Hello -

I'm about to make my 2nd batch of bio. I used the the acid/base process on my first batch, and got the titration down to 3.5, but I had problems during the wash (it was never-ending). My oil for this 2nd batch also titrates at 7, so I have to use the acid/base process again.

Everything I've read seems to indicate that heat is an important element in a successful acid treatment. Is this the case, and if so, what is the optimal temp? A number of sources seem to say that between 130 and 140 deg is ideal.

Also, is there any way that heat can negatively impact the process?

I ran my first acid batch at around 125 degrees, and agitated it for about 4 hours. I'd like to get the titration as low as possible. Based on some recent readings, I'm going to use a target titration of 3, but an acid multipler of .16. With 40 gals of oil titrating at 7, the math works out to .64 ml of acid per L of oil ((7-3)*.16), with the total amount of acid used = 97ml (.16 x 151.42 L/gal).

Anything I'm missing? Any additional watch outs? (I ran the oil through a shower head @ 140 degrees for 3 hours to dry it out...it's dry).

Thanks...

Chris

Ooops...the math should be .64 x 151.42 = 97ml. Answer was correct, but the math inputs indicated were wrong.

Go for it, the gotchas are heat and water in the oil. Let us know how it turns out.

Hooknline -

In what way is heat a gotcha? Just by the simple fact that you have to do it? I ask because a friend of mine told me that if you run the process too hot, it creates additional FFA, and I've never read anything to that effect. I was wondering if anything I did during the first acid stage led to the my washing problems.

Thanks...

Chris

Keep the heat at 130-145 if you can do it safely. Lower than that seems to be an issue.
Heat at those temps causing extra FFA's..I dont think so. 300F for a time..yes it will, but not at the temps we process at

ckirk

-the process as outlined by hook is bang on! Esterfication will not occur at room temperature even after 10 days. Dry wvo is as if not more important in the esterfication process than the transesterfication (normal base) process As for FFA’s fatty acids break away from the triglyceride for many reasons and become ffa’s. cooking with the vo and heating and cooling are the main cause. Heating for the ae process will have less of an effect on creating more ffa’s than the pump mixing will, so don’t over mix Tom

Unless you pressurize your reactor the methanol will limit the temps to around 170F.

make sure you have a good setup to trap the methanol vapors and return them to the tank.

the temps you mentioned are fine. I only know it works that hot because in the summer the pump on my water heater reactor will self heat the oil..ie no heating element needed.

like the other said..WATER is BAD!..

you didn't give much details about your setup..My 2nd reactor is also my wash/dry tank. So I start with 'dry' oil and dry it some more, just in case there water. I dry it the same way I dry biodiesel.

if you have lots of oil that titrates the same..please feel free to join the thread asking for acid/base processors..you might be able to help hone in the multiplier.

-dkenny