Divide students into pairs or quads. Students should use the
Creating Bioenergy Experiment worksheet to design the experiment. Either assign a variable to student groups or allow students to select the variable. Students will need to specify which variable is dependent, which variable is independent, and which conditions are controlled.
Conduct an experiment to observe how methane is produced by fermentation. Use the results to support claims about the benefits and limitations of bioenergy in your community.
Design and conduct an experiment to determine the best conditions for producing methane gas from food waste.
Possible variables for investigation:
- Light exposure
- Temperature
- Organic components
- Water
- pH levels
- Optimal carbon-nitrogen ratios for increasing methane production
Materials
16-oz or 32-oz plastic bottle with cap (any soda, electrolyte water, or water bottle will do)
Balloon
½ to 1 cup shredded food scraps (vegetables, fruits, or even leftover lunch)
3 to 4 teaspoons organic soil
1 beef stock cube
Water
Directions
Add the shredded food scraps, the organic soil, and the beef stock cube into the plastic bottle. Next add a little water. Finally, place a balloon over the bottle.
Put the bottle with the mixture in a warm place and let the fermentation begin.
Observe what happens over the next few days. Note any changes.
Note: Please note that the balloons can explode if not monitored. If you have access to the following materials, you can also try this:
Cut a hole in a plastic bottle cap and put aquarium tubing in (sealed with tape or paraffin wax). Fill an inverted graduated cylinder and plastic shoebox with distilled water. The other end of the tubing goes in the graduated cylinder. As methane is produced, the amount in millimeters (mL) can be measured with the graduated cylinder.
