On Mon, Aug 21, 2006 at 10:08:58AM -0400, Thomas Kelly wrote: > Rafal, > 1 - 2L test batches w. virgin oil ..... Good > > 99% pure KOH V. Good > (If you are concerned about the purity and have > NaOH of known purity you can test the KOH)
I know that. However, KOH that I've bought doesn't look perfectly fresh ie. it is not completely translucent, as my NaOH was a couple of months ago. Now, I have both of them slightly calcinated which shows up as a trace of dust (really, just a little bit) on the bottom of a bottle I use to mix the methoxide solution. > Temp and agitation also sound good. > > If there is water in the methanol you will make more soap (emulsion) > and there will be less methanol ---> incomplete reaction (emulsion). No, the methanol is also very pure - the same supplier. I started with pure and a bit expensive chemicals, to gain more experience and avoid troubles that might be caused by urity. > As I understand it, you have done test batches w virgin oil and > have gotten unsatisfactory results .... emulsions upon washing. You are > concerned about incomplete reactions. That's right. > Question #1: Are you careful to exclude the glycerine byproduct from the > wash? Last time I settled the mixture of ester and glycerine byproduct for 24 hours and got nice separation. I carefully removed glycerine from the bottom (similar construction to the test processor on JtF pages) _and_ I settled the ester with just a bit of byproduct on the bottom (difficult to remove completely) for the next 12 hours. Then I syphoned off a 200 ml sample for test using elastic pipe, from the middle of the container. Nice, clean and pale yellow product. My only concern is that it's not transparent, but rather cloudy - likely due to incomplete reaction. > Question #2: The oil titrated at 0.925 ml of .99KOH.. This is significant. > Have you run a batch with an additional .9 - 1.0 g KOH/L you got from > titration? Not yet - that's why I'm asking for your opinion. After the mails I've received I'm going to try it. I tried it once, with NaOH, but I didn't add such a small amount (divided by 1.4), but rather 20% more. I was afraid of the lye calcination, so I tried to add more, according to what I read. That was probably too much - no luck and washing problems. > 3.5g 100%NaOH/L of oil = 4.9 g 100%KOH/L of oil Of course, I realise that. > Add 0.9 - 1.0 g of the KOH (from titration) you would be using 5.8 - 5.9 g > of KOH/L of oil. > > This additional .9 -1.0 g represents an increase of 18 - 20% over the > amount used for virgin oil w/o FFAs. When you consider that your KOH may be > less than 99% pure, > the amount needed would be even higher. This could very well be the cause of > the incomplete reaction. > > Treat the virgin oil as if it was WVO. Include your titration results in > the amount of KOH to be added and run a batch exactly as you have before. > Let us know how it worked out and we'll proceed from there. Surely I will. > Of course you could go out and buy some "high quality" veg oil that > titrates zero, but then we would not get the answer to the puzzle. Exactly. Besides, led by curiousity, I tried to titrate a better oil I had. It was also pure rapeseed oil, just the quality was better. Titration result was .750ml or so. I wonder, what would be the result when a really fine quality oil was tested (sunflower perhaps)... -- cheers, Rafal Szczesniak **mir[at]diament.iit.pwr.wroc.pl Samba Team member mi***[at]samba.org +---------------------------------------------------------+ *BSD, GNU/Linux and Samba http://www.samba.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/
