hi everyone,
i need some opinions on this white stuff that settles out of my bd lately.
washing generally removes it but i wanted to try some unwashed..
i did my reaction it filtered through my sock easily and into another drum.
but within 2 hours this cloudy white **** formed on the bottom and im not putting that in my tank..
any ideas wat it is and why it forms??
heating the oil to take any water out dosent make a diff and i did a titration for the correct caustic mix..its not tallow which generally apears when its cold in the morn and disapears when it warms..so any help would be appreciated
thanks chris

What type of oil did you use, Vegi or tallow?
What was the titration?
How much methanol did you use?
Is the white stuff flakes or what?
How thick a layer does it make?
What does it feel like?
What happens if you mix it with water?
How cold does the BD get?
How do you mix your BD?
For how long?
As it seems this problem has just started, is anything different now than it used to be?

Any other observations that would be useful?

Tilly SBC/IBA ;

[This message was edited by tilly on 22 October 2001 at 08:04 AM.]

In particular are you using less methanol than before? Try a batch with 25% methanol.

G;day Chris & Others
I have seen the dreaded whith stuff to. Don't know what it is or why it forms sorry. I have seen it at vairing mixes eg 100lit W.V.O Methanol @ 17% NaOH 420gms. eg2 100lit W.V.O Methanol @ 19% NaOH 500gms. eg3 100lit W.V.O methanol @ 18% NaOH 600gms. Probley has produced less with more Meth. Does filter out when cold 12*C or lower. IT appears speckly on a jar. When settled looks like fat. Redaly disolves between fingers. I use veg oil from a chicken shop. Mix in a steel 44 for a good hour with 12v outboard also help along at start of mix with a stick.
Also their after washing but no dout reduced.
Always learning Still confused.

Did the source veggie oil have a 'buttery' or 'think and gooey' texture? If so, try your reaction with only the dark brown, easy flowing stuff most likely at the top of the drums.

White stuff *may* be soap or unreacted free fatty acids or hydrogenated oil.

Cheers, IAn

or monoglycerides

The white stuff is complex
Thats another way of saying we dont really know what it is.
Michael SBC/IBA

I thought some of you guys would have known right off the bat that it is methyl stearate.

Used veggie oil contains Oleic and stearic acids.

At fluid temperatures the biodiesel will move just fine through your system and burn just as well. If the temp drops the methyl stearate starts to solidfy and becomes heavy so it drops out.

If you do not want to take chances, chill and let settle.

I only get any amoun of this stuff with the use of tallow or animal fats when I use veggie oil I still get a little but it is much more managable

even so chris as u are using a sprah system I have an update for u if u care to contact me I believe that u still have my email if not let me know via this forum and I will contact u

just for interest when I have an excess of TDWS I increase the amount of water I spray onto the BD to a 1:1 ratio and then allow to sit for a day this usually does the trick if not do again it really aint that big a problem!

BC

My experience tells me Neutral pegged your source of the "White Layer" above. When you squeeze the Methanol, there forms a layer of white stuff.

Is methyl stearate the same as tallow ?

Thanks Roger in WA. While methyl stearate certainly has a high melting point it is not the only thing involved. Monoglycerides are always present to some degree.

1. If there is a lot of tallow in the mix the monoglyceride will contain more stearate than usual. One would expect stearate monoglyceride to solidify more readily than the others.

2. If you don't use enough methanol there will be more monoglycerides.

So, combining points 1 and 2 above, we can work out that skimping on the methanol will cause more of a problem with high tallow than with low tallow oil.

I think Tilly made this observation long ago.

All monoglycerides are good emulsifiers so they can be washed out with water but, being emulsifiers, they will take good BD with them. And, being emulsifiers, they will make settling out of the wash water slow and troublesome.

[This message was edited by neutral on 25 October 2001 at 09:30 PM.]

how true neutral 007 although if you take the first wash and put it to one side and allow it to settle out I have recovered a considerable amount of BD from this especially when I have mixed in tallow with my veggie oil to make up a viable amount to work ,, as I said before if u wash with more water u will rid the rest of the BD of the DWS amd get on with washing the main load then go back and seperate the other stuff and add that to the next wash u dosimple but it works..

KISS

BC

ok biocruiser no i havent got your email since i put a new hard drive in the puter please mail me on crewit@wn.com.au
well i used standars meth mix and titration and on the first wash got a fair bit of white crud, i gathered this boiled to remove water this looked like lard at room temp i then reacted it again and it seperated into 2 layers dark and light so i concluded my reaction was not 100%..
so i will change my next mix to a recirc pump for reaction..i also think the unreacted oil is tallow that hasnt busted..im suprised at the 100% pure cottonseed that has absorbed tallow from cooking..anyway with 2 washes it is lovely and clear with no white ****e settleing out ..
thanks fellas
chris

oky doky Ill be in touch soon

BC

As I listen to Neutral I know I will end up with this monoglyceride or methyl stearate because the oil I use is high in tallow and the oil is hydrogenated and if I short the methanol I will end up with a higher amount of it. My question is what to do with it after I pull it from the BD. It is not water soluable so is it biodegradeable ?Can I dump it on the ground or feed it to cattle ?
I live on a farm but I do not want to poison the ground or the cattle and I already know what happens when it goes in the diesel engine as the temperature drops. Any ideas? Thanks!

Monoglycerides are no more poisonous than any fat or oil. Totally biodegradable. Harmless to cattle - just a source of energy really, like any fat.

Being glycerides they contain, by definition, combined glycerol so should do the same thing in an engine as unreacted starting material, only more so because there is relatively more glycerol in them. But they won't be there in large amounts, maximum about 4%, so perhaps they will do no harm at all.

If you make a bad batch of course you will also have some diglycerides and unreacted starting material. That is why I argue against cutting the methanol down too low. But there seem to be plenty of people using minimal methanol and not reporting problems.

How good the BD needs to be probably depends on the type of engine. Has anyone got any information that shows that some engines are more tolerant than others

G'Day


So no more skimping on the Meth ah.
Might still play with meth % in some test batches though.
Thank's again Gentlemen
Not as confused always Learning
Regards Rob

Not when playing with tallow best to stay with 22-25 % meth per volume

BC

I have been playing with "skimping" for many months now, trying to reduce my costs. The best way to reduce required methanol is to process in a enclosed vessel, eliminating evaporation. I am able to process at 12% Methanol, but my WVO is relatively low in animal fat. It titrates at 4 G/L. Since it is now getting colder out I will be raising my Methanol up to 15%, as I notice that it is easier to start my motor with higher Methanol recipes.

The enclosed processor also is nice because you don't breathe any fumes while processing, and only wear a mask while mixing up the Methoxide.

Great work guys,
Rog