Hi There
Tp Gear did a bit on this a while back - cleaned up the old fat with a filter and mixed in a small amounyt of meths - for some reason - worked fine. If you are interested CAT in North Wales do a course of converting engines to run on veg oil, including an actual conversion as part of the course. Now remember whilst old chip fat, bio-ethanol etc IS greener - much much greener than mineral oil, it is not 'green'. Far more carbon goes into producing it than is held with in it. Now if you can find a source of locally produed Organic oil that is being farmed and delivered using same then it may well be close to carbon neutral...
I do not know the ins and outs but there are things that you can do to the oil/engine to allow you to run it with out any mineral oil being burnt. There is a company close to us who make the stuff and sell it commercially - the Swansea show Environment Tent generators all run on the stuff. Unfortunatly by the time they have collected the old oil, treated it, paid the tax and added in enough to keep their kids out of care it costs more than standard diesel.
R
