Alcohol as a Fuel: Recycling Wastes into Energy
Note: A permit must be obtained from the Bureau of Alcohol, Tobacco, and Firearms before you begin this experiment. It is illegal to make alcohol without a permit.
To see if it is possible for a household to construct a simple and inexpensive still capable of recycling its fermented organic garbage into a grade of ethyl alcohol that would meet most of the household's energy needs.
- 6 feet (1.8 meters) of %-inch (0.85-cm) copper tubing
- coffee can with top and bottom removed
- small bowl
- pressure cooker
- oven thermometer
- 2-gallon (7.6-liter) plastic container
- 11,2 gallons (5.7 liters) warm sterile water
- 1 cup (0.24 liter) granulated sugar
- 3 cups (0.72 liter) pureed apple peelings
- sugar hydrometer
- 1 teaspoon (5 ml) active dried yeast
- fermentation lock
- proof hydrometer
- kitchen stove
- 4 fuel-burning lamps
- 16 ounces (0.45 kg) each gasoline, benzene,and kerosene
- adult helper
A small portion of sugar and apple peelings will be used to simulate a fraction of a household's weekly organic garbage output. These items will then be combined with water and active dried yeast for distilling in a plastic container. This mixture yeast will be allowed to ferment for approximately 4 to 5 days in a warm, dark environment. The fermented substance will then be placed in a simple pressure cooker still and will be distilled into alcohol. The amount of fuel produced will be measured and multiplied by the weekly output of organic garbage per household to determine the average amount of ethyl alcohol a household could produce. The alcohol will then be tested to compare its burning time and environmental effects with that of more traditional energy fuels.
Part I-Build the still.
- Apply for a permit from the local Bureau of Alcohol, Tobacco, and Firearms to produce a small portion of ethyl alcohol for home fuel experimentation.
- Begin your experiment by constructing a simple pressure cooker still. With the help of an adult, coil half of the copper tubing five times (leaving the other half extended) and fit the coil within the coffee can so that the end of the coil bends down and out of the bottom of the can into a bowl. Bend the remaining extended copper tubing in an arc over to the pressure cooker. The end of the tubing should hook over the top of the stem on the cooker's lid.
- Remove the pin from the lid of the pressure cooker and place the oven thermometer in its place. (This will measure the temperature of the alcohol within the pot.) Put the still aside.
Part II-Ferment the organic garbage.
- Fill the plastic container with the warm sterile water. Add the sugar and the pureed apple peelings. This entire mixture, which is called mash, should consist of exactly 20 percent sugar from the table sugar (sucrose) and the sugar found naturally in the apple peelings (fructose). This percentage can be accurately determined by placing the sugar hydrometer into the mash.
- Mix these items well and add the active dried yeast for distilling to the mash. Cover the container and place the fermentation lock in the lid of the container. The lock will indicate when fermentation has begun and when it has ended. Place the entire unit in a warm, dark environment at around 80 degrees Fahrenheit (27 degrees Celsius) (such as a furnace room) to ferment for about 4 to 5 days. If there are bubbles in the fermentation lock, then fermentation is occurring; if there are no bubbles in the lock, then fermentation has ceased.
Part III-Distill the fermented mash.
- After fermentation, strain the mash through a cheesecloth, measure the amount of liquid yield, and measure its alcohol proof with the proof hydrometer. Then place the liquid into the pot of the pressure cooker and attach the lid with its copper coil system that you built in Part 1. Fill the coffee can unit with ice. Place the still unit onto a stove and heat the contents to about 173 degrees Fahrenheit (78 degrees Celsius) (the temperature at which alcohol boils). Open a window or a vent to provide proper ventilation of the fumes.
When the contents inside the pressure cooker are heated to about 173 degrees Fahrenheit (78 degrees Celsius). alcohol vapors running through the coils will condense within the coffee can containing ice and come out of the other end of the copper coil into a bowl or cup.
- During this distillation process, the alcohol vapors running through the coils will condense within the coffee can filled with ice and come out of the other end of the copper coil into the bowl (see illustration). Measure the proof of this alcohol with the proof hydrometer and pour it back into the pot again to be distilled a second time in order to attain an even higher proof. Repeat this process until you have achieved the highest possible proof of alcohol from your still.
- Measure the amount of alcohol fuel you have produced with the 2 gallons (7.6 liters) of mash. Use this figure to calculate how much alcohol fuel could be produced from what you estimate to be the average weekly household output of organic garbage.
- Next, prepare four fuel-burning lamps that will each burn the same amount of alcohol, gasoline, benzene, and kerosene individually. Time the longevity of their flames to see which one lasts the longest. Note which one creates the least amount of smoke and odorous fumes.
- What was the highest proof you were able to obtain in your alcohol?
- How much alcohol was produced from 2 gallons (7.6 liters) of mash? From your calculations, how much alcohol could be produced weekly from the organic garbage of an average household?
- Which fuel burned the longest and most efficiently? How long would the average weekly household yield of alcohol last? Would this satisfy most of the household's energy needs? How does alcohol as a fuel source compare to the traditional fuels?
Warning is hereby given that not all Project Ideas are appropriate for all individuals or in all circumstances. Implementation of any Science Project Idea should be undertaken only in appropriate settings and with appropriate parental or other supervision. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. For further information, consult your state’s handbook of Science Safety.