mark, I;'m not surprised that you don't have a 'glycerine' layer after the first stage. First of all, the more I think about it, the more I doubt that it's glycerine you sometimes see in the bottom of the container at the end of the first stage- someone correct me again if I'mn wrong- but if it's an esterification of free fatty acids, rather than a transesterification of an intact triglyceride, it seems to me that there wouldn't be much glycerine breaking off other than the very small amount of trans-e that's (very slowly) occurring.
Jon Van Gerpen's research on this process considers this layer to be excess methanol, combined with some water that is formed in the reaction. Presumably there'd also be a little bit of glycerine if any transesterification is happening as well, all in the same layer as the water/methanol. I believe that Todd also calls it first stage methanol rather than first stage glycerine, and if you look at how 'runny' it is, it looks like methanol more than like glycerine (at least the few times I"ve seen it). Van Gerpen's method (that's the exceedingly-high-methanol industrial process, somewhat different than Aleks' process and hard to do if you don't have methanol recovery and cheap energy) finds that depending on the amounts of methanol used and the amounts of water produced, the excess methanol/.water sometimes coalesces on top of the esters/oil, and sometimes ends up below the oil phase. The stuff I saw/made using his method created a layer that looked exactly like the watery 'glycerine' that I've seen using A;leks' method. However I have not always produced this aqueous layer in Aleks;' method, and I frequently used that method with nice oil, just like you. So my guess is that it's somehow connected to the amount of water produced, and that the condition of the nice oil might have something to do with it. I would also guess that how dry the oil is in the first place would be a contributing factor. Anyway, I don't worry when I don't see first stage glycerine in ALeks method, as that seems quite normal to me in my experience. On the other hand I usually don't look for it, so it may appear more often than I am aware of. Todd in the post below suggests removing any first stage alcohol (the dark layer, sometimes below and sometimes above the oils).I would add that if you do this change, be prepared to add a similar amount of fresh, anhydrous methanol, to replace any that is removed, to make sure there is enough for the second stage reaction. mark --- In biofuel@yahoogroups.com, "Appal Energy" <[EMAIL PROTECTED]> wrote: > Mark, > > Earlier I was curious if you were using oil or an oil/fat blend (WVO). > Should it be presumed that the feedstock at the beginning of the second > stage and prior to reheating is still liquid? If so, should it be presumed > that there was a layer of extra alcohol above the oil, perhaps slightly > darkened? > > If so, and were it me, I'd separate the feedstock from such a layer and then > conduct the second stage, just to isolate variables. Second, if you're > getting "jelly" out of a SVO, you might wish to back off the caustic some. > Jelly, or glop soap is a condition that results from too much caustic in the > presence of water. It doesn't take much to push what is primarily a > transesterification reaction into one that is directed towards > saponification (soap making, aka "jelly"). > > You might (or perhaps might not) care to take a look here. > http://groups.yahoo.com/group/Biodiesel/message/2504 It's a step by step > "how to" that runs the base side of an acid base experiment in three > separate stages, rather than all at once. > > That's not to declare that it should be done in such a manner. But it does > indicate that glycerin drop in the second stage can occur with less than a > requisite amount of caustic. > > Take your time and take no short cuts. It works and works well. > > Todd Swearingen > ------------------------ Yahoo! Groups Sponsor ---------------------~--> Get A Free Psychic Reading! Your Online Answer To Life's Important Questions. http://us.click.yahoo.com/Lj3uPC/Me7FAA/CNxFAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/