Snow flakes in Biodiesel?

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

The last few batches have had small ( .5mm ) whitish flakes suspended evenly and accumulated on the bottom. The wash seperation was weird, slowish seperation with globby water bubbles falling out of the biodiesel. it eventually settels out (40 minutes) with what looks like the perfect seperation. I washed 7 times, nothing like an emulshion, water clear... at first the BD looked clear, I put some in the frig. 30f it fogged up but when it returned to room temp that's when the snow flakes showed up!!! When you heat the stuff it clears right up ? I'm stumpped??? What the heck do I have here and is there a way to fix it?
Jess

[Matt Senior Member Find all posts View Profile Close Matt]

Re: Snow flakes in Biodiesel?

Jess what you have most likely are higher melting point methyl stearates. They melt at a higher temp than the majority of your feed stock, and when the bio is first made since its hot they do not appear until it chilled and then thawed.

They are biodiesel just in another form.

If you lived in a warm climate I would not worry but as they can block filters if not melted back into the liquid and in colder cilmates I would cold filter your bio before using it.

Matt

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

Re: Snow flakes in Biodiesel?

I have been trying, and am going through the filters. It's killin me. My batches are 150 gallons at a time. I live in a climate with cold winters. So basicly it looks like I have to find out which of my resturants is giving me the high temp mental stearates and save them for warmer days. It's true I did not have this problem all summer. Does anyone have a filter suggestion, I inspected my Ford filters yesterday I think the micron size on them is letting most pass, though there was spotty build up. My furnace filter on the other hand keeps clogging. I tried melting the whole batch, it goes away but comes right back. My 15 micron filters clog instantly at $4.00us a pop.
Thank you, if anyone has an inovative filter idea for my recent 150 gallons I would be most happy!

I just went out and searched "methyl Stearates, biodiesel" and found: saturated monoglycerides and quality problems - Topic Powered by eve community
It appears that you can mix some isopropanol in the BD before the flakes show up to prevent the problem, any comment on that?

[Matt Senior Member Find all posts View Profile Close Matt]

Re: Snow flakes in Biodiesel?

Jess it looks like someone is using animal fats in their cooking as its these that normally give the high melting point fats.

The bext thing to do is to settle your biodiesel and draw off only the liquid biodiesel and leave the flakes to accumulate and use once it comes warm again next summer. Its also termed the dreaded white stuff too I believe.

Matt

[Chris Senior Member Find all posts View Profile Close Chris]

Re: Snow flakes in Biodiesel?

Jess
The suggestions for your issue in this forum so far make sense
The last one is the most practical one
If you want to use your 150 Gallons of bio leave it outside for a few cold nights let the flakes settle out decant the top layer and use it, the remainder you can use in the hotter days
If you want to have a go at it try to get some ether and mix about 3-5% and not more than 10% with the flaky stuff
Do a sample and stic it in the fridge if it dilutes the sample while in the fridge and you get no flakes go ahead and use it
The stuff is called Aerostart and comes in an aerosol can, normally used to start half dead engines
I am sure you can buy it in bulk
I have no Idea of cost where you live so you have to look into the economics of that as well
In so far as trying to find out why, the possibilities are enormous
You will have as many reasons as to why it does that as well as many solutions
No point in pursuing a dead track so as to find out why since you have no idea of what raw material you have used and neither have the people you got the oil from
The best way is to apply simple rules and use the stuff let it settle out in the cold
If you can stick it in a coolroom for a few days so much the better
Good luck

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Snow flakes in Biodiesel?

If you look at the feedstock oils you get from each supplier, you will rapidly locate the oil which has a high stearic acid content. It will be the one with solid oil in it. If they all have solid oil at your temperatures, it will be the hardest of the solid oils.

Settling of the bildiesel and use of the upper layer is highly recommended. Retain the high melting point biodiesel for summer use.