Why all the excitement of fuel-cell vehicles?

[silverpig]

Originally posted by: h2powerman

And hydrogen, whether compressed or not is always a fire hazard. Sure there's no oxygen in the tank, but there's a whole ton of it in the air we breathe. Get a leak in the tank or lines, and a spark and you're fvcked.

Actually this isn't entirely true. Hydrogen is a flamable gas and should be treated with respect. This said many of the tanks that are legal by DOT have been installed with internal and exterior valves, some even with flame arestors built in which in both cases help to prevent the tank from igniting or exploding, even in the case of a upside down vehicle. All tanks that are DOT certified also have static charge grounding devices for the tanks. So as you can see even with the high pressure, the natural ability that h2 has of being safe, it is nice to have multiple redundancy to keep the public from hurting themselves. Myself included. []

For more information please check out www.ahanw.org. Thanks!

They don't put multiple redundant safety systems on things that AREN'T dangerous... When was the last time you saw safety valves, plexiglass, and a warning sign around a banana? Just because there are safety mechanisms in place doesn't make hydrogen any less flammable.

 

[h2powerman]

Originally posted by: silverpig

Originally posted by: h2powerman

And hydrogen, whether compressed or not is always a fire hazard. Sure there's no oxygen in the tank, but there's a whole ton of it in the air we breathe. Get a leak in the tank or lines, and a spark and you're fvcked.

Actually this isn't entirely true. Hydrogen is a flamable gas and should be treated with respect. This said many of the tanks that are legal by DOT have been installed with internal and exterior valves, some even with flame arestors built in which in both cases help to prevent the tank from igniting or exploding, even in the case of a upside down vehicle. All tanks that are DOT certified also have static charge grounding devices for the tanks. So as you can see even with the high pressure, the natural ability that h2 has of being safe, it is nice to have multiple redundancy to keep the public from hurting themselves. Myself included. []

For more information please check out www.ahanw.org. Thanks!

They don't put multiple redundant safety systems on things that AREN'T dangerous... When was the last time you saw safety valves, plexiglass, and a warning sign around a banana? Just because there are safety mechanisms in place doesn't make hydrogen any less flammable.

I didn't say that it is any less flammable. The reason there are as many safety mechanisms are because of the fear of hydrogen, this fear should be no more than any other conventional fuel, but it isn?t, because isn?t in their face everyday. Hydrogen can be dangerous along with any fuel if you don't treat it correctly. I have seen people shooting propane bottles for the hell of it, or blowing things up with gasoline and diesel. There are regulations with these fuels to help people who respect them, having more safety systems doesn?t make a fuel more or less dangerous.
As for a bannana there are safety issues with that too when you deal with importing and exporting. But I understand your point, but fuels any fuel shouldn't be treated as food or clothing in general.

 

[Chaotic42]

Originally posted by: spyordie007
ugg, somebody just pointed out to me that the contest was posted to an area on our forums that was not publicly accessable. I've fixed it so you guys can get to it.

-Erik

I sent off my banner application. It was something fun to do to kill the time.

 

[spyordie007]

FCs are much simpler to make than an IC engine. They are just a stack of repeating components.

I dont know that I would say they are simpler to make (a PEM is after all a fairly complex component) but the basic operation is certainly simpler (and no moving parts!)

The neat thing about the way they can be stacked is that they can be fit into virtually unlimited space configurations. GM has a fuel-cell concept platform that simply has a 3" thick floor and the fuel-cell spans the entire length of the vehicle, they than stuck 4 small electric motors on each wheel and the drive components take virtually none of your body space (plus it gives them a lower center of gravity).

They don't put multiple redundant safety systems on things that AREN'T dangerous... When was the last time you saw safety valves, plexiglass, and a warning sign around a banana? Just because there are safety mechanisms in place doesn't make hydrogen any less flammable.

Any energy storage mechanism is going to have it's safety concerns. Whether it be chemically, electrically, or kineticly stored it's always important to follow carefull safety guidelines; especially as the amount of energy increases.

Hydrogen is flammable and that very fact poses a safety concern, I dont there there is anyone here suggesting otherwise. It is our belief (the AHANW) that hydrogen can be made one of the safest storage mechanisms for energy.

And hydrogen, whether compressed or not is always a fire hazard. Sure there's no oxygen in the tank, but there's a whole ton of it in the air we breathe. Get a leak in the tank or lines, and a spark and you're fvcked.

something I would like to add for this, if there is a spark or flame located at the source of a leak *nothing* will happen since the mixture is too rich (in the case of a flame it's generally extinguished as the compressed gas will cut off oxygen to the flame source). The spark or flame source would need to be located at a point where the hydrogen has mixed with sufficient oxygen to become flamable, as I said before generally your hydrogen gas will have dissapated well into the atmosphere by than (assuming adequate ventilation, but than again you wouldn't want to have anything burn without ventilation).

-Erik

 

[spyordie007]

Well if a fuel cell exploded you would likely be vaporized in a instant. But if a gas tank exploded you have a higher chance of burning alive in a horrible grizzly death.

Oh I missed this, vaporized? Do you think a fuel cell is some kind of hydrogen bomb or something? Generally speaking if a fuel-cell were to rupture you would be just fine.

Here is a good article about an experiment the university of miami did on a couple of cars, one hydrogen and the other gasoline. See how they both fared under fire:
http://evworld.com/view.cfm?section=article&storyid=482

-Erik

 

[Regs]

lol, just trying to lighten up the argument a little. If fuel cells cost less than gas, im all for it. 25 dollars it took me to fill up my tank for a week.

 

[Lizardman]

Fuel cell fuel will probably cost the same or more than gas. But there is no way to tell untill there are mass stations to produce H2.

 

[Atrail]

I don't know anyone who is really "excited" about fuel-cell vehicles.

 

[CTho9305]

Interesting article, Erik. The question of a rupture remains. Gasoline tanks tend not to explode, because liquids don't burn as fast as gases... whereas I've seen demos with hydrogen balloons, and even pure hydrogen mixes with oxygen fast enough to produce quite a bang. Show me the 30+ mph crash tests, then I'll believe .

 

[PingSpike]

Originally posted by: Atrail
I don't know anyone who is really "excited" about fuel-cell vehicles.

I am. Well, any hydrogen fueled vehicle really. This thread was very informative about the capabilities of hydrogen fuel.

I really think this country needs to get its ass in gear and start moving away from our huge dependence on foriegn oil. It stands to cripple us. Since hydrogen can essentially be harvasted from water, it really has potential. Sure it might be a costly process now, but with a little research and time it could be made reasonable. Economies of scale...when you're just doing it in a lab somewhere its going to cost a lot more than if you built a whole facility whose purpose was to make it.

Like has been said, more important than IC hydrogen engines versus fuel cells is getting the infrastructure in place. That is the real challenge IMO.

 

[B00ne]

The answer to your questions are easy: First has to do with erroneous assumption that fuel cells are inefficient. Right now they are abouttwice as efficient as gasoline engines.
Second burning hydrogen will inevitably produce NOx since hydrogen burns hotter than gasoline probably more so than a conventional engine.

Now combine half efficiency of the gasoline varient with the low energy density (per volume) of hydrogen (even in liquid state) u would have cars that still produce large amounts of pollutants and have a awful low range

 

[Lizardman]

Originally posted by: B00ne
The answer to your questions are easy: First has to do with erroneous assumption that fuel cells are inefficient. Right now they are abouttwice as efficient as gasoline engines.
Second burning hydrogen will inevitably produce NOx since hydrogen burns hotter than gasoline probably more so than a conventional engine.

Now combine half efficiency of the gasoline varient with the low energy density (per volume) of hydrogen (even in liquid state) u would have cars that still produce large amounts of pollutants and have a awful low range

There are buses today that use FCs as there power source. They just fuel back up when they get back to the bus depot. If a bus can drive around all day on one tank of fuel then I wouldn't consider that an awful range.

You are correct about the low energy density of H2, but there are other methods of harvesting the H2 that may prove more efficient such as using a direct methanol FC. Right now DMFC are ideal for portable electronics becuase of there high energy density, but low power. (DMFCs only gives off H20 and C02 as biproducts) I just mentioned this to give as an example of that fact that there are other options besides just using compressed H2 for power.

I am not sure when you mean when you say burning H2 produces NOx since I thought we were talking about FCs and not using H2 in an IC engine. A typical FC that would be used for a car produces no pollution.

 

[B00ne]

Yeah fuel cell buses but I was talking cars that have hydrogen powered combustion engines would have a low range because of their low efficiecy (unless they have hug tanks)

No the original poster was saying that fuel cells are not good and hydrogen powered IC would be the way to go - I was merely pointing out that fuel cells are the better solution....

 

[Lizardman]

Originally posted by: B00ne
Yeah fuel cell buses but I was talking cars that have hydrogen powered combustion engines would have a low range because of their low efficiecy (unless they have hug tanks)

No the original poster was saying that fuel cells are not good and hydrogen powered IC would be the way to go - I was merely pointing out that fuel cells are the better solution....

Oh ok, sorry just misunderstood your statement.


A safety comment. H2 and Methanol are safer to use than gasoline. I did some research and they have lower auto ingntion temperatures and their flamability limit is safer than gas.

If a tank of hydrogen ruptured in a car it would simply float away since it is lighter than air, with gas it just stays at the scene waiting for a spark to hit and ignite it.