Processing Groundnut Oil

[RichardP]

Picked up a load of groundnut oil last week, and having not used this before did a quick Dr Pepper test, all looked good, good glyc separation etc.
So today I did a 100ltr batch of the stuff, it was dewatered yesterday in the processor, and then had a good glyc wash. The oil was about as dry as you could get it before anyone asks!
Using my normal method of 2 stage titless, gave it first stage of 2.5ml/l methylate (1250ml) and 13 ltrs meth, 90/10 gave 3ml dropout, so then 4ml/l (600ml) and a 3 litres of meth. All seemed to process fine, dropped out a sample and this is where it went a bit odd.

There was  again good glyc separation, did a 5/45 which just went completely cloudy with lots of whispy bits floating around, odd, so I warmed the 5/45 up a few degrees from 20 to 23 in some warm water and it went completely clear, then cloudy again when it cooled a bit. I've had cloudy 5/45's so added another 200ml and a litre of meth and processed for 30 mins. Next 5/45 showed exactly the same as before:


I've never seen this before, but then I've never processed peanut oil. Odd as well as the first stage 10/90 was perfectly normal, straight dropout, no floaty crap like in the second.
I buggered about with a few samples but it made no difference to the outcome by adding more catalyst, so I pre-washed and then fully pump washed the batch and that went without a hitch, the finished bio looks normal


I have two sample sat in the fridge at 3-4C now, one straight peanut bio, which has gelled up quite badly, and one 50/50 with rapeseed bio which is clear as a whistle.
The cloud point appears to be around 13c for the straight groundnut oil, but the bio also goes cloudy around that point too, I expected it to be a lot lower.

So to me it's a temperature thing with this oil, now does any else process the same oil and get the same issue on the 5/45 like that above or have any tips for this stuff to pass on?

[Tony]

That's interesting - a friend of mine had some oil that did a 3/27 like yours (lots of balls in the settled layer) and we never found out why.  Didn't seem to reprocess any better. I wonder if it was groundnut oil?

[nigelb]

That's a whole bunch of oddness there Rich.

I've never come across groundnut oil...how did you manage to get hold of some?

[RichardP]

Certainly is much oddness Nige, seems to blend ok with my usual stuff. It washed so easily and quickly too, though I misted it for some additional time just to get the temp down to see what it did when below 20c. Needless to say it started to thicken up towards ambient water temp.

[nigelb]

I had a thought today about your predicament Rich....could it be a case of "over processing?"  You say that the first stage 90/10 was normal and yet the second stage was where the problems started.

Groundnut is an unknown quantity as regards feed stock so maybe it's a tad sensitive when being processed in this way. Just a thought

[RichardP]

It is wierd, maybe next time I may try lower stage 2 ASM, may work. I may do one more small batch to see what happens, after that I'll just mix the feedstock before processing.

Nige - sent you a pm.

[greasemonkey]

Isn't groundnut oil quite flammable, compared with the likes of rapeseed and sunflower? I'd say it could be the equivalent of a lighter fraction of oil. I'd go with what Nigel says, it doesn't need as much processing. (Not that I've actually made any bio yet.......)

[RichardP]

When you say 'shouldn't need as much processing', in what sense?

Do you mean less time mixing/processing or less chemicals? I already use quite a low ASM base of 2.5, which gave a dropout of 3ml on a 10/90 which isn't too unusual so one would expect the normal stage 2 of around 4asm to be ok to fully convert without dropout.
What is unusual is that by the final 5/45 as in the pic above, if it were unconverted mono or diglycerides, then that would cause problems when water water washing, especially when doing pump washes which it didn't, so I can only presume there was full conversion, and the dropout is temperature related, even at 20c. Also had a jar of the finished bio outside overnight and it was very thick this morning and it wasn't cold. As soon as it warmed up it was fine.