just about everything I have read says use one or the other, but no one seems to want to say why to use one or the other? is there a difference? why do i want to use one over the other?

Thanks

Both work very well. NaOH sources are 95-98%pure so what you titrate is what you use. KOH is usually 88-95% pure. If you use NaOH to titrate your oil you have to multiply that ammount/liter by 1.4 to get the ammount of KOH to use. I just make my titration solution from the batch of KOH I am using so that my titration number = the ammount of KOH/liter I need + 7.5gm/L for the reaction.

Some have found that their glycerin byproduct turns solid very quickly using NaOH, because NaOH makes hard soap, whereas KOH makes liquid soap keeping the byproduct liquid.

I use KOH;

1) its no more expensive where I am than NaOH.
2) The glycerin stays liquid, even after the methanol is removed, so I can continue to pump it and pour it to move it around without having to warm it up.
3) The glycerin stays liquid, so I can leave it in the processor without fear of plugging the pipes.
4) It dissolves faster in methanol.
5) It lets me run a single base stage, if necessary, of higher titrating oil than NaOH can run in a single stage. I've done 9ml oil single stage, just accepting some yield loss. That would be a 6.4ml titration with NaOH, which is well beyond the 5ml limit commonly imposed.

Take a look at some of these threads.
http://biodiesel.infopop.cc/eve/forums?a=search&reqWord...Type=1&search=Search
DD

It's also more tolerant of water in the reaction.

Hello sharpdan

quote:

Originally posted by sharpdan:
It's also more tolerant of water in the reaction.

I have never heard that before. Can you be more specific as to what you mean by more tolerant?

Hi Tilly, I haven't done the tests myself, but I have seen reference to it several times related to purity of methanol and a not perfectly dry oil.

The way I understood the posts was that you could have more water with KOH and not affect the reaction as much.

Dan,

quote:

The way I understood the posts was that you could have more water with KOH and not affect the reaction as much.

Makes sense, given that NaOH soap is solid. So, very high soap from KOH = difficult (but doable) wash, very high soap from NaOH = blob O'Jelly!

so far sure sounds like KOH is what I want to use.

I read somewhere that you can use the glycerin as a fertlizer? I have not seen much about this but that would be very good for me. Do you guys have any more info on that?!

quote:

Originally posted by Tubular031:
I read somewhere that you can use the glycerin as a fertlizer? Do you guys have any more info on that?!

Try here.

Ken