What happens if I use NaOH for the titration, put the titration number into the biodiesel-o-matic spreadsheet and use the calculated amount for KOH in the process? Will I be adding the right amount of KOH, too little or too much???

Why would you want to do this and screw up a batch?

I must admit, I've only done some 1 L batches...waiting on my equipment on order...but one constant theme I see in this forum is when people have problems with their process, it usually stems from not following the tried and true methods that the brilliant guys on this forum have posted...and one of those steps is using the same BASE for titration and process...

Wayne,
My brain is a little foggy, but I think the conversion factor is 1.4. So you would take the NaOH titration and multiply by 1.4 to get the right KOH titration number.
DD

Dandy Don,

I'm guessing you are using base 5 NaOH and dividing KoH base of 7.0. Questions:
1) Isn't 7.5g/L KoH the latest std? This would make the conv. factor 1.5. Don't know if it really matters that much...

2) If the above method is how you obtained the factor, does the 1.4 ratio still hold true as an oil titrates higher?

3) Is there an advantage of using a different base for titration than processing? Seems any cost savings would be minuscule, especially if one is using KoH for processing.

It still seems to me that this can be a cause for errors, and if there is no advantage, does not seem worth the risk.

Thanks

quote:

Originally posted by Dandy Don:
Wayne,
My brain is a little foggy, but I think the conversion factor is 1.4. So you would take the NaOH titration and multiply by 1.4 to get the right KOH titration number.
DD

This holds true only if the hydroxides used are of equal purity. This is typically NOT the case. Titrating with the hydroxide you use accounts for purity and hydroxide carbonation (spoilage).

Last batch I did that at x1.56 for 90% pure KOH, titrated with my old NaOH because I kept getting strange readings from my new KOH titration solution.

Yeah, I said my brain was a little foggy on it as it has been a long time since I have worked anyone through this issue.
Of course the ideal situation is to titrate with the catalyst that you will be using. But sometimes the ideal situation doesn't happen.
DD