Can anyone shed some light on a correct way to measure the FFA's when you're doing an acid esterification. I read the post by Kenito Oko but looking at the responses it became very confusing. The Lye issue between KOH, NaOH and step #1 says add 125 solvent, is that ml and what is the solvent? I know alcohol and toluene but how much of each to make the correct solvent? Overall the whole things is very confusing so if anyone would like to help me with a correct and detailed breakdown of this procedure it would be greatly appreciated.

actually i don't follow his method but I have worked out an easy method. its sort of base on the FATTA method.

1. titrate th oil using 0.1%KOH solution. this is the standard BD making solution. my KOH is 90% pure
2. take the ml from the titration and subtract 3
3. take the result and multiply by 0.2. is the ml of H2SO4 needed per liter of oil.

mix the Acid with methanol, about 12% of the oil volume.

heat the oil to 130F or 55C. mix for until the titration reaches 3ml or stops falling. proceed with the normal base process.

-dkenny

What if I used NaOH would that work as well? Do you have another suggestion besides acid when it comes to fighting high FFA's? Thank you for your help

I haven't tried it with NaOH but it should work if you adjust the numbers correctly.

others have used sodium silicate but I don't know the math behind it use.

make sure you add the acid to the methanol before you mix to the oil.

-dkenny

Dkenny,

On the 2nd (Base) stage, do you subtract the methanol previously used (12%) or use use full 20%+ for the base stage.

thx

yes I subtract the 12%. so the total between the two stages is 20%.

of course the 20% also depends on passing the 27/3 test. so more and/or a 2nd base stage might be needed.

-dkenny

dkenny,

would you be kind enough to give your interpretation of what the Naoh version would be, I'd like to try it, but don't want to ASSUME

thx

ok I'll give it a shot but NO guarentees.. I haven't tried Naoh

but if the KOH numbers are
titration 13 ending 3 = 10 * 0.2 = 2ml/liter

convert to NaOH - try anyway
Titration 13, Naoh would be 13/1.4=9.2
then ending point help determine the amount of H2SO4
I use 3. this would be 3/1.4=2.1
9.2-2.1 = 7.1

7.1 * 0.2 = 1.42ml/liter something is not quite right..

it seems that if this is multiplied by 1.4 it comes close to
2mls... or if a different scaling factor??
so 0.2*1.4 = 0.28 instead of 0.2.

I don't think the amount of methanol should change
so use 12% of the oil volume.

after the acid stage is finish use the rest of methanol and the normal amount of caustic for the titration.

good luck, if you try this please report back.

-dkenny