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by
Robb Mandelbaum


Biofuels could be a crucial weapon against both rising temperatures and dwindling global oil supplies. They are made from organic material such as plants, so they essentially recycle existing carbon in the atmosphere instead of releasing new carbon from the depths of the earth; they are also, in principle, endlessly renewable. But the best-known biofuel, ethanol, is looking decidedly unpromising right now. Today most ethanol in the United States is made from corn, using an energy-intensive process that may not actually save a lot of fossil fuel, and in any case America cannot produce enough ethanol from corn to really matter.

Scientists have long tried to devise an efficient way to make ethanol from a wider range of raw materials, especially waste products rather than food. The U.S. government has calculated that the country could generate 1.4 billion tons of biomass a year. This could make 100 billion gallons of fuel or more, enough to meet much of America’s demand for motor gasoline. One approach to tapping into all that biomass focuses on cellulose, the material that gives plant cells their strong walls. The cellulose is converted into sugar and then from sugar into ethanol. But despite decades of research, the technology is still far from commercially viable.

Now several companies, including Coskata and Range Fuels, say they have cracked the problem. They are pursuing a different strategy, one that turns any carbon-rich matter into a gas, which is then converted to liquid fuel. This approach can use any organic material, so the potential sources for this fuel are virtually unlimited. Soon, the companies claim, they will be able to refine vast quantities of noncorn ethanol. Coskata even predicts they will do so for as little as $1 a gallon.

Biofuels could be a crucial weapon against both rising temperatures and dwindling global oil supplies. They are made from organic material such as plants, so they essentially recycle existing carbon in the atmosphere instead of releasing new carbon from the depths of the earth; they are also, in principle, endlessly renewable. But the best-known biofuel, ethanol, is looking decidedly unpromising right now. Today most ethanol in the United States is made from corn, using an energy-intensive process that may not actually save a lot of fossil fuel, and in any case America cannot produce enough ethanol from corn to really matter.

Scientists have long tried to devise an efficient way to make ethanol from a wider range of raw materials, especially waste products rather than food. The U.S. government has calculated that the country could generate 1.4 billion tons of biomass a year. This could make 100 billion gallons of fuel or more, enough to meet much of America’s demand for motor gasoline. One approach to tapping into all that biomass focuses on cellulose, the material that gives plant cells their strong walls. The cellulose is converted into sugar and then from sugar into ethanol. But despite decades of research, the technology is still far from commercially viable.

Now several companies, including Coskata and Range Fuels, say they have cracked the problem. They are pursuing a different strategy, one that turns any carbon-rich matter into a gas, which is then converted to liquid fuel. This approach can use any organic material, so the potential sources for this fuel are virtually unlimited. Soon, the companies claim, they will be able to refine vast quantities of noncorn ethanol. Coskata even predicts they will do so for as little as $1 a gallon.

Range Fuels initially hoped to feed its refinery with leaves and small limbs that the timber industry cannot process. The Georgia Forestry Commission reports that each year loggers leave behind some 8 million tons of waste wood, including too-small living trees, within a 75-mile radius of the new refinery—enough for four of Range Fuels’ plants. But getting that material to the refinery has proved difficult. “The timber industries are really not set up to do that,” says Range Fuels’ Mandich.

Nobody has yet figured out how to compact forest leftovers for transport. “Have you ever tried to move your leaves in the fall?” asks Richard Hess, a scientist studying the problem at Idaho National Laboratory. “You fill up this garbage sack and it doesn’t weigh anything. That’s the problem. It takes a lot of energy to move air.” Still, Hess expects optimized handling systems will be ready by 2012, meeting the government’s goal and in time for a wave of new refineries. “We’re rich in opportunities to make fairly epic gains,” he says. Until then Range Fuels will source its wood chips from whole trees—not a waste product at all, but a commodity used to make paper pulp.

It might not be long before the ethanol companies are paying to get more biomass waste headed into their plants. According to Richard Bain, a researcher at NREL, the estimated cost of producing a gallon of ethanol stands at $2.10 today. By 2012 this should fall to $1.33—at least for those companies using steam to turn biomass into syngas (several firms, he says, have developed this technology). At the same time, the steep price of gasoline—and corn—means that next-generation ethanol can be profitable even if its price doesn’t reach what Khosla Ventures’ Kaul calls the “holy grail” of $1 a gallon. Freed from the bad rap of corn ethanol, bio­fuel-powered cars could then drive us toward a better future.