DIY Hydrogen Generator





Introduction: DIY Hydrogen Generator

About: I am a german student and joined Instructables, because I like to build your projects and share mine with you.

This Instructable shows, how to build an easy DIY hydrogen generator.

Materials needed for this project:
- Empty container with lid
- Cables
- Pencil
- Luster terminals
- Hot glue gun
- DC Power Supply
- Drill
- Funnel
- Balloon

Step 1: Build the Anode

For the anode, you need an old pencil, a knife, a luster terminal, cables and a hot glue gun.

Take the pencil and strip it with a knife, until you have the lead. Put the lead into the luster terminal and tighten the screw. (Don't screw the terminal too tight, as that will break the lead)

Strip the ends of a cable and put the ends into the other side of the luster terminal.

Seal the terminal and cable with hot glue. Make sure everything is watertight. The only part which mustn't be covered in hot glue, is the lead.

As you can see I used two pieces of lead and put them into two terminals. I connected the two terminals to the same cable. This increases the lead surface, and gives us a higher production quantity.

Step 2: Build the Cathode

For the cathode, you need a cable and a cable stripper.

Strip 10-20cm of the cable and roll it around a pencil. This piece of copper, is the finished cathode.

You can also attach a piece of copper metal to the cathode to increase the surface.

Step 3: Build the Cap of the Container

For this step, you will need the lid of your container, the funnel, a drill, your anode, your cathode and the hot glue gun.

Drill a hole into the lid of your container, the hole should be big enough, for the end of the funnel.
After you drilled the hole, insert the end of the funnel and attach it with hot glue. (Be careful, that the hot glue isn't too hot! If it is too hot it will melt through the funnel and your container.)

After the glue is cold, glue the cathode on the inside of the funnel and the anode on the outside.

Know that you attached the electrodes, drill a small hole into the lid and put the cables through. Seal everything with hot glue.

Step 4: Hack the Power Supply

Before hacking the power supply, please make sure it isn't plugged in!

Hacking a power supply is easy. You only have to connect the green cable with a black cable (ground). Make sure not to solder the two, because in case of a short circuit you have to disconnect the two cables and reconnect them in order to reset the fuse in the power supply (It's a good idea to put in a switch).

The power supply will start running, as soon as the green cable is connected to the ground. Now you have a DC power supply!

To use the power supply, strip a blue cable (-12V) and a yellow cable (+12V). Put the stripped cables into a luster terminal.

Step 5: The Final Setup

Now that everything is finished, you only need to fill the container with tap water (you should also add a bit of salt) and place the lid on top.

Attach the cables to the power supply and turn the power supply on. (You should see small bubbles rising from the electrodes now)

The last step is to put a balloon on top of the funnel, to catch the hydrogen gas.


NEVER attach the hydrogen generator to a normal power outlet.
!ONLY use low voltage currents!

Hydrogen is highly FLAMMABLE make sure you don't burn the gas uncontrolled or in closed buildings. Also make sure, to keep a safe distance when burning the gas.

Step 7: Educational Part

If you are not only interested in building a hydrogen generator, but also in the chemical background, please read this part of the instructable.

Electrolysis is an endothermic reaction. This means, the reaction is only running if you add energy to the system. This is achieved with our DC-Power supply. The power supply pulls the electrons out of the anode and pushes them to the cathode.

The electrons are from the water molecules. The power supply forces the water molecules (HHO) to split into a positive loaded hydrogen Ion (H+) and a negative loaded hydroxide ion (OH-).

Due to electromagnetic forces the positiv loaded hydrogen ions are pulled towards the cathode, and the hydroxide ions are pulled towards the anode.

As the cathode offers electrons to the hydrogen ions, the hydrogen ions become hydrogen gas (HH).

Because the anode pulls electrons, it takes the electrons of the hydroxide ions and the hydroxide ions become hydrogen ions, as well as oxygen gas (OO). The hydrogen ions travel to the cathode afterwards.

Why do we use pencil lead as the anode?:
We use pencil lead as anodes, because metals (except for platinum) are oxidised due to electrochemical reactions in the container. That means if you use an iron anode it would basically rust away while you produce hydrogen. The same thing happens when you use copper. The copper turns into copper oxide. This slows down your hydrogen production and gives the water a bad colour.

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Remember that when Hydrogen collects it is lighter than air and when it burns it always burns upward instead of laterally as is the case with heavier combustibles. This makes it safer and easier to control than might be the case with gasoline, propane, etc. There are many nay-sayers who are afraid and against the use of Hydrogen, but it is actually safer than other combustibles and as mentioned by others it can be generated by solar power, making it the least expensive fuel that is available now and in the future.

Right on arvevans, but after witnessing 4 cars blow up with various gaseous fuels I still don't feel safe in a car with a high pressure gas cylinder in the boot/trunk. Hyundai have just opened the first hydrogen refueling station in Australia. I really hope that efficient safe ways of carrying the gas in cars follows soon.

Honestly I'd think that they'd have a good few safety measures in place.

(Possibly- when a leak [minor or major] is detected, a secondary cylinder of a non-flammable, non toxic gas could also be released...)

Just think about how many gasoline filled cars cought fire. And how many people died in them due to the fires. I don't think that gas is unsafer than gasoline.

Seems like I have unintentionally stirred up hornets nest of dogma here so I am obliged to apologize but I can't leave without attempting to clarify.
My daughter and I were in a petrol/gasoline van that caught fire from a leaking fuel line, we had plenty of time to get out. Same story with one of my friends and his family. Lost the vehicles though, they just burned out, no explosions, it may well have been less destructive with gas fuel. I suggest you check the stats about car fires.
BUT fuel fires are not really the main consideration of my work, we are trying to reduce the gas pressure of the stored fuel. I concede I am probably over cautious (nervous) when considering the immense
potential energy in a gas cylinder but I have seen some memorable
explosions. Nevertheless I have to assure readers that a lot less LPG accidents have happened now stronger regulation is controlling gas conversions. I try to keep that in my mind when I am in a taxi.

Check the stats and numerous TV shows like the Mythbusters: Gasoline/petrol cars seldom catch fire and almost never explode, that is a movie myth. The stats on gas powered cars are less defined but from personal experience: An LPG fuel tank in a car near my house exploded in the middle of the night a few years ago. The trunk/boot lid landed in the middle of the street. The cause of the explosion was never explained. I admit that since LPG conversion was regulated and restricted backyard conversions less incidents have occurred.
What many people don't realize is that typical hydrogen tanks have much greater pressure than other gases. I have worked in research labs most of my life and I have seen the damage done when a compressed gas cylinder had a burst regulator; the damage done when a gas cylinder exploded a manifold; the damage done by a pressurized fire extinguisher when it malfunctioned. I consider all pressurized gas storage systems as a potential hazard, particularly hydrogen fuel tanks zapping along the road at 100MPH.
I am not alone on this, I have worked on research projects funded by car manufacturers to develop metal hydride and high surface area molecular sieves etc to permit carrying hydrogen at lower pressures to reduce weight and reduce explosion hazards. I am now retired and I have no idea how/if the safety of hydrogen storage in cars has been improved; I hope so. I do know that the car manufacturers do not mention this issue when promoting hydrogen fueled cars.

I never meant, that gasoline cars explode. What I wanted to say was, that if a LPG or CNG tank explodes in the back of your car (because that is where they place them), you are probably safer in the drivers seat, then you are if the whole car catches fire, due to a gasoline leak.

This is just the main dirrefence between gasses and liquid fuels. Liquid fuels burn long. This gives you a chance to escape. But if you can't escape (due to deformation of the car etc.) you are pretty sure dead.
Gasses explode in a short periode of time with much energy, but they won't burn for a long time, as all the energy is in the explosion. If the explosion is in the back of the car, you have chances to survive.

What I want to say is: Fuel always has a high "energy density" and if this is set free uncontrollable it is dangerous, no matter if it's a gas or a liquid. You have to be lucky to survive a crash with both. The only thing we can do is try to make it safer.

Yep...I have been in the center of a few gas explosions and all I got was singed eyebrows. Nevertheless I once had cause to investigate a terrible fatality where kids were playing with matches in the back of a van that had been fitting with LPG by an uncertified fitter. It does depend a lot on the conditions of enclosure and gas/air ratios. Overall I agree I would rather be in a gas fire than a liquid fuel fire.

Why is it that whenever anybody posts anything with the word HYDROGEN in it all the nay-sayers come out of the woodwork to hijack the original thread or article and convert it to be about running cars (or NOT) on browns gas. This is not what this Instructable is all about. Hijacking the Instructable of someone who is learning, or trying to educate others is rude, inconsiderate, and only shows a lack of knowledge about the subject at hand.

You brought up the issue of fuel first and I only sought to extend your bald statement about safety from my research experience working to develop safe efficient ways of transporting hydrogen. Incidentally research funded by car manufacturers concerned with the safety issue. If my efforts to inform and educate is considered rude and inconsiderate then I apologize.

Light_Lab ...Your witnessing 4 cars blowing up makes the case for "hydrogen on demand" systems for use with internal combustion engines. Adding hydrogen or "Browns Gas" into an engines vacuum system from a device that has created it by splitting water only when the engine is running replaces the need to carry a tank around and maintaining a need for a centralized system of supply for hydrogen. I do realize though that Brown's gas is the mix of hydrogen and oxygen from water and, that the scenario I presented is one where the Browns gas is an addition to an engine that runs on liquid petrol fuel, either gasoline or diesel but it is possible to have an engine run entirely on Browns gas on demand and propelling a car about 200miles from a quart of water.

A very promising situation yielding a weeks worth of local driving with under one gallon of water.

Indeed, hydrogen phobia is very frustrating because if you go try and buy hydrogen at a gas supplier they are very paranoid about selling it and it's like pulling teeth to get them to sell you some. Yet propane and acetylene are no problem! I think it should be mandatory that all outdoor advertising balloons be required to use hydrogen because helium is just too valuable to waste on frivolous applications like that, and when the helium is gone it's GONE, there's no making more.

Yeah, its not like a lot is going to happen even IF the balloon catches fire.

Its not a good idea to use in blimps though, because you are actually risking peoples lives if that catches fire.

Hydrogen is also much cheaper, so the ballons would be potentially cheaper.

This looks really nice but is the pressure enough to inflate a balloon?

1 reply

if you build it properly than yes it is if u want the baloon to float then you need to have a seperate funnel. have the negative side ( hydrogen) bubble through another container with distilled water so the pressure can build up but be careful of static diacharge hydrogen is explosive.

Thank you for sharing this. I have looked all over the net and all I keep finding is HHO generators. On a side note, any idea how long the electrods will last in hours? Or how long the gas will keep for, in say a 20 oz plastic bottel? (May consider takeing down all the nonrelavant info.)

1 reply

this is an hho

I have a question. Where does the oxygen go? From what I understand, the anode produces one gas and the cathode produces the other. Most electrolysis systems I have seen, have a vent over both and the O2 comes out one and H2 the other.

Am I confused, or would this unit not produce a balloon full of both gases?

Please let me know if you have an explanation. I really want to make a low pressure H2 generator and this seems simple enough to suit my needs.

Also, mythbusters mentioned that tap water and regulat table salt could produce chlorine gas which is also bad news and heavy.


2 replies

the anode produces oxygen gas and the cathode produces hydrogen gas and in this case they all end up in the balloon so you have a hydrogen-oxygen mixture in the balloon.

Also if you use salt it will produces chlorine gas but you can replace the it with baking soda and the chlorine will be gone!!

one thing if you're using salt or baking soda there will be sodium hydroxide which then can be neutralized by adding vinagar to it