Sometimes when we collect oil there is some sort of fungus floating on top, a few times its been really bad like 2" layer of foam.

Does anyone know what causes this or if it is harmful to the reaction process even though we filter and heat the oil to 220F to drive out water?

We pick most oil up on a regular basis so it doesnt sit out long. The one time it was really bad was on a weekly pickup- we even talked to the owner and showed him although he had no idea what it was. Perhaps someome else dumped something in the barrel?

I'll try to get some pics next time we see this

quote:

what causes this

wet oil

My A&W's wash their grills and dump it in the oil I have put extra barrels for them to dump their was in but seems to be to much trouble for the girls I guess.
Anyway the wash makes for a brown foam on the top of the oil and will smell kind of sour (they have just started this, this summer) I have just made a batch of diesel from it smelled a bit sour till the process but did well and made good fuel (it did settle for for a couple of days then heated before processing so any water was gone).
This may or may not be what your stuff is but mine has just came up this year with the same thing they don't seem to know what it is. Still think it is wash.
Curt

I do a water wash with baking soda on all my oil, the baking soda reacts with the FFA and water in the oil and makes soap and the reaction also releases CO2 bubbles, the bubbles carry bits of food and crud up to the top of the oil and makes 3-4 inches of grey-brown foam. If they are washing out there fryers they are likely also using some sort of fryer cleaner stuff, these almost always contain a bit of lye to cut the oil film, the lye works the same as the baking soda and will produce CO2 bubbles that produce the foam. The foam can be skimmed off the oil or if you let it set for a few days it will eventually collapse and drop to the bottom of the barrel with all the other crud and water. The foam should not cause a problem if coarsely removed from the oil before reacting it, the oil should even be a bit cleaner.

quote:

Originally posted by Tim c cook:
I do a water wash with baking soda on all my oil, the baking soda reacts with the FFA and water in the oil and makes soap and the reaction also releases CO2 bubbles, the bubbles carry bits of food and crud up to the top of the oil and makes 3-4 inches of grey-brown foam. If they are washing out there fryers they are likely also using some sort of fryer cleaner stuff, these almost always contain a bit of lye to cut the oil film, the lye works the same as the baking soda and will produce CO2 bubbles that produce the foam. The foam can be skimmed off the oil or if you let it set for a few days it will eventually collapse and drop to the bottom of the barrel with all the other crud and water. The foam should not cause a problem if coarsely removed from the oil before reacting it, the oil should even be a bit cleaner.

So from what you're saying its drain cleaner, they put their grease trap cleanout in our containers.

I have a letter going out to all our sources to thank them and remind them that we can't make fuel from water or grease trap cleanouts, along with a sheet of guidelines for them to share with staff and post.

That is not exactly what I was trying to say, they are probably NOT using drain claner to clean there fryers, there are many products available for cleaning deep fryers, all that I have looked at do contain some amount of lye, so do spray-on oven cleaner products.

I doubt they are adding sump grease crap to there dumpsters but even if they did you CAN still make biodiesel from it, it will just titrate to a high number and require more lye to be used in the conversion to biodiesel.

The fact that there is some small amount of water and lye getting into your collected oil in not really a bad thing as the lye and water will convert some, if not all, of the free FFA in the oil into soap, reducing the amount of FFA in the oil will lower it's titration number, it MAY also waste a bit of good oil by also converting it into soap, the amount of usable oil that is converted into soap will depend on the amount of lye and FFA in the collected oil.

There will always be a bit of water (frozen food - blood - etc) in collected used vegoil even if you don't see any free water on the bottom of the container, very tiny droplets of water can stay suspended in the thick oil, these droplets may not be heavy enough to drop through the thick oil, by deliberately adding water to the oil I find the added water can cause these tiny water droplets to form together and become heavy enough to finally drop out of the oil over time if the oil is at least 80 deg f(more time is better, I settle my oil for at least 2 weeks as 100 deg f, oil still does not pass the hot pan test, I then pass the oil through a flash evaporator).

We did our pickup last night and one source is a local hospital, its by far the nastiest place because our container is next to the trash compactors.

There was a 2" layer of crud on top, it was too dark to take photos with my phone. I scooped it off and put it in a nearby dumpster. It was like a fluffy substance floating on top.

Another pizza joint, there was bubbles coming up from the bottom. On the bottom there was 2-3" of stuff that looked like flour or pizza dough.

Our oil sources are pretty regular titrating in the 3-5 range.

Those sound like 2 stages of my baking soda water washed settling oil. After stirring in the BS water there are bubbles of CO2 rising in the oil for about the first week, these bubbles create a 3-4 inch thick dark gray/brown foamy head, the BS/water/FFA reaction produces a thick creamy heavy soap in the oil. Once the bubbling stops the water and soap settle to the bottom and the head of foam collapses into about a 3/4 inch thick floating mat, if settled a few more days this mat will eventually drop to the bottom also, you end up with some pretty clean oil, still needs more cleaning but it is clean enough to save about 500% on my filter usage compared to before the water washing.

Sometimes all the soap will create an emulsion that won't let the water settle out of the oil, I then stir about 4 cups of dry kitchen flour into the oil, over a couple days the flour absorbs enough water that the remaining water and soap starts to settle, the flour does not absorb any oil so ends up as a thin pancake batter just above the free water at the bottom of the barrel.

interesting, thanks for the info!!

Hello. I wondered if anyone is familiar with a super effective WVO filter that is being made in Asheville? I've heard it's been testing for a year and can handle almost anything poured into it. Thanks. Claire

quote:

Originally posted by Tim c cook:
Those sound like 2 stages of my baking soda water washed settling oil. After stirring in the BS water there are bubbles of CO2 rising in the oil for about the first week, these bubbles create a 3-4 inch thick dark gray/brown foamy head, the BS/water/FFA reaction produces a thick creamy heavy soap in the oil. Once the bubbling stops the water and soap settle to the bottom and the head of foam collapses into about a 3/4 inch thick floating mat, if settled a few more days this mat will eventually drop to the bottom also, you end up with some pretty clean oil, still needs more cleaning but it is clean enough to save about 500% on my filter usage compared to before the water washing.

Sometimes all the soap will create an emulsion that won't let the water settle out of the oil, I then stir about 4 cups of dry kitchen flour into the oil, over a couple days the flour absorbs enough water that the remaining water and soap starts to settle, the flour does not absorb any oil so ends up as a thin pancake batter just above the free water at the bottom of the barrel.

Tim, Do you have more info regarding this process? Does the baking soda/water mixture have any effect on PH? I am very concerned about acids in my WVO. I feel that the presence of acids is the #1 killer of modern diesel engine components.

Thanks for your help.

quote:

Originally posted by clairek:
Hello. I wondered if anyone is familiar with a super effective WVO filter that is being made in Asheville? I've heard it's been testing for a year and can handle almost anything poured into it. Thanks. Claire

no, have not heard any such news. There are many very effective filters on the market, the more effective they are....the greater the number of zeros in the price.