Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: willbuild on February 06, 2015, 11:39:12 PM
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Have a batch that kept turning to an emulsion every time I tried to water wash. Normally I do an acid wash then 3 or 4 10% water washes without any problems.
Heated the bio and dryed then left in a drum to settle for 4 days.
Then drained the bio back into processor leaving the waxes in the drum (about 5% of total volume) . It still emulsifies when I try to wash.
Do I reprocessed the batch along with the waxes?
My 50/50 tests show a clear split with a white layer in between.
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I had exactly the same thing recently, and my process is almost identical to yours. That said, I don't think the issue is with the process. It's covered in this thread ... http://www.biopowered.co.uk/forum/index.php/topic,2316.0.html (http://www.biopowered.co.uk/forum/index.php/topic,2316.0.html)
The feed stock for that batch was from a new (new collection for me) Indian restaurant. The oil was some of the best I had recently, titrating at 0.5 NaOH and was almost as clear new. The only unusual thing about it was it had a yellow tinge. The staff say they only cook poppadoms and onion bhajis in it.
I got a cloudy 3/27 with no dropout and after a couple of emulsions and many washes, the bio just wouldn't clear.
I've now left it settling for three weeks and a sample has cleared with an accumulation of something white in the bottom of the jar. I've yet to try and water wash this settled sample and try to isolate the white stuff to check if it's soap.
In short if your 3/27 was acceptable don't try and wash, just settle over a long period.
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If you're leaving it to settle why not gently mist some water over it each day to give it a helping hand
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3/27 test was cloudy but no fall out. So Will try and settle.
The white layer in the 50/50 test was a lot less in the test I did yesterday compared to last week.
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Filtered the batch out of the settling tank through j clothes and its been settling for 10 days. when I did a 50/50 shake test the water was hazy with a thin white layer.
Heated a sample of the waxes that I filtered off and added some metoxide. The sample split 80/20.
I left the sample out overnight (0c) and it had waxed. Does this mean they are HMPE's?
I made a new batch 70 litres of bio and before demething ( no wbd) added 30 litres of the settled bio, mixed, then checked again with 3/27 test and did my normal acid washes.
4 washes later with no signs of emulsions the bio is back in settling tank.
Have done a 50/50 test from top of tank after just 1 hour and have clear water.
Will keep my fingers crossed for the morning.
If the waxes are mono di glyrides they can be reprocessed and if they are HMPE's they can be washed out? Or is it the other way round. ???