HHO-only Diesel car

[smallscaleH2]

Originally Posted by RedDevil

If you compress hydrogen like generated with your own electrolyser and you cannot guarantee that no oxygen will seep in along with it then you run a very high risk.
If you compress straight Brown's gas (yes 'HHO') then it goes beyond being a risk. Lethal detonation is a certainty.

After what RedDevil said about HHO (see above), it got me thinking: if it's so explosive, even at relatively low compression, wouldn't it be a good fuel for Diesel vehicles (again, only for city use, not for long-distance driving). Like hydrogen, it's a completely clean fuel, so I'd like to use it for this.

At present, it's mostly tested when mixed with a fossil fuel (gasoline or Diesel), but a quick search revealed that some people have indeed used it as a single fuel (not mixed).

Range is going to be far worse than with hydrogen (since that's compressed), and an HHO electrolyser would need to be fed by a battery (and water tank).
So, like battery-electric vehicles, it would be limited to what energy you can store in the batteries, and conversion efficiency is even far worse (less than half of battery-electric vehicles since we'll be using an internal combustion engine). The upside though is that the conversion would not cost much and is easy to do (if you already have a Diesel engine-powered vehicle). Also, this conversion can be done with Diesel-engine vehicles, whereas hydrogen conversions would only be possible with gasoline-powered vehicles.

So, anyone here at ecomodder knows whether this will work, and does anyone also know the correct air/fuel mixture to use for HHO(-only) ?

[samwichse]

LOL running an engine off uncompressed HHO as the sole fuel!!!

Range: 0.3 miles.

[smallscaleH2]

Originally Posted by samwichse

LOL running an engine off uncompressed HHO as the sole fuel!!!
Range: 0.3 miles.

How did you calculate the 0,3 miles ?

Also, I do mean to use an on-demand system, so the idea isn't to store the HHO in a tank (uncompressed). Rather the energy comes from a battery that generates uncompressed HHO (on-demand) from a water tank -via an HHO electrolyser obviously-.

So, if you use a same battery as you would use in an electric car, you'd get about half the range of the electric car (well that's the theory at least, in practice, the voltages of those electric car battery packs will be higher than what you need for the electrolyser, so you'll need to use a different battery). But still, I do think you'll get acceptable range (at least for city use).

But to be sure, we'd have to calculate it out.
From hydrogen I know the energy in it is 0,003 kWh/l @1 bar (so uncompressed)
From Brown's gas, I have no gasoline gallon equivalent (kWh/l) information, so I can't calculate it.

Also, for the air/fuel ratio, I'm equally lost. Hydrogen has a ratio of 34.3:1

I'm assuming the air/fuel ratio needed for Brown's gas should be even higher, as I'm assuming it's much more energetic (I once heard it was 4x more energetic). This would then mean you could drive further with it (if you inject it in this proper ratio).

How do you calculate the amount of liters of fuel you need btw per liter of engine (so say for a 1 l engine, or hence a 4 cylinder, 0,25l per cylinder), using a known air/fuel ratio (say 14.7:1 for gasoline) ?

[smallscaleH2]

According to this site,
hydrogen has 50,000 Btu's per pound whereas Brown's gas has about 66,000 Btus per pound. So, that means it would (presumably) be 32% more energetic
(66 000 - 50 000 = 16 000 / 50 000 = 0,32 x 100 = 32 )

If so, than it would have 0,00396 kWh/l
(0,003 kWh for hydrogen x 1,32 = 0,00396 )

The same site also mentioned that you could generate 340 litres of Brown's gas (13.6 cu. ft.) per kilowatt-hour. If so, than the amount of energy you could generate per 1 kWh battery would be 1,3464 kWh
(340l x 0,00396 kWh/l) so that would be even more energy than the energy in the battery itself.

This doesn't seem right. I guess there are probably some incorrect figures here, so let's calculate it out another way.

At wikipedia we read at the Brown's gas page:
"Theoretically, a ratio of 2:1 hydrogen/oxygen is enough to achieve maximum efficiency; in practice a ratio 4:1 or 5:1 is needed to avoid an oxidizing flame."

So if we consider that oxygen does not add any energy, and only the hydrogen in the HHO adds energy, then HHO could be
- 50% less energetic then hydrogen (2:1 H2-02 ratio)
- 25% or 20% less energetic then hydrogen (4:1 or 5:1 H2-02 ratio)

Depending on this, it could have:
- 0,0015 kWh/l
(0,003 kWh for hydrogen x 0,5 = 0,0015 )
- 0,00225 kWh/l or 0,0024 kWh/l
(0,003 x 0,75 = 00225 ; 0,003 x 0,8 = 0,0024 )

Regarding the amount of energy you could generate with it:
I could not find any data on the efficiency of HHO electrolysers, but there is data of the efficiency of hydrogen electrolysers (which granted, work at a different way). But still, it gives an idea. Anyway, PEM electrolysers are 94% efficient, alkaline electrolysers are 43-67% efficient. So let's say the HHo electrolysers are 50% efficient. Then how much liter of gas could they generate ?

Calculation:
A 1 kWh battery could then generate 0,5 kWh on HHO gas.
The HHO gas has an energy of (and now we use a range of found data above): 0,00396 kWh/l or 0,0015 kWh/l or 0,00225 kWh/l or 0,0024 kWh/l
So:
0,5 kWh /0,00396 kWh/l = 126 liter
0,5 kWh /0,0015 kWh/l = 333 liter
0,5 kWh /0,00225 kWh/l = 222 liter
0,5 kWh /0,0024 kWh/l = 208 liter

[samwichse]

Look, this is the last I'm posting in one of these threads because they become worse and worse as they go on. This probably belongs in the unicorn corral for math failures being interpreted as over unity garbage.

A 2L diesel going down the highway at 60 mph is turning 2000 rpms. This imaginary diesel is drawing 2L into itself every other revolution. 16.7 times/sec. So 33.3L/sec. For simplicity I'm going to say 2:1 air to your atmospheric pressure tank. So about 10L/sec from your 250L tank is 25 seconds. Or 0.4ish miles traveled.

Or generating it from an onboard battery? So you're going to take a 1kw battery, use it at 50% efficiency to make this gas, then burn that gas 30% efficiency in an engine. Thereby getting 167wh of motive force from it and adding a 9ft^2 tank "somewhere" in the car.

You could literally get more than twice this improvement in FE by throwing an extra (small) deep cycle battery in your car and disabling the alternator for a while.

None of this even approaches making basic, logical sense enough for it to even be a valid thought experiment.

[teoman]

Don't bash the fellow. He is going through the natural thaught process as we all have.

When the hype first came around we all said "cool, hydrogen power" then did the calculations to discover that it was not even remotely possible.


He is a little bit late in the game an generally anyone who is capable of crunching the simplest numbers now knows how inefficient hydrogen generation is. Combined with the fact that people have been trying to push hydrogen boosters and other nonsense to the market people are generally fed up with topics related to hydrogen.

[RedDevil]

Originally Posted by smallscaleH2

According to this site,
hydrogen has 50,000 Btu's per pound whereas Brown's gas has about 66,000 Btus per pound. So, that means it would (presumably) be 32% more energetic (etc)

Since you derived the idea from my quote I feel entitled to comment, with trepidation.

That statement there is bunk; it is wrong at several levels. That whole website is complete nonsense. And here is why:
It does not matter if the oxygen comes from the air or is contained within the gas itself when it comes to calculating BTU's. Oxygen is just the reactant that oxydates (!) the hydrogen. Only the hydrogen counts as fuel.

Hydrogen has an atomic weight of about 1 unit per atom. Hydrogen gas consists of molecules made up with 2 hydrogen atoms, weighing 2 units per molecule.
Oxygen has an atomic weight of about 16. A molecule of oxygen is 16 times as heavy as a hydrogen molecule; as both are perfect gases, per volume oxygen is 16 times as heavy as hydrogen gas.

Browns gas is a mixture of 2 molecules of hydrogen for every molecule of oxygen. Therefore it is 2/3 + 16/3 = 6 times as heavy as hydrogen, and it only has 2/3 of the hydrogen molecules.

So Browns gas has just 1/9th or 11.111% of the BTU pure hydrogen gas has per weight, and just 2/3ds or 66.666% of the BTU per volume.

So while Brown's gas is less powerful as a combustible than you think, the real problem is that, in essence, it is not a combustible at all. It is an explosive, and as an explosive it has no equals when it comes to bang per weight.
When it explodes it will not complete the reaction; the temperature gets so high that some of the hydrogen and oxygen start to lose their bonds again, and the reaction will only complete when it can shed its heat or mix with the surrounding gases.
Hence the tendency of these mixtures to create a whistling sound when exploding; the gas blows out only partly fused to water molecules, creates a vacuum that though extremely hot, still sucks back in the gas, which lost some heat on the way out and back in, reacts again; blows out, new vacuum, etc.

It may seem strange that such an explosive gas contains only so much power. But a simple gasoline engine uses 14 times the weight of the gasoline it uses on air. That is a lot of air for a little bit of gasoline.
Compared to Browns gas, you exchange the non-combustible oxygen atoms with the same amount of carbon atoms, who are very much combustible - and lighter than oxygen to boot.

Now you wanted to use it as the sole fuel in a diesel engine.
Well, diesel engines ignite by pressurizing the air-diesel mixture to beyond the detonation point. But it won't fire all in one go; it burns slowly enough to spread the bang so it won't knock too hard. Because diesel is a mixture of long and short hydrocarbons it will not all react at once.
If you would get the detonation point right with Brown's gas (if that is possible!) then the reaction would complete or reach its plasma phase within a fraction of a millisecond. While diesel engines are sturdy, they may not be able to withstand that; and if they do, it would be very noisy indeed.

You'd need to mix in at least 3 times as much air than Brown's gas or you'd just be wasting the excess because it could not react completely. But the uncontrollable detonation remains problematic. The largest auto manufacturers break their heads trying to get the diesel-style combustion working for gasoline properly. Pure hydrogen, whether mixed with air or pure oxygen, would only be even harder.

So, it is not like your idea is sound with just a few problems to solve.
It is fundamentally wrong in all of its stages.
You should be aware that hydrogen and Brown's gas have already been researched to the bone. You cannot expect surprises there within existing fields of technology.
You certainly cannot expect to get anything useful without understanding the basics - but if you get to grips with that you'd abandon the project.
Better abandon it now, when you've not yet chanced to kill yourself nor wasted too much money.

[seifrob]

Originally Posted by teoman

Don't bash the fellow. He is going through the natural thaught process as we all have.
...

Trouble is he does not listen, or at least it looks like he does not want to hear. Instead of that he simply makes another thread with similar content.

[RedDevil]

Originally Posted by teoman

Don't bash the fellow. He is going through the natural thaught process as we all have.

When the hype first came around we all said "cool, hydrogen power" then did the calculations to discover that it was not even remotely possible.


He is a little bit late in the game an generally anyone who is capable of crunching the simplest numbers now knows how inefficient hydrogen generation is. Combined with the fact that people have been trying to push hydrogen boosters and other nonsense to the market people are generally fed up with topics related to hydrogen.

I understand and I don't want to hurt his feelings unnecessarily, but I felt obliged to fast-track the process.
Because a 250 liter tank of Browns gas under atmospheric pressure is more deadly than a hand grenade or a small stick of dynamite.

My chemistry teacher ignited a layer of Browns gas foam on a dish washing tile.
Water, soap and maybe one liter of gas filled foam... What could possibly go wrong?
Nothing went wrong.
But no less than 10 teachers from the neighboring classes came storming in to check everyone was all right, and we were impressed with the strength of the classroom windows; none of them broke!

I once witnessed a huge lightning strike in a flagpole less than 10 meters away. I'm unsure whether the bang was harder or not.

[oil pan 4]

Originally Posted by teoman

Don't bash the fellow. He is going through the natural thaught process as we all have.

When the hype first came around we all said "cool, hydrogen power" then did the calculations to discover that it was not even remotely possible.


He is a little bit late in the game an generally anyone who is capable of crunching the simplest numbers now knows how inefficient hydrogen generation is. Combined with the fact that people have been trying to push hydrogen boosters and other nonsense to the market people are generally fed up with topics related to hydrogen.

Agreed, this is where I also was about 20 years ago.