Biodiesel Shelf Life

[Witchdoctor Biofuels Forum Newbie Find all posts View Profile Close Witchdoctor]

Is there a shelf life with biodiesel?
Does it need to be stored out of the light?
Thanks for the help.

Dave

[Terry Syd Senior Member Find all posts View Profile Close Terry Syd]

Re: Biodiesel Shelf Life

Biodiesel can oxidise and create polymerisation. This can lead to a slight increase in viscosity, a potential for deposits and a slight increase in cetane. Commercial biodiesel will often have stabilisers added to the fuel as it may be stored for long periods before use.

The best idea is to store biodiesel in in closed containers so that there is a minimum of contact with oxygen.

You can tell when the biodiesel starts to oxidise as it starts to smell like paint varnish.

There has developed a general rule (I think it was University of Idaho that suggested it) that biodiesel should be used within the first six months after manufacture. Homemade biodiesel usually gets used up fairly quickly (even faster with fuel prices rising), so the issue of oxidation doesn't usually arise.

I've used some very old biodiesel that smelled very strongly of paint varnish without any ill effects.