Hi Keith and everyone,Thanx a lot, these arethe answers I was looking for! I just wanted to be sure that I do it all correctly.Keith Addison [EMAIL PROTECTED] wrote:Hi again DanielSorry there was some confusion in the responses to your message. Forget about the advice to use more lye, especially as you'd already said you'd tried that and got worse results. It's very unlikely that you need to change the basic quantity of lye for it to work right. Just to be sure, what kind of oil are you using, both virgin oil and WVO?On the first few timesI used virgin oil, and then I used WVO.The thing is that it wentbetter with the WVO than with the virgin
oil... (maybe my measuring tools are poor...)You're working with one-tenth of a gram margins, which is okay, but you should do whatever you can to be able to feel confident that you're staying within that margin and that your other measurements are accurate too. This is definitely the most common reason for earners' test-batches failing the tests.My NaOH scales are accurate (I use the digital lab scales accurate to0.01 gr,at my lab in the university). I weigh the lye in a plastic bag on the scales. To the matter of fact,I weigh 3.55 gr, because every time when I throw the lye into the methanol,a fewlye grainsstick to the plastic bag by the electrostatic force. The Lye doesn't get wet, asthe grains stay separate from each other.I will try to find a small plastic container to replace the plastic bag. I think my volume measurements
areless accurate, although I rescaled it with a 50ml test tube.Just to be sure, I use a bit more Methanol than the standard 200ml- about 220ml). I did a titration with 1% NaOH, and got magenta\pink after 2.3 ml (2-3 times). So I put 5.8gr (3.5 +2.3) of NaOH, and got with the best washing quality test ever! The biodiesel got separated in 20 minutes with a paper thin layer between. The third wash was cristal clear. Beginners luck? :-) Why knock it?In order to be sure that it is really working, I've tried different concentration of NaOH. But then I got excellent separation in the washing test also with 6.2gr of NaOH... How can that be?Increasing the lye from 5.8 to 6.2 grams is a 0.4g increase. You titrated the WVO at 2.3 ml, and that's probably accurate, or not far wrong. That's nice oil, ideal for newbie test
batches, not too much FFA. WVO at 2.3 ml can probably take a 0.4g lye variation, as long as you process it properly. Virgin oil can also take that variation, which is why I don't think altering the lye amounts will help you.But 6.5 ml titration WVO will not be so forgiving, there's much less margin for error, and 10.5 ml WVO will not be forgiving at all - now you need not only good processing but exact amounts of lye as well. With these high-FFA oils you should use a little extra lye, as advised at our website. But newbies should avoid oils like that, 2-3 ml is ideal, so that's not a concern for you now.How do you mix the methoxide?I mix 200+ ml (~220 ml)of methanol with 3.5 gr of NaOH in a glass jar, till all the lye is dissolved (1-2 hours). I couldn't find any KOH with a reasonable price yet. I've found it only at lab suppliers, and
their prices are high because they sell small quantities. How are you processing the biodiesel - how do you agitate it, for how long, at what temperature, how do you maintain temperature control?I process the biodiesel in a 1 gallon (4 liter) plastic processor, for about 70 minutes, at about 55 degrees C. I keep it between 52-57 degrees C.I heat it on a electrichot plateand control the temperature witha thermometer. I agitate it with an electric drill (fast and strong) and a stirrer we made from a steel rod with a piece of flat steel brazed to it. Was my magenta really pink and not magenta??? :-) What's the difference, really? It probably depends who's looking.Actually it doesn't matter, this will work just as well: when it starts to change colour and stays that way for 15 seconds. You have to add the 0.1% NaOH solution
carefully, drop by drop, one drop at a time, stirring all the time and waiting to see the effect of each new drop. It's a sort of murky grey colour once you've stirred up the isopropanol, the oil sample and some of the NaOH solution, that is no colour at all, then suddenly it's not just murky grey and takes on a little colour. Wait, see how long it stays there. If it goes grey again in a few seconds, add another drop. When the tinge of colour stays for 15 seconds, you've got it.Anyway, Daniel, it sounds like you're doing just fine. Keep going and you'll get there, not too far to go. Good luck!BestKeithI'm going to scale upmyprocessor to 5 or 10 litters at a time, any tips?Thanx again! Daniel___Biofuel mailing
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