B—You made a couple of interesting remarks in your article which I would like more clarification on, if possible. You mentioned scrubbing your processor, something I have never done, although I have tipped my processor to drain it as much as possible. Is scrubbing the processor necessary?
C&S— Cleaning up residual waste (it can throw off ratios) from previous batches in your processor is very important for accurate and successful future reactions, but if you have not had any issues up until now (after 2½ years), that is probably not your problem and tipping the processor to drain out the dregs is adequate. We use the “open 5-gallon spackle bucket method” which is probably a little more susceptible to contamination than your sealed Appleseed processor. You can never be too clean though, and if you want to really be sure, pumping several gallons of nice hot water through your machine might not be a bad idea. Just make sure you let it thoroughly dry inside the tank and hoses before mixing-up a batch of BD.
B—Also, do you think the KOH could be bad? It isn't clumping, such as I observed once when some humidity got into a bag (which we threw out). I did not think it was the problem.
C&S—You keep your container sealed, so no, this wouldn’t seem to be the problem either.
B—You mentioned in your article on making biodiesel that excess heat could cause trouble. This I did not know. It is possible that I heated the oil too much; how much is too much? I think one batch was around 145 degrees. My understanding was that warm was good--helped the reaction.
C&S—Excessive heat can cause some of the sodium methoxide (the methanol/lye mixture) to vaporize and boil-off when it is first introduced to the oil as well as during the mixing process. This ultimately would cause an imbalance in ingredients (too much oil, and not enough sodium methoxide). That batch’s temperature of 145 degrees Fahrenheit is a little too high (100 degrees Fahrenheit is usually adequate), and is probably right on the edge of causing a boil-off problem, so keep the temperature closer to 100.
Ultimately, the answer to your situation could be a little bit of all of these problems, or just a couple of them in culmination. Like any good trouble-shooter, go through them step-by-step until you find the little miscreant that’s causing all your woes. : ) Hope this helps, Beverly, and feel free to write back with further questions.
Best,
Christine and Scott