'unreacted FFA and 5% remix prewash- thumbs up! Re: Weekly update

Seth Moody wrote:

> Morning Brian,
> quick answers?
>
>> What is the 5% prewash method again?
>
>
> 5% prewash is the procedure used to help drop out unreacted FFA's,
> Glycerin and any soap that was just created during reation.
>


there's no such thing as unreacted FFA (free fatty acids) because FFA's
turn into soap almost immediately when lye is present. Besides, FFA
aren't water soluble so wouldn't be affected by this procedure most likely.
 If you're seeing FFA in the biodiesel for some reason (you'd do that by
titration), it's usually because of degradation of the biodiesel (ie
oxidation or rotting via bacteria in storage) or because of using acid
somewhere in the process.


I've done soap testing (www.biodieselcommunity.org/soaptest) after doing
the 5% remix, and it can cut soap levels almost in half sometimes.
Excellent technique. However, Brian is asking aobut using that INSTEAD
of washing, which isn't a good idea unless you have a good drying
process- the prewash adds water to the biodiesel which won't dry out
easily unless you let it sit for a LONG time (ie you'll see some
cloudiness to the biodiesel after doing the remix process, and that is
water that creates that haze)

The remix prewash is discussed extensively at the forum
http://biodiesel.infopop.cc