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Thread: Hydrogen as a deisel engine additive

  1. #1
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    Hydrogen as a deisel engine additive

    Let me start off by saying that I understand conservation of energy and the laws of thermodynamics. I know you can't use water for fuel, and you can't power a semi-truck soley on hydrogen produced by an onboard electrolyzer.

    But... I have read quite a few claims that using an onboard electrolyzer, and flowing that hydrogen into the air intake will increase the fuel mileage. Is there any mechanical engineering explanation for why this would or wouldn't work? (ie - does the alternator not produce enough electricity? or does it overproduce electricity which is why it allows for some extra to be used in the electrolysis?) Or how efficient it would be? based on a chemical explanation?

  2. #2
    How much is the reported increase in mileage?

  3. #3
    flat Earth skeptic Aqueous Id's Avatar
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    Any improvement would have to come from some other cause, for example, injecting a combustible gas in the air intake changes a pressure and/or temperature that was suboptimal to begin with. But if it were by design, it makes no sense that the manufacturer would not have simply altered the design to improve fuel efficiency and boost sales. So already something is wrong with this picture.

    The other thing you ask is whether the alternator is producing excess electricity that is being wasted. The problem here is, with no load on the alternator, you are wasting fuel on friction. Then, when an electrical load is applied, a mechanical load is added to the friction load. So there is nothing available to waste. Current has to flow to produce power, and power consumed is power taken from the engine.

    Also, note that when the alternator is charging the battery, hydrogen is produced, although in such small amounts it is negligible. But that is wasted. So it's kind of ironic. That is, I can conceive of a system that keeps the battery in overcharge (electrolysis) and evolves hydrogen gas this way...so that may be another avenue for someone to swindle truckers, for example a plastic header that snaps onto the battery, collects the vapor and sends it through a tube into the air intake.

    Another way to picture this, is to pretend the alternator was powered by magic, and you could take all the energy for free and use it to improve mileage. Wiki says a liter of diesel yields about 39 MJ. Let me assume a 13V alternator, that requires 3MA∙s = 833 Ah. So if you could sustain 833 amps out of a 13V alternator, you could produce the energy of one liter of diesel in one hour of driving. This is assuming perfect conditions. So now you have to imagine how much fuel a rig will normally burn at, say 60 mph, in one hour. You are going to get one more liter for free. All you need is an 833 amp alternator, powered by magic. One source I found estimates 2 miles per liter. So in 60 miles you might expect to burn 30 liters. Your 833 amp supply would then bump that down to 29 L, so your mileage improves from 2 mi/L to 2.07 mi/L, or a 3.5% improvement. All for 833 amps! Wiki says a semi alternator can develop around 140A, which is about 17% of the 833A we were hoping for, so now the 3.5% improvement drops to about 0.6% improvement. And that was by magic, and under perfect conditions.

    As you might expect, it's hard to push a semi with an alternator.

  4. #4
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    Quote Originally Posted by Aqueous Id View Post
    Any improvement would have to come from some other cause, for example, injecting a combustible gas in the air intake changes a pressure and/or temperature that was suboptimal to begin with. But if it were by design, it makes no sense that the manufacturer would not have simply altered the design to improve fuel efficiency and boost sales. So already something is wrong with this picture.

    The other thing you ask is whether the alternator is producing excess electricity that is being wasted. The problem here is, with no load on the alternator, you are wasting fuel on friction. Then, when an electrical load is applied, a mechanical load is added to the friction load. So there is nothing available to waste. Current has to flow to produce power, and power consumed is power taken from the engine.

    Also, note that when the alternator is charging the battery, hydrogen is produced, although in such small amounts it is negligible. But that is wasted. So it's kind of ironic. That is, I can conceive of a system that keeps the battery in overcharge (electrolysis) and evolves hydrogen gas this way...so that may be another avenue for someone to swindle truckers, for example a plastic header that snaps onto the battery, collects the vapor and sends it through a tube into the air intake.

    Another way to picture this, is to pretend the alternator was powered by magic, and you could take all the energy for free and use it to improve mileage. Wiki says a liter of diesel yields about 39 MJ. Let me assume a 13V alternator, that requires 3MA∙s = 833 Ah. So if you could sustain 833 amps out of a 13V alternator, you could produce the energy of one liter of diesel in one hour of driving. This is assuming perfect conditions. So now you have to imagine how much fuel a rig will normally burn at, say 60 mph, in one hour. You are going to get one more liter for free. All you need is an 833 amp alternator, powered by magic. One source I found estimates 2 miles per liter. So in 60 miles you might expect to burn 30 liters. Your 833 amp supply would then bump that down to 29 L, so your mileage improves from 2 mi/L to 2.07 mi/L, or a 3.5% improvement. All for 833 amps! Wiki says a semi alternator can develop around 140A, which is about 17% of the 833A we were hoping for, so now the 3.5% improvement drops to about 0.6% improvement. And that was by magic, and under perfect conditions.

    As you might expect, it's hard to push a semi with an alternator.
    Keen, but you're a little off topic.

    ok so:

    alternator to electrolysis = loss of energy
    electrolysis used to make hydrogen = loss of energy
    hydrogen burning in the motor = added fuel
    so the question is:

    Does the addition of water as an energy source compensate for the loss in the electricity production stages?

  5. #5
    flat Earth skeptic Aqueous Id's Avatar
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    Quote Originally Posted by kingcarrot View Post
    Keen, but you're a little off topic.
    Why off topic? Weren't you asking if the claim was feasible?
    ok so:

    alternator to electrolysis = loss of energy
    electrolysis used to make hydrogen = loss of energy
    hydrogen burning in the motor = added fuel
    so the question is:

    Does the addition of water as an energy source compensate for the loss in the electricity production stages?
    Water is not an energy source. It is the waste product of some other energy source that was spent, producing water. Energy is produced when bonds are made. The chemical bonds between hydrogen and oxygen have to be broken to produce hydrogen gas, and that costs energy. So hydrogen is a fuel, but water is not. When you burn hydrogen in oxygen, the bonds form to make water, and energy is released. Now the water is depleted of energy until the next time you split the bonds by passing a current through the water.

  6. #6
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    Quote Originally Posted by Aqueous Id View Post
    Any improvement would have to come from some other cause, for example, injecting a combustible gas in the air intake changes a pressure and/or temperature that was suboptimal to begin with. But if it were by design, it makes no sense that the manufacturer would not have simply altered the design to improve fuel efficiency and boost sales. So already something is wrong with this picture.
    Whats wrong is that they are only burning diesel. you can add things to the diesel to help it burn better, like more air, for example, with a turbo charger. And generally the market is slow to react to new technology so I think your hitting on the sociological implications. I'm more concerned with the mechanics here.

    Here's the abstract from one experiment:

    The addition of hydrogen has been shown to decrease the formation of NOx, CO and unburned hydrocarbons. Added hydrogen in percentages as low as 5-10% percent of the hydrocarbon fuel can reduce that hydrocarbon fuel consumption. The theory behind this concept is that the addition of hydrogen can extend the lean operation limit, improve the lean burn ability, and decrease burn duration.

  7. #7
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    Quote Originally Posted by Aqueous Id View Post
    Water is not an energy source. It is the waste product of some other energy source that was spent, producing water. Energy is produced when bonds are made. The chemical bonds between hydrogen and oxygen have to be broken to produce hydrogen gas, and that costs energy. So hydrogen is a fuel, but water is not. When you burn hydrogen in oxygen, the bonds form to make water, and energy is released. Now the water is depleted of energy until the next time you split the bonds by passing a current through the water.
    You got me. So is the hydrogen sufficient? You seem adept at sourcing and crunching the numbers. Care to help me out?

  8. #8
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    Does the addition of hydrogen as an fuel source compensate for the loss in the hydrogen production stages?

  9. #9
    Curmudgeon of Lucidity Grumpy's Avatar
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    kingcarrot

    As I understand it the Hydrogen is used to accelerate the ignition and burning of the deisel allowig more fuel to be burned efficiently. In turbocharged deisels used in tractor pulling they use propane for that purpose and run insane boost levels and fuel loads. The hydrogen is actually HHO, it includes slightly ionized hydrogen atoms(and thus no H2)and oxygen plus water vapor. Watch it, that stuff can easily explode. I'd stick with propane(dangerous enough!).

    I'm in the middle of building an SHO 3.2 liter that will be turbocharged and use a mixture of methonal and water(basically window washer fluid) injected to cool the charge and suppress detonation. It's going into my 1979 Pinto hatchback along with a five speed and a Cobra IRS.





    Grumpy

  10. #10
    flat Earth skeptic Aqueous Id's Avatar
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    Quote Originally Posted by kingcarrot View Post
    Does the addition of hydrogen as an fuel source compensate for the loss in the hydrogen production stages?
    No. Because the energy used to produce hydrogen is greater than the energy released when you burn it. In a perfect system, they would be equal, but that still gets you nowhere.

  11. #11
    Quote Originally Posted by Aqueous Id View Post
    No. Because the energy used to produce hydrogen is greater than the energy released when you burn it. In a perfect system, they would be equal, but that still gets you nowhere.
    Not if it improves the combustion efficiency of the fuel being used.

    Semi's use a LOT of fuel.

    They get about 6 mpg and put about 150,000 miles or more per year on them, so even a 1/2% improvement in combustion efficiency would be worth over $500 per year.

    I'm not saying this works (I have no idea), but there are other avenues for potential gains in combustion efficiency.

  12. #12
    Quote Originally Posted by Grumpy View Post
    I'm in the middle of building an SHO 3.2 liter that will be turbocharged and use a mixture of methonal and water(basically window washer fluid) injected to cool the charge and suppress detonation. It's going into my 1979 Pinto hatchback along with a five speed and a Cobra IRS.
    Just WOW!

  13. #13
    flat Earth skeptic Aqueous Id's Avatar
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    Quote Originally Posted by kingcarrot View Post
    Whats wrong is that they are only burning diesel. you can add things to the diesel to help it burn better, like more air, for example, with a turbo charger. And generally the market is slow to react to new technology so I think your hitting on the sociological implications. I'm more concerned with the mechanics here.

    Here's the abstract from one experiment:

    The addition of hydrogen has been shown to decrease the formation of NOx, CO and unburned hydrocarbons. Added hydrogen in percentages as low as 5-10% percent of the hydrocarbon fuel can reduce that hydrocarbon fuel consumption. The theory behind this concept is that the addition of hydrogen can extend the lean operation limit, improve the lean burn ability, and decrease burn duration.
    This is what I meant in my first statement, that there may be inefficiencies by design that an additive happens to help correct. The reduction in nitrogen compounds is secondary, since we want to burn carbon. I doubt that CO matters much, but unburned hydrocarbons (diesel) is a big issue. This was why I suspected that Hydrogen may simply be increasing the cylinder temperature, thus helping the diesel burn faster. If that's the case, I question why there is not a standard additive that does the same. Again, the volume of hydrogen gas coming out of his gas generating unit would seem to be very small, meaning that just about any small heat increase would help.

    As for why additional hydrogen molecules would chemically promote combustion of diesel, I'm not sure where that argument goes. The hydrogen will steal oxygen, so I'm little puzzled what they mean.

    As for turbocharging, here you are overcoming the inefficiencies of carbueration, that is, atomizing or vaporizing the liquid to get a clean burn. If the molecules stay packed together, they won't be exposed to oxygen fast enough to burn. Anything that promotes an even mixture ought to be as good as it gets.

    Also note, when dealing with inefficiency improvement, a small cost in energy up front can produce a huge savings downstream, depending on the extent of the inefficiency.

    Also, now I see where I may have gone off topic, since this discussion apparently revolves around efficiency.

  14. #14
    flat Earth skeptic Aqueous Id's Avatar
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    Quote Originally Posted by adoucette View Post
    Not if it improves the combustion efficiency of the fuel being used.

    Semi's use a LOT of fuel.

    They get about 6 mpg and put about 150,000 miles or more per year on them, so even a 1/2% improvement in combustion efficiency would be worth over $500 per year.

    I'm not saying this works (I have no idea), but there are other avenues for potential gains in combustion efficiency.
    I understand now that that the claim revolves around efficiency improvement. I understood earlier that it was about specific energy of the fuel.

    I am still puzzled by the ability to take a stock vehicle, and improve its efficiency. I believe the mfr's have more incentive than anyone to improve efficiency, in order to promote sales. I believe your capitalist bent is in this direction. Am I wrong? So why aren't they already doing it? That's why I said before, something's wrong with this picture.

    Suppose for example, I get 10% efficiency by raising cylinder temp 100°. Is there something the mfr knows is harmful about that (ie reduces life, explodes, etc)? These kinds of ideas condense in the back of my mind when I hear about how shade tree mechanics have outsmarted the brain trust at GM.

  15. #15
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    Quote Originally Posted by adoucette View Post
    Just WOW!
    AGREED! That's going to haul ass!

  16. #16
    flat Earth skeptic Aqueous Id's Avatar
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    Quote Originally Posted by Grumpy View Post
    kingcarrot

    As I understand it the Hydrogen is used to accelerate the ignition and burning of the deisel allowig more fuel to be burned efficiently. In turbocharged deisels used in tractor pulling they use propane for that purpose and run insane boost levels and fuel loads. The hydrogen is actually HHO, it includes slightly ionized hydrogen atoms(and thus no H2)and oxygen plus water vapor. Watch it, that stuff can easily explode. I'd stick with propane(dangerous enough!).

    I'm in the middle of building an SHO 3.2 liter that will be turbocharged and use a mixture of methonal and water(basically window washer fluid) injected to cool the charge and suppress detonation. It's going into my 1979 Pinto hatchback along with a five speed and a Cobra IRS.

    Grumpy
    Yes I would imagine any flammable gas might promote mixing and of course cylinder temp.

    Hey, be careful Grumps, I know you know what you're doing, but still we don't want to be reading about Gremlins per sq in, Gremlin ballistics, and/or Gremlin relativistics next week in the headlines.

    Just kidding. I had a friend in college who took a tank truck, modified it to run off of chicken shit, and it worked. It was a miserable (literally) crappy vehicle. Unfortunately it took exactly 1/2 tank to get home from the chicken farm, then it would sit and ferment, and he had just enough to get back. So it turned out not impress anyone, but it passed for a Master's thesis.

    But you're looking good. I bet you can't wait to fire that baby up.

  17. #17
    Curmudgeon of Lucidity Grumpy's Avatar
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    Aqueous Id

    The point is not to increase the heat by burning the hydrogen, but to use the rapid burning characteristics of hydrogen to raise combustion pressures earlier in the stroke to increase total torque. If set up right you can also burn even more diesel more efficiently. Air is usually not a problem(almost all diesels are turbocharged already)as they run with wide open throttle at all times with a healthy excess of air, diesel power is controlled completely by the injected volume of fuel.

    adoucette

    Long time no speak. Hope you and yours are all fine. I'm doing as well as a broke down old fart can be expected to do.

    I've been drooling all over that motor since I got it. Pretty. Shiney. 225 HP stock, 480 at 16 pounds of boost. 8500 rpm redline! Basically I only have to change the pistons(8.5 CR forged), the rest of the motor is up for 500 HP and up(some are getting 700+ on stock blocks).

    I bought a 71 Pinto off a man in 1979 and he went and bought this one new. He passed away 3 months later and his widow would not sell it for gold(I know, I must have talked to her 15 times in 30 years). When she passed I bought it off of her nephew with 6446 miles on it, kept in her garage for 30 years. I'm putting it together so I can go play "Here Kitty, Kitty" with the Ferraris and Lambos out on the Tail of the Dragon

    Grumpy

  18. #18
    flat Earth skeptic Aqueous Id's Avatar
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    Quote Originally Posted by kingcarrot View Post
    You got me. So is the hydrogen sufficient? You seem adept at sourcing and crunching the numbers. Care to help me out?
    We can crunch on hydrogen if you like, but if all they are doing is improving efficiency, I wouldn't know where to start, since I don't understand exactly what was suboptimal before they optimized it.

    Hydrogen as a fuel is crunchable, because we know what we are dealing with.
    here's the most basic idea

    electrolysis: 2 H2O → 2 H2 + O2
    combustion: 2 H2 + O2 → 2 H2O

    before I go further, just check out this comment:

    The most common and decisive counter-argument against producing this gas on-board to use as a fuel or fuel additive is that the energy required to split water molecules exceeds the energy recouped by burning it.[15] Additionally, the number of liters per minute of gas that can be produced for on-demand consumption through electrolysis is very small in comparison to the liters per minute consumed by an internal combustion engine.
    and that cites
    Schadewald, Robert J. (2008). Worlds of Their Own - A Brief History of Misguided Ideas: Creationism, Flat-Earthism, Energy Scams, and the Velikovsky Affair. Xlibris. ISBN 978-1-4363-0435-1.

    I like the title anyway.
    I'll be back with some numbers.

  19. #19
    flat Earth skeptic Aqueous Id's Avatar
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    Here's a source that explains why there is an increase in efficiency by adding hydrogen.

    Hydrogen has the ability to burn at extremely lean equivalence rations. Hydrogen will burn at mixtures seven times leaner than gasoline and five times leaner than methane [3]. This lower limit is governed by the Le Chatelier Principle [4]. The flame velocity of hydrogen is much faster than other fuels allowing oxidation with less heat transfer to the surroundings. This improves thermal efficiencies. Efficiencies are also improved because hydrogen has a very small gap quenching distance allowing fuel to burn more completely. [B]The only drawback to hydrogen is that even though its lower heat value is greater than other hydrocarbon fuels it is less dense therefore a volume of hydrogen contains less energy[3,5].
    https://docs.google.com/viewer?url=h...Combustion.pdf

  20. #20
    Curmudgeon of Lucidity Grumpy's Avatar
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    Aqueous Id

    Also to be considered is that the HHO is only injected during high load conditions but the electrolysis is continuous and stored up between uses. I have no idea if this is practical but some have shown improvements in short term power increases. I know for fact that propane works with high boost(40 pounds and up) tractor pullers burning diesel, but they blow those things into little tinkly pieces on a regular basis. I've seen Cummings truck engines(like in a Dodge pickup)pull 1600 hp on a dyno with propane injection(and BIG turbos, compounded), but you couldn't pay me enough to be in the same room when they are doing it.

    Grumpy

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