Self-refueling engine

[BTV Engineer]

I've been hesitant to post this because it's not my idea, I think it's a crank.

The thread title is my interpretation of what my boss has occasionally talked about. He has this (imo) crazy idea about fueling an engine with water alone. I get the impression that he thinks he's the first person to come up with this. He claims he understands that there is no such thing as a free lunch but he still thinks that his idea is viable.

Summary: Create an engine that would take in water into the combustion chamber, break it down to hydrogen and oxygen, burn the hydrogen and oxygen, take the resultant water exhaust and reuse as fuel.

Recently he brought this idea up again and fleshed out one specific idea he has that I'm sure won't work. He thinks you could create a vacuum in the combustion chamber which would boil the water and then disassociate the gaseous H2O using an electron gun. I'm not sure why he mentioned an electron gun (like from a CRT) but I'm sure there are major problems with just creating the vacuum.

I'm no physicist but I'm thinking there are serious problems with creating a vacuum in a combustion chamber sufficient to boil the liquid water and keep it as a gas. My gut feeling is that the gaseous water would expand to fill the chamber and raise the pressure. Depending on the pressure and temperature you might just end up with liquid water again, even if only as water droplets.

Even assuming you can maintain a gaseous water state you have the problem of breaking the gaseous water to H and O. I know you can't get 100% so you'd be left with some water vapor. Under pressure the remaining gaseous water would return to a liquid. In order to get a good vacuum you'd need to be at BDC (bottom dead center) and to get any work out of this you'd have to compress the H and O then ignite the mixture. That remaining water would interfere with any combustion.

Recycling the water vapor exhaust appears to be another major complication and wouldn't net much usable water. Although my boss thinks you could carry very little water and you'd be recycling the water vapor exhaust.

It seems to me it would be simpler to just use electricity to breakdown water, retrieve the hydrogen and use it as fuel in an engine designed for it. Storing the water and processed hydrogen external to the engine makes more sense. Then you'd only have to carry the hydrogen fuel. Obviously this is already done today.

So, just how many problems are there with my boss's idea?

[premjan]

Maintaining a vacuum would take energy. Dissociating the molecules would require energy too. Where's the free lunch?

[Headache]

Not to mention that water is a lot more than just H2O...

It is a crackpot idea, based on cereal box physics.

[Buck Laser]

I once bought all the gas saving devices for sale in the J.C. Whitney catalog--you know, one saved 20%, another 17%, 27%, and so on. All together, I was saving so much gas that I had to stop and draw off the extra gas in my tank.

[BTV Engineer]

Maintaining a vacuum would take energy. Dissociating the molecules would require energy too. Where's the free lunch?

My boss has discussed this as some type of modification to a standard automobile internal combustion engine. I asked how he would create the vacuum and he's talked about using a starter motor to turn over the engine. The expansion of the combustion chamber would create the vacuum and once the engine was running the system would be self sustaining, the recovered water would be the fuel for future combustion. So while not a "free lunch", he thinks it would be nearly 100% efficient. I've mentioned that this would be quite impossible as there would be losses all along the process.

Originally, many months ago, when he first discussed this he was thinking "free lunch" in that he was sure the process would be 100% efficient. Take water in, break it down to H2 and O, ignite said elements, get back all the water you put in to reuse as fuel. I told his this would never work and while he has conceded that the process would not be 100% efficient he still maintains that it would be quite close. He just thinks there would be be technological hurdles to overcome.

I'd like to hit him with facts that would show why this is a crackpot idea. Sadly, I should just give up as he appears to be quite resistant to critical thinking skills. But I did want to mention the idea here.

[jayh]

Originally, many months ago, when he first discussed this he was thinking "free lunch" in that he was sure the process would be 100% efficient. Take water in, break it down to H2 and O, ignite said elements, get back all the water you put in to reuse as fuel. I told his this would never work and while he has conceded that the process would not be 100% efficient he still maintains that it would be quite close. He just thinks there would be be technological hurdles to overcome.

In a perfect world, the energy you get from burning the products is exactly equal to the energy required to dissociate them. Since this is not a perfect world, you get back much less than you put in.

[premjan]

For example, an O-H bond of a water molecule (H-O-H) has 493.4 kJ/mol of bond dissociation energy, and 424.4 kJ/mol is needed to cleave the remaining O-H bond. The bond energy of the O-H bonds in water is 458.9 kJ/mol, which is the average of the values.http://en.wikipedia.org/wiki/Bond_dissociation_energy
The energy needed to dissociate water is not trivial I believe. It may be relatively easier to maintain a vacuum though every time you introduced some water into it the water would have to be completely dissociated and then burned into loquid and removed for the process to be efficient.

[Yggdrasill]

The only question you need to be asking is "Where's the energy coming from?"

Water in itself does not contain chemical energy, so there's no way to use it as a fuel. It can be used as an energy conveyor, by splitting it into H2 and O2 and combining the two components elsewhere, but that isn't at all efficient, and you certainly don't get any surplus energy out of it.

The only way for your bosses idea to work is if there was zero loss (and you can count work as a loss to the process). I think we can all agree that cars use energy, so it cannot work.

[premjan]

Basically it is a question of whether you believe the law of energy conservation or not. If you don't, then there isn't any problem with this kind of machine.

[BTV Engineer]

The only question you need to be asking is "Where's the energy coming from?"

Water in itself does not contain chemical energy, so there's no way to use it as a fuel. It can be used as an energy conveyor, by splitting it into H2 and O2 and combining the two components elsewhere, but that isn't at all efficient, and you certainly don't get any surplus energy out of it.

The only way for your bosses idea to work is if there was zero loss (and you can count work as a loss to the process). I think we can all agree that cars use energy, so it cannot work.

The last time he brought this up, this argument was what I used; I don't think it really sunk in. You guys have given me a few ideas that I can use on him. I think in the end he'll still think that it would work if the "difficulties" could be overcome. Maybe he thinks that one of those difficulties is the Law of Conservation of Energy. :D

[Lógos Sokratikós]

Basically it is a question of whether you believe the law of energy conservation or not. If you don't, then there isn't any problem with this kind of machine.

:rolling:

Pure gold
:notworthy:

[SteveP]

Maintaining a vacuum would take energy. Dissociating the molecules would require energy too. Where's the free lunch?

So while not a "free lunch", he thinks it would be nearly 100% efficient. I've mentioned that this would be quite impossible as there would be losses all along the process.

Originally, many months ago, when he first discussed this he was thinking "free lunch" in that he was sure the process would be 100% efficient. Take water in, break it down to H2 and O, ignite said elements, get back all the water you put in to reuse as fuel. I told his this would never work and while he has conceded that the process would not be 100% efficient he still maintains that it would be quite close. He just thinks there would be be technological hurdles to overcome.

I'd like to hit him with facts that would show why this is a crackpot idea. Sadly, I should just give up as he appears to be quite resistant to critical thinking skills. But I did want to mention the idea here.


Even if it were nearly 100% efficient, all it would achieve would be nearly 100% efficient use of the chemical energy stored in the battery when you first started the car - and doing that by splitting out hydrogen from water and burning it in an internal combustion engine isn't going to be anywhere near 100%. An Otto cycle car engine is only about 20-25% efficient for starters.

Your boss would be far better off just having a straight-out battery powered car and either;

Keep buying new batteries when they go flat,

or (probably better idea), recharge the car from mains power point at work.



Your boss is attempting alchemy.

[skepticalbip]

A more simple (fewer energy conversion steps) perpetual motion machine would be an electric car with a generator coupled to the drive shaft to recharge the batteries.

And then there is always this:

http://i108.photobucket.com/albums/n7/skepticalbip/misc/closedcyclemillgif.jpg

where the idea is to use a water wheel to grind grain but also connect a pump to the water wheel to lift the water so that it can flow over the wheel again.

[gregfl]

I am sorry to break this to your boss..but this was done years and years ago. Here is a picture of the inventor who was murdered by the the shado government in collusion with the oil consortium who swiftly bought up the technology and buried it in area 51. They then created a fake UFO crash conspiracy to cover it all up.

You can read the whole story on www.geewhizIneeedascienceclass.com

http://www.physics-book.com/images2/perpetual_motion1.gif

[peanutaxis]

Perhaps what disturbs me most is what the anvil is for!?

[Yggdrasill]

It's so that the magnet has something to pull on...

[gregfl]

Perhaps what disturbs me most is what the anvil is for!?


typical carrot and stick approach...to free energy!


lol

[Dirge]

I once bought all the gas saving devices for sale in the J.C. Whitney catalog--you know, one saved 20%, another 17%, 27%, and so on. All together, I was saving so much gas that I had to stop and draw off the extra gas in my tank.

With the price of gas, you should be selling the excess.

[MxM111]

consider this engine as a black box - you do not care what going inside, it is closed system. Yet, according to your boss it produces energy, that probably can be used to drive a car.
So basically you have a source of infinite amount of energy. It contradicts to everything we know about energy.

[gregfl]

consider this engine as a black box - you do not care what going inside, it is closed system. Yet, according to your boss it produces energy, that probably can be used to drive a car.
So basically you have a source of infinite amount of energy. It contradicts to everything we know about energy.

youtube and the internet in general are full of these over unity and perpetual motion claims. If you press them for evidence they claim special properties, mysticism, that 'science' is only a theory, or that you are closed minded. Hell, they sound just like a bunch of theists.




Most of them are either scientifically challenged, intentionally ignorant, attention seekers, or as my father used to say, have just enough information to be dangerous.

[MxM111]

consider this engine as a black box - you do not care what going inside, it is closed system. Yet, according to your boss it produces energy, that probably can be used to drive a car.
So basically you have a source of infinite amount of energy. It contradicts to everything we know about energy.

youtube and the internet in general are full of these over unity and perpetual motion claims. If you press them for evidence they claim special properties, mysticism, that 'science' is only a theory, or that you are closed minded. Hell, they sound just like a bunch of theists.




Most of them are either scientifically challenged, intentionally ignorant, attention seekers, or as my father used to say, have just enough information to be dangerous.

I do not care about those, those are behind hope. But the original poster of this thread seems to be reasonable person and he just does not have enough knowledge of this kind of things and this is why he asked question. I am trying to help him, not those " scientifically challenged, intentionally ignorant, attention seekers"

[gregfl]

Summary: Create an engine that would take in water into the combustion chamber, break it down to hydrogen and oxygen, burn the hydrogen and oxygen, take the resultant water exhaust and reuse as fuel.

Recently he brought this idea up again and fleshed out one specific idea he has that I'm sure won't work. He thinks you could create a vacuum in the combustion chamber which would boil the water and then disassociate the gaseous H2O using an electron gun. I'm not sure why he mentioned an electron gun (like from a CRT) but I'm sure there are major problems with just creating the vacuum.




So, just how many problems are there with my boss's idea?

This is just so silly.

1) to mainain a vacuum, you need a pump. to run a pump, you need a motor. Where will the energy come from?

2) to run an electron gun or to perform electrolysis in any manner, you need again a motor that generates quite a bit of energy. Again, where will the energy come from? These things don't run on wishes.



So, before we ever get an electrolysis going in the manner of your boss' fantasy, , you are running a big (seperate) motor to 1) maintain a vacuum and 2) electrolyse water.

Assuming the contraption actually functioned at all, we know that electrolysis returns about 30 percent of the energy put into it on a good day. The rest is expended mostly in the form of heat energy. So, instead of his theory, that his motor would produce energy, it would in fact be an inefficient means to run the car, again assuming it would work at all.

In conclusion, he would be much better off just running the car on the motor that would have been used to create the vacuum and power the electrolysis circuit (electron gun or whatever).


"The law that entropy always increases, holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations — then so much the worse for Maxwell's equations. If it is found to be contradicted by observation — well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation." — Sir Arthur Stanley Eddington, The Nature of the Physical World (1927)

[gregfl]

youtube and the internet in general are full of these over unity and perpetual motion claims. If you press them for evidence they claim special properties, mysticism, that 'science' is only a theory, or that you are closed minded. Hell, they sound just like a bunch of theists.




Most of them are either scientifically challenged, intentionally ignorant, attention seekers, or as my father used to say, have just enough information to be dangerous.

I do not care about those, those are behind hope. But the original poster of this thread seems to be reasonable person and he just does not have enough knowledge of this kind of things and this is why he asked question. I am trying to help him, not those " scientifically challenged, intentionally ignorant, attention seekers"


I wasn't speaking of the Op, but rather of his boss.

[MxM111]

I do not care about those, those are behind hope. But the original poster of this thread seems to be reasonable person and he just does not have enough knowledge of this kind of things and this is why he asked question. I am trying to help him, not those " scientifically challenged, intentionally ignorant, attention seekers"


I wasn't speaking of the Op, but rather of his boss.

LOL! I know that you were not talking about OP :D But even for his boss, it may be easier to explain not in terms of complex calculations of bond energies vs extracted work, but in terms of simple concept. I think that you can't get simpler that that black box approach that I suggested. If his boss does not understand that, than he will be categorized as "significantly challenged" as well :).

[gregfl]

I wasn't speaking of the Op, but rather of his boss.

LOL! I know that you were not talking about OP :D But even for his boss, it may be easier to explain not in terms of complex calculations of bond energies vs extracted work, but in terms of simple concept. I think that you can't get simpler that that black box approach that I suggested. If his boss does not understand that, than he will be categorized as "significantly challenged" as well :).

The black box analogy is spot on. It is also where most of these guys make one of their major blunders ...they draw the box way too small. As an example, one of the big ones going around the net is "plamsa induction" conversion of water to 'aquafuel'. the process is basically taking a welder, some carbon rods, plugging it in submersed in water and the ensuing gases (hydrogen and oxygen gases aka 'hho') are collected. This is supposedly over unity because they calculate the energy in the arc(bogus) and compare it to (bogus) readings of the energy in the gas. The glaring error is they don't even try to calculate the amount of energy going into the welder and compare it to the ensuing available energy in the gas.

In other words, the black box is drawn to small, and it is easier to make miscalculations that really skew the results if the 'black box' isn't shown to include all the energy in vs energy out. This is why, when the proponents of all of these supposed contraptions that can run by themselves, etc. are pressed to demonstrate it, they can't. they never have and baring some earth shattering result that violates the laws of physics, likely never will.

Free energy claims are, like theistic proof of god claims, fun for a while, then they get too easy to refute due to repetition of the same errors and they become boring. On the bright side, they then become fun to make fun of!

[Davedave]

Those pesky laws of Thermodynamics are always getting in the way. I'd definitely vote for anyone who said they would amend or rescind them. Until then, however, a water-powered car is not going to be feasible. Hydrogen combustion using H2 produced by disassociating water should be seen more like a battery than a fuel source. It may be good for storage or transport of energy, but it will never yield more energy than was used to make it.

Hydrogen combustion has several other quirks that make it difficult at this point. For starters, the temperature produced by hydrogen combustion will melt or at least weaken steel. I had a friend build a hydrogen combustion engine into a VW beetle (and, no, he didn't leave the stock air-cooling system), but it still dropped the engine out. It's an engineering problem, no doubt, but it's an issue. Also, you would have to have onboard storage of O2, because if you burn H2 in air, you get a lot of NOx, which is also a greenhouse gas. It all depends on what your goals are, of course, but I think that, from an environmental perspective, hydrogen is a red herring.