can liquid caustic be used instead of lye in making biodiesel or wvo?

 

If you mean Caustic Soda that is the same thing as Lye.
They are both Sodium Hydroxide (NaOH)

If you are getting liquid caustic soda (a NaOH water solution) use it in the titration step.
You should be able to find the percentage of NaOH on the label somewhere then dilute it to .1%.

If there are other chemicals present in the solution I would not use your liquid caustic soda.

 

we use 50% caustic soda where i work. so, i should just add water to bring it to .1%??

 

Yup

50% = 500mg/ml of solution.
to make .1% add 2ml of your caustic soda solution to 1 L water

 

well the lye is going to be pretty cheap, but the mehtanol is kind of pricey. is there any way to reclaim it.

 

you can recover unreacted methanol from both the glycerin and BD products of the reaction. In fact it is recommended that you do so as it makes cleaning the BD easier and cheaper plus the methanol can be reused.