Hi Joe, >If the answers to questions 2 and 3 are yes then it would explain a lot.
I think so. >Then the answer to question one could be that although the BD did not >pass >the QT if it was settled long enough that there is no glycerol it would >be >consistent with the emergent theory. No? Let us be clear re: "The emergent theory". Is it : Very small amounts of unreacted Mono- and Di- Glycerides combined with unsettled Glycerin Mix will produce emulsions, but the same amount of the Glycerides or the Glycerin, alone, do not? (There is an additive/multiplicative/? effect when both are present) I think the results seem to indicate this. Or is the "emergent theory": The Glycerin Mix settles more slowly from the product of incomplete reactions? Consistent, yes, but not evidence for the hypothesis. If it turns out to be the case it would be a good example of the old "double-whammy" effect. Incomplete reactions contribute the unreacted Mono- and Di -Glycerides needed for the emulsion which in turn slow the settling of the Glycerin Mix which also contributes to the problem. The significance of whatever emerges may be dispelling a misconception. I know of people who view "No problems with the wash" as a sign that they achieved complete reactions. I've been told: "I would have gotten emulsions if I had any unreacted oil." A buddy of mine recommends letting the BD settle for a few days .... "a week if you can." "It seems to take care of any problems." ?????? I tell him: Do a QT try dissolving 25 ml of the BD in 225 ml of methanol. (12.5 ml BD in 112.5 ml methanol). I don't know why homebrewers resist QT-ing their fuel. Good Day to You, Tom P.S. I think we will eventually get to the bottom of the effect of glycerides on settling time. I've stocked up on BD for my car (passed QT) in anticipation of a push to make heating BD. I'll be able to get settling times on quite a few batches of "poor quality" BD, but won't be running any 'good quality" batches, for comparison, for a few weeks. ----- Original Message ----- From: Joe Street To: biofuel@sustainablelists.org Sent: Monday, August 13, 2007 4:41 PM Subject: Re: [Biofuel] Glycerin as an Emulsifier (was GlycerineSettling Time) Hi Tom; If the answers to questions 2 and 3 are yes then it would explain a lot. Then the anwer to question one could be that although the BD did not pass the QT if it was settled long enough that there is no glycerol it would be consistent with the emergent theory. No? Joe Thomas Kelly wrote: On Friday 8/10, I noted that: >II. Glycerin Cocktail: Time to Separate (wash test) > good quality BD + water + glycerin cocktail > 2 hours* > poor quality BD + water + glycerin cocktail > 2 hours* It almost 2 days for the "good quality" BD to separate out. There was a very clear soap layer between the BD layer and the water layer. It's almost three days now and the "poor quality" BD still has an emulsion layer. More than half of the BD layer is emulsion. My thoughts: 1. Glycerin, itself, separated from the "cocktail", is not an effective emulsifier 2. Presence of just the glycerin "cocktail" lengthens the time needed to separate water from BD 3. The glycerin cocktail in combination with even small amounts of unreacted Mono- and Di- Glycerides forms emulsions during wash. ***Keep in mind that my "poor quality BD" failed the Methanol Solubility Test (the "Warnqvist" Quality Test), in that the resulting mix was cloudy, and given time, an observable, but difficult to measure, amount of residue (unreacted glycerides) dropped out. There were not globs of residue. This was not real bad BD. It is used in my home heating system. Questions/Comments: 1. Unreacted Mono- and Di- Glycerides have a reputation as being very effective emulsifiers. They are present in the BD that I make to heat my house. Why don't they form emulsions when I stir wash this BD? 2. If glycerin cocktail (unsplit) is present, the same levels of Mono- and Di- Glycerides form emulsions, when they are only shaken . Does this represent a cumulative or synergistic effect? The cumulative/synergistic effect of glycerin cocktail and unreacted glycerides on emulsion formation would explain a couple of observations: a. Incomplete reactions coupled with short (6 - 8 hour) settling times often produce emulsions in the wash. Longer settling times 2 days or more ----> no emulsions. The glycerin has settled out b. After breaking emulsions (1st and even 2nd wash), subsequent washes go well w/o emulsions forming. The Mono- and Di-Glycerides are still present, but the components of the glycerin cocktail have been, for the most part washed out. 3. Does the glycerin cocktail settle out of incomplete reactions more slowly than from complete reactions? Tom ----- Original Message ----- From: Thomas Kelly To: biofuel Sent: Friday, August 10, 2007 2:46 PM Subject: [Biofuel] Glycerin as an Emulsifier (was Glycerine Settling Time) Andres, Jan, Joe, Keith, and anyone else who has been following the saga, It would seem that glycerine, itself, is not an effective emulsifier. I've spent the morning "experimenting" in the kitchen. I did "Wash Tests" on BD that passed the QT and BD that failed the QT. I tested one group with glycerine split from the cocktail (using Phosphoric Acid) and another group with unsplit Glycerin "cocktail". Volumes used: Biodiesel 150 ml Water 150 ml Glycerin (split and unsplit) 4 ml Temp: 70F (~22C) I. Glycerin split from the cocktail (used Phosphoric Acid): Controls: Time for clear separation (min) good quality BD + water 1 - 2 poor quality BD + water 3 - 4 Experimental: good quality BD + water + glycerine (split) less than 5 poor quality BD + water + glycerine (split) less than 5 II Glycerin Cocktail: good quality BD + water + glycerine cocktail > 2 hours* poor quality BD + water + glycerine cocktail > 2 hours* * At 2 hours there is a thin layer of BD (1 - 2 mm) The rest appears to be an emulsion. Andres and Jan, you are correct. Glycerin, itself, did little to retard separation of BD and water. Something in the "cocktail" does seem to be an emulsifier. (The soaps??) Some questions remain: 1. The BD that failed the QT (incomplete reaction) was obtained from a tank that feeds my heating system. It contains unreacted glycerides, but does not produce an emulsion when shaken in water, nor did it produce emulsions when it was stir-washed. Why not? 2. At Joe Street's suggestion I took a sample of BD that had settled for about 10 hours. Twelve hours later, more "glycerin" had settled out. Today, still another 24 hours later, even more has settled out. Could this small amount of unsplit glycerine (with associated soaps) be the cause of the emulsions I got when I started making BD? It would explain why settling for a day or more seems to eliminate the problem. 3. Does the glycerine mix (or soaps) settle out more slowly in BD from incomplete reactions? Tom -------------------------------------------------------------------------- _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/ ---------------------------------------------------------------------------- _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/ ------------------------------------------------------------------------------ _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
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