Animal fat titration

[oily Member Find all posts View Profile Close oily]

Have a friend that has a large supply of animal Fat and has made a batch of bio,
the problem is that there is a layer of white above the Glycerine
I have sugested that he might have produced some soap and that is usaly because of to much sodium hydroxide.
Has anybody else made bio from animal fat and is it the same rule of thumb that you start with 3.5 gram of lye per 1 ltr of new oil ????
When he did the tritation it only needed 1 ml of lye to turn pink !!!
If you could help I would be greatful and I will pass it on to my friend
Oily

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

Re: Animal fat titration

Have a friend that has a large supply of animal Fat and has made a batch of bio,
the problem is that there is a layer of white above the Glycerine
I have sugested that he might have produced some soap and that is usaly because of to much sodium hydroxide.
Has anybody else made bio from animal fat and is it the same rule of thumb that you start with 3.5 gram of lye per 1 ltr of new oil ????
When he did the tritation it only needed 1 ml of lye to turn pink !!!
If you could help I would be greatful and I will pass it on to my friend
Oily

One of the problems with titrating high melting point oils and animal fats, is enbsuring that all of the oil is liquid and dissolved in the alcohol. It may be necessary to heat the sample to be titrated in a water bath, top maintain the solution during the titration. Oils falling out of solution will give low titration values.

Current thinking is to use 5 g/l of NaOH and 7 g/l of KOH (then corrected for purity), rather than 3.5 and 5 g/l respectively.

THe process must be kept well above the Melting Point of the triglyceride for the duration of the process (around 4 hours total at >40 °C)

If the sample you have is cold, the white layer may be solid biodiesel (methyl stearate, methyl palmate, etc), which only needs to be heated slightly to be a usable fuel.
If the biodiesel has been washed, the formation of mono- and di- glycerides, which can cause issues, causing the "Dreaded White Stuff" between the wash water and the biodiesel. This is obviously not the case in your sample.

To determine the nature of the white layer, take a sample and heat it to 20°C. If it melts, it is probably high MP biodiesel.
If not, heat it to 40°C. If it melts, it is probably high MP triglyceride.
If it doesn't melt, I do not know what it is.

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

Re: Animal fat titration

Have been making biodiesel from beef fat this week, i had to keep the oil heated for the titration and that was 2.6gm, and i have moved away from the basic 3.5gm of noah or 5gm koh and have been using a base of 7gm koh that is 90% pure will up that rata next time to 7.8gm koh plus titration.
The result for me using the higher base rate is washing is very easy to do now i use an electric drill with a paint stirrer use that for 5 minutes medium revs i reckon about 500rpm do 4 washes the 4 wash water is crystal clear and i check the ph of the third and fourth wash using swimming pool test strips the third wash has a ph of 8 the fourth has a ph of 7.
but when the temp goes below 10 its starts to form solids that fall and sit on top of the wash water.
I have been using a fish tank heater to keep my 20 lt processor above 25 celsius, it has a thermostat and does a good job its stainless steel 180watt.
Today i put a container of biodiesel made from beef outside on the ground at 6am it was 10 celsius inside and it was clear outside after 5 minutes its solidfyed all around the sides and bottom and was liquid in the middle, put it back in the house got home tonight and it was still a little cloudy.
For me i have found if i use less than 7gm of koh washing is very sensitive makes heaps of soap that needs more washing, i think that is because not enough koh means there is FFA in the oil.

[Robert Administrator Find all posts View Profile Close Robert]

Re: Animal fat titration

I'm moving this thread out of "sydney biodiesel users" and into the "making biodiesel" forum, where I think it will find itself more comfortable

[oily Member Find all posts View Profile Close oily]

Re: Animal fat titration

Thank you all for your replys I have already passed on the information with a further sugestion that he joins the group.
I myself never stop learning about Bio, I guess that is what makes it so enjoyable.
Cheers OILY