Hello again Doug. The forming of FFA in the presence of water is an auto-catalyst process, meaning that the more FFA:s there are, the more rapidly the further production of FFA:s. This is due to the fact that this is an acid-catalyst reaction which will continue for as long as there is water present in adequate amounts. The FFA and water values are in general higher at the bottom of the vessel, the other way around at the top. WVO often contains detergents because the cleansing of the frying oil vessels at the restaurants or factories is done with detergents and water. Some people pour this stuff into the used oil. The best way of avoiding this, is of course to let the WVO supplier know that the detergent - containing WVO is of scientifically less value, since the detergents are contaminations and cause a great deal of troubles. The other way of dealing with this is to vacuum -evaporate the WVO at 90oC, where the emulsions should break up. The third way is to reduce the water content and react the WVO in the normal way, adding further washing sequences and expecting a lower yield of biodiesel than usual.Any soap formation can be scattered with acid treatment. IPA is a good solvent for titration, unlike methanol or ethanol, which are hardly soluble in oil. I think you have a good base recipe. Do not change it, before you have examined the quality of your raw material. The solution to your problems is most likely to be found there. With best regards Jan Warnqvist AGERATEC AB
[EMAIL PROTECTED] + 46 554 201 89 +46 70 499 38 45 ----- Original Message ----- From: "Doug Memering" <[EMAIL PROTECTED]> To: <Biofuel@sustainablelists.org> Sent: Friday, August 12, 2005 3:50 AM Subject: [Biofuel] Re: Re: A beginners titration question > Jan, > > Thanks for the help. > > Hello Doug. > > Keith has made an excellent input to you questions but I felt it necessary > > to add some aspects of your problem: > > The rule no1 when taking samples is to make sure - as possible- that the > > sample is representative for the batch. This sounds simple, but if you are > > I am still working with fairly small batches so I have been drawing the > complete batch > out of my holding tank and then taking the test sample from that. I have > been titrating that batch > multiple times and getting the variation even from that. > > > dealing with high water content together with high FFA levels you will > have > > Does water content itself cause variation or is it changes in the amount of > water content > that would cause the variation in the titration? > > > different titration values if sampled from the top or from the bottom. If > > there are detergents in the oil, this actually may help. It is a > > Detergents? What's the likelihood of picking up detergents in the WVO from > a restaurant? Is this something I should watch for or is it simply a matter > of more washing? > > > disadvantage when washing the biodiesel though. > > By using IPA for titration, the general idea is to have one clear phase > > consisting from IPA, water, KOH (or NaOH) and oil. The EN standard for > > determination of acid number which is likewise determined by titration > > strongly recommends that the amount of IPA should be increased if the > > solution becomes cloudy or turbid. > > The solution was definitely turbid, but Keith's recommendation (unlike James > Bond) > was to do the test in a beaker or jar rather than a test tube so that it > could be > stirred and not shaken > > > By using methanol for titration, you are out of standard procedure. > > When I started out I got a titration procedure from another site, before I > found JTF. The procedures > were nearly identical except in the list of what you needed it said to use > either > Isopropyl, Ethyl, or Methyl. Since I had already invested in a bunch of > Methyl alcohol > for this adventure and didn't have any isopropyl on hand I started using it. > My limited college > chemistry had me in the frame of mind that a solvent is a solvent. That's > why I asked for an > explanation. I can see where the my results could be shifted by what > alcohol I am using but it didn't > make sense to me that the type of alcohol would cause the huge variation in > the test. > > > And - possibly annoying Keith - the EN requirement for a good titration is > > that the solution stays magenta for at least 15 seconds. > > This was happening, there was a distinctive cross-over point where the > solution would > turn magenta for like 10 seconds and then fade to pink. It is just that > event happened at > substantially different amounts of NaOH. > > Heating was mentioned as well, and that could be a part of my problem too. > I was heating the WVO then mixing it with the alcohol which was at about > 95F. > I didn't hear the reagent either. I gather they should all be near the > process temperature. > > Thanks again > > Good luck to you further on ! > > With best regards > > Jan Warnqvist > > AGERATEC AB > > > > _______________________________________________ > 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/
