Are hydrogen cars bad for the environment?

Question

If producing hydrogen fuel from water uses as much energy as it releases, then the hydrogen is not produced from water, right? If hydrogen cars produce water instead of carbon dioxide and the hydrogen did not come from water in the first place, this results in gain of water. This water will eventually become water vapor, which is a greenhouse gas, and will cause the same problems as carbon dixoide. It may even cause more due to the excess water vapor in the air causing increased rain.

Am I understanding this wrong or has no one bothered to think of it?

Answer 1

It depend.people produce hydrogen by seperating the H in H2o.That takes electricity.It depands on the electricity source.

Answer 2

You've asked a bunch of questions.  I'll try to hit most of them.

There are a variety of ways to produce hydrogen.  The two most common are to use electrolysis of water or to "crack" fossil fuels.  The first requires more energy than the second, but it's completely renewable if you generate the electricity used from renewable resources.  For instance, erect a windmill and use the electricity to produce hydrogen from water.

Basically the idea is to produce portable energy using non-portable energy production.

Any long-term solution for hydrogen production for fueling cars is going to require a renewable resource of hydrogen, so cracking fossil fuels isn't on the list.  Thus, no net gain of water.

As for the water vapor -- the assumption is that increasing the amount of water in the atmosphere won't be a bad thing.  It will rain very very slightly more often, which is considered a good thing.  But the amount of water produced by hydrogen cars would not be significant compared to the amount of water that evaporates off our oceans.  A drop in the bucket, so to speak.

Answer 3

Hydrogen cars are developed to replace cars using petroleum products. So obviously it is more environmently friendly than the existing cars.

Hydrogen for cars will be produced from water using electrolysis process (see on web) and used for running vehicle. Hydrogen is just energy storage system from one form to another rather then new source. So this hydrogen from water is produced using electricity which is generated from more clean and environmently friendly source other than petroleum products.

As hydrogen is produced from water it will mix with oxygen to form water, so balance in water content no excess water. Moreever water vapour from this cars are very negligible to cause green house effect. CO2 from todays cars are ver much responsible for reen house effect.

Answer 4

Hydrogen cars using renewable energy sources to release the hydrogen from water are great for the environment.   You take out the same amount of water that you make when you burn it.  If you condense the steam back to water it's chemically pure water and can be used to make more hydrogen.  

Please read 'The Solar Hydrogen Civilization' by Roy McAlister.   He's a hydrogen revolutionary thinker who's been running cars on hydrogen since 1964 if I recall correctly (mid sixties anyway)

Answer 5

yes, water vapor, and little bits of hydrogen escaping into the enviroment.

this will deplete the o-zone layer, and make the earth more humid/warm

Answer 6

Hydrogen can come from many sources. Cheapest one is natural gas. Splitting water can be done, but is very inefficient.

The gain of water is minuscule though. Most of gasoline is hydrogen, when we burn it, a lot of water is released.  

Answer 7

Most large oil companies are betting on Hydrogen being the next cash-cow. They are going mainstream into the hydrogen stripping of natural gas - and getting paid by the governments to send the CO2 back underground again. This is not only a bad idea on paper - but there was an accident in India where whole villages were killed by a CO2 leak from underground. This is just storing up problems for the future.

They are pressurising the wells with this to extract more oil/gas easier - so is a win-win situation for them. They get more fuel out - and get a government subsidy to do it !

Answer 8

ask yourself this; is water bad for the environment? how about in a rainstorm when lightning strikes, rain hits the bolt, does this cause pollution? it causes hydrogen.water is emitted from my exhaust, thats why i had to drill a small drain hole in my muffler, to keep it from rusting out. stainless ehaust would work but too expensive for me. some mufflers, anymore already have a factory drain hole in them to keep them from rusting out with normal usage.

Answer 9

At the moment most hydrogen is produced by steam reforming of methane which happens to give off CO2.

Electrolysis would be able to split water to give us hydrogen without any CO2 emissions provided you use energy from clean power sources to do it (e.g. nuclear, hydro, geothermal, solar and wind, fuel production would be a better use of solar and wind than electricity generation since it wouldn't require reliability).  Thermochemical processes like the Sulphur-Iodine cycle will probably end up more efficient if you can get the temperatures required (a Gen IV reactor would be ideal for that).

As for water vapour; our current hydrocarbon fuel sources already give off quite a bit of the stuff (C3H8 + 5O2 -> 3CO2 + 4H2O for burning of propane) and that water vapour isn't causing us any problems (the CO2 is the global warming worry), water vapour is a pretty potent greenhouse gas but it doesn't last in our atmosphere very long so we can't really change the concentration of water vapour directly (it only really changes as a feedback).

Answer 10

you liberals think everything is a greenhouse gas....water vapor is just harmless water,,,even co2 is just food for plants.....hydrogen cars don't produce energy they just take elect power [mostly made by burning coal and transfer it to auto use...no magic cure to anything

Answer 11

You aren't being silly, but a calculation shows it is not a great concern,

To correct someone else's error, when iso-octane, common components of oil, burns the reaction is:

1.C8H18 + 25.O2 =>  8.CO2 + 9.H2O

So burning a gallon of gasoline uses about  42 pounds of oxygen and produces about  8.5 pounds (1.03 gallon) of water.

To produce the same amount of energy burning hydrogen we have:

466.H2 + 233.O2 =>  466.H20

To get the same energy as a gallon of gasoline, we burn 2.05 lb of hydrogen using  16.4 lbs of oxygen and producing 18.5 lb of water.

Note that hydrogen fuel uses much less oxygen (the same amount of O2 is produced in electrolysis) but produces more than twice the amount of water.

If we converted all 84million bbl of oil burned daily (~4m bbl is used as plastic and fertilizer feedstock) to hydrogen fuel, this would mean an additional  35 billion pound of water (4.2 bill gallon) each day.   It sounds like a lot, but the atmosphere contains 3 million times this amount of water.

Answer 12

To produce hydrogen from water you have to split the hydrogen away from the oxygen using either heat or electricity. The hydrogen is still produced using water regardless of which method you use.

The best way to produce the hydrogen would be to build a large solar plant in arizona, west texas and california. Then use the output from those plants to produce the hydrogen.

The hydrogen did come from water so no, its not a net gain. Water vapor is not a greenhouse gas and does not cause the same type of problem that CO2 does.

Your understanding is slightly flawed, but thats ok. You have a good basic line of thinking that needs minor adjustment.

Answer 13

water vapor is a greenhouse gas?