A. Preparation of Sodium Methoxide
1. Measure 0.35 grams of Sodium Hydroxide in a small, 100 ml beaker
(you may substitute 0.90 grams of Potassium Hydroxide for the Sodium Hydroxide)
2. Add 20.0 ml of anhydrous methanol (methyl alcohol)
3. Mix for about 5 minutes, or until the sodium hydroxide is dissolved
4. Set the Sodium Methoxide solution aside and proceed with Part B
B. Preparation of Biodiesel
1. Measure 100 ml of fresh, unused vegetable oil in a 100 ml graduate cylinder
2. Pour all the vegetable oil into a 400 ml beaker
3. optional: Heat the oil to 100*F to 110*F (38*C to 43*C), and then turn off the heat.
4. Carefully add the Sodium Methoxide from part A with stiring
5. Mix with stirring for 15 minutes. Note any changes observed in the mixture.
6. Transfer the biodiesel mixture to a separatory funnel.
7. Allow 8 to 24 hours for the glycerine to separate from the biodiesel.
8. Separate the glycerine (bottom layer) from the biodiesel (top layer).
C. Quality Control: Testing Your Biodiesel
1. Visual Inspection
One Layer: One Homogeneous Soap layer
Two Layers: SUCCESS
Three Layers: Middle Soap Layer
2. Specific Gravity a. Measure the mass of a clean, dry, 100 ml graduate cylinder b. Measure the volume of biodiesel in the pre-measured graduate cylinder c. Measure the mass of the cylinder and biodiesel. d. Subtract the mass of the empty cylinder to determine the mass of biodiesel e. Divide the mass of biodiesel by its volume f. Accepted density is 0.860 g/ml to 0.900 g/ml)
3. Cloud Point and Gel Point a. Place a capped bottle of biodiesel in the freezer or ice bath until it becomes
opaque. Measure its temperature. Record its Cloud Point. b. Continue cooling the biodiesel until it forms a solid gel. Place the sample
at room temperature. Measure the temperature when the liquid and gel
phases are both present in the sample container. Record the Gel Point.
5. Percent Yield Accepted value is 98 - 102 %)
Volume of Biodiesel x 100 = % Yield
Volume of Vegetable Oil
Washington Academy's Field Ecology Program Donald R. Sprangers, Advisor www.washingtonacademy. org

1. Visual Inspection a. Describe the appearance of your biodiesel after a minimum of 24 hours of settling.
2. Specific Gravity ( accepted desity is between 0.860 g/ml and 0.900 g/ml) b. Does your biodiesel pass inspection? a. Mass of clean, dry 100 ml graduate cylinder b. Mass of graduate cylinder and biodiesel c. Mass of 100 ml of Biodiesel d. Volume of biodiesel in the pre-weighed graduate cylinder e. Density: Divide the mass of biodiesel (c) by its volume (d)
Mass of Biodiesel (c) = ________________ grams/ml
Volume of Biodiesel (d) f. Does your biodiesel have an acceptable density?
3. Percent Yield Accepted value is 98 - 102 %)
________ grams
________ grams
________ grams
________ ml
Volume of Biodiesel x 100 = % Yield
Volume of Vegetable Oil
4. Cloud Point and Gel Point a. Place a capped bottle of biodiesel in the freezer or ice bath until it becomes
opaque. Measure its temperature. Record its Cloud Point. b. Continue cooling the biodiesel until it forms a solid gel. Place the sample
at room temperature. Measure the temperature when the liquid and gel
phases are both present in the sample container. Record the Gel Point.
Cloud Point = _____________*C
Gel Point = ______________*C
Washington Academy's Field Ecology Program Donald R. Sprangers, Advisor www.washingtonacademy. org