Okay, I haven't been able to determine what exactly causes the acid stage to create water. Could someone please explain? Next, does this water need to be removed? If so, where will the water be (top/bottom, etc) and when in the process do you remove it?
thanks
travis

Hi Travis,
look here (van Gerpen paper)for a brief explanation of the reaction:
http://www3.me.iastate.edu/biodiesel/Technical%20Papers...20after%20review.pdf

good luck Dieter

Thanks, very informative. So as I read the paper, the water/methanol was removed. Is everybody out there who does acid/base removing the water? I have done successful acid/base without removing the water, but never could get the post-acid treatment titration to below 4. Is this why? I read on the forum a formula for acid/base that did NOT require water removal. Is this not correct?
thanks

The formula I used was dkenny's, whereas no draining is done between the stages. Is there anything wrong with this? I have good yields, but don't quite pass 3/27. If you do drain, is the water on top or bottom? I would think it would be on bottom, but other posts say it's on top.

Hi Travis,
I think water removal is nessesary because the water stops the process of esterificaion.
Thats why van gerpen et al are using a two stage acid esterification with water removal between the two process stages.
In their paper they described their tests, where they didnt reached a ffa content below
2% with only one step.

hope that helps

good luck, Dieter