Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: Head Womble on July 04, 2011, 01:24:05 PM
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Hi All
This is my first post on here,
but I'm an active member on the vegetableoildiesel site.
Anyway I thought I'd post my findings when using the AAF method.
First I'll give you some info on my system.
It's a steel 180L (batch size) GL with pre-heat (feed stock) drum,
110LPM pump,
single stage eductor (gives a tank turnover of around 500lpm),
Squirrel (flash evaporator sort of thing, for de-mething),
Quad core condenser with still head heat exchanger,
PID temp control.
AAF it's self,
I heat and glycerol pre-wash my oil inside the reactor and after dropping the gly drain the oil back into the pre-heat drum,
the oil finds it's own level between the two, this leaves about 20L inside the reactor wich is enough to run the venturi,
so I then suck the methoxide into the reactor (no the 20L of oil doesn't turn into soap), once this is inside I pump in the rest of the oil.
Doing it this way I got a 27/3 pass after just 25mins.
I have yet to do AAF with the eductor fitted, but with a normal process the eductor has dropped my reaction times from around 1 hr to just 20mins,
so doing AAF with the eductor should drop times even more (I'm hopping for 10mins).
For those that don't understand how AAF works, just think of it this way,
if you add orange scwosh to a glass of water it hardly mixes at all, but when you do it the other way round it mixes very well.
Now as the bio reaction is all about mixing you can understand why AAF is so effective.
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Now I wish I had a separate dewatering tank - trouble is I dewater in the GL so can't... unless... maybe dump the dewatered oil out into a drum except for 20l to circulate, then suck in Methoxide, then suck the oil back in.
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Hi Tony
I don't dewater in the feed stock drum,
I course filter the oil as it goes in and then it sits there until I pump into the reactor.
Oh, and I also sometimes heat the oil so I can melt solids in there.
I will be adding a pump so I can dewater in there as well, but that's way down on the todo list.
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I tried AAF once. I have no preheat tank so had to clean an HDPE oil settling tank. Heated in the processor and transferred to the clean tank. Didn't want to put oil much over 65°C into HDPE. So by the time everything was sorted with the methoxide, the oil had cooled some what. Seemed to work but wasn't a fair trial at low temperatures.
You defiantly need a preheat tank and, in my case especially, the space to house it!
So how do you dewater?
Mark, can you have a bash at integrating your text with and elaborate on, the AAF page here ... http://www.biopowered.co.uk/wiki/Arse_about_face Any pics of the set up would be good and perhaps we could add a table similar to the processor state diagrams.
If you need any help, just shout.
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Ok mate, I'll see what I can do in the next few days.
Haveing a nightmear of it at the mo with a very wet batch of oil.