batch looks like chocolate frij

[julianf]

Dealing with some problem oil yesterday.

A mix of palm, lard, a tiny bit of liquid, and some water.  Previously melted and cooled, so a kind of pumpable emulsion.

What I should have done was get it hot, and settle out the free water before adding any glyc, but I added 20℅ potassium glyc on heat up.

Got something that looked like those chocolate milkshake drinks.

At 65c it finally went smoothish (assume the lard portion melted at around this point) but samples would still only partially split (about 1/4 clear on top of the black layer)

I left the heater on till late (I'd imagine 75c ish, but I did not check) and then shut down for over night settling.


I'm wondering what will await me when I return?

[Tony]

When I've done this before, with water in the mix, I've had some clear stuff on top then creamy slops all the way down to the glyc layer.

[julianf]

I dont mind creamy slops, so long as i can separate out the glyc.

One significant disadvantage of inline heaters is that they done allow you to keep the batch hot without mixing.

So, im hoping that the separation will occur quicker than the job cools to below lard melting point (which is around 60c. 30-40 according to wikipedia, but not in my experience)


edit:

I remember now, its not lard (pig) but dripping (beef) - hence the higher melting point.

[dgs]

I've done this quite a few times, usually with frymax type stuff containing lots of water. After heating and running off all the excess water you can the secret is to put plenty of glycerol in the mix, up to a 50/50 mix if you can do it.

The glycerol doesn't have to be ex-process stuff (in fact it would be a waste to use this) It can be used once or twice before as long as it doesn't have the brown top layer (excess water)

I still have the glycerol tubs round the back that I used, top 50% is brown with water.

I have found beef dripping can be difficult to process. A few years ago I had a 'run in' with some of the stuff, mixed 50/50 with oil. It ended up with the dripping portion sticking to the side of the processor. I had to handball it out into plastic bags and dump it, what a job, never again.

[julianf]

I went out early to check on the sample id taken -

top 25% looked like set oil
bottom 75% looked like glycerol

now my concern is that either -

a) the ratio is skewed as maybe the pump was not turning over the batch quick enough (so what i took really was 75% glycerol / 25% oil)

or

b) the sample cooled before it could properly separate


So, i wonder what is in the reactor.  It would have cooled slower than the sample, but not slow enough that it will still be above 60c today.

[julianf]

ps.

in the past when ive done pure beef dripping batches, the methylester product has a melting point of about 13c ish.

so not good to use for anything other than the height of summer.


...but last time i was running on it, i thought the fuel gauge was inaccurate (i thought it had solidified around the float mechanism and was keeping it from falling)

what i later realised was that the mpg was unnaturally high (i never normally notice any change, but this was significant)

[dgs]

I have seen reports on infopop re the higher mpg when using bio derived from lard/dripping.

I would personally re-heat with more glycerol.

[julianf]

I just took the time to go and see -

Pumped out from the drain port of the reactor - what came out was like some sort of slightly gelatinous stuff - a bit like cooling custard - fluid, but with a bit of a 'wobble' to it.  Would create small peaks in the receiving container, rather like whipped cream.

Took out aprox double what id put in in gycerol, and then to clear oil.

Ive just topped up the reactor with known-good oil, and 1/8 (12.5%) fresh glycerol. I did not put in more glycerol this second time about, as i think ive broken the back of it, and diluted it with a fair bit of known-good oil. 

I may do a third, small, glyc wash if its still looking bad after this one.  It takes more time, but id rather do more, smaller, washes, than fewer larger ones.

[julianf]

Did not bother with the 3rd glyc wash.

Dosed with S1 chem.  Glyc seems to be splitting out nicely (which, i find, is always an indication of a forthcoming 'win')

I wont be counting my barrels just yet though!

[Head Womble]

I've dealt with tallow before, a complete PITA.
I burnt out two heaters in one batch, possibly due to a build up of BCB's on the element.

Doing the gly washes I ran it at a higher temp, IIRC 90°, this helped with separation.

But as you have noticed it gives great mpg and more power as well.