Thread: Hydrogen Fuel cell/ Joe cells with Landys

it all depends on condition of your engine and how ificant it is (some injected ones need looms to stop them overfueling)
browns gas is a bit more complicated and most designs a suseptable to bumps
so a simple forsed hidrogen setup is brobably better to start playing with
i have a book hear i can but on a dvd and send if your intrested

Originally Posted by hillbilliywheelchair

it all depends on condition of your engine and how ificant it is

OK then, let's use some known quantities then - how about we talk in terms of a brand new (0km, std factory trim or freshly rebuilt equivalent) Isuzu 3.9l 4BD1T. I know it's an older design, but it's tried and true and there's no electronic management system to have to work around. I don't know the efficiency figures for this particular engine, but surely someone here can help us with that info?

Originally Posted by hillbilliywheelchair

browns gas is a bit more complicated and most designs a suseptable to bumps

How so? Excuse my ignorance on this, but I would have thought that a common ducted brown's gas generator would actually be less susceptible to bumps than a separated electrode hydrogen/oxygen generator, as it could (theoretically, at least) operate at any angle up to the point where the electrolyte covered the outlet port - in a conical vessel with sufficient neck length (> 1.5 times the neck diameter) the cell should be able to be laid over to almost the same angle as sides of the vessel itself (momentarily, at least) without either uncovering the electrodes or covering the outlet port.

Could you please point out where my logic is flawed?

Originally Posted by hillbilliywheelchair

so a simple forsed hidrogen setup is brobably better to start playing with

Can you please explain what you mean by a 'Forced Hydrogen' setup? I'm not sure I follow.

Originally Posted by hillbilliywheelchair

i have a book hear i can but on a dvd and send if your intrested

Thanks for the offer, I may take you up on it at a later stage.

OK, well, according to the figures on the website BrownsGas.com, who sell gas generators for running cutting/brazing/soldering torches etc, you need approximately 100 Watts per Litre of gas generated per minute, so bear with me while we bash some numbers about....

So, using VERY rough numbers, to produce enough gas to displace 10% of your diesel consumption (assuming 10l/100km) then you'll obviously need 1 litre of gas per 100km, or 10cc of gas per km. (Like I said, bear with me. )

Another assumption for timeframe says you're travelling at 100km/h, and so that means you're doing roughly 1.67km/minute, so you're requiring approximately 17cc of gas per minute.

So far that all looks good, if you need 100 Watts per litre per minute then to make 17cc per minute you only need a measly 17 Watts, or 1.42 Amps @ 12 Volts.

Pretty convincing, hey? I could nearly sell these things on the basis that you can generate enough gas to displace 10% of your current fuel consumption with less energy input than it takes to run your interior cabin light...

...BUT - I haven't included one very important factor called "Energy Density"...

Diesel has an energy density of approximately 32.8 MJ/kg, whereas Hydrogen has an energy density of about 142MJ/kg. So one kilogram of Hydrogen has about 4.33 times the amount of energy as one kilogram of Diesel.

Still sound good? OK, well one kilogram of Diesel is approximately 1.18 litres by volume - now for the kicker - one kilogram of Hydrogen (@STP) is just over 11,123 litres.

This is where it all falls over.

The last lot of numbers means that while Diesel has roughly 27.8 MJ/litre available energy, Hydrogen only has about 0.013 MJ/litre available energy. This means that in order to replace 10% of the energy requirement for your vehicle - i.e. 1 litre of diesel, or 27.8MJ of energy, per 100km - you'd need to supply 2,138.5 litres of gaseous Hydrogen per hour (at 100km/h).

Given the requirements of 100 Watts per litre per minute to generate the Hydrogen, and the requirement of 35.6 litres per minute (2,138.5 litres/60 minutes), this translates to around a 3.5kW power requirement to run the gas generator.

In terms of current that translates to approximately 292 Amps - or about the same current that your starter motor draws each time you hit the key.

Somehow I'm not seeing the efficiency in it...

ok almost on the correct track BUT
you have based your numbers on browns gas, browns gas being produces with a different electrolyte is the most efficient electrolysis way of producing gas so you production numbers will be a bit on the high side.

secondly you are using numbers for a strait hydrogen oxygen burn which is not what happens under compression with diesel nitrogen etc present.

have a look at how Dgas works as it is more simlur to that than the track you have taken.

how ever your results are close to mine i got 102 amp per minute.

Originally Posted by clean32

...browns gas being produces with a different electrolyte is the most efficient electrolysis way of producing gas so you production numbers will be a bit on the high side...

Yes, because a common ducted browns gas generator appears to the simplest system for one to DIY - the generator, at least. As for a different electrolyte, I'm not sure what you mean there - the systems I was looking at were just using distilled water.

You also say my "...production numbers will be a bit on the high side..." - which ones?

Originally Posted by clean32

secondly you are using numbers for a strait hydrogen oxygen burn which is not what happens under compression with diesel nitrogen etc present.

Agreed. As I said early in my post - they were VERY rough numbers. Essentially I was working it out as I wrote the post. But surely you must also agree that in order to reduce the amount of diesel consumed by one litre, you must replace the energy that would have been provided by that litre of diesel? Some of that will come from the improved combustion of the diesel that is already present, but most of it will come from the additional combustible hydrogen that has been introduced.

Now I have to admit that I haven't included the additional benefits of improved combustion into my calculations, but I would have to say that without a significant background in chemistry, physics, and mechanical engineering, then the calculations to include those factors are likely to be beyond the average Joe. (pun intended!)

Originally Posted by clean32

have a look at how Dgas works as it is more simlur to that than the track you have taken.

In what way? In that it does improve combustion and reduce emissions? I can concede that. However, even with a diesel/LPG system you're still providing additional energy by introducing the LPG into the mix.

Originally Posted by clean32

how ever your results are close to mine i got 102 amp per minute.

I'm not sure I'd completely agree there - there's a fairly big difference between 102 Amps and 292 Amps. Would you care to share you calculations?

im not going to tackle your post as written but will try to explain it another way, it is quite logical once you get it.

Heat will not push a piston down. but it is heat that excites what ever is in there to push the piston down. if you were to produce a total vacume in a combustion chamber and then manage to introduce heat, nothing would happen.

to follow that line of though and oxygen and hydrogen reaction will only produce water, thats simple. but water is smaller by volume than that oxygen and hydrogen as a gas. so logically if you were to use only oxygen and hydrogen in a combustion chamber it would suck the piston up not push it down.
well that doint happen ether, the piston will go down but only because heat is produced as a by product of the reaction or burn. this heat turns the water to steam.

so rather than calculate just the amount of energy produced you must calculate the difference in volume between the oxygen and hydrogen gas and its product steam at a given tempter. i think you will fined that there is very little difference.

BUT if we were to introduce another gas like nitrogen to replace some of the o & H gasses we would see a very different response, Nitrogen which takes no place in the reaction is heated and becomes the main force in pushing the piston down.

next,lets add some other stuff, carbon for example. now we have oxygen hydrogen and carbon present in the reaction, this is where things start to get more complicated. but in short all IC motors are the same regardless of the fuel. diesel and petrol are just a bunch of carbon and hydrogen all linked together, Octane = 8 Centaine = 10, think of it that way. once you understand that, then you will understand that the reaction in a combustion chamber is just a matter of mixing up what ever is put in there, pulling it to bits and building up new stuff to come out the back pipe.
to put it another way, diesel has less hydrogen than petrol but more other stuff to be heated up and push the piston down. petrol has more hydrogen but less other stuff. by adding more hydrogen to a diesel you are making it a bit more petrol like or the reaction a bit more petrol like. its is not to separate reactions diesel oxygen and a hydrogen oxygen. for example you will not get water out of you tail pipe if you add hydrogen to you diesel, ( well you do any way but not much and there is little change.

being very over simplistic but i hope it helps.

Oh browns gas, its only difference is what you add to the water, apart from that it looks the same. but if you dont add any thing DC current will not flow very well, just dont add salt.

Originally Posted by clean32

im not going to tackle your post as written...

I do wish you would, please - I asked a few questions in there that I'd like to see answers to if possible.

Originally Posted by Jonno_G

I do wish you would, please - I asked a few questions in there that I'd like to see answers to if possible.

but i have answered your questions, as for the maths i have already done this ( some where)