The FATTA method (esterify FFA's) - Development by Kevin Tidball and Michael Fox

The FATTA method



This is not for those who don't like failed batches; the proportions and process methods are still under experimentation.

THE PROCESS IS AIMED AT HIGH FFA CONTENT OILS AND ANIMAL FATS WHERE UNDER NORMAL BASE REACTION LOW YIELDS ARE ACHIEVED (<65%).>60C and cool slowly.
Filtering could be required to separate glycerol and soaps from ester.

What happens to the H2SO4, it is neutralized
2NaOH + H2SO4 ---> Na2SO4 + 2 H2O

This produces water, but no more than when neutralizing the FFA with a base.

An example of the acid reaction

2000ml Fat at 50C
400ml CH3OH (Higher volumes of Methanol were used in the original experiments)
2ml H2SO4

Reaction time (minutes) titration value (ml)
0-min 4.0
30-min 3.4
60-min 3.2
90-min 2.8
120-min 2.6

Indicated a reaction time of 2 hours was needed.

Go to www.biotechsa.net to find out more.

Determine the percentage of FFA in oil

In order to determine the percent of FFA in the oil, a process called titration is used. The vegetable oil is first mixed with methanol. Next, a mixture of Sodium Hydroxide (NaOH) and water is added until all of the FFA has been reacted. This is confirmed by checking the pH of the mixture. A pH of about 9 signifies all of the FFA has been reacted. Virgin vegetable oil from the same feed stock will usually titrate at approximately the same level, so checking every batch is not necessary. Waste Vegetable oil feed stocks will vary greatly. Every batch must be titrated.

The following items are needed to perform an accurate titration.
- Two 50mL flasks - One 5mL graduated pipette
- A 1mL dropper
- A 10mL dropper
- A mixture of NaOH and water in 0.1% concentration
- pH solution and color chart

The NaOH water mixture can be prepared by adding 1 gram of NaOH to 1000ml distilled water. The mixture will be more accurate if it is first made as a 1% solution (10grams NaOH to 1000ml water). Next, add 100mL of the 1% solution to 900ml of distilled water. This will make a 0.1% NaOH solution.


The process for titration is as follows:

1. Place 10mL of Methanol in a 50ml flask
2. Add 1mL of vegetable oil (mix the oil thoroughly prior to drawing 1ml)
3. Mix the oil with the Methanol using the squirting action of the dropper
4. Add the ph indicator solution (usually 3 drops, check instructions)
5. Place 15ml 0.1% NaOH (know as titrant) solution in a 50ml flask
6. Draw exactly 5ml of the NaOH solution into the graduated pipette
7. Add the 0.1% NaOH to the methanol/oil mixture one drop at a time. Mix the solution using a swirling action between the drops. Using the eyedropper to mix the solution may help if the oil forms drops in the bottom of the flask.
8. Continue to add 0.1% NaOH until a pH of 9 (blue-green color) is reached. This may require more than 5ml. Refill the pipette and continue. Note the amount in ml that was required.
9. Look up the corresponding amount of NaOH required for the entire batch in Table 3. Multiply the amount by the number of gallons of oil to obtain the required amounts.

Table 3. Titration information

ml titration--------%FFA-------------NaOH (grams) per gallon
0------------------0----------------13.25
0.5----------------0.3578222--------15.15
1------------------0.7156445--------17.025
1.5----------------1.0734667--------18.925
2------------------1.431289---------20.825
2.5----------------1.7891112--------22.7
3------------------2.1469334--------24.6
3.5----------------2.5047557--------26.5
4------------------2.8625779--------28.3875
4.5----------------3.2204002--------30.28
5------------------3.5782224--------32.1725

WHAT IS THE RIGHT CHOICE OF FEEDSTOCK TO MAKE BIODIESEL IN SOUTH AFRICA

Feedstock selection plays a key role in the successful production of biodiesel. Virgin vegetable oils are ideal for production because they are clean, pure and need little or no pre -treatment.Used edible oils, are less expensive, but require more attention, as their chemical and physical properties can vary between collection sites. Animal tallow represents the least costly feedstock, but requires pre and post production treatment.
The following information represents the requirements of the feedstock oil and raw materials used in the CPU:

• Oils and fats of vegetable or animal origin
• FFA content < 1.5%
• Water content < 0.1%
• Free from solids and other substances
• Methanol: Technical grade
• KOH (potassium hydroxide)

Wiew: www.biotechsa.net for further details.