Biofuels: The Ultimate in Recycling

Will there come a day when you can use the oil that your egg roll was fried in to power your car? How about the potato peels left over from making instant potatoes? Or the turkey guts poultry processing plants discard?

In fact, that day already has come. Facilities that convert organic matter, called biomass, into clean-burning fuels are more and more often choosing to use waste products from other processes to produce biofuels.

Ethanol and biodiesel are the most common biofuels, and they provide environmentally friendly alternatives to gasoline and to petroleum diesel fuel. Best of all, using surplus materials to produce biofuels solves another big problem: what to do with all the waste we generate.

Ethanol, an alcohol, is produced after yeast or microbes break down a plant's sugars and starches. Combined with gasoline, it adds oxygen to the car engine's combustion process, allowing the fuel to burn more cleanly. A company in Idaho makes ethanol using potato waste from a nearby potato processing plant. A cheese factory in California makes it from unused whey. Almost anything that ever grew can be processed to make ethanol.

Biodiesel, made from chemically-altered plant oil or animal fat, is an alternative to petroleum diesel and will work in any diesel engine. When used as a substitute for petroleum, it reduces total air pollution by more than 50 percent and cancer-causing substances in the exhaust by 94 percent. About half of the biodiesel that's produced in this country is made from used vegetable oil.

Most intriguing of all is the oil produced by a machine developed by Changing World Technologies that uses a thermal depolymerization process (TDP) to take materials apart at the molecular level. The machine was designed to turn almost any waste product into high-quality oil, pure minerals, and clean water. It applies heat and pressure, the same forces nature employed to turn ancient vegetation into fossil fuels.

However, what took nature thousands or millions of years takes this machine a couple of hours. The company's Philadelphia plant has been operating for four years, taking in waste of all kinds: turkey innards, tires, city garbage, muck dredged up from the harbor, medical wastes. What comes out is light oil, gas, and minerals, all pure and harmless. A larger TDP plant in Carthage, MI, expects to turn 200 tons of daily turkey-processing waste from the Butterball factory just down the road into 10 tons of gas; 21,000 gallons of water; 11 tons of minerals; and 600 barrels of petroleum and other oil. More plants are planned.

Although producing biofuels generally costs more than pumping petroleum out of the Earth, the added cost is offset by many benefits. These alternative fuels provide energy without harming our environment and depleting our country's resources. They offer the added bonus of solving our solid waste problems. It's a good deal for Planet Earth!


The process of burning.

The watery part of milk that separates from the curds in the process of making cheese.

Back to Top


  1. Where does biomass come from? What is an example of biomass?
    [anno: Biomass come from organic material, such as food scraps.]
  2. How is biomass used?
    [anno: Biomass is used to produce biofuels.]
  3. What is one way people can recycle biomass at home?
    [anno: Answers may vary but could include that people can create a compost pile or start a compost bin to recycle biomass at home.]
  4. Why do you think that the creation of energy from biomass is not more widespread? Do you think this might change in the future? Why or why not? Write a few sentences to explain your answer.
    [anno: Answers will vary.]