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Environment

Biofuels Reality Check

by Pamela Zurer, Deputy editor-in-chief
July 24, 2006 | APPEARED IN VOLUME 84, ISSUE 30

The escalating violence in the Middle East underscores the urgency for the U.S. to invest in alternatives to petroleum energy. Even those diehards who still resist the idea that combustion of fossil fuels is causing unprecedented global change can hardly argue that it is good policy to depend heavily on oil imports from nations that are unstable, hostile, or both.

With the Energy Policy Act of 2005, Congress gave a big push to fuel derived from biomass as an alternative to gasoline for cars and trucks. The law requires that 4 billion gal of renewable fuel be mixed with gas this year, increasing to 7.5 billion gal by 2012. (The U.S. consumed about 140 billion gal of gas in 2004, according to the Department of Energy.) The act doesn't dictate which renewable fuels to use, but ethanol derived from corn currently dominates other alternatives. President George W. Bush gave biofuels a further boost in his State of the Union address last January, where he laid out a goal of making fuel ethanol "practical and competitive" within six years.

Here at C&EN, we are constantly reporting developments in biofuels. Whether related to policy, business, or R&D, biofuels are news. But a paper covered in this issue by Senior Editor Glenn Hess throws some cold water on the enthusiasm for corn-derived ethanol (see page 27).

Neither ethanol from corn nor biodiesel from soybeans can satisfy more than a small fraction of U.S. demand, according to Hess's story on a study by researchers at the University of Minnesota. "Even dedicating all U.S. corn and soybean production to biofuels would meet only 12% of gasoline demand and 6% of diesel demand," the authors write in the Proceedings of the National Academy of Sciences (2006, 103, 11206).

Their comprehensive life-cycle analysis considers every facet of the energy used in producing crops and converting them to biofuels. Considering the outputs, the researchers find biodiesel has a greater net energy benefit than ethanol. They also note the severe environmental impacts of the heavy use of fertilizer and pesticide in growing corn. "Energy conservation and biofuels that are not food-based are likely to be of far greater importance over the longer term," they conclude. Cellulosic ethanol made from the inedible portions of plants, wood chips, sawdust, switch grass, and other sources may prove the best alternative to petroleum, they say, though the technology is still a ways off.

Given that corn-derived ethanol is no panacea, what should we be doing? Here are my ideas:

◾ Stop feeding human food to animals. Any significant switch to energy as an agricultural commodity will disrupt our current systems anyway, so why not impose some logic? At a great cost in energy, some 60% of the U.S. corn crop is used as animal feed. But as Frances Moore Lapp?? pointed out 35 years ago in "Diet for a Small Planet," cattle can convert inedible plants to protein. We don't need to stuff them with grain and legumes that could be better eaten by hungry humans or converted to fuel.
◾ Impose a stiff federal fuel tax. Nothing promotes energy conservation like high fuel prices. Consumers are already turning away from gas-guzzling SUVs and flocking to energy-efficient hybrids. Are there any politicians out there with the backbone to admit that sometimes tax increases are a necessity? The working poor could be protected by appropriate tax credits.
◾ Dedicate half of the fuel tax revenues to mass transit. People use mass transit when they can ride safe, reliable, comfortable, and affordable systems. Let's make them widely available.

Give the other half of the tax revenues to solar energy and battery R&D. With biofuels, we're trying to convert into a convenient form the sun's energy that plants have captured. (The same can be said for fossil fuels.) Aren't we smart enough to eliminate the middleman? My dream is to drive a car powered by compact batteries charged by superefficient solar panels. Here's where the creativity of the chemistry community can change the world.

Please don't just write and tell me how these ideas can never work. Instead, I'd like to hear your ideas for getting us out of the energy hole we've dug for ourselves.

Views expressed on this page are those of the author and not necessarily those of ACS.

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