Hello Jeff >Dear all, > Need help in this process. I have read about this procedure and >followed it exactly as it said in the JTF.
Uh-huh... Sorry, I get a sinking feeling when someone says that. >I even bought a digital pH meter to make my life easier but this >proved otherwise. > Putting the pH meter into oil Why did you put the pH meter into oil? What oil? >the reading does not stop moving, it take minutes to accertain >whether the pH meter has stopped at a correct reading. Thereafter, >when we titrate it, So you titrate it *after* you put the pH meter into oil? >the pH meter goes "wild" again. Is there any better way to read the >pH. I think all my titration results is as "wild" as the pH meter's >reading and that will make my process "wild" as well. I am trying >to get the pH reading at 7 +_ 0.5 Why? Where in the titration process do you have to get a pH reading of 7 +_ 0.5? > From what I read, this should not give us too much of a problem. >Right? Any other suggestion on this titration process? Well, you say things that wouldn't be included in following the titration procedure exactly as said at JtF. Some people say don't use a pH meter, throw it away... and then the same people say you can use phenol red instead, though it only goes to pH 8, not the required pH 8.5. At JtF we say use either a pH meter (preferably a good one) or phenolphthalein, though we prefer the pH meter and we say why, along with a further explanation from a list member. One reason these people say a pH meter is "useless" is that they claim you can't measure the pH of oil or biodiesel with a pH meter anyway because a pH meter can only measure an aqueous solution. Yes you can measure the pH of biodiesel with a pH meter, if it's a special one, and in some cases it doesn't even have to be a special one. This is also explained at JtF. There are also directions on how to use and maintain (and callibrate) a pH meter. Anyway the oil you're measuring in titration IS an aqueous solution, or an aqueous mixture anyway, since you're adding 0.1% NaOH (or KOH) solution to the oil-isopropanol mixture, and the other 99.9% of that solution is distilled water. Anyway, nowhere does it say that in titration you have to put the pH meter into oil, nor that you need a reading of pH 7. So I'm afraid I haven't a clue what you've been doing, so I can't say anything about your results. Maybe you should start again: Biodiesel from waste oil http://journeytoforever.org/biodiesel_make.html#biodwvo Basic titration http://journeytoforever.org/biodiesel_make2.html#titrate Better titration http://journeytoforever.org/biodiesel_make2.html#bettertitrate Accurate measurements http://journeytoforever.org/biodiesel_make2.html#measure pH meters http://journeytoforever.org/biodiesel_make2.html#pHmeters Phenolphthalein http://journeytoforever.org/biodiesel_make2.html#phenol pH meters vs phenolphthalein http://journeytoforever.org/biodiesel_make2.html#phvs Stock methoxide solution http://journeytoforever.org/biodiesel_make2.html#stockmeth Poor man's titration http://journeytoforever.org/biodiesel_make2.html#poor Is that what you've been following? Best wishes Keith Addison Journey to Forever KYOTO Pref., Japan http://journeytoforever.org/ >Jeff _______________________________________________ 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/
