View Full Version : Hydrogen as a deisel engine additive


kingcarrot
02-25-12, 12:25 PM
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?

adoucette
02-25-12, 01:40 PM
How much is the reported increase in mileage?

Aqueous Id
02-25-12, 04:01 PM
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.

kingcarrot
02-25-12, 04:44 PM
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?

Aqueous Id
02-25-12, 04:53 PM
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.

kingcarrot
02-25-12, 04:59 PM
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.

kingcarrot
02-25-12, 05:02 PM
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?

kingcarrot
02-25-12, 05:03 PM
Does the addition of hydrogen as an fuel source compensate for the loss in the hydrogen production stages?

Grumpy
02-25-12, 05:19 PM
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.

http://i739.photobucket.com/albums/xx36/robertdbreedlove/Christmas2010026.jpg
http://i739.photobucket.com/albums/xx36/robertdbreedlove/Christmas2010029.jpg
http://i739.photobucket.com/albums/xx36/robertdbreedlove/102_6369.jpg

Grumpy

Aqueous Id
02-25-12, 05:19 PM
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.

adoucette
02-25-12, 05:30 PM
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.

adoucette
02-25-12, 05:32 PM
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!

Aqueous Id
02-25-12, 05:41 PM
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.

Aqueous Id
02-25-12, 05:50 PM
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.

kingcarrot
02-25-12, 05:54 PM
Just WOW!

AGREED! That's going to haul ass!

Aqueous Id
02-25-12, 06:07 PM
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.

Grumpy
02-25-12, 06:21 PM
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:jawdrop:).

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:xctd:

Grumpy:cool:

Aqueous Id
02-25-12, 06:22 PM
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.

Aqueous Id
02-25-12, 06:49 PM
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=http%3A%2F%2Fwww.panaceauniversity.org% 2FHydrogen%2520Enriched%2520Hydrocarbon%2520Combus tion.pdf

Grumpy
02-25-12, 07:03 PM
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:cool:

Aqueous Id
02-25-12, 07:58 PM
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:cool:

Wow no kidding. This is why I think the mfr's are not pushing the envelope, presumably due to safety and reliability.

As for high load, that what I was just beginning to understand, after seeing a chart that shows no appreciable performance change, until right at peak, and then an additional 15% hydrogen adds a boost, for about 8% improvement in efficiency. I've always thought it was a scam, but now I'm seeing a small window for some kind of claim. And yes, large volume gas production costs way too much electricity, so you would want to build it up and store it. That would seem to contradict the mileage claims though, because you'd be robbing Peter to pay Paul.

Grumpy
02-25-12, 10:02 PM
kingcarrot

I did not mean to hijack your thread, sorry.

As to the HHO systems, I would pass, there are better, more reliable and safer ways of doing this, your stored HHO is a time bomb that could be set off by static electricity, it takes a large amount of unrecoverable energy to produce and seems it would have limited utility. Propane gives you the same types of benefits and you can carry a quite large supply. You'll need a common rail electronic injection motor and a Bully Dog(or similar)reprogrammer to take full advantage, plus you may want to up the springs in the turbo waste gate for more boost. With a stock turbo you'll probably be limited to about 300-350 hp, but torque will be close to 600 ft/lbs, great for towing. Going even further and be prepared to pull out your wallet and empty it on the parts counter as you will need a bigger turbo and a stronger drivetrain(the Allison can be built to handle more torque but it's not cheap), but at those levels you WILL twist your driveshafts into pretzels if you don't blow the chunk out of the rear axle first. Even if they live, the axle shafts are on borrowed time. There are heavier duty parts available but you would think they were made of some sort of gold alloy for what they cost. But you would end up with a snorting monster of a truck that would still get decent milage as long as you control your right foot.

Grumpy:cool:

kingcarrot
02-25-12, 11:50 PM
numbers yet?

kingcarrot
02-27-12, 11:05 AM
I'll be back with some numbers.

Numbers?

adoucette
02-27-12, 11:17 AM
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.

Sure.

But have you considered how much H2 that would be?

As has been pointed out, a Semi gets about 6 miles per gallon of Diesel.

So, while tooling along at 60 mph, it's burning 10 gallons per hour.

Do you really think you can produce the equiv of 1/2 gallon of liquid H2 per hour with the energy put out by an alternator?

Trippy
02-27-12, 01:55 PM
kingcarrot

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
^ New best friend.

wlminex
02-27-12, 04:06 PM
How soluble is hydrogen in hydrocarbon fuels; point being: one might inject pressurized hydrogen into the hydrocarbon fuel just prior to intake and ignition.

Grumpy
02-27-12, 04:21 PM
Trippy

Are you a Ford man, too? It's a disease that has no cure wherin you KNOW that the Ford is always going to win, despite any so-called evidence to the contrary, as the other cars must be cheating!

Grumpy:cool:

spidergoat
02-27-12, 04:31 PM
grumpy, I hope you relocated the gas tank. I wanna turbo my 2001 Focus!

Trippy
02-27-12, 04:50 PM
Trippy

Are you a Ford man, too? It's a disease that has no cure wherin you KNOW that the Ford is always going to win, despite any so-called evidence to the contrary, as the other cars must be cheating!

Grumpy:cool:

Yeah, most days. I don't talk to loudly about it because I'm surrounded by Holden fanatics.

My first car was supposed to be a Ford Anglia, but I pissed away most of the money that I was supposed to use to restore it to a useable condition.

Having said that, the only way I could fit into it was to take the front seat of its rails and have it sitting hard against the back seat.

That and I just really like the idea of what you're doing. I have a number of ideas that I would love to try out, but lack the capital to invest in them, and if I'm being honest with myself, although I thoroughly understand the theoretical aspects, I was never given the opportunity to learn how to apply them.

Grumpy
02-27-12, 05:03 PM
spidergoat

Fuel cell for sure, one with a bladder and foam. About $180 from Summit, but good insurance. They actually changed the tanks in 1974 and statistics from the time indicate that Pintos had firey accidents at rates no different from Impalas and Chevy Trucks and only slightly elevated from other vehicles. The stink was caused by callous interoffice memos that said it would have only required about $12 each to fix the problems(filler pipe going further into the tank and a shield between the tank and the rear axle)but Ford management nixed it due to the desire for profits. A shame since the Pinto was a decade long success that sold in numbers beat only by the Model T, Citreon 2CV and the Volkswagon. I had a 71(1600, drum brakes)and a 1980 wagon, one of the first and one of the last. This one is my 6th. It is a roomy small car(for two, anyway)that handles very well, and cute and rare in this day(everybody's got Mustangs, no one has a Pinto at all the car shows I go to). Plus it will hold almost every Ford engine made...

http://i290.photobucket.com/albums/ll241/cfb289/Boss9%20Build/002.jpg

That is a 526 ci Boss 429

http://i290.photobucket.com/albums/ll241/cfb289/Boss9-022611046.jpg

And that is a 427 SOHC with a blower on top. Wish they were mine!

http://www.britishv8.org/MG/LeRoyBarton/LeRoyBarton-EA.jpg

This is what mine will look more like(that's a MGB with an SHO)

Grumpy

spidergoat
02-27-12, 05:09 PM
Wow, sweet! I hear you can get a V8 engine kit for the focus too, with rear wheel drive. But I'm sure it's easier in a Pinto.

Grumpy
02-27-12, 05:36 PM
spidergoat

What year Focus? Ztec or Duratec?

Either can be turboed to close to 300 hp, but you really don't want more than that going through the front wheels without a Torsen or Wavetrac limited slip. Wish we had the European focus with four wheel drive in the states.

Grumpy:cool:

spidergoat
02-27-12, 05:41 PM
z-tec, and I would be happy with 180-200! But I don't know enough about it...

Aqueous Id
02-28-12, 12:41 PM
Numbers?

Sorry.. I wandered off.

Here I will pick up where I left off. The question now is: how to generate enough H2 to provide a mix with diesel, the intent being to bump the efficiency, not to gain something from nothing, as I first understood the claim.

Adoucette hit the nail on the head: how to generate 1/2 gal of H2. That may not even be sufficient. One source I found claims you need a 15% mixture to achieve 8% mileage improvement, so I will assume that is the design requirement. This bumps us up to 1.5 gal/hr hydrogen generating capacity. That's not gas, that's how much water must be electrolyzed! It's hefty, as we will see.

6 mpg × 1609 m/mi ÷ 4.54609 L/gal ≈ 2123.6 m/L

60 mph × 1609 m/mi ÷ 3600 sec/hr ≈ 26.8167 m/s

diesel burn rate: 26.8167 m/s ÷ 2123.6 m/L ≈ 0.012628 L/s

rate of electrolysis: 15% of 0.012628 L/s ≈ 0.001894 L/s (liquid water)

hourly water consumption: 0.001894 L/s × 3600 s/hr ÷ 4.54609 L/gal = 1.5 gal

Now for the electrolysis:

0.001894 L/s × 55.6 mol/L = 0.105318 mol/s

2 electrons are needed to liberate a mole of H2:

0.105318 mol∙H2O/s × 2e-/H2O = 0.210636 mol∙e-/s

0.210636 mol∙e-/s × 96,485 C/mol∙e- = 20323 C/s

20323 C/s = 20323 A.

Now the question is: where do we get 20kA of electricity?


The standard potential of the water electrolysis cell is -1.23 V at 25 °C at pH 0 (H+ = 1.0 M).

20323 A × 1.23 V = 25 kW

The maximum available power from the alternator is

140 A × 13 V = 1820 W.

Obviously this is impossible. I have ignored the problem of sending 20 kA down any conductor without huge ohmic loss, I've assumed perfect efficiency in the wet cell, which is impossible, and I've ignored size of the plates and deterioration by plating out the electrode material.

My next move is to try to rethink what the claim is really saying. Perhaps they were talking about 15% mixture by vol of gas, not liquid. If so, we can divide the result by 22, since a volume of gas has 1/22 the moles of the equivalent liquid volume:

25 kW ÷ 22 = 1136 W

This places us within reasonable operating capacity of the alternator, but efficiency of the wet cell will steal that gain. For example, if we assume 50% efficiency:

1136 W × 2 = 2273 W

but we can only produce at most

1820 W ÷ 2273 W = 80%

Therefore we need to reduce our assumption of 15% mixture down to

15% × 80% = 12%

I don't know what happens when we do that. Now let's see how we're doing with production of current:

20323 A × 2 ÷ 22 = 1848 A

Still huge. But this was assuming a single cell. Now suppose we break them into a series. Ten cells in series gives:

1.23 V × 10 = 12.3 V

1848 A ÷ 10 = 185 A

But we can only produce 140 A, so we must derate our mixture further:

140 A ÷ 185 A = 75.7 %

12% × 75.7% = 9%

so this would seem to be the limit on mixture.

Last but not least is to look at plate design. Here is what happens when you pass electrons through an electrode:

http://www.hho2u.com/images/304-usedstainless-steel.jpg

One of the facts missing in the fine print is that you are consuming the electrodes, not just water. That can get expensive, unless you have a cheap supply. I'm going to go off and look at plate design and come back to this later.

I still don't know if I am anywhere close to what the manufacturers are claiming. I would need to see their numbers.

Emil
02-29-12, 06:30 AM
Oops ... I did not notice this thread !
How about a new engine design? (not a four-stroke engine)

Grumpy
02-29-12, 09:25 AM
spidergoat

http://cdn.burtonpower.com/skin/frontend/default/bpp_theme/images/BurtonPower/TechTips/Ford-Zetec-E-Engine.jpg



These guys can help if you want to stay naturally asperated...

http://www.burtonpower.com/tuning-guides/tuning-guide-pages/ford-zetec-e-tuning-guide.html

And this will tell you how to build a 300-500 hp turbo...

http://www.fiestaturbo.com/articles/zetecturbo/

Grumpy:cool: