Joe, For the sake of precise concepts, gliceryn is NOT an emulsifier. Emulsifiers contains a clear lipofilic and hidrofilic zones in the molecule. Which is an emulsifier is the partially reacted mono or di-glicerides, but in a crystal clear liquid there are not emulsions or dispersions. Glycerin is dissolved in the BD and separates from the liquid BD phase with time. ----- Original Message ----- From: Joe Street To: biofuel@sustainablelists.org Sent: Thursday, August 09, 2007 11:30 AM Subject: Re: [Biofuel] Glycerine Settling Time
Tom; It makes sense. Glycerin is an emulsifier. Have you ever tried dosing the batch again with a little methoxide? After you remove the glycerin it doesn't take much to get the last bit of the reaction to go and settle out the remaining glycerin. Of course this is well known already. Kenji and many others do straight base catalysis as a two stage deal. You can do a methanol test of sorts and the unreacted oil will settle out. Then you can use the measured amount of unreacted oil in the methanol test vial to estimate the percentage unreacted oil in your batch and dose accordingly with the stoichiometric amount of methoxide. Assume neutral oil for this calculation. Rod and I do this regularly if the batch fails the QT and it works like a charm. Will save you settling time in the long run. Big skies Joe Thomas Kelly wrote: Joe, I took a sample from my latest batch of BD destined for my boiler (failed QT; but very little residue dropped out). It had settled for almost 10 hrs. That was yesterday morning. Today there is a small, but noticable, bit of glycerine on the bottom. More settled out after the initial 10 hrs of settling. I don't have any results with good BD to compare it with. If it turns out that glycerine settles out slower from incomplete vs complete reactions, it would answer the question I asked about getting emulsions when I washed low quality BD after letting it settle overnight, but not getting emulsions when it settled for a few days to a week. It would also help with a friendly disagreement I have with a friend. He seems to think that unreacted glycerides will settle out of the BD given time. He has taken to going with about 16% (vol/vol) of methanol in his batches. His logic: "Unreacted oil causes emulsions, right?" "The emulsions I get in the first wash after settling the BD overnight are due to the unreacted oil?" "When I let it settle for a week or more I don't get emulsions, therefore the unreacted oil must have settled out." More likely: Some unreacted glycerides are still there, but after a week of settling more of the glycerine has settled out. Even a small amount of glycerine compound the emulsifying effects of the unreacted glycerides ..... Yes? By the way, I always ask him "Did you do a quality test?" His answer: "Oops, I forgot." Thanks Joe .... and Rod ..... for bringing this to my attention A push to make a lot of BD for heat is just around the corner. It might be best to include more settling time in the schedule. Tom ----- Original Message ----- From: Joe Street To: biofuel@sustainablelists.org Sent: Tuesday, August 07, 2007 3:02 PM Subject: Re: [Biofuel] Biofuel Quality Test Hey Tom; Take a sample from your fuel after settling 6-8 hrs and set it asside in a mason jar for the longer period and see what settles out. Rod believes that glycerin settles slower in a poorly completed reaction. I believe he is right. And yes it only takes a little glycerin to emulsify your wash. Joe Thomas Kelly wrote: Mike, I let mine settle for a week when I can. It washes much easier. I doubt that it does anything for an incomplete reaction though. That is to say, I don't think the unreacted oil will settle out. But: I have been wondering about something. When I started making BD it would never pass the methanol quality test. I inevitably got emulsions in the wash. Now, when I make BD for my "oil"-fired boiler, I use only about 16-17% (vol/vol) of methanol. The BD does not pass the quality test, but I don't have the same emulsion problems. Is it because I let it settle longer (24+ hours vs 6 - 8 hrs)? Does the presence of a small amount of glycerine/soaps make that much of a difference when trying to wash BD from an incomplete reaction? Tom ----- Original Message ----- From: "Mike Weaver" <[EMAIL PROTECTED]> To: <biofuel@sustainablelists.org> Sent: Monday, August 06, 2007 2:46 PM Subject: Re: [Biofuel] Biofuel Quality Test FWIW - I let the batch settle for a week or so (the lazy man's way) and that also seems to help w/ this. Thomas Kelly wrote: Shawn, I suspect that the "dense substance at the bottom of the flask" was unreacted glycerides, indicating an incomplete reaction. I now drain a sample of the mix towards the end of processing. - Shut off the pump - Drain a sample and turn the pump back on - Allow the glycerin to settle for a few minutes - Perform Jan W's quality test on the top (crude BD) layer There is still glycerin in the mix, but if I have succeeded in getting a complete reaction, I do not get an insoluble residue on the bottom. I repeat the test after washing the BD. It is a quick, easy test, and the result, whether it passed or failed can be added to the methoxide for your next batch ..... no wasted methanol, costs nothing to perform the test. Best to You, Tom ----- Original Message ----- From: "shawn patrick" <[EMAIL PROTECTED]> To: "Biofuel Mailing List" <biofuel@sustainablelists.org> Sent: Friday, September 07, 2007 9:03 AM Subject: [Biofuel] Biofuel Quality Test Good Day All, My question is in regards to the Quality test develop by Jan Warnqvist. Is this test to be performed on the product before or after the glycerin has been removed, or does it matter. I performed the test with out removing glycerin and found that I got a clear bright phase except you could tell that there was a more dense substance at the bottom of the flask. I assumed that was the glycerin since just extracted a sample from the process without separating BD from glycerin. Does the glycerin dissolve in the methanol?? Was I looking at the unprocessed materials in my BD?? Regards Shawn Patrick _______________________________________________ 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/ _______________________________________________ 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/ ------------------------------------------------------------------------------ _______________________________________________ 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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