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Arc welder transformer for HHO cell

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large_ghostman

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Just wanted some thoughts on this. I have a water voltameter, it came from school and is really old, so old the wires have platinum coatings on the tips for the electrodes! It was a old Griffin and George model.

Anyway normally I use RO water with a single drop of 96% Sulphuric acid added to make it conduct better, the electrode go into separate burette type collectors with taps on the top. I will take some pics in the morning so you can see the set up.

These collectors and the water go into a large glass tube of around 2 ltr capacity, you wack 12V 2A through the electrodes and get one column of Hydrogen and one of oxygen (marvellous). The gases never come into contact with each other.

Now upscaling this, I dont want to use the normal electrodes. I got hold of some really hard, long graphite rods. These are around 3cm thick and 10" long.

I was going to cut them down and seal the copper wire so it didnt come into contact with the water, then just use the graphite ends up into the burettes to get the gas. Heat will be a problem, so 4ltr milk containers filled with saturated salt water and frozen, this gives me ice at around -17C (measured). Crush this and add tap water to make a very cold slurry, place the water tube in the cold slurry.

I have seen anti flash back devices made from copper tube, basically 1/4" tube into 1/2" then 1/4" again, the 1/2" tube was filled with stainless steel fine wool.

I have a method of filling a front wheel tractor tyre inner tube (small one), to a good psi for storing the oxygen (I dont need that often). The hydrogen I will use as its made, one use is for my Gas Chromatograph, the other is for use like an inert gas is on a methane reactor. hydrogen has some advantages over nitrogen for methane production.

Now the questions............

This isnt intended to run for long each time, Would it be better to lower the voltage? its around 24V out of the welder, I am hoping to use around 30A current (lowest setting on the welder). I should be able to make enough Hydrogen to do small GC runs, normally I use Nitrogen but for some apps hydrogen is alot more accurate. buying a cylinder of hydrogen is a nightmare and the rental each month makes it a no go.

Thoughts and suggestion??? And no this isnt for a normal make your car go faster rubbish! This is a serious question at an attempt to produce low pressure reasonable volume Hydrogen. Not too sure what I will use the Oxygen for yet, but it will be stored well away from the house :D. Yes I have an arduino hydrogen detector for leaks in the GC.
 

hyedenny

Active Member
WTF?!?
Hydrogen is not an inert gas.
How the heck does one use nitrogen in methane production?!?
Storing pure oxygen in rubber is NOT a good idea.
You're right about the car/rubbish part -- but what rubbish is this for?
 

Les Jones

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Hi LG,
Another potential danger may be oil in the compressor that you use with the oxygen. Oils and oxygen under presure can form ozonides which are explosive. I don't know how high a presure is required for this to happen but it is probably worth researching. I think ozonides are quite sensitive like nitrogen tri iodide. Your schemes remind me of some of the thing I tried to do as a teenager such as electrolysing molten sodium hydroxide to get metalic sodium and making diethyl ether using ethyl alcohol and concentrated sulphuric acid. (I think it worked by removing a water molecule from the alcohol) I must have been lucky to get away with it as I used a bunsen burner to heat the flask.

Les.
 

chemelec

Well-Known Member
If your Hydrogen is PURE, No Oxygen or Air mixed in it, than Flash back is Not a Problem.
Hydrogen Can't Burn without Oxygen.
 

tcmtech

Banned
Most Helpful Member
Why not just make your Hydrogen with common chemical reactions like Sodium Hydroxide and clean aluminum shavings mixed in with your RO water? o_O

Aluminum + Sodium Hydroxide → Hydrogen + Sodium Aluminate
2Al (s) + 6NaOH (aq) → 3H2 (g) + 2Na3AlO3 (aq)
 

large_ghostman

Well-Known Member
Most Helpful Member
WTF?!?
Hydrogen is not an inert gas.
How the heck does one use nitrogen in methane production?!?
Storing pure oxygen in rubber is NOT a good idea.
You're right about the car/rubbish part -- but what rubbish is this for?
Methogens hate oxygen, some more than others. Nitrogen can be used with some to exclude oxygen. However Hydrogen is used for the stricter types, and as I am sure your aware Hydrogen is used in conjunction with CO2 to make methane via the metabolic pathways within the organisms.


No compressor as such involved, vac pump out a container with two one way valves, evacuate the container and close both valves. Then open the valve to the oxygen side, oxygen as evolved fills the vacuum. Once at STP close oxy side valve and open inner tube valve, use tiny (all I got) diaphragm HP pump to inject small stream of high pressure water (85 psi) into oxy container. Wate3r displaces the oxygen and the only place it can go is the inner tube.


Using electric instead of chemical is for a greater control of production, chemical reactions require alot more work and faff to get a steady stream of known volume into a gas chromatograph, or I would go the HCl and Al route, but then I also have to wash and dry the gas etc as the FID on the GC would pic up all impurities within the gas and totally ruin the results. Hydrogen is only needed/used when Helium (next best gas) or nitrogen (most common used), is not sensitive enough to pick up low FID signals on the GC.

Thanks for the inputs guys, all welcome and made me rethink and evaluate.

Oh and hyedenny I specify exactly what its for in my first post ;) actually I mention the uses twice, one being this part. Rubbish it may be, it may also be pointless, but at 16 it is a deep learning experience. One day I will do do something with my life that my dad would of been really proud of. This is just part of my journey to that destination.

"I have a method of filling a front wheel tractor tyre inner tube (small one), to a good psi for storing the oxygen (I dont need that often). The hydrogen I will use as its made, one use is for my Gas Chromatograph, the other is for use like an inert gas is on a methane reactor. hydrogen has some advantages over nitrogen for methane production."

Filling a methane reactor with Hydrogen is often used in multi tank systems, not so often in inefficient 1 or 2 tank systems.
 

hyedenny

Active Member
"Methogens hate oxygen, some more than others."

I think you mean "methanogens." But now I'm even more confused -- Are you intending on using bacteria or electricity?!?! If you're using bacteria, why the hydrogen? There are probably easier and safer environments for the bacteria to live.
 

large_ghostman

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I am making a methane bioreactor. Mine is based on a different design to normal, it is more like a cows stomach. Cows actually belch more methane than they fart. So the microbes responsible (not just bacteria), are found in the various stomachs. The problem is isolating and growing the growing the different cultures.

If you take cow ****, then yes you can produce methane. The problem however is the efficiency is very low, for best results you need specific microbes. These you harvest from a freshly killed cow, you get the stomach (all 4 of them) from the slaughter house. Then you isolate immediately, one of my problems is the distance to the slaughter house. So I need hydrogen to isolate some of the cultures, I also need it to help grow them and separate the different microbes in my lab.


I am aiming for high efficiency, so one of the 5 chambers in the reactor will be evacuated with Hydrogen. This gives the best conditions for one particular microbe. Its very common practice in professional systems to use Hydrogen when starting or refilling a two or more chamber system, or for separating different cultures.

Methane is actually produced from hydrogen and CO2, although the CO2 isnt around long being converted almost straight away.
You also need a little nitrogen, a atmosphere solely containing Hydrogen at the start retards the process. If you like I can sift through the papers I have for you to look at.

My other use for Hydrogen, and likely to be the one I need the most Hydrogen for, is so I use it as both a carrier and FID gas in a Gas Chromatograph. This use has little to do with Methane, so your kind of fixating on one thing, when the reality is having Hydrogen on tap has more than one application for me. Because of my age hiring and buying a large Cylinder of it is not really practical.

I do have the gauges etc for the cylinder, but delivery to where I live is £80, the cylinder of Hydrogen is £180 and the monthly hire cost of the cylinder is £44 (without vat). Then I would have the cost of the trolley and all the other stuff to comply with the regulations.............

For the amounts I am likely to use it makes more sense to make. I have 11 different cultures so far, I have gone as far as I can using other gases and culture media. Now I want to look at one particular microbe, from alot of reading of papers I know that trying to culture it without Hydrogen is a non starter.

Yes I made a spelling mistake, you will get used to that with me. You might eventually get used to my mad projects, or maybe not.
 

tcmtech

Banned
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or I would go the HCl and Al route, but then I also have to wash and dry the gas etc as the FID on the GC would pic up all impurities within the gas and totally ruin the results.
I mentioned Sodium Hydroxide and Aluminum NaOH + Al which should give you a rather clean gas byproduct to work with. Or at least one that a pass through a simple desiccant plus charcoal powder filtration would likely come out clean since there are no other potentially gaseous byproducts other than Hydrogen and possibly water vapor if you ran it to hot which would be no different than your electrolysis system would have the potential to create.
 

large_ghostman

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I mentioned Sodium Hydroxide and Aluminum NaOH + Al which should give you a rather clean gas byproduct to work with. Or at least one that a pass through a simple desiccant plus charcoal powder filtration would likely come out clean since there are no other potentially gaseous byproducts other than Hydrogen and possibly water vapor if you ran it to hot which would be no different than your electrolysis system would have the potential to create.
But the rate is still harder to control, you cant rapidly adjust the rate of gas produced, with electric it is almost instant. I played with the chemical route and it was a mare. With electric I have alot more control, yes the graphite wears, but that isnt much of a problem. Although the amount of gas needed isnt huge, it does need some volume. With the chemical route you cant stop instantly if something starts to go wrong, I do alot of chemistry and it would worry me to try this the chemical route.
 

tcmtech

Banned
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The way I think of these sort of chemical reactions is like working with a positive displacement hydraulic pump. Build the pressure you need then just dump the rest out via a relief valve.

If it was me I would do the reaction a containment vessel with a dedicated relief valve to keep its pressure and contained volume of gas up above whatever pressure and feed rate you need then just draw off it with a common pressure and or flow regulator from that.

It's just a thought.
 

large_ghostman

Well-Known Member
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The way I think of these sort of chemical reactions is like working with a positive displacement hydraulic pump. Build the pressure you need then just dump the rest out via a relief valve.

If it was me I would do the reaction a containment vessel with a dedicated relief valve to keep its pressure and contained volume of gas up above whatever pressure and feed rate you need then just draw off it with a common pressure and or flow regulator from that.

It's just a thought.
For small amounts, for say the bio stuff then yes chemical is an option, but it leaves you with a waste product and the cost is higher. For the Gas Chromatograph I need good control and the amounts of chemicals and waste etc, IMHO makes the electrical route more practical. I can sit at the pc controlling a GC run and simply dial up or down the current to regulate the hydrogen. With chemicals I have to alter drip rate and faff, and again I am left with a chemical I dont have much use for.

I can run the welder on the small diesel generator with bio fuel at around 14p an hour. Plus sodium hydroxide is rough on glass etc etc. I still use the chemical route with bio cultures at the moment, its one reason i started looking at other options.
 
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