Titration Test

Titration test is done to establish how much free fatty acid is present in the WVO, and establish how much additional lye to add to compensate for it.

So for every 1 ml titration result add an extra 1 gram of KOH or NaOH for each liter of WVO.

Step 1: Make a 1% Reference Tester Solution You will need:

* 1 gram KOH or Na0H 
* 1 liter Distilled Water

Note: The accurate measurement of the catalyst is critical, so use a scale that has a resolution down to at least 0.01gr if possible. Inaccurate measurements now will result in failed batches later.

Step 2: Blank Titration (Optional)

Alcohol becomes slightly acidic with age, which would effect your results. We can test our alcohol by performing a blank titration on it. A blank titration is the same as a normal titration but without the WVO. A blank titration neutralizes any acids that the isopropyl alcohol (IPA) contained, so you're starting with a 'blank' slate and your real titration only reads the free fatty acids instead of the acids in the IPA .

* 1. Add 10 ml of IPA to a measuring beaker.
* 2. Add 3 drops of phenolphthalein.
* 3. Swirl till its is a murky yellow color.
* 4. Add your reference solution with a syringe drop by drop while swirling.
* 5. As soon as it turns purple, stop! it is now neutralized all the acids in the IPA. This is your starting point. You will now add oil to the mixture for the actual 'titration' step.

Step 3: Oil Sample:

a. If you did a blank titration:- Measure out exactly 1 ml of WVO with an syringe into the same measuring beaker containing your blank titration liquid. This liquid will turn yellow after you add the WVO.

b. If you did not do a blank titration:- Measure out exactly 1 ml of WVO with an syringe into a clean measuring beaker, add 10 ml of IPA, then add 3 drops of phenolphthalein, keep swirling the measuring beaker to dissolve everything. It will become a murky yellow color.

Note: Make sure you use a different syringe to measure WVO and IPA. Again the measurement of the WVO is very important, make sure it is accurate.

Step 4: Add and Measure Reference Solution:

At first your mixture will be yellow. Start adding your reference solution with a syringe and swirling the measuring beaker, make a note of how much reference solution (in ml) you're adding. As you keep adding, it'll start to show a change to pink, but will revert back to yellow as you swirl. Once it's uniformly pink and stays that way for at least 30 seconds, stop adding reference solution and count how many ml's you've added.

Note: Do not use the same syringe for WVO and your reference solution, use IPA to clean them.

Step 5: Calculate:

How much reference solution did you use?

Each 1 ml of reference solution corresponds to 1 gram of KOH or NaOH you'll need to add when making your batch.

4ml of reference solution is about the most you should accept, If your test takes more than 4ml of reference solution, don't use that WVO unless you know how to deal with high FFA WVO. Most WVO should take about 1 - 3ml on the titration, bad WVO can take 10ml or more, which is unusable with base only process.

* For KOH: number of liters of WVO x (7gr + titration test qty)
* For NaOH: number of liters of WVO x (5gr + titration test qty)

Calculation Example: (NaOH)

* Titration reading = 2ml
* WVO qty to be processed = 90 lt's
* 90 liters x (5 gr NaOH + 2)
* 90 x 7 = 630 grams NaOH