Glyc not falling out

[Dickjotec]

Hi
15 years making bio never had this.
Good used oil. Well settled. Two stage process. 200L batch. 20l meth 900gm sodium.
First 5/45 test after 30 min remainder of bio after settling  showing fallout and clear. 1ml fallout in test.
Second test after 1 hour .5 fallout but bio  very cloudy and no glyc showing after settling.
Left for an hour but no gly to drain from processor just thick cloudy liquid. Left to settle but still no normal glyc.
Any ideas?

[dgs]

Hi
15 years making bio never had this.
Good used oil. Well settled. Two stage process. 200L batch. 20l meth 900gm sodium.
First 5/45 test after 30 min remainder of bio after settling  showing fallout and clear. 1ml fallout in test.
Second test after 1 hour .5 fallout but bio  very cloudy and no glyc showing after settling.
Left for an hour but no gly to drain from processor just thick cloudy liquid. Left to settle but still no normal glyc.
Any ideas?

Not enough info for me Dick.

Temperature? was the 20 litres/ 900gms just the 1st stage. if so chemicals on 2nd stage? Has any glyc dropped at all. if not did you do the 2nd stage with the glyc still in.

[Dickjotec]

Temp 35c this was the first stage but I usually only do the one as both my vehicles are happy with veg so a small fallout is fine. Oil is the same as I always use as it all comes from the same place.
Very small glyc less than a cup full.
 It is now in a holding tank. The top 50l ish looks good clear bio. I will leave it a day or two to see what it does. Very strange. Pity I can’t post a pic.

[dgs]

If it doesn't separate just re-heat and add ad least the same amount of glycerol that you assume is in there. As it cools the whole lot will drop.

[Dickjotec]

Thanks for that. It has now sort of separated but the fallout is not like the normal dark brown glyc I get that sets solid just a light soapy slop. The bio though is nice and clear. More of the slop than the glyc amount that is normal. I will try heating some and adding old glyc at the WE.

[dgs]

Thanks for that. It has now sort of separated but the fallout is not like the normal dark brown glyc I get that sets solid just a light soapy slop. The bio though is nice and clear. More of the slop than the glyc amount that is normal. I will try heating some and adding old glyc at the WE.

It is strange that this sometimes happens. The addition of more glyc always seems to work.

[Dickjotec]

Thanks for that. It has now sort of separated but the fallout is not like the normal dark brown glyc I get that sets solid just a light soapy slop. The bio though is nice and clear. More of the slop than the glyc amount that is normal. I will try heating some and adding old glyc at the WE.

It is strange that this sometimes happens. The addition of more glyc always seems to work.

Would be interesting to know how frequently this has happened to others.

[nigelb]

It happened to me a few batches ago but jug samples indicated it was a methanol deficiency.

[Dickjotec]

It happened to me a few batches ago but jug samples indicated it was a methanol deficiency.

I did wonder about that. 10% meth is low. In the past when I had lots of meth about I would use a bit more. Will experiment on Sunday when I have time.

[dgs]

It happened to me a few batches ago but jug samples indicated it was a methanol deficiency.

That's strange. The specific gravity ratio of glycerol to partly converted oil should be much higher using such low percentages of methanol. It should actually drop more efficiently.

I've always questioned the 10% methanol process (methanol starvation) There doesn't seem to be any point of using such a low % of methanol and normal amounts of catalyst. The two need to be in proportion with each other based on oil quality and conversion required, especially with the current price of hydroxides.

For a 90% conversion a methanol % of 14% is more in order.