nightmare batches!!!

[Vijay]

I've tried 5g and 50ml and got about5% bio on top.

I thought it was soaps that took a while to drop with KOH, didn't realise it was for glycerol too

I'm currently trying 5g and 50ml. I'll titrate after seeing how that works

[dgs]

How much oil is in this test Vijay?

[Vijay]

How much oil is in this test Vijay?

1l sample tests

[dgs]

No Wonder there was no reaction on stage 1 with only 2gms of KOH. If your oil was average titration (say 3 to 4) then you would need a total of 11 to 12gms of KOH to achieve full conversion. Base for KOH is 8.

Also why the shortfall of Methanol, you have only used 5% You need at least 14% in stage 1 to get anywhere.

Why don't you try another litre of oil and add 10 gms KOH in 140mls of methanol, bet you get good conversion then and glyc will drop a lot sooner.

Wish I was there with you, I'de soon sort out that lot for you.

[Vijay]

No Wonder there was no reaction on stage 1 with only 2gms of KOH. If your oil was average titration (say 3 to 4) then you would need a total of 11 to 12gms of KOH to achieve full conversion. Base for KOH is 8.

Also why the shortfall of Methanol, you have only used 5% You need at least 14% in stage 1 to get anywhere.

Why don't you try another litre of oil and add 10 gms KOH in 140mls of methanol, bet you get good conversion then and glyc will drop a lot sooner.

Wish I was there with you, I'de soon sort out that lot for you.

This is 85l of oil I've already tried to process with 1360g koh and 18l meth. The gylc didn't drop. So today I have been trying to get 1l samples to convert by adding methoxide of different mixes

[dgs]

Ah, ok with you now. Sounds as though your batch needs 'seeding' with more glycerol. Heat it and add more glyc as you are pumping it , usually works ok.

[Vijay]

Ah, ok with you now. Sounds as though your batch needs 'seeding' with more glycerol. Heat it and add more glyc as you are pumping it , usually works ok.

I can try that tomorrow. How much glyc to 85l would you suggest bud and pump for how long??

[dgs]

Heat it to 50ish, add as much glyc as you can, mix for half an hour, let it settle and see what you get out.

[Vijay]

on now and will let it settle overnight

[dgs]

on now and will let it settle overnight

Good lad!

[Vijay]

I put some of the glycerol mixed batch into some bottles last night and it looks like the glycerol has dropped and left semi dark bio on top. Will do a 27/3 test shortly and hopefully be able to drop the glyc in the processor

[Vijay]

slight dropout on the 27/3 test but I'm not worried about that as the car is a veg runner anyway.

Separating the glycerol has been a little fun with dark bio but the main thing is I have bio - happy days!!!

So how did you know adding old glycerol would drag down the new glycerol, just experience?

[countrypaul]

Both experience and logic! The main reason for the glycerol not to drop is likely to be the presence of soap basically not allowing enough small globules of glycerol to amalgamate and drop. Adding more glycerol and mixing for a while will result in more globules which amalgamate with each other and dropout bringing the soap with them - at least thats my theory.

[Vijay]

did you just make that up lol it's a good theory and it seems to have worked for me   It's actually a good easy thing to try though and something I'll no doubt try when I attack the other failed batches

[countrypaul]

did you just make that up lol it's a good theory and it seems to have worked for me   It's actually a good easy thing to try though and something I'll no doubt try when I attack the other failed batches

Not entirely, I remember from my undergrad days that changing the zeta potential can result in precipitation within colloidal chemistry. It has also been disscussed, quite  a while back, that applying a high voltage across the bio diesel mix can significant accelerate the glycerine drop out.  Whilst not the same situation it sems a reasonable analogy