Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: neisel on November 09, 2015, 12:21:53 PM
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I've been waterwashing a batch since Friday afternoon, at least 20 times & am at my wits end with this one.
Normal 2 stage procedure except I added some acid to break an emulsion which was starting on the 2nd ww (1st after 7% pre-wash).
It looked odd after the 7% pre-wash as there was no discernible soap, that appeared later after several washes. Now I seem to be in cloudy water limbo & it's not getting any clearer. Can't believe there is any soap left, especially as I know I underdosed the 2nd stage, so WTF is causing the cloudiness & how do I get rid of it?
TIA.
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higher melting point esters, precipitating out with the cold?
mono/di esters?
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It's 14 degrees here today & much warmer in the oily shed, don't think the ambient temp is a factor.
After a further 3 w washes it is clear. What a COMPLETE bastard this batch has been.
I'm thinking the problem has something to do with the added acid. It's the only factor which is different from the normal routine.
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If you intentionally under dosed the 2nd stage it may be unconverted oil. Even a 10/90 pass is only about 98% or so.
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neisel, you didn't say if your 10/90 was clear. If there was a lot of soap after the glycerol/water wash you may have produced a lot of FFA's with your acid wash. This could be the cause of your washing problems?
A while ago I intentionally slightly under converted a batch (0.2 mls dropout on 10/90) I water washed it and it did wash OK but the water was never as clear as I like to see it. After finishing the batch I did another 10/90 (optimistically thinking some of the unconverted oil may have been partially emulsified and washed out) still 0.2 dropout.