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DIY Biodiesel


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Seeing as biodiesel can't be bought anywhere for whatever reason I'm going to try to DIY.


This will be to run my generator on, which is a lister type slow speed engine.


I should be able to get hold of used vegetable oil, so I'll try with that.


As far as I can figure there are three routes you can go.


First is to mix in vegetable oil with diesel and run on that. Various sites on the web say up to 50:50 is fine. Just filter the oil first.


Second is to run the engine directly on the vegetable oil. This seems relatively easy to do. You need to have a separate tank for the vegetable oil and a valve to switch between diesel and the vegetable oil. The vegetable oil needs top be pre heated to make it thinner, so to do that I will run a copper coil in the fuel line around something hot on the engine. Either the radiator pipe or the exhaust, I'll see what works. Then basically you start the engine on normal diesel, when it is at operating temperature you switch to the vegetable oil, and before you shut down you run on diesel for a bit to get the last vege oil out of the system. You just need to filter the oil first to get the fish and chips out.


As described here : http://www.ehow.com/how_7499370_run-diesel-waste-oil.html


The third route is a bit more complex, you chemically separate the vege oil into diesel and glycerine, which is not a complicted process apparently. You then have a diesel substitute that you can run any engine on with no modifications.


So to start with, I will try no 1: I made hamburgers and chips last night so have about 1l of used sunflower oil. I'll filter it, throw in the diesel tank and start that sucker up. That will probably be about 20% vege oil. 


I'll then have a look at modifying the engine so it can run directly on vege oil. Watch this space.

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Quick lunchtime experiment:
Filtered the oil from last nights chips, got about 600ml. Mix some with some diesel to check that it dissolves (dish on the left, about 50-50 diesel and oil). So that looks fine, so in the diesel tank it goes. Probably about a 10% vege oil, diesel mix. I'll run the genny tonight for a bit, can't see any harm being done at such a low concentration.
So did I make free diesel, or free chip oil?



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Thanks, the next stage of the project is to frequent all of the local bars and restaurants and find out if I can get used oil for free or very cheap. Its a tough job, but someone has to do it.....


Running the generator now on my oil blend. Seems to work...... :)

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