Lots of HHO gen. Qs.

[JRMichler]

Originally Posted by sunburnt

1) Is DC current necessary? Use 120v AC current directly?
Why would current direction make a difference?

2) If AC no good, then a bridge rec. for pulsed DC?
So no expensive power supplies are needed.

8) How to calculate HHO use only, liter vol. per liter of engine?
Running gas and HHO both is an overly complex setup.

9) Safe HHO storage methods? Tank types, etc.

I'll give straight answers to some of the OP's original questions.

Yes, DC current is necessary. Bridge rectifier should work just fine. That's because oxygen is generated at one electrode, and hydrogen at the other. Those two gases should not be mixed until inside the engine. Separately, hydrogen burns and oxygen accelerates burning. Together, they form a bomb.

A course in high school chemistry and another course in high school physics should be enough to do the calculations. I'm too lazy, so I won't. Those who have done the calculations found that using electrolysis to generate an amount of hydrogen equivalent to a gallon of gasoline will cost several times as much as a gallon of gasoline in electricity cost alone.

Hydrogen is very difficult to store. The atoms are so small that they permeate right through solid steel. Hydrogen causes hydrogen embrittlement in steel.

[mort]

Originally Posted by sunburnt

Any info and suggestions are appreciated.

120v, ~ 30 plates, 2 active and 28 passive for 2v operation.

1) Is DC current necessary? Use 120v AC current directly?
Why would current direction make a difference?

2) If AC no good, then a bridge rec. for pulsed DC?
So no expensive power supplies are needed.

3) How thin can plates be? Maybe heavy foil?
Why use more material than is needed to keep the plate flat?

4) Stainless plated aluminum? Maybe cheaper than all stainless.

5) Minimum ideal spacing between plates?

6) Most gen. units have 1 lower inlet and 3 upper outlet holes.
This so the gas can exit easily?

7) Best way to shake bubbles free from plates?

8) How to calculate HHO use only, liter vol. per liter of engine?
Running gas and HHO both is an overly complex setup.

9) Safe HHO storage methods? Tank types, etc.

Hello!
I'll reply directly to your questions as best I can.

"120v, ~ 30 plates, 2 active and 28 passive for 2v operation."

This isn't right. Wall voltage is a sine wave with peaks at about 170 volts. You should aim for just over 1.5 volts per cell. I have no idea what active and passive mean in this context.

1. DC is necessary, AC will reverse the reaction every half cycle, and you get no gas evolved.
2. A bridge is acceptable. But the water is only dissociated into gasses when the charging voltage is above the equivalent "battery" voltage for the cell. That's about 1.5 volts. The AC from a wall plug is a sine wave, since excess voltage only heats the water - it doesn't make more hydrogen, there are efficiency issues with using unfiltered bridge rectified AC.
3. There is a trade off between plate stiffness and insulating spacing. If you can find a sufficiently porous insulator then the plates could be supported by the insulators.
4. For equivalent use SS is slightly cheaper than aluminum.
5. Plate spacing is mostly a mechanical issue. The plates cannot touch, and you need to have a way to separate the hydrogen from the oxygen.
6. yes.
7. Why? Gravity seems to work fine.
8. I don't understand this question. A gallon of gasoline (about 6 lbs per gallon or 2.7 kg per gallon) contains about the same energy as about 1 kg of hydrogen. If your car needs 15 gallons to travel 450 miles, it will need 15 kg of hydrogen to go 450 miles.
9. There are no economical and safe ways to transport usable quantities of hydrogen. Liquified - requires refrigeration and still wastes some hydrogen as boiling some off keeps the rest cool. And the insulated pressure vessel is expensive. High pressure tanks are limited to about 5000 psi, that allows about 30 g/l - 15 kg will take up 500 l, about 130 gallons. And a leak is a disaster. Hydrogen is unique in this regard: For all other gasses at pressure when the pressure is reduced through, say, a pin hole leak, the temperature of the gas lowers - the gas gets cold. In the case of hydrogen the leak gets hot. Hydrides, so far are experimental and generally of lower density than high pressure, but may be safer. The dozen or so alternate hydrogen storage methods are covered by wikipedia. None are in commercial use.

You can probably generate hydrogen at home cheaper than the equivalent energy of gasoline. But storage and transportation in the car is likely to be very expensive.

-mort

[oil pan 4]

Originally Posted by JRMichler

Those who have done the calculations found that using electrolysis to generate an amount of hydrogen equivalent to a gallon of gasoline will cost several times as much as a gallon of gasoline in electricity cost alone.

I did back in 2008, when a rash good intentions and a serious lack mathematic and scientific understanding with some mass hysteria upon the realization that $3/gal gas was here to stay lead people to believe hydrogen was somehow on the verge of being a dirt cheap motor fuel of choice.
I calculated that it would take some where on the order of $15 to $20 worth of power to generate 2kg of hydrogen. 2kg of hydrogen contains about the same BTU value of a gallon of gas burned in air.
So you pay $20 to replace gasoline with a more dangerous, more difficult to store, nearly impossible to transport fuel that has limited to poor combustion qualities in an ICE.
Any further questions as to why everyone isn't using it?

An electric vehicle or regular vehicle running an alternator delete makes way more sense.

[RedDevil]

Originally Posted by Cobb

Why hasnt this been moved to the unicorn section?

We need an HHO section. Seriously. There is so much HHO blah and so few unicorns around, poor beasty is getting overworked.

[elhigh]

Originally Posted by mort

You can probably generate hydrogen at home cheaper than the equivalent energy of gasoline. But storage and transportation in the car is likely to be very expensive.

-mort

This is the one part of your answer I find highly questionable.

Given the best proton exchange method and high quality platinum electrodes and optimized voltages and whatever ultra-top-drawer catalyst you might have handy, you might see 80% efficiency. The power delivered via the grid is already conveyed by a lossy, inefficient system, must we compound that loss further with yet another conversion?

Every conversion necessarily carries a commensurate loss in efficiency; you cannot get a perfect outcome by using X kilojoules worth of electricity to generate X kilojoules worth of hydrogen, which would then yield X kilojoules worth of energy when you used the hydrogen (however you used it). You CANNOT. The universe doesn't work that way.

As lousy as they are with their 20-25% thermal efficiency, gasoline engines actually do a pretty good job of getting things done. The gasoline is ignited to release heat, expanding the gases in the cylinder, pushing on the piston, turning the crank and driving the car.

If you want to do that with hydrogen, then take all the losses in the simple process I just described as a percentage, multiply them all times each other, and then multiply that by whatever percentages represent hydrogen. Don't forget the losses in the national power grid, they're pretty significant. Estimates suggest maybe, on a very very good day, about 50% of the heat energy in the coal actually comes out of consumers' wall sockets as usable power. Usually it's a lot less.

Hydrogen has huge potential, I won't argue that. But it will require a radical leap in how it's generated before it's ready for prime time, and the assorted HHO systems haven't found it.

NOTE: I am not an engineer, physicist or chemist. I'm halfway smart and am paraphrasing several articles I've read on the subject. I may have missed some finer points but I'm confident I got the meat of the matter correct.

[JRMichler]

Here's a good article on the costs for various methods of generating hydrogen: Hydrogen Basics - Production

Gasoline has about 128,000 BTU's per gallon. If gasoline is $3.80 per gallon, that's $30.00 per million BTU's.

[mort]

Originally Posted by elhigh

NOTE: I am not an engineer, physicist or chemist. I'm halfway smart and am paraphrasing several articles I've read on the subject. I may have missed some finer points but I'm confident I got the meat of the matter correct.

I believe you misread my post. What I said was: "You can probably generate hydrogen at home cheaper than the equivalent energy of gasoline." I meant that amount of money you need to pay for electricity would be less than the amount of money you pay for the equivalent amount of gasoline.
You can check all these assumptions via some wikipedia page, probably.
Conversion efficiency for simple electrolysis is about 70%
The amount of energy in a gallon of gasoline is 33.557 kw-hr (which is about the same as 1 kg of hydrogen). So it requires about 48 kw-hr to produce 1 kg of hydrogen. The hydrogen gas equivalent to 1 gallon of gasoline costs 48 times whatever a kw-hr costs where you live. Today's pump price for gasoline in the USA is $3.654 per gallon. US electrical rates vary over a wide range. Here in Los Angeles this month I pay 17.8 cents per kw-hr, so a gallon equivalent of hydrogen is about $8.55. vs ($4.13 at the pump) But if you are an industrial user in Oklahoma your equivalent cost for hydrogen is $2.61. But even a residential customer in Washington state sees $4.18 per gallon equivalent. You can produce hydrogen cheaper than you can buy gasoline, if you live in the right place.
-mort

[mort]

Originally Posted by JRMichler

Here's a good article on the costs for various methods of generating hydrogen: Hydrogen Basics - Production

Gasoline has about 128,000 BTU's per gallon. If gasoline is $3.80 per gallon, that's $30.00 per million BTU's.

Note on that page it says this:

... producing hydrogen from electrolysis with electricity at 5 cents/kWh will cost $28/million BTU ...

-mort

[ecoTex]

Note on that page it says this:Quote:... producing hydrogen from electrolysis with electricity at 5 cents/kWh will cost $28/million BTU ...-mort

According to this page....

Average electricity prices around the world: $/kWh

a kwh of electricity in the USA costs $.12.
I guess you can make anything economically viable if you get to make up the prices of everything. Just ask any government anywhere.

[user removed]

Even pure liquid hydrogen would need almost 4 times the volume to equal the energy content of an equivalent volume of gasoline at room temperature.

I spent a day with two gents who were trying to sell HHO systems in eastern Va. It was before I joined this forum and I had a Del Sol that averaged about 43 MPG for me. I was showing them around the area where I have lived most of my life.

When they told me how much I could increase my mileage with an HHO system, my response was "why not just make it totally HHO powered". They said "it doesn't work like that". My mind immedaitely realized they were actually saying "it doesn't work".

Virginia had passed laws that required any HHO systems to pass the same emissions testing that was required of the same car without an HHO system. I did a little research and when I found the actual energy content of a liter of HHO, which is 14/16ths oxygen I realized that the 1.5 wooden matches per liter of HHO equivalent was the best way to explain it to people like me who do not have the educational background to understand the obvious.

The two gents were focusing on diesel truckers, who if they understood diesel engines would accomplish more by having their injectors tested and brought to specs as most of them slowly loose breakoff pressure as they age, from 1800 PSI to 1400 and even lower (based on my Mercedes experience). This pressure drop causes poor atomization and the clouds of smoke you see from some diesels.

Alternators do not produce "free" energy and anyone who thinks they do is not even trying to understand Carnots Law. Adding loads to your alternator means more fuel consumed, with that single conversion efficiency at less than 34% tops, more like half that for the average vehicle. All the rest of the "tweaks" to "fool" your engine into running leaner are just more attempts to justify what is simply not possible, since every time you convert energy into useful work you loose some of that energy.

Just figure out how to make your engine run "lean burn" if you want to, like pgfpro is doing (and my hat is off to him for his fabulous work) and forget about HHO, which is 80% oxygen (by atomic wieght) and if you don't understand that oxygen is not a fuel and has no energy content then more discussion is a total waste of time and intelligence.

Do the research, come back with a realistic rational description of a system that passes all of the tests and I would be one of the first to install that sytem, but if you do I want to run on 100% hydrogen, but the fuel tank would be larger than a tanker truck unless the hydrogen was liquid.

40 years ago they built liquified natural gas carriers and Newport News shipyard. There was an article in Argosy magazine that discussed the hypothetical ship to ship collision in New York harbor where the cryogenic tanks in the LNG carrier were ruptured. The fireball would be stupendous. After that article the insurance carriers refused to insure the LNG carriers under any circumstances and they were mothballed.

regards
Mech