This is a copy of a information I posted a couple of years back.

I thought it might be a good idea to produce a Hydrogen Facts thread, which should be particularly useful for anyone interested in its use as a fuel.

This idea of this thread then is to provide a handy source of reference and somewhere that information gathered from numerous sources can  all be found in one place.

I’ve noticed over the years that there appears to be much confusion surrounding the energy released from combusting hydrogen, so thought that clearing this up would be a good starting point. 

Most of the confusion seems to arise because comparisons of energies released by various fuels is not always compared fairly, or indeed accurately. For example, comparing fuels by volumes can be very misleading, especially in the case of hydrogen due to its extremely low density.

The following table is known to be accurate, and gives a figure for the energy released when a mass of 1kg of the fuel is completely burned in oxygen.


Carbon, C (as in coal)    2C(s) + O2(g) = 2CO(g)...............................................................33,000kJ

Methane, CH4 (as in natural gas)    CH4(g) + 2O2(g) = CO2(g) + 2H2(g)............................ .50,000kJ

Octane, C8H18 (as in petrol)    2C8H18(liquid) + 25O2(g) = 16CO2(g) + 18H2O(g.................45,000kJ

Methanol, CH3OH   2CH3OH(liquid) + 3O2(g) = 2CO2(g) + 4H2O(g)....................................20,000kJ

Carbohydrates (sugars and starches)…..products are CO2(g) and H2O(liquid).............average 17,000kJ

Animal Fats……….products are CO2(g) and H2O(l)................................variable, but typically 40,000kJ

Hydrogen, H2   2H2(g) + O2(g) = 2H2O(g)......................................................................120,000kJ

(g) = gas, (l) = liquid, (s) = solid


So, if we are comparing energies released by mass, then hydrogen clearly possesses the greatest energy by far.

The problem is that hydrogen liquid has a low density, so as a fuel, larger volumes of it are required when compared to say petrol.

For example liquid hydrogen has a density of just 72 kilograms per cubic metre, petrol is around 737kg/m3 and water 1000kg/m3.

So while mass for mass hydrogen releases the greatest amount of energy upon combustion in oxygen, its low density means that volume for volume, around 4 times more liquid hydrogen would be needed to equal that of a given volume of petrol. Hence hydrogen, even in liquid state would require substantially greater volumes to be carried on board a vehicle in order to get it to travel for the same distance as a vehicle fueled with petrol.

Of course, when we are talking about powering a vehicle with liquid hydrogen as fuel, there is also the issue of not only producing the hydrogen initially, but also in compressing it into liquid state.

Here’s an interesting piece I found:

Quote

Here's what Pimentel (1996, p. 211-212) has to say.

In terms of energy contained, 9.5 kg of hydrogen is equivalent to 25kg of gasoline ( Peschka 1987). Storing 25 kg of gasoline requires a tank with a mass of 17 kg, whereas the storage of 9.5 kg of hydrogen requires 55kg, (Peschka 1987). Part of the reason for this difference is that the volume of hydrogen fuel is about 4 times greater for the same energy content of gasoline. Although the hydrogen storage vessel is large, hydrogen burns 1.33 times more efficiently than gasoline in automobiles ( Bockris and Wass 1988). In tests a BMW 745h liquid-hydrogen test vehicle with a 75 kg tank and the energy equivalent of 40 liters of gasoline had a cruising range in traffic of 400 km, or a fuel efficiency of 10 km per liter ( Winter 1986).

Carrying liquid hydrogen around as a fuel has never really appealed to me due to the problems associated with it in liquid state. So whether it be used to drive and ICE or a hydrogen fuel cell to power an electric motor, the problem of carrying, storing and indeed refuelling are obstacles I feel too great to make it worth the effort. This of course is to say nothing of having to produce the hydrogen in the first place.

Now here’s the thing, and the beauty of water. Any given volume of water - even though it contains the oxygen atom as well as hydrogen - actually contains more hydrogen than pure liquid hydrogen of an equal volume.  This for me is the real appeal of on-demand production of hydroxy from water.

Of course we are extremely hampered by the conservation of energy laws, but that is not to say that some laws cannot be rewritten if new information comes to light or new discoveries are made that perhaps question whether or not these laws truly take into account every factor.  By this I mean that some laws generally work great and calculations are accurate within most useable parameters, but the same law can fall apart under certain specific conditions whereby the physics we know seems to go out of the window. I believe Ohm’s Law is one such case.  So there are always possibilities – always hope!

I assume many of you have seen this, but for reference, here is an interesting you-tube video detailing the amount of hydrogen (gas) required to run a vehicle:

https://www.youtube.com/watch?v=7qzrI20VPCw

Note: If anyone finds that I’ve provided incorrect figures anywhere, either through a typo or otherwise, please speak up and I’ll correct any mistakes.

Thanks Farrah.

Reference:
http://hydrogen.pnl.gov/cocoon/morf/hydrogen

Great info and video.

Thanks for sharing!

I don't dispute those numbers on 100% hydrogen in the video, but the Key Word (100% hydrogen which can be bought in a bottle 99.9% at any local gas supplier) is not what I am working with. There is a difference when you add oxygen to the mix, there is also a difference when you strip electrons from the mix. I just wonder what the numbers would be if all this was taken into consideration. Can someone post those numbers. I think that would be a better comparison to gasoline. As I have stated there is a difference in the gas. I can make bubbles that go poof (100%) hydrogen, I can make bubbles the go pop 2 to 1 ratio, and I can make bubbles that go pow, 2 to 1 ratio with electrons striped. And the government and scientist can make a reaction from hydrogen that goes boom! Anyone care to explain how this is compared to gasoline? If you want to make the kind of gas that that video is talking about get you a car battery hook it up to a cell until you drain the battery dry even better yet make you a split cell and just use the hydrogen, that way you can get rid of the oxygen. I know I am dumb as a coal bucket when it comes to science, physic and most large math formulas. But I know there has to be a difference in a poof driving down a piston compared to a pow driving down a piston or even a boom!. I want mind at all to delete my post if people find it non topic related. I would like to have numbers based on what we are really dealing with. Please share those numbers please. With oxygen in the mix, with one electron stripped, two electrons stripped and so on. We all know that the hydrogen bomb has a huge amount of energy when released. Now just for comparison if we could release that energy on demand (LOL) how many times would that push a car around the world compared to a gasoline car. All I am trying to say is they are different energy levels other that 100% hydrogen. The guy in the video may have his numbers together for people that carries a bigger coal bucket around than I do. Not only that, he does not figure in the gasoline that goes out the tail pipe that didn't get burned or was burned up by the cat. converter. I guess because it comes out the tail pipe it is considered rocket fuel.

Ok, where to start.

Hydrogen Bomb - nothing at all to do with what we are doing, that is thermonuclear atomic fusion stuff, think the core of a star - definitely does not happen in our electrolysers!

The 100% hydrogen you buy in a bottle is no different from the 100% hydrogen produced by an electrolyser. The fact that a common-duct electrolyser produces hydrogen AND oxygen is of no consequence, as oxygen is only the oxidiser enabling the combustion of hydrogen. You can't ignite pure hydrogen, it requires the presence of oxygen! Therefore for the hydrogen to combust it does not matter if it is reacting with the oxygen in the air around us, or the oxygen evolved at the anode of an electrolyser.

You will note that the figures quoted above ALL relate to the energy released when combusted in the presence of oxygen.

As for electrons being stripped off, well this is what Meyer suggested was happening, which is complete nonsense to begin with. Electrons do not travel through liquids. Charged ions carry the current through liquids.

And here's another interesting snippet of info:

If you have a cylinder of hydroxy, HHO, or whatever else you want to call the gas, and ignite it, then you will get a bigger - as you put it - POW, than if the cylinder was 99% hydrogen.

"If you have a cylinder of hydroxy, HHO, or whatever else you want to call the gas, and ignite it, then you will get a bigger - as you put it - POW, than if the cylinder was 99% hydrogen."

Farrah, I have heard that before, but is it true?  Can you point to any scientific papers or explanations  that explain why hydroxy is more powerful?

Hi HMS

It's simple really. If there is not enough oxygen in the mix to react with all the hydrogen, then some of the hydrogen will always remain and hence somewhat stunt the overall reaction. Conversely a stoichiometric amount of H2/O2 will fully react and hence give the greatest overall reaction.

Quote from Farrah Day on February 2nd, 2014, 12:32 PM

Hi HMS

It's simple really. If there is not enough oxygen in the mix to react with all the hydrogen, then some of the hydrogen will always remain and hence somewhat stunt the overall reaction. Conversely a stoichiometric amount of H2/O2 will fully react and hence give the greatest overall reaction.

I do think it has been experimentally proven if you have a less than ideal mixture, lacking Oxygen, any Nitrogen in the mix is much less likely to produce NO, NO₂, or NO_x.  Makes for an easy way to remove that "something just blew up" smell.   :D  Oh how I do miss it so...

Quote from Matt Watts on February 2nd, 2014, 01:13 PM

I do think it has been experimentally proven if you have a less than ideal mixture, lacking Oxygen, any Nitrogen in the mix is much less likely to produce NO, NO₂, or NO_x.  Makes for an easy way to remove that "something just blew up" smell.   :D  Oh how I do miss it so...

You're quite right, there can be other reactions if air is present. The same happens in an ICE using hydrocarbons when the stoichiometric amount for a full (or clean) burn is not met. That is when you can get reactions with nitrogen.

However, the case in point is dealing solely with the combustion of hydrogen and oxygen. The hydrogen can only react with the oxygen present in the mix. A complete burn requires enough oxygen for all the hydrogen to react with, hence in the case of just hydrogen and oxygen, the gas mix needs to be two thirds hydrogen to one third oxygen.

Farrah Day, two points about your last post. The first point about the nitrogen in the mix with the burning process, it doesn't matter if it's with hydrogen or gasoline. When ever the temperature in the cylinder is exceeds @ 2000 degrees F, the nitrogen will link up with the oxygen and form NOx gas. The egr valve on a modern vehicle, recirculates exhaust gas to lower the cylinder temperatures to keeps this reaction from taking place. It's a thermo bonding effect.

The second point I want to make ,is with using HHO gas in an ICE. You will always have a lean burn when using HHO. The HHO is already at the perfect ratio for burn like you state, but when you add outside air into the mix, you are adding another 20% oxygen to the ratio. So now we have a lean burn with oxygen left over. If the temps exceed the 2000 degree point we get NOx. So when Stan mixes in spent exhaust gas to slow down the burn rate of the hydrogen, he's actually lowering the cylinder temps as well.
Don

Yep Dyno, I know and I agree.

With reference to Meyer, apart from the lack of carbon in Meyer's recycled exhaust gases, the biggest difference is obviously the water content. And of course water is exceptional at absorbing heat energy.

Quote from Farrah Day on February 3rd, 2014, 11:05 AM

Yep Dyno, I know and I agree.

With reference to Meyer, apart from the lack of carbon in Meyer's recycled exhaust gases, the biggest difference is obviously the water content. And of course water is exceptional at absorbing heat energy.

All correct.

Gary Hendershot (a.k.a. Smart Scarecrow) also observed lowering the exhaust valve lift on the cam has the same effect as recirculating exhausted water vapor.  Instead of handling it externally, just leave a majority of it in the cylinder.  The unfortunate side effect of water vapor is it is a very poor lubricant, taking us all the way back to whether an ICE is a suitable arrangement for turning Hydroxy into mechanical energy.  If your engine has plasma polished cylinders, piston rings and piston, the answer is maybe; if not, the answer is a definite no.

If Stan would have put 100,000 miles on his buggy, he would have discovered the additional engineering hurdles that await him.  Might want to consider why he looked towards a Hydroxy powered water heater.  Surely he would have noticed how rapidly engine lubrication is corrupted using Hydroxy as fuel.

Not to despair, there are other engine designs that eliminate metal-on-metal contact suitable for Hydroxy fuel.  Turbine designs with non-contact impellers would fit the bill.  The implementation of these into automotive applications would be expensive, because not only would you have to replace the engine, but the transmission as well, preferably with a CVT.

Guess what I'm getting at is whether anyone has prepared a serious cost analysis to pursue this so-called technology?  Clearly, none of this will end up being "free" energy, at least not in an automotive application, or a home generator for that matter.  You might get something to work for the short-term in your garage, but that's about it.  My suggestion is to figure out exactly what the fundamental processes are that would allow someone to obtain excess energy from the decomposition of water, then adapt that understanding to a more suitable device for harvesting that excess energy.

Just saying...


DISCLAIMER

I'm just an old guy with crap for brains so please disregard anything that doesn't fit in your personal paradigm of how the world works.

Reference Materials:
http://www.afdc.energy.gov/
http://www.afdc.energy.gov/fuels/fuel_comparison_chart.pdf

http://hydrogen.pnl.gov/cocoon/morf/hydrogen
http://hydrogen.pnl.gov/cocoon/morf/hydrogen/article/103 (Click "no thanks" if you don't want to sign up)
http://hydrogen.pnl.gov/cocoon/morf/hydrogen/article/401 (Click "no thanks" if you don't want to sign up)

#1 Hydrogen The most abundant Element in the Universe.

#2 All of the other Elements in the periodic table came from Hydrogen Atom.

The Question..

Counting all the billions of years that space has been around
Why is there more Hydrogen in the universe instead of helium?