solving the problem of hydrogen powered cars?

[NonTechGuy]

hydrogen would make the ultimate fuel with lots of power and literaly no hazardous biproduct but the big problem plagueing this thought is the fact that hydrogen can actually leak through solid steel containers.

you guys are the elite of the learned, any ideas on how this problem could be solved?

 

[dkozloski]

The leakage is VERY small and only becomes a problem when the leakage contaminates a vacuum in an electronic device such as a CRT in a hydrogen atmosphere. You're stomping on pissants while elephants are running up and down the halls. The real problem is the weight and hazerdous nature of the container required to withstand the tremendous pressures of hydrogen storage.

 

[Turkey]

Yeah, I thought the real problem(s) were containing enough usable hydrogen in small portable tanks, creating a container that doesn't burst into cataclysmic flames when a car is hit, and creating an infrastructure of hydrogen filling stations???

 

[Evadman]

Also, look at the amount of hydrogen you would need. At the same 14:1 ratio used today ( 14 lb's air to 1lb of fuel ) you would bee looking at somewhere along the lines of 1700 cubic feet of hydrogen per hour burned at WOT assuming 400 CFM of air intake ( an average 6 cyl car )

That's a lot of hydrogen. I believe they would be able to get tanks today that would meet safety standards at about 5000 PSI.

 

[NonTechGuy]

<< Yeah, I thought the real problem(s) were containing enough usable hydrogen in small portable tanks, creating a container that doesn't burst into cataclysmic flames when a car is hit, and creating an infrastructure of hydrogen filling stations??? >>



we have propane powered cars and trucks that have not solved that problem of exploding when you hit them. if you see a truck with a white cylindrical tank in the back, make sure you don't hit him

 

[kat5iv]

I thought i remember seeing on the discovery channel a couple years back that some chemests had found a way to combind the hydrogen with some form of carbon, and they could than fit something like 15 times more hydrogen per cubic inch than they could by compressing it.

- jason

 

[n18mets]

kat5iv, did this substance look like black pelets? I vaguely remember a similar claim either on Discovery or TLC.

 

[highwire]

For stoich mix it would be Air -> 21% O2 + H2 -> H2O + N2, etc.

Say, 500 cu ft air X .21 = 105 cu ft O2

105 cu ft O2 + 210 H2 -> 210 cu ft H2O (steam,gas) + lotsa heat + the rest of the air components.

So, the gaseous ratio ( not weight) requires about 210 cu. ft h2 to burn 500 cu ft air.
(minor error - O2 is a bit heavier than air)

Note: All perfect gases have the same density of molecules at the same temp/pres.

The N2 that is just along for the ride will, as usual, be partly converted to nasties like NO2, N2O3, er .... just call it NOX.

The hydrogen will, if the container is steel, embrittle it, causing indeterminate loss of strength.

Oh, you need nukes to make the H2. In fact, "hydrogen" is code for nuclear power. Other Jerry Brown (Moonbeam) methods will, as any practitioner of arithmetic can tell, be found to be impractical.

But, I am all for it. Whoever is about to inherit this country by default should start saving NOW to pay for all of this.

 

[jamarno]

Why not a 50/50 mixture of H2O2 and water? Peroxide is about as flammable as gasoline at that concentration.

 

[Shalmanese]

Ungh, this is a point that always pisses me off.

Hydrogen is not a fuel source unless we are tlaking about fusion or we find some miraculous hydrogen deposits under the seas.

Hydrogen is a means of extremly compact fuel storage. You still need an abundant, cheap source of energy to GET the hydrogen in the first place.

There has been some work, however, of enclosing hydrogen in nanotubes so that there is a very controlled burn rather than an explosion so it would make it perfectly safe and easy to transport.

 

[Beau]

<< You still need an abundant, cheap source of energy to GET the hydrogen in the first place.. >>

Vast solar fields electrolyzing water. Not cheap, but very abundant. Probably close to the cost of oil rigs and drilling facilities.

 

[Jerboy]

The current problem is lack of storage container. Hydrogen can not be liquified unless super-cooled and can't stay liquid no matter how much pressure apply as it is above its critical temperature at room temp.

 

[PowerEngineer]

<< Hydrogen is not a fuel source unless we are talking about fusion or we find some miraculous hydrogen deposits under the seas. >>





<< Hydrogen is a means of extremly compact fuel storage. You still need an abundant, cheap source of energy to GET the hydrogen in the first place. >>



You are absolutely right about this Shalmanese! Too many people seem to think that the answer to civilization's long-term energy needs are electric cars, hydrogen gas, fuel cells, etc. when all of these currently rely on some sort of exhaustible fossil fuel. Aside from hydroelectric dams (which bring their own environmental problems), we've yet to produce significant amounts of energy from renewable resources. As Beau says, right now it's just too expensive. Let's hope for a technological breakthrough to change that!

 

[Daovonnaex]

Ford Motor has developed a method of storing hydrogen in a solid state with refrigeration (no, I don't know how it works). The primary barrier is cost, as it is 4x as expensive as gasoline here. There's no reason it couldn't be introduced in Europe or Japan, though. The ramp up in production would then lower prices enough to have it introduced here.

 

[Shalmanese]

I havent been keeping abreast with the issue but so far the contenders for storage are:

Metal Hydrides: expensive and toxic if leaked but highly stable

Solid Hydrogen: Only theoretical right now but Hydrogen compressed to immense pressures at low temps turns into a metal which is apparently stable at room temp

Nanotubes: Hydrogen is stored in nanotubes for a controlled burn. Nanotubes are expensive right now

Pourous ceramics: Extra weight of ceramic fairly prohibitive.

Plain old cylinder: Fatality rate of car accidents shoots up to 0.998

 

[Armitage]

<<

<< Hydrogen is not a fuel source unless we are talking about fusion or we find some miraculous hydrogen deposits under the seas. >>





<< Hydrogen is a means of extremly compact fuel storage. You still need an abundant, cheap source of energy to GET the hydrogen in the first place. >>



You are absolutely right about this Shalmanese! Too many people seem to think that the answer to civilization's long-term energy needs are electric cars, hydrogen gas, fuel cells, etc. when all of these currently rely on some sort of exhaustible fossil fuel. Aside from hydroelectric dams (which bring their own environmental problems), we've yet to produce significant amounts of energy from renewable resources. As Beau says, right now it's just too expensive. Let's hope for a technological breakthrough to change that! >>



Yea, this is the kind of thing that always cracks me up when somebody spouts off that we should all be driving electric cars.
The fact is that unless your getting your electricity from nukes, natural gas, or some form of renewable source (solar, wind, etc.), electric cars are more polluting then a modern internal combustion engine of similar capability.
Where does most of our power come from in the US? Coal. The absolutely dirtiest thing to burn!

Hydrogen might be even worse then electric due to losses involved in producing it, but it could help improve air quality in urban areas.

Of course, a hydrogen powered vehicle that emits only water vapor wouldn't qualify as a zero-emission vehicle in California.

 

[jdurg]

Hey hiwire, you do not need nukes to make hydrogen gas. If you want to make hydrogen gas, just put some salt in some water and run a current through it. The hydrogen will collect at the anode, and the oxygen will collect at the cathode. It is actually quite easy to produce hydrogen gas. The problem, however, comes with containing it. Hydrogen gas is simply two protons and two electrons. That's it. It is incredibly light, and incredibly small. The one way I can think of that would be useful in a hydrogen gas powered car would be to generate hydrogen on the fly. The car would end up being a hybrid H2/electric car. You could then store the hydrogen as water in a big tank, then run a current through the tank to generate the hydrogen and oxygen gas. The H2 and O2 could then be directed towards the engine where the stoichiometric combustion would take place. That would be the easiest way to do it. However, the amount of electricity needed to generate the gasses would be a little bit high.

As mentioned by someone else, H2O2 would be useless. Hydrogen peroxide is VERY unstable. It easily decomposes into water and oxygen gas just by sitting in a warm area or being exposed to light. (That's why high concentration H2O2 bottles have special caps. It's to allow the oxygen gas to escape.) With all the heat and shaking that happens in an automobile, the H2O2 would decompose quite rapidly. Also, it's just as hard to get hydrogen gas out of H2O2 as it is to get it from water. So if one wanted to use H2O2, it would just be easier and safer to decompose water.

Finally, those carbon compounds that hydrogen can be stored in are called Buckminsterfullerenes, I believe. They are soccerball like cages of carbon atoms that are able to hold materials inside of them. I believe that is what may have been mentioned earlier.

Hopefully I was able to clear some things up. (I'm a forensic chemistry major who is graduating this May. Chemistry is the one field that I am completely confident about my knowledge in. )

 

[Armitage]

<< Hey hiwire, you do not need nukes to make hydrogen gas. If you want to make hydrogen gas, just put some salt in some water and run a current through it. >>



Where does ther electricity come from?
That's what he is referring to the nukes for.
The point is that hydrogen is more an energy storage medium then an energy source.



<< The hydrogen will collect at the anode, and the oxygen will collect at the cathode. It is actually quite easy to produce hydrogen gas. >>



Being a chemist, can you give us any feel for the thermodynamic efficiency of this process.
ie. if you dump a Kjoule of electric power into the procees, what is the energy capacity of the hydrogen produced?
I think I've heard about 80% being a practical upper limit.



<< The problem, however, comes with containing it. Hydrogen gas is simply two protons and two electrons. That's it. It is incredibly light, and incredibly small. The one way I can think of that would be useful in a hydrogen gas powered car would be to generate hydrogen on the fly. The car would end up being a hybrid H2/electric car. >>



I suspect that batteries would be more efficient for a hybrid concept then generating hydrogen on the fly.



<< You could then store the hydrogen as water in a big tank, then run a current through the tank to generate the hydrogen and oxygen gas. The H2 and O2 could then be directed towards the engine where the stoichiometric combustion would take place. That would be the easiest way to do it. However, the amount of electricity needed to generate the gasses would be a little bit high.

As mentioned by someone else, H2O2 would be useless. Hydrogen peroxide is VERY unstable. It easily decomposes into water and oxygen gas just by sitting in a warm area or being exposed to light. (That's why high concentration H2O2 bottles have special caps. It's to allow the oxygen gas to escape.) With all the heat and shaking that happens in an automobile, the H2O2 would decompose quite rapidly. Also, it's just as hard to get hydrogen gas out of H2O2 as it is to get it from water. So if one wanted to use H2O2, it would just be easier and safer to decompose water. >>



Not to mention that H2O2 is an oxidizer and very corrosive to boot See some of the history of the V2 rocket which used an H2O2 oxidizer.



<< Finally, those carbon compounds that hydrogen can be stored in are called Buckminsterfullerenes, I believe. They are soccerball like cages of carbon atoms that are able to hold materials inside of them. I believe that is what may have been mentioned earlier.

Hopefully I was able to clear some things up. (I'm a forensic chemistry major who is graduating this May. Chemistry is the one field that I am completely confident about my knowledge in. ) >>

 

[highwire]

jdurg -

I did the current in saltwater thing when I was nine or ten. Fun. It also generated some chlorine bleach along with the H2 and O2 for some reason. I got my current through a transformer connected to Detroit Edison's coal fired plants. So, in my case, coal energy was the source to produce my hydrogen.

But, for you, we have to move fast - you graduate in May. Here is a good link written by a rare genius, Dr. John McCarthy of Stanford. It's heavy on logic, light on jargon. (no pictures though)
nuclear energy FAQ

I extracted this from the above link:


<< To some extent "hydrogen" in the energy literature is a code word for nuclear energy, since many articles promoting hydrogen don't say how it is to be generated economically in the quantities required to run an economy. >>



It is part of his broader subject, <a target=new class=ftalternatingbarlinklarge href="http://
http://www-formal.stanford.edu/jmc/progress/index.html">PROGRESS AND ITS SUSTAINABILITY</a>
which contains the following subjects:

Energy in general, nuclear energy, solar energy, food supply, population, fresh water supply, forests and wood supply, biodiversity, various menaces to human survival, the role of ideology in discussing these matters, useful references. Other problems are discussed in the main text including minerals and pollution.


There is enough there to keep ANYONE from being mistaken for a journalism major.

 

[highwire]

jdurg -

I'm teasing, of course. I am certain you know your subject very well. But you did miss the energy source idea.

I is my impression that it may be difficult to get a balanced view on today's campuses in areas such as ecology, energy and other realms of government interest. I believe Dr. McCarthy's very valid views may displace some common superstitions and are a good counterbalance to some popular notions presented as Gospel at too many schools.

Thus my recommendation to read the above links. You can't beat the price.

 

[Turkey]

<< The fact is that unless your getting your electricity from nukes, natural gas, or some form of renewable source (solar, wind, etc.), electric cars are more polluting then a modern internal combustion engine of similar capability.
Where does most of our power come from in the US? Coal. The absolutely dirtiest thing to burn! >>



According to this site, this site, and this site (see top), a modern coal power plant converts between 33% and 45% of the available energy in coal to electricity. Contrast this to this site, this paper, and this page, the actual efficiency of a four-stroke (car) engine is between 25% and 30%. So even if the least efficient coal power plant loses 10% of its power over the lines (it doesn't), then it would still probably be more efficient to get your energy from the plant. As for emissions, coal byproduct cleaning/scrubbers are continually improving, meaning that the emissions are getting continually cleaner from a coal plant. For a particular gas powered car, emissions are continually stale or increasingly dirty. Which isn't to say the emissions are better or worse in one or the other (couldn't find any data).

Gasoline is as much of an energy storage as it is an energy source... It's not like gas stations are built on top of oil reserves and they just pump it up. First it has to be found (one of the biggest parts of an oil company's expense sheet, btw), then extracted, then transported to the processing plant, then processed in a million and a half different ways, involving various forms of heating and cooling, then transported again. The total amount of energy expended so we can get in our cars and drive to the grocery store in an SUV is staggering. With a nuclear/hydrogen or solar/hydrogen plant, the whole finding and transportation to the processing plant steps are eliminated because we know where all the big water reserves are and the plants would be built next to them. So there's no real difference between gas and hydrogen in the area of source/storage, except it may take less total energy to deliver a mile's worth of H2 to us than a mile's worth of gas.

 

[jdurg]

Aahhhhhhhh.... Misunderstood what you had meant by "Oh, you need nukes to make the H2." I thought you meant that the only way to generate hydrogen gas is through a nuclear reaction. That's why I was kind of befuddled.

With the thermodynamic efficiency of the whole hydrogen combustion process, I'm not exactly sure. I don't have my p-chem book handy with me and haven't remembered the thermodynamic properties of hydrogen. lol. From my best guess, I'd say that it would be on par with modern sources of energy. With the modern combustion engine, a lot of energy is lost as heat. In fact, the majority of the energy is lost as heat. Same thing would happen with hydrogen combustion. There would be a great deal of energy that is "lost" in the form of heat. However, there would still be plenty left in the form of expanding gasses to provide the propulsion needed to move the pistons.

The one great thing that hydrogen combustion does have going for it is the fact that the only byproduct would be H2O gas. The water vapor would just go into the atmosphere. Also, there is a HUGE supply of water on the earth. Basically, the fuel would be recycled.

(Yeah, the current through some salted water is pretty fun. You need the salt in the water to provide a carrier for the current. Pure H2O ionizes very poorly, therefore making it difficult to carry electricity. By putting salt in the water, you provide the ions neccesary to allow current to flow. The mentioning of the bleach being made reminds me of something I forgot to mention earlier. When the current is passed through the water, the hydrogen gas collects at the anode while oxygen gas collects at the cathode. However, chlorine gas will also form and collect at the cathode. That's the problem. Chlorine gas is VERY corrosive, toxic, and dangerous. There would have to be a way to remove the chlorine gas from the oxygen. The water can only hold so much chlorine before it can't hold anymore. That's a problem that I forgot. )

Sorry I couldn't provide anymore information about the thermodynamics of the reaction. I don't have that memorized off the top of my head, and p-chem wasn't exactly my strong point. I'm better at the nuclear/analytical part of chemistry.

Highwire, thanks for the links. Very good information there. Before I decided on chemistry, I wanted to become a nuclear scientist. But then after my first physics course, I couldn't take any more. lol. But I was well aware of the information contained in the links. I have always thought that more nuclear plants should be built. The NRC here in America is VERY strict on their rules. People who fear an accident like Chernobyl are just plain misinformed. The style of reactor used in Chernobyl was a very unstable one. The people running the reactor also did some incredibly stupid things which led to the meltdown. The design of plants here in America is much different and would make a Chernobyl like accident almost impossible. Also, the accident at Three Mile Island was greatly exaggerated. Little, if ANY, radioactive material left the plant. Safety protocols by the NRC prevented a major accident. Finally, a breeder type reactor could be built that would generate more fissionable fuel than it creates. That could solve a bunch of problems. Sadly, the American public craps their pants whenever a nuclear plant is mentioned.

 

[Armitage]

<< According to this site, this site, and this site (see top), a modern coal power plant converts between 33% and 45% of the available energy in coal to electricity. Contrast this to this site, this paper, and this page, the actual efficiency of a four-stroke (car) engine is between 25% and 30%. So even if the least efficient coal power plant loses 10% of its power over the lines (it doesn't), then it would still probably be more efficient to get your energy from the plant. As for emissions, coal byproduct cleaning/scrubbers are continually improving, meaning that the emissions are getting continually cleaner from a coal plant. For a particular gas powered car, emissions are continually stale or increasingly dirty. Which isn't to say the emissions are better or worse in one or the other (couldn't find any data). >>



Sure, big electric plants are more efficient. But there are alot of losses between the plant and the wheels. I have a paper that breaks it all down, and shows that a chevy cavalier (not exactly a mileage champ) pollutes less then some particular electric car with much less performance powered by fossil fuel fired plants. Sorry, I can't find it at the moment, so feel free to dismiss it until I do
In any case, the losses:
power transmission
battery charging losses (ever feel how hot a recharging battery can get)
battery leakage losses
battery discharge losses (heat again, discharge some batteruies by shorting them, and they can explode or melt)
motor losses (heat again)
All of these losses are multiplicative.

You could argue that direct drive electric motors are more efficient then a mechanical transmission. And mabe you use regenerative braking as well.
And you could also argue that gasoline has transportation costs, but so does coal & fuel oil.

Electric cars do make sense in some circumstances, such as when you have clean power (go nukes!), or if you need to move your polution source out of urban areas. But its not the panacea some make it out to be.

In any case, I'll look for that paper. Google didn't turn it up either with the search I tried.

 

[Turkey]

<< power transmission
battery charging losses (ever feel how hot a recharging battery can get)
battery leakage losses
battery discharge losses (heat again, discharge some batteruies by shorting them, and they can explode or melt)
motor losses (heat again)
All of these losses are multiplicative.
>>



Hm... hadn't thought about the fact that there would be additional losses specific to electric cars such as the battery losses. But to be fair, gas-powered cars also have power transmissions which is a big source of power loss. And state of the art batteries (NiMH and Li+) don't need to be discharged. Hm... I'd be interested in seeing the paper .



<< Electric cars do make sense in some circumstances, such as when you have clean power (go nukes!), or if you need to move your polution source out of urban areas. But its not the panacea some make it out to be. >>



Agreed . Hybrid diesel-electrics, on the other hand...

 

[Shalmanese]

<< Hey hiwire, you do not need nukes to make hydrogen gas. >>



I think he was reffering to nuclear energy to create the said electricity



<< If you want to make hydrogen gas, just put some salt in some water and run a current through it. The hydrogen will collect at the anode, and the oxygen will collect at the cathode. >>



actually, NaOH will collect at the cathode assuming you are using table salt.



<< It is actually quite easy to produce hydrogen gas. The problem, however, comes with containing it. Hydrogen gas is simply two protons and two electrons. That's it. It is incredibly light, and incredibly small. The one way I can think of that would be useful in a hydrogen gas powered car would be to generate hydrogen on the fly. The car would end up being a hybrid H2/electric car. You could then store the hydrogen as water in a big tank, then run a current through the tank to generate the hydrogen and oxygen gas. >>



argh Argh ARGHH ARGHHHH!!! Stop this insanity. This is exactly what I am talking about, generating hydrogen on the fly? For a forensic chemist, maybe you should do some work on conservation of energy and stoichiometry. the amount of energy required to generate H2 from H2O would be equal to the amount of energy released when H2 reacts to form H2O so, not including any losses, you would be breakeven. Why not just use the bloody electricity to power the car. The whole point of H2 is that you can generate electricity with something like nuclear or solar energy and then USE the energy in a car where a portable nuclear power plan is not possible.



<< The H2 and O2 could then be directed towards the engine where the stoichiometric combustion would take place. That would be the easiest way to do it. However, the amount of electricity needed to generate the gasses would be a little bit high.

As mentioned by someone else, H2O2 would be useless. Hydrogen peroxide is VERY unstable. It easily decomposes into water and oxygen gas just by sitting in a warm area or being exposed to light. (That's why high concentration H2O2 bottles have special caps. It's to allow the oxygen gas to escape.) With all the heat and shaking that happens in an automobile, the H2O2 would decompose quite rapidly. Also, it's just as hard to get hydrogen gas out of H2O2 as it is to get it from water. So if one wanted to use H2O2, it would just be easier and safer to decompose water.

Finally, those carbon compounds that hydrogen can be stored in are called Buckminsterfullerenes, I believe. They are soccerball like cages of carbon atoms that are able to hold materials inside of them. I believe that is what may have been mentioned earlier.

Hopefully I was able to clear some things up. (I'm a forensic chemistry major who is graduating this May. Chemistry is the one field that I am completely confident about my knowledge in. ) >>



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