Hydrogen conversion and its waste

Now, its been a few years since I did science and there has been a lot of hype lately about hydrogen conversions for cars. Now to me this does seem to offer a few problems that seem to not get mentioned or over looked in the hype.

1. To create hydrogen you need electricty, adding another element to the process when you could just get the power direct from electricity, so overall is it more efficient?

2. Depending on where you get your electric from its orginal source may not be that green, as we get alot of our power from coal power stations. While nucular is not looked at in a good way, it is far greener.

3. Waste, hydrogen conversion produces oxygen as its waste, which is not a bad thing though oxygen on its own is not good for you. Could we end up producing to much?

4. If your turning water to hydrogen and oxygen, then are you not at some point going to be using alot of water so even that one day would run out, a long time off I know, but still something that would happen.

5. Burning hydrogen as a fuel would produce waste but what is that waste, after all there is always a by product from the engery coversion as a fuel, though I can't remember what.

So can anyone enlighten me, or will I need to find some time tonight to perform to 'key' research.

5. Waste product is, I believe water. Hydrogen reacts with oxygen in the air and you get H20? Summit like that?

2. I guess it's far easier to "green up" the 100 or so power stations than doing the same to twenty million cars. Although I vaguely remember (perhaps incorrectly) that the modern internal combustion engine is actually more efficient (in that stored chemical energy gets transferred into motion) than most power stations.

Originally Posted by Grinch

Now, its been a few years since I did science and there has been a lot of hype lately about hydrogen conversions for cars. Now to me this does seem to offer a few problems that seem to not get mentioned or over looked in the hype.

1. To create hydrogen you need electricty, adding another element to the process when you could just get the power direct from electricity, so overall is it more efficient?
No, it's a very inefficient process. Basic thermodynamics tells you that by the process of change, energy will be lost regardless.

2. Depending on where you get your electric from its orginal source may not be that green, as we get alot of our power from coal power stations. While nucular is not looked at in a good way, it is far greener.

Nope. But the idea is if we have sustainable electricity, then we can create hydrogen cheaply in the large quantities we need. Disposing of Nuclear waste would become an issue if we were all to adopt it.

3. Waste, hydrogen conversion produces oxygen as its waste, which is not a bad thing though oxygen on its own is not good for you. Could we end up producing to much?

Nope, as when you burn the Hydrogen it reforms with the oxygen

4. If your turning water to hydrogen and oxygen, then are you not at some point going to be using alot of water so even that one day would run out, a long time off I know, but still something that would happen.

You'd be limited by how much you could store. Could we store enough of the sea on land in order to make a substantial dip in the ocean levels?

5. Burning hydrogen as a fuel would produce waste but what is that waste, after all there is always a by product from the engery coversion as a fuel, though I can't remember what.

It's water that would come out of the exhaust- and back in to the atmosphere.

So can anyone enlighten me, or will I need to find some time tonight to perform to 'key' research.

It's a daft idea really. Until we have an abundance of electricity it won't be possible, and even then it won't be green. It will however give you more choices as to locate where the pollution is, and work around that.

Originally Posted by MiniMatt

2. I guess it's far easier to "green up" the 100 or so power stations than doing the same to twenty million cars. Although I vaguely remember (perhaps incorrectly) that the modern internal combustion engine is actually more efficient (in that stored chemical energy gets transferred into motion) than most power stations.

Yep car engines are very efficicent, though its not cheap to convert them.

Originally Posted by MiniMatt

5. Waste product is, I believe water. Hydrogen reacts with oxygen in the air and you get H20? Summit like that?

So that would mean... split water in to oxygen and hydrogen...
Burn hydrogen, get energy, then it gives more water...
You sure??? The must be some loss somewhere?

4. Conservation of energy means that energy can't ever be lost, only transferred. Energy and matter are tied. If the earth is a closed system (which it isn't but I guess for the purposes of cosmic timescales it's as good as) then in theory we still have the same amount of matter on the planet and thanks to a constant fresh supply of energy (light from the sun) we should have the means to never run out of matter or energy.

Summit like that

Originally Posted by gettin2dizzy

Nope, as when you burn the Hydrogen it reforms with the oxygen.

So none of the hydrogen is lost when it is burnt?

[SoulKiss]

Originally Posted by Grinch

Now, its been a few years since I did science and there has been a lot of hype lately about hydrogen conversions for cars. Now to me this does seem to offer a few problems that seem to not get mentioned or over looked in the hype.

1. To create hydrogen you need electricty, adding another element to the process when you could just get the power direct from electricity, so overall is it more efficient?

2. Depending on where you get your electric from its orginal source may not be that green, as we get alot of our power from coal power stations. While nucular is not looked at in a good way, it is far greener.

3. Waste, hydrogen conversion produces oxygen as its waste, which is not a bad thing though oxygen on its own is not good for you. Could we end up producing to much?

4. If your turning water to hydrogen and oxygen, then are you not at some point going to be using alot of water so even that one day would run out, a long time off I know, but still something that would happen.

5. Burning hydrogen as a fuel would produce waste but what is that waste, after all there is always a by product from the engery coversion as a fuel, though I can't remember what.

So can anyone enlighten me, or will I need to find some time tonight to perform to 'key' research.

1)Hydrogen if created by splitting it from water is best seen as an energy storage medium than a fuel. It is not 100% efficient.

2) Due to that inefficiency, it only make sense if you have a lot of electricity to waste - so loads of nuclear power plants would be good - think of it as a way to make your car/bike nuclear powered. If nuclear fusion comes along, it will make electricity ultra-cheap and so the inefficiency wont matter.

3, 4 and 5 together) If splitting hydrogen rather than using naturally occuring you get a pretty good "circle of life"

Starting with water and adding electricity gives you hydrogen, burning hydrogen gives you the means to generate power and water, which then gives you the water back.

Its actually VERY hard to destroy matter, it just tends to get converted to something (even if that is as intangible as light in the form of photons.)

Originally Posted by Grinch

So none of the hydrogen is lost when it is burnt?

Nope Unless it's a Hydrogen Lorry, in which case it's probably leaking hydrogen all over the god-damn road.

[G]

A bigger problem from it all is that a Hydrogen cell is in real terms relatively unstable.....it would have to be very well protected in a car incase there was an accident.

An then there another bigger problem terrorists will just love hydrogen cars......anyone every seen a hydrogen fuel cell being blown up (check out youtube).....wouldnt be to hard to rig a car up to explode.