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How Are People that Glyc Pre-Treat Draining off Byproduct?
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Hi
To the folks that are Glycerol pre-treating their feedstock, what method of Glycerol removal are you using to have so much (I'm assuming) pure Glyc? ... ie: I suppose not using a 5% prewash with Glyc still in the BD? This would produce watered down Glyc... I'm assuming this would be less desirable for Pre-teatment?
Thanks. P
 
Location: Vancouver | Registered: November 02, 2005Reply With QuoteReport This Post
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After pre treat,the glyc is not pure,it is dirtier-it has taken on all the crud and most of the water from the feed stock-in return it has really cleaned up and given up some meth to the feedstock and lowered the tit value.The glyc settles out in an hour or two(I leave overnight to make sure).
I do not do 5% water prewash in processing(want to keep extra water away from the glyc,but others say it still works ok)
 
Location: UK | Registered: October 14, 2008Reply With QuoteReport This Post
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Hi,
I pretreat and do 5% prewash. (34gallon batch, 2+stage)

What I do is, after the initial reaction and drain, I keep ~4 gallons (a cubie) of raw glycerin separate and sealed for my next pretreat. That's a little more than 1/2 the glycerin yield per batch.

The remainder is needed to reintroduce for the 5% after passing 27/3 (Varnquist test).
Also, I dont use a full 5% water.

My results are T-3, down to T-1 and much cleaner, drier feedstock. I never get past 2 stages, so far.

Good luck.
Brian


1996 K2500 4x4 6.5TD
 
Location: Southern Indiana USA | Registered: June 20, 2008Reply With QuoteReport This Post
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Weldshop
So you only leave in about 1/2 your glyc for 5% prewash? You get no emulsion this way? What % water do you use in pre-wash?

Also in general if people aren't pre-washing how do they avoid emulsions? What exactly is the procedure used?
thanks P
 
Location: Vancouver | Registered: November 02, 2005Reply With QuoteReport This Post
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To avoid emulsions,I make sure I have passed 27/3 test,then drop absolutely all the glyc byproduct before the bio is committed to the wash tank-first wash is only 2%-5% of batch size and very gentle-subsequent washes are ~10% and more aggresive building up as I progress.For me the most important bit seems to be making sure you keep the glyc out of the wash tank-this is the killer.Try washing a sample from the top of the batch and compare that with a sample from the bottom-you will see what I mean.
Hope this helps.
 
Location: UK | Registered: October 14, 2008Reply With QuoteReport This Post
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PD
-5% water for a prewash is tooooo much if the byproduct has been removed, cut the water amout to two or three% and avoid over mixing. how much time to mix will depend on your processor, and the volume output of the pump. Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post



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I put just about a gallon water in. Mix for ten minutes or so.

Here's a similar discussion leading to my first try ending successfully.
http://biodiesel.infopop.cc/ev...=570106432#570106432

Try it.

Brian


1996 K2500 4x4 6.5TD
 
Location: Southern Indiana USA | Registered: June 20, 2008Reply With QuoteReport This Post
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p.s.---- I say 5%, because that's the known procedure.
More like 2-3% for me.
I no longer have soap skins on top in the settling tank after de-mething.

Brian


1996 K2500 4x4 6.5TD
 
Location: Southern Indiana USA | Registered: June 20, 2008Reply With QuoteReport This Post
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tarelec
How do u make sure you "drop absolutely all the glyc byproduct before the bio is committed to the wash tank"? We know that as the meth evaporates with time it gives up further glyc. Do you wait for several days before washing or something?
P
 
Location: Vancouver | Registered: November 02, 2005Reply With QuoteReport This Post
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I settle overnight(I use a poly cone tank,with a small band heater round the cone-only 80 watts,but just enough to stop my glyc gelling-I use NaOH)-then drop glyc,then wait for 1/2 hr,and try dropping some more(second drain off yields about a cup full)-repeating this process until no more glyc shows in the bio.My bio is usually quite a light colour so the glyc shows up quite easily.The glyc is kept for pre-treating the next batch-so hopefully recycles any bio dropped with the glyc.
I don't know that I am getting all the glyc out but I have found putting extra effort in at this stage,realy pays off.
 
Location: UK | Registered: October 14, 2008Reply With QuoteReport This Post
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quote:
Originally posted by PD.Vancouver:
tarelec
How do u make sure you "drop absolutely all the glyc byproduct before the bio is committed to the wash tank"?


It isn't critical as any remaining glycerol will be washed out along with the soap, methanol and left over reactant. Some simply settle and use, but I beleive in a good washing and drying before consumption.
 
Location: Winnipeg, MB | Registered: July 31, 2008Reply With QuoteReport This Post
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Nothing will turn the wash into an emulsion faster that a little by product!!! and it is vertually impossable to drain it all without loosing some biodiesel. the best idea would be to learn to deal with it!. I do two static washes prior to pump washing, that removes most of the soap, and methanol then I start the pump washes. Also, controlling the amount of water you use in the wash will help to prevent the dreaded emulsion, I keep the water quantity to 5% or less. Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post



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I'm with you on that one Tom-I think you always said,"I'd rather have a little bio in my byproduct,rather than byproduct in my bio"
 
Location: UK | Registered: October 14, 2008Reply With QuoteReport This Post
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Biotom
"Controlling the amount of water" in what wash? Pre-wash, first static wash? Also how long do u settle between washes... like after you've finished adding the water is there ever a even slight emulsion layer, perhaps especially so after a "pump wash". If so you must have to let it settle, yes? I've found that these emulsions that one occasionally gets say 1/2 way thru your wash routine will usually settle out if allowed to settle for maybe several hours. My entire wash routine after initial 5% pre-wash is usually about 5 - 6 static washes other wise I can see emulsion. Maybe I'm gun shy but I keep any agitation to a minimum.
Comments?
Thanks. P
 
Location: Vancouver | Registered: November 02, 2005Reply With QuoteReport This Post
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