Since early humans discovered fire and subsequently discovered that meat tastes pretty good barbecued, mankind has moved steadily from one innovation to the next. But the past two hundred years is where we really got going.
- 1800 The first steam engine to use the pressure of expanding steam, rather than the vacuum created by condensing steam, increases power and efficiency and shifts the industrial revolution up a gear.
- 1837 Charles Babbage designs his Analytical Engine. Unlike his earlier Differential Engine, it could do more than just perform calculations. It could be programmed and incorporated an arithmetical unit, utilised flow control in the form of branches and loops and had integrated memory. Your computer works the way it does because of the Analytical Engine.
- 1880 The electric light bulb is perfected. You're welcome, Vegas.
- 1942 The first nuclear reactor is built, making nice clean nuclear power possible. And the production and testing of so many nuclear weapons that the background radiation worldwide increased to such an extent that carbon-dating can be used to confirm the vintage of some old wines, but lets try to focus on the C02-free electricity, shall we?
- 1957 The first man-made satellite, Sputnik 1, is launched into orbit and starts the 'space race'.
And now, at the pinnacle of our development, we have the £5 kettle. Pinch me. Okay, I might have gone round the houses with this one, but I think you know what I'm getting at: a kettle used to be a significant(ish) purchase, now it's almost an impulse buy. I nearly did. Luckily, an under-utilised area of my brain (the area responsible for rational thought) stepped in and pointed out that I already had a kettle and had absolutely no need of another. But what happens if you do end up buying a kettle you don't need? What do you do with it? I suppose you could just keep it as a back-up, in case your main kettle fails, but I have a much better idea: electrolysis.
As you are no doubt already aware, water is composed of hydrogen and oxygen, essentially two parts hydrogen to one part oxygen. Using your impulse-bought kettle, it should be possible to separate the two and collect the hydrogen. In its standard, off-the-shelf state, your £5 kettle, like any other, passes an electric current through an element. This causes the element to heat up, and this heats the water (assuming you haven't filled it with beer, to see what happens) to boiling point. All you need to do is cut the element in the middle and form the ends into two electrodes, which will point upwards. These two electrodes will pass a current through the water, 'cracking' the water into its component parts. Placing an inverted test tube over the cathode (the negatively charged one) will allow hydrogen to be collected, using a thin, flexible tube that reaches to the top of the test tube. This tube will also be pressed into service as a siphon, to remove as much air as possible from the test tube, so that the first test-tubeful isn't just air. If you're going to turn this £5 kettle into a means of manufacturing hydrogen, you don't want the hydrogen to be contaminated. Unless you just want to fill a small balloon with H2 and see what happens when you hold a lit match to it, in which case, enjoy. I mean, I wouldn't do it, but maybe I'm just too fond of my eyebrows.
Of course, kettles use alternating current, which is a problem, as you'll need one negatively charged electrode to collect the hydrogen and this requires direct current. No biggie: just get an inverter to convert AC to DC. I couldn't find one that would take 230V AC and output 230V DC, but did find a promising looking inverter that puts out 48V DC, which should be plenty. Maximum current is given as 13 amps, so the improvised water cracker shouldn't give your household electrics any problems.
Next problem is how to actually collect the hydrogen. The good news is that there are a lot of air compressors out there which are more than up to the job of taking in gas and storing it under pressure until needed. The bad news is it's going to be a right bugger to get the air out of the tank,so that you can fill it with hydrogen. And you have to be careful not to suck hydrogen out of the test tube too quickly and end up getting water in the compressor. And compressors with tanks tend to be petrol-powered, making them unsuitable for indoor use. And you'll need an oil-free compressor. And this could cost £1k or more. Although I suppose you could always use a deflated airbed, suspended vertically, a foot or so above the top of the kettle, so that the hydrogen naturally inflates it. This method is considerably cheaper, but brings its own problems. For example, you'll need to keep the airbed well tethered to stop it heading for the clouds, since hydrogen is, of course, lighter than air. Also, you'll end up with a few cubic feet of extremely flammable gas in what is basically a balloon. Not ideal storage.
However you collect and store your hydrogen, keep in mind that for every three litres of water, there is a potential two kilograms of hydrogen (excuse the mental chemical arithmetic) and this is, dependant on temperature, over 20,000 litres. Most kettles have a capacity under two litres, but, even assuming you put in 1.5 litres of water, that's a potential 10,000 litres of hydrogen. Not bad for a fiver.
However, thanks to competing side reactions (really not going into that here), you actually end up producing less than that, but it should still easily inflate an airbed or five. Another problem is that while water does conduct electricity, it's not very good at it. Pure water actually has about one millionth the electrical conductivity of seawater. In order to increase the conductivity of the water to the point where electrolysis happens reasonably quickly, you need an electrolyte. In other words, add salt. The process can be hurried further through the use of an electrocatalyst such as platinum, but, unless your £5 kettle has a platinum-coated element, probably best to forget about it.
To sum up: fill the modified kettle with saltwater and suck the air bubble out of the inverted test tube, then connect the end of the tube to the compressor inlet (assuming you don't want a Hindenburg in the back garden). Switch on the kettle, the test tube will now start to fill with hydrogen. When it's almost full, start the compressor (which should be empty: not even air inside) and the hydrogen will be collected and stored. What you do with the hydrogen is entirely up to you. Hydrogen actually has many applications, although these are mostly industrial, so, unless you have an overwhelming desire to hydrogenate fat, all you can really do with it is use it to power a fuel cell. What? You don't have a fuel cell in the garage? Ah. Must admit, I don't know how to build one of those.
The more I think about it, the more I begin to wonder if this was such a great idea, after all. Firstly, you're using electricity to extract hydrogen gas from water, then going to some trouble to collect and store the gas for use in the fuel cell you don't have, to generate electricity.
Then there's the equipment required. Including the price of the kettle, the inverter I found on trcelectronics.com and an oil-free compressor with a capacity of 100 litres (from a company called Bambi VT), the water cracker will cost £2733 to build. Plus delivery charges.
Expensive things, kettles.
