Four promising bio-fuels from everyday foods.

Four promising bio-fuels from everyday foods.

Mention the topic of turning food into fuel (think: corn into ethanol, soybeans into biodiesel) and you'll likely land in a heated debate. Yes, Americans burn through 388.6 million gallons of gasoline each day-but many say that biofuel production isn't sustainable and it takes agricultural land away from growing food. So why not use leftovers? Meet four pioneers who are doing just that.

Whey into Ethanol

* How it works: Whey permeate, a by-product of cheesemaking, consists mostly of the sugar lactose, which is fermented into ethanol and blended with regular gasoline.

* Who's trying it: Joe Van Groll, owner of Grand Meadow Energy in Stratford, Wisconsin, and a few plants in Europe.

* Comparative cost: 80¢-$1.00 to produce one gallon versus $1.50-$2.00 to produce ethanol from corn.

* The numbers: Van Groll produces 26,000 gallons of ethanol per year now (from 260,000 gallons of cheese whey). That's enough to power 52 Americans' cars for a year.

* Timeline: Ethanol made from whey is on the market now, and it is indistinguishable from other types of ethanol-based gasoline.

Eggshells into Hydrogen Fuel

* How it works: Eggshells release and absorb carbon dioxide repeatedly, in a reaction that produces hydrogen fuel, an emission-free source of power and heat.

* Who's trying it: Liang-Shih Fan, Ph.D., distinguished university professor of chemical and biomolecular engineering at Ohio State.

* Comparative Cost: The patented technology isn't being developed commercially yet.

* The numbers: The U.S. produces 450,000 tons of eggshells yearly, which could generate enough energy to sustain 168,000 American drivers for a year.

* Timeline: "As soon as we have an investor," Fan says.

Corncobs into Ethanol

* How it works: Cellulose, the main component of corncobs, is more difficult to break down and ferment than corn, but POET Energy is developing a process to do it efficiently.

* Who's trying it: POET, the world's largest ethanol producer, is converting an existing biorefinery in Emmetsburg, Iowa.

* Comparative Cost: POET is still in the research phase, assisted by a grant from the U.S. Department of Energy.

* The numbers: Using the cobs will produce 27 percent more ethanol per acre of corn. To produce the goal of 25 million gallons of ethanol from cobs (which would power 50,000 Americans' cars for a year), POET would need to use the cobs from about 275,000 acres' worth of corn.

* Timeline: Operation of the converted biorefinery will begin in 2011.

Animal Fat into Synthetic Fuel

* How it works: Animal by-products (and vegetable oil) are converted into diesel fuels, including one product chemically equivalent to jet diesel.

* Who's trying it: Dynamic Fuels, a partnership between Tyson Foods, Inc. and Syntroleum Corporation.

* Comparative Cost: The fuel has enhanced performance characteristics and is renewable, so will likely carry a premium.

* The numbers: The first plant will produce 75 million gallons each year-enough to power a 757 jet on a round trip from New York to Los Angeles more than 10,000 times.

* Timeline: A new plant near Baton Rouge will be operational in 2010, with plans for more plants in the works.