Creating An Automated Hydrogen Generator At Home

Everyone and their pet hamster probably knows that the most common way to produce hydrogen is via the electrolysis of water, but there are still a number of steps between this elementary knowledge and implementing a (mostly) automated hydrogen generator. Especially if your end goal is to create liquid hydrogen when everything is said and done. This is where [Hyperspace Pirate]’s latest absolutely not dangerous project commences, with the details covered in the recently published video.

Automated hydrogen generator setup, courtesy of [Hyperspace Pirate]'s dog drinking bowl.
Automated hydrogen generator setup, courtesy of [Hyperspace Pirate]’s dog drinking bowl.
Since electrolysis cannot occur with pure water, sodium hydroxide (NaOH) is used in the solution to provide the ions. The electrodes are made of 316 stainless steel, mostly because this is cheap and good enough for this purpose. Although the original plan was to use a stacked series of electrodes with permeable membranes like in commercial electrolysers, this proved to be too much of a hassle to seal up leak-tight. Ergo the demonstrated version was attempted, where an upturned glass bell provides the barrier for the produced hydrogen and oxygen. With this system it’s easy to measure the volume of the produced hydrogen due to the displaced water in the bell.

Once enough hydrogen gas is produced, a vacuum pump is triggered by a simple pair of electrodes to move the hydrogen gas to a storage container. Due to hydrogen embrittlement concerns, an aluminium tank was used rather than a steel one. Ultimately enough hydrogen gas was collected to fill a lot of party balloons, and with the provided information in the video it should be quite straightforward to reproduce the system.

Where the automation comes into play is with a control system that monitors for example how long the vacuum pump has been running, and triggers a fail safe state if it’s more than a set limit. With the control system in place, [Hyperspace Pirate] was able to leave the hydrogen generator running for hours with no concerns. We’re hopeful that his upcoming effort to liquify this hydrogen will be as successful, or the human-rated blimp, or whatever all this hydrogen will be used for.

33 thoughts on “Creating An Automated Hydrogen Generator At Home

  1. “…the most common way to produce hydrogen is electrolysis” not actually true, it is by the action of gut bacteria , over 8 billion humans do this not to mention other animals. Seriously I’d like to try it as a project (in glass not gut) but I have no idea how to find the right bacteria (other ones in the gut release CO2).

    1. I’d also suggest stripping the hydrogens from a hydrocarbon or ammonia feed stock is in practice much much more common than electrolysis. Electrolysis is however very easy to get started in, something any one of us can set up a primitive generator out of junk quite easily, even more easily if we don’t care to exclusively capture only the hydrogen. Where the chemical processes require a bit more knowledge and thought to scale down to a bench top.

    2. Microbial hydrogen production is not great, for a variety of reasons depending on how you’re trying to do it. The metabolism tends to be inefficient, or the product impure, or it needs difficult to maintain (if you want active cells) conditions. The general feeling is that meaningfully useful microbial hydrogen production isn’t going to be possible without some hefty genetic engineering.

  2. Yeah maybe electrolysis at home but syngas is made on massive industrial scale.
    Also, making H2 at home is easier with some drain cleaner and a wad of aluminum foil. When I was small my neighbor’s dad was amusing himself with just such a set up, filling balloons and letting them go. Thinking back that may have been my first exposure to actual chemistry other than baking soda plus vinegar –> getting yelled at for messing up kitchen.

      1. You can use zinc instead of aluminium , it is quite easy to save up lots of zinc castings (since they break so easily!). Then you only have to buy the lye which is pretty cheap. And no problems with keeping the oxygen and hydrogen separate. WIth the bonus of being able to simultaneously zinc plate any copper items youmight wish to

  3. I hope those pumps and motors aren’t the normal brushed variety (sparks) and that the H2 path has zero leaks. Plus no relays, no switches blah blah you get the idea. For really small quantities and bench top demo of electrolysis, no problem. But concentrating or compressing and larger quantities seems potentially problematic. Otherwise this may just be a scale model of the Hindenburg and they just don’t know it yet.
    Quick google shows a big cylinder of H2 costs ~$80 not including deposit. Food for thought.

  4. Warning: some oxygen and hydrogen will dissolve in the water and diffuse out the wrong side of the glass jar, so running the cell for a long time can lead to an accumulation of explosive amounts of hydrogen around the cell. Don’t run the device in a poorly ventilated room.

    1. Solubility of Hydrogen in water is something like .0015 g of H2 per kilogram of water.
      Solubility of Oxygen is a little better, at .04 g of O2 per kilogram of water.

      At these levels, I don’t think think the solubility will be an issue.

      Perhaps you are thinking of highly pressurized gases, such as used in scuba?

      1. That’s about 16 ml of hydrogen in a liter of water – but the solubility isn’t the point. Once the water gets saturated, the hydrogen at the surface starts to diffuse out as more hydrogen dissolves in. It won’t hold on to the gas and the hydrogen in the glass jar will eventually diffuse out through the water – especially when the water is hot.

        1. I’d worried about dissolved oxygen being released into the hydrogen. You get explosive mixtures over an extremely large range of oxygen/hydrogen volumetric ratios.

          1. How is this a better hack then simply filling balloons from my Oxi-Acetylene tanks?

            ‘Big boom’ is a solved problem.
            Tequila and Tannerite are my favorite formula.
            This might be useful for people living in police states.

          2. You need about 5% of oxygen in your hydrogen to make it explosive, and the bell is getting emptied repeatedly. The guy already shows that the oxygen concentration is low enough to not cause a bang. I’m worried about the room around the device, where the escaping hydrogen can pool up at the ceiling and increase in concentration.

    2. I doubt that will be a problem, the production rate is rather low and what little hydrogen might be diffusing out the wrong side is not going to stick around even in a pretty poorly ventilated space that long. Scale this up so you are producing a huge amount in a small volume or be running it in a really really well beyond the normal level of airtight sealed room I’d agree it becomes worth worrying about. But with how mobile and reactive hydrogen is actually building up an explosive mix at this scale of production I’d suggest is almost entirely impossible – It will all be escaping or reacting harmlessly with something else first.

      The problem for explosive hazard on a setup like this is very very very much more from a leak in the hydrogen side somewhere – and even that is going to be relatively hard to make into a really dangerous mix with such low production rates. Buildings even poorly ventilated ones are way more leaky than that in general I’d suggest. Still far better to have good ventilation when it is even remotely possible that something dangerous could happen of course, I just really can’t see at this scale of production actually being a problem.

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