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Originally posted by Diesel Drinker:
you gotta get that water out because acid esterification is a dehydration reaction.

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If I understand biochemistry correctly, the NaSO4 should actually act as a drying agent, so filtering out that layer ought to take out a lot of the water.

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But you might have to boil everything out (water and methanol) in order to get it dry enough for the esterification step.

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I would think that the acid esterification would flow naturally with some heat and agitation provided that you have enough methanol and acid catalyst. After that you would need to add a base to neutralize the acid and get the ph to 7.

But I've never tried this. Experiment and let us know what works.

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Originally posted by Green_Guy:
Hello Guys!

I Got 3 layers in a bottle from acidifyind biodiesel Byproduct ...

I think that top layer is FFA (and some BD), middle layer is Glycerin (saturated with salts), and bottom layer is sodium sulfate... The idea is to reprocess the FFA layer (Acid Esterification) to make MetilEsters (BD)...

I want to process the top layer ALONE, not mixed with used oil like in the FATTA method..

Someone can help ? .. How much H2SO4 ? .. and how much CH3OH ?? .. Should this work ??

PS: ... Methanol was not recovered yet, and may be some water also from 5% prewashes... The Ph of the solution is 4 .. (from the acidification with H2SO4)

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Originally posted by Rick G:
You have raised an interesting idea. If I may make some initial comments. As an experiment, 1) seperate sample of the upper phase layer (FFA's & BD) from the other two layers.
2) Assuming that it is substantially FFA's dilute it 10-fold in isopropyl alcohol to get the 50-90% FFA's down to a reasonable level of 5-9% then titrate a 1.0 mL sample to get NaOH equivalents.
3) Use the conversion factors provide by Neutral and others to calculate the Acid Values and the recipes above for the conversion.
I wouldn't worry too much about the residual methanol since it will just help push the methylation reaction but if you are really concerned about measuring the methanol remember that the methanol evaporates easily so if you carefully measure 100 ml of your initial FFA layer warm to 65-70 deg C until the no more volume reduction and then remeasure the volume you will have a reasonable measure of the methanol content. (example 100 mL initial vol. - 70 mL final volume = 30 mL methanol or 30%.
I think that you will find that the FFA layer will contain very little water. However again by heating a measured quantity to 100 deg C then remeasuring you can estimate the water content. You can get a sense of how much water is in the FFA layer just by heating some over a stove. Any significant amount of water will boil.
You have a good idea, good luck and please report back. I hope to follow up on it myself. Thanks.

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Originally posted by erdem_ozcan:
hello green-guy;
what kind of feedstock are you using? and please tell me acid value and titration value of your feedstock.

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Originally posted by adiver2b:
Hi All. I am also trying to do this and was wondering what the proportions were that have been tried so far. Do the quantitys mentioned in the url provided by erdam_ozcan look like they are correct. 1000 grams ffa, 25 grams sulfuric acid, 200 grams methanol. This is where I am going to start.