Just want to make sure i understand the function of the prewash and how I can make my biodiesel better.

My current process makes soap which results in a sort of jello in the biodiesel. By adding water at the end of the reaction process, any excess Lye in the solution will bind with the water and fall out. Since there is no more NaOH in the solution, it will not bind to the FFA and make soap. This would allow me to put in a bit more lye then my titration indicates but still get a good batch. Is that correct?

For my titration I use the red liquid that comes in swimming pool test kits, some people here seem to indicate that it is not good. What else should I be using?

You may want to consider switching to KOH as a catalyst if you are going to experiment with overloading the lye. Koh is very forgiving and will not solidify in your drain. It requires a little more in volume, so it costs a little more per batch, but it mixes with little or NO EFFORT. Kind of disappears into the methanol. Some stubborn flakes require about four sloshes to dissolve.

I gave up phenol red and penophenowhatsthis for tumeric spice. In your grocers aisle. Did I mention cheap and no shipping, works great, turns from yellow to red?

Norman

That red pool test stuff (phenol red) works just fine for me. Plus I get great dropper bottles from it for a liquid medicine I take every four hours.

Hello juliena

You misunderstand the reason for the 5% wash at the end of the reaction.
The FFA's are already converted into soap, that happens at the begining.
The 5% wash just removes a very large portion of the soap that would normally remain in the biodiesel with the glycerine layer.
It also releases a small amount of the biodiesel that is bound up with the soap.

If enough soap is removed then the soap Jel will not form, but you may have to wash another time or two to remove enough soap to insure there is no jel form.

If you use the correct procedure phenol red from the swimming pool shop will work fine.
For the easiest method of titrating you can not beat the World Famous Chopstick Titration Techinque (Pat Pend)which contains the correct procedure for using Phenol red, Phenolphthalein and Turmeric as the indicator.
I like the colour of turmeric best.