShield tank passed all testing protocols, including the ability to withstand a 30 cal. round.

The TriShield design performed so effectively that the round fired did not damage the tank at all, and a 50 cal. round was required to penetrate the tank.

edit/ fixed the massive url

 

[Nemo888]

Gasoline is much better for the environment.

from The Hype about Hydrogen
Chapter 5, Key Elements of a Hydrogen-Based Transportation System

The book estimates the hydrogen fueling infrastructure could cost half a trillion U.S. dollars. Liquefying which would require 40% of the energy content of the hydrogen. Liquid hydrogen would evaporate at the rate of 4%/day. Just generating the electricity to liquefy 1 kg of hydrogen would release 8 to 9.5 kg of CO2 into the atmosphere. By comparison, burning a U.S. gallon of gasoline, which has a similar energy content, would release about 9 kg of CO2.

Compressing hydrogen to 10,000 psi (70 MPa) would require about 10% to 15% of its energy content, and take about 7 or 8 times as much volume as the same energy in a gasoline tank. At 8,000 psi (55 MPa), a pressure tank would cost $2100 per kilogram of hydrogen.

The book argues that the most cost effective method of hydrogen generation is from natural gas and generates CO2, which is a potent greenhouse gas. Furthermore, the electricity required to generate enough hydrogen to replace all the gasoline in the US would be more than all the electricity currently produced.

 

[munky99999]

I have actually never seen such critiques against hydrogen cell technology before. I’ll be shooting down to my chapters and see if they have this book.

The book estimates the hydrogen fueling infrastructure could cost half a trillion U.S. dollars.

The cost can be slowly incorporated over 5-10 years or however long. The big problem would be if they ignore the situation until the fossil fuels completely run out. Then they end up spending the money anyhow.

Just generating the electricity to liquefy 1 kg of hydrogen would release 8 to 9.5 kg of CO2 into the atmosphere. By comparison, burning a U.S. gallon of gasoline, which has a similar energy content, would release about 9 kg of CO2.

The difference is that the gasoline technology is basically set. The hydrogen cell technology is still in development and may become more efficient. As the DoD says, it may help to reduce gas costs.

Simply put I haven’t really studied the hydrogen cell technology. I don’t know if any of those #s are correct or not. Not to mention that my first link is from the USA department of defense. Certainly they have a clue what they are talking about.

The reason why they are looking for alternatives for fossil fuels is because fossil fuels are relatively dated. Perhaps the hydrogen cell technology will never make it cost less, but at least they will have a fuel source which isn’t going to die out.

 

[Nemo888]

I think electric cars(most batteries are 99% efficient), bio-diesel and ethanol are much more efficient. Even making oil from coal is better for the environment. But the technology will mature in time. I was talking about this yesterday to someone:

http://www.oilcrisis.com/hydrogen/
“in the conversion of electricity to hydrogen and back again, we are forced to admit a loss of more than HALF of the original electricity that we started with (some estimates put this loss considerably higher). Bearing this in mind, we are confronted with a very sobering fact: Of the number of generators needed to supply energy to this conversion process, less than half as many would be necessary if we never made the conversion to hydrogen in the first place! In a renewable context that is driven by solar and wind, this will effectively amount to sacrificing more than half of the photovoltaic panels or wind generators just to overcome the losses inherent in such a circuitous conversion scheme.”

“The analysis shows that an elemental "Hydrogen Economy" for road transport would have a low well-to-tank efficiency and hence a low environmental quality. In particular, if the electrical energy were generated in coal-fired power plants, the well-to-tank efficiency might fall below 20%. Even if the hydrogen were used in fuel cells, the overall energy efficiency would be comparable to that of steam engines in the early half of the 20th century, while the CO2 emissions would have significantly increased due to the growth of overall energy consumption.’

And take into account how are you going to put enough of the lightest element in the universe in a car to go more than 150 miles.

 

[munky99999]

Bio-diesel is usually mixed in with standard diesel; usually something like 5-15% area. Oil from coal also won’t last long. And laptop battery humvees won’t be moving very far.

While hydrogen cell might be wasteful at the present time, it may just be enough to help pinch off the fossil fuels and allow them to last slightly longer.

Now it’s bedtime and I can’t guarantee the quality of this post.

 

[Colin Parkinson]

Hydrogen is ok if you have oodles of free power to produce it and oil is expensive, hence the reason why Iceland is going to Hydrogen in a big way. It may find a role in power generation replacing smaller gensets in the field, but as Honda has made even baby gensets quiet, efficent and with less pollution they have an up hill battle.

I for one didn't cry a tear for Briggs and scrapiron when they lost most of the market to their ancient arm lenghtening devices.

 

[Kirkhill]

I am waiting for the day when somebody decides to dump on Iceland for reducing the Earth's Core Temperature by tapping into all that Geo-Thermal Energy.  And by the way does releasing geothermal energy increase or decrease Global Warming?  It seems to me it reduces the Core Temperature while increasing the Surface Temperature.  Is that a net gain, net loss or net-net even?

 

[GAP]

In Iceland they are taping into hot fissures. So if it's a fissure it is therefore a lost lamb to the core, therefore a zero sum game. 

 

[a_majoor]

Hydrogen is a difficult substance to work with. The energy density is quite low, and containing the stuff requires epic engineering challenges no matter if you use metal hydrates, high pressure tanks of compressed gas or cyrogenic liquids. Logistics troops won't apprieciate handling hydrogen in the field either.

Hydrocarbon fuels have high energy density, are liquid at sensible temperature ranges and are relatively non corrosive and non toxic, so can be handled without a great deal of difficulty. (If you don't believe me, think about what you are doing when you go to the self serve gas station.....).

Hydrocarbon fuels can also be utilized directly in a device called a Solid Oxide Fuel Cell (SOFC), so when the development challenges are overcome, we will have the ability to extract a far greater percentage of the energy contained in a hydrocarbon fuel than presently possible. Some estimates with combined cycle systems (the heat generated by the fuel cell is captured to recover more energy) is up to 70% recovery can be achieved, but even a 35% efficiency is more than double a current internal combustion engine.

 

[Kirkhill]

In Iceland they are taping into hot fissures. So if it's a fissure it is therefore a lost lamb to the core, therefore a zero sum game.   

Good point GAP but heat has to come from somewhere and go somewhere.  Maybe in the interests of humanity we should be asking the Icelanders to do their bit to reduce Global Warming in the ecosphere and insulate those fissures.  ;D

 

[GAP]

That's just begging a silly answer....but I'm too tired to start another water/fissure thread......although the thought of using TyVek and styrofoam insulation held together by gun tape....has me thinking.....no...noo......don't go there!!!    ;D

 

[exsemjingo]

Whatever else happens with alternative energy, military applications should be the last to give up gasoline.  Gas, Diesel, and Ethanol can be kept even in open containers if there is absolutely nothing else available.  Hydrogen, on the other hand, needs to be in an insulated, pressurized container.  The smallest leak would let all the gas float away, if it didn't explode upon escaping.
It's for a similar reason that tanks do not run on propane.

 

[chrisf]

The book estimates the hydrogen fueling infrastructure could cost half a trillion U.S. dollars. Liquefying which would require 40% of the energy content of the hydrogen. Liquid hydrogen would evaporate at the rate of 4%/day. Just generating the electricity to liquefy 1 kg of hydrogen would release 8 to 9.5 kg of CO2 into the atmosphere. By comparison, burning a U.S. gallon of gasoline, which has a similar energy content, would release about 9 kg of CO2.

I've never understood this argument... but I hear it so often... as it assumes that the power generated to produce the hydrogen is produced by burning fossil fuels... though I'm assuming (And I may stand to be wrong here) that the bulk of power produced, at least in North America is produced from Nuclear and Hydro stations... and with the ever rising cost of fossil fuels, the bunker C and diesel generators that remain will become less and less important soon...

 

[a_majoor]

How electrical energy is generated depends on where you are and what resources are available. Nuclear energy will get a rough ride whenever it is brought forward, the last commercial nuclear powerplants were licenced in the late 1970's, and even then many were never completed (the movie "The Abyss" was filmed in an abandoned containment structure that was flooded with water for the purpose). So called alternatives are "alternative" because they operate at the margins of the laws of physics (i.e. intermittent, low energy density, high proportion of energy recycled into process etc.)

For a breakdown of global electrical generation as of 2002, try this: http://www.penpals.la/world/factbook/fields/2045.html

In the mean time, logistical, engineering and practical requirments make liquid hydrocarbon fuels THE choice for mobile operations, and given the energy losses for breaking down hydrocarbons to get the hydrogen, they are also the the choice for stationary units as well. We can be clever and use different systems to extract the hydrocarbon energy (gasoline, diesel, turbine, steam, Solid Oxide Fuel Cells, magic), and what we use depends on things like how we need to extract the energy (i.e. mechanical energy, electrical energy, thermal energy), so there is no "one size fits all" solution.

 

[chrisf]

As I suspected, after looking at the world fact book, it seems the bulk of the world's power is generated by Hydro, Nuclear, and "other" means, not by hydro-carbons...

Which begs the question where the statistic concerning burning fossil fuels to feed fuel cells keeps coming from...

 

[a_majoor]

There seems to be a terminology error here:

Which begs the question where the statistic concerning burning fossil fuels to feed fuel cells keeps coming from...

Fuel cells by themselves consume some sort of fuel in an electrochemical reaction to generate electricity. The source of your confusion, I think, is that hydrogen fuel cells (like the Ballard Systems PEM used in buses) require hydrogen as the fuel, and so electrical energy has to be used to break down the natural gas (most common process to get industrial hydrogen) or water to extract the hydrogen. Since a fairly large proportion of electrical energy in the United States comes from coal fired thermal plants (fossil fuel: 71%), the writers make the natural assumption that getting hydrogen in the United States required the burning of coal.

SOFC's can get around the problem by consuming hydrocarbon fuels directly. Current devices run very hot (10000C) and need to be warmed up slowly to operating temperature so they don't crack or shatter (a big disadvantage in vehicle applications), so most development is in the area of stationary generators. The ability to utilize the waste heat is also simpler with a stationary device, you can treat it as a boiler and add a steam turbine downstream, mass and size would make this a bit unwieldy in a car or truck.

 

[exsemjingo]

As I suspected, after looking at the world fact book, it seems the bulk of the world's power is generated by Hydro, Nuclear, and "other" means, not by hydro-carbons...

Which begs the question where the statistic concerning burning fossil fuels to feed fuel cells keeps coming from...

Begging is a type of asking, so thanks for doing it.  Industrial Hydrogen is usually made from methane, aka natural gas.  Since natural gas burns by itself, why use this Hydrogen for fuel?  Once in a while you may see a "natural gas vehicle", but these have not been an economical alternative for at least 10 years.
Hydrogen can be made from water, but at 100% efficiency the energy used in production is exactly equal to the energy available in it's use.  Gasoline is expensive enough as it is, though it's energy margins are far more favorable.
In short, I can see the day hydrogen is used as fuel, but it is the same day when most people can no longer afford to drive.

 

[eerickso]

I find the arguments against hydrogen fuel cells in this article very weak:

http://www.sfu.ca/casr/ft-winz1.htm

Hydrogen can easily be stored outside the pressure hull so I don't think energy per volume is a large issue. Energy per weight is not an issue since tonnes of water are needed to make a sub neutrally bouyant.

If the apollo missions found the weight and volume acceptable, I think that submarines should be okay with it?

I was wondering if an onboard electrolysis machine would be feasible so that they could "plug-in" at foriegn ports"?

Furthermore, hydrogen fuel cells are completely silent. This is an accepted FACT.

 

[Simon]

My company manufactures a super capacitor charger (SCC) for a forklift fuel cell manufacturer. This is required if the fuel cell is allowed to run dry. This shuts down the fuel cell and just adding fuel (hydrogen) wont help. The cell requires a boost by building up a charge in the super capacitors. This means there needs to be another source of electricity nearby.

The super caps are there to store energy so that when the device calls for more energy than the fuel cell can provide the super caps provide that additional energy. They are also there to provide the starting energy for the fuel cell. A good example is a forklift picking its load and accelerating forward at the same time.
Im not sure that it would be appropriate to use this technology in a forward position given these limitations.

 

[eerickso]

I agree. I don't see any addtional advantages to replacing terrestrial diesel generators with fuel cells.

I think fuel cells are a winner in the Navy because:

They eliminate the need to surface in order to convert one form of energy into another.
They eliminate noise signature.
They reduce IR signature.

I agree that fuel cells are weak in the power area (nothing is comparable to a capacitor for power)

I am not a submariner, but isn't it true that 99% of the time, subs are generally creeping around when submerged.

Maybe they can have capacitors/batteries for the 1% of the time that they need some serious muscle?