Bacteria/Biocide

[Jordan]

I was wondering if anyone uses a biocide to keep their WVO from going rancid.
During my process I pick my WVO up, condense it into cubes and squeeze the air out of them before letting them settle for a few months. The oil gets passed through a simple centrifuge 1 or 2 times and is stored in a 1000l tote, I fill cubes as I need them. I have tried to remove as many variables as I could for bacteria to spread but the tote isn't air tight so it's been in the back of my mind. I haven't had any problems doing this for the past year but the thought of hundreds of litters of oil going bad is unsettling and something I want to avoid. What are your thoughts? Solutions?

[Luna-Sea]

Hey,
I have not had any problems with bad funk yet.
Keeping the outside of the tote clean and shaded helps.
You can add a bit of racor stuff when you use it in your van if you are worried.I like to avoid treating the tote to keep the bulk of it "Suzukied" (environmentally benign) in case of spillage.
Sometimes I will get a questionable cuby and not use it. You will be able to see or smell a bad one.

I leave a little air hole on my tote lid too, I am terrified of
some kind of tote poping expansion,though I have never heard of one happening.On occassion a sort of film will form on top of the oil, floaties and a bit of oxidation, it is skimmed of easily enough.

Right On!
And Stay Greasy...

[jessef]

Biocide is the best thing you can add to your wvo/svo/bio.

Kevin and Noel have been professing biocide use for years and they know their grease

[Jordan]

Recommendations?

[jessef]

google professor

WVO will not grow bacteria and algae if it is dry. Get a centrifuge to really dry it. I've had WVO sitting in my storage drum for over a year now. No smell, no algae, no color change, nothing. Looks as fresh as the day I centrifuged it. Store it full in a sealed drum with little air above it and if it is dry, it should last a long time.

But if bacteria and algae do grow, the best biocide is RUG. It kills everything even at very low concentrations. I put about a liter of RUG per 55 gallons to kill all the bugs. This happened to me once only, before I got my centrifuge. I suspect you can get away with even less RUG.

It's not living organisms that cause WVO to go rancid anyway (at least in the strict sense of the word). Rancidity is caused by other chemical molecules attaching themselves either onto the glyceride backbone (in the case of mono or diglycerides that have an open carbon sitting there) or onto the fatty acid groups themselves. Unsaturated fatty acids are particularly sensitive to this since they have double bonds sitting there waiting for something to react with. The higher the degree of unsaturation, the faster it goes rancid.

Rancidity in and of itself doesn't present a problem for use of WVO as a fuel-though the oil will smell funky. Bacterial contamination, though, is a problem-but can be controlled easily enough by keeping your oil dry and clean. Polymerization of oil can also present a problem, but you have to really abuse your oil to have that happen.