A Northamptonshire man destroyed his garage and badly injured himself at the weekend while attempting to make biodiesel from used cooking oil. A devastating explosion levelled the makeshift reprocessing plant on Saturday afternoon, when sparks from an electric drill being used to mix ingredients ignited explosive vapours. Firemen hastened to deal with the smoking wreckage, in Middleton Cheney, and the unnamed thrifty motorist was airlifted to hospital with 20 per cent burns. "Firefighters would like to urge members of the public to take extreme caution if undertaking such chemical mixtures in their own homes," said a statement from the Oxfordshire...snip
The injured biodiesel fancier reportedly made motor fuel from used cooking oil obtained from his local Chinese takeaway. Such oil can often be used in diesel vehicles without preparation, but this will typically knacker the engine in short order. It is normal to treat the oil with alcohol and other ingredients before use, and this process was apparently underway when the mishap occurred.
The explosion would most probably have been caused initially by alcohol fumes building up in the garage, a process likely enhanced by the hot weather this weekend. Open-air - or at least better-ventilated - biodiesel manufacture might have been wiser.
http://www.theregister.co.uk/2008/07/28/takeaway_biodiesel_fireball_horror/