Biodiesel in the Classroom
This year, chemistry teacher Brad Wacker wanted to include in his class an activity that would demonstrate a real world use of chemistry, that being the production of biodiesel from used and new vegetable oil. Not only can individuals make their own fuel source and reuse vegetable oil at home, but homemade soap can also be produced. To meet this goal, Mr. Wacker had the students bring in vegetable oil, used and new, so they could convert it into biodiesel. He then was given a Mini Grant from the Cissna Park Education Foundation to fund the purchase of hot plates/stirrers and separatory funnels.
The students used the hot plates/stirrers to heat and combine mixtures of methoxide and their vegetable oil. They all marveled at the stirring capabilities of the apparatus since it used a magnetic bar that was attracted to a spinning magnet below the hot plate. As the temperature increased, some of the students started to observe a change in color as the oil was being transformed.
Once the biodiesel was made, the students had to separate it from the other product of the reaction, glycerol. The biodiesel was then poured into the separatory funnels and left to rest for a few minutes. After a period of time, two distinct layers appeared. The bottom layer, the glycerol, was drained from the bottom of the separatory funnel into an extra beaker. Finally, the biodiesel was removed from the funnel and placed into a separate container.
The students really enjoyed the experience of using equipment that was beyond beakers and graduated cylinders and now have a familiarity with a real world application of chemistry that they did not possess at the beginning of the year.