Can we run out of hydrogen?

Question

I know cars can run off of water, so if that's our alternative fuel, then we'll burn the hydrogen.But my question is this, how does the exhaust become water vapor and for that matter if the hydrogen burns up were does it go, and can we run out of hydrogen eventually?

Answer 1

technically, yes we can run out of hydrogen as it is one of the few molecules that the earth's gravity is not strong enough to hold on to. however this is a very.... very.... very.... slow process and will practically never happen as there is so much hydrogen and it happens soooooo slowly.

the very basic way of thinking of a hydrogen engine is that hydrogen goes in - burns (fuses with oxygen) - and comes out H2O... as i said, its way more complicated then that but that can make it much easier to understand.

2H2 + O2 --> 2H2O

Answer 2

Well, presuming we are getting the hydrogen from water in the first place, no we will not run out.  Hydrogen plus oxygen makes water.  Closes the circle.

Hydrogen is good only as a portable fuel (say, to replace gas) because you need to put energy IN to make it from water, and that energy has to come from somwhere, again presumably from the sun or gravity or a combination of the two (solar, wind, tide, hydro), or from nuclear or geothermal, both of which should be considered limited in practice.

Basically what I am saying is that hydrogen can replace gasoline, but it really isn't an energy SOURCE, it is just a different way of using energy made from another already existing source (a battery serves the same purpose in this sense).

I also wonder what effects will arise if we go into large scale electrolysis of water to make hydrogen fuel.  What will dumping all that water into the atmosphere of urban areas do?  What will happen in the places we take the water (it will have to be sea water because we already have serious problems with fresh water supplies for meeting our living needs).  What about all that oxygen released when making hydrogen fuel from water-is that going to become an issue?  It isn't clear that the upside outweighs the downside on this one.  It might, I just don't have enough info to judge.

Answer 3

burning hydrogen produces water. you learn this in Chemistry class. no, we can't run out.

Answer 4

When hydrogen is burned or run through a fuel cell it is combined with oxygen and becomes water vapour.  We can't run out.