Beyond Ethanol

Many environmental advocates have promoted the benefits of using ethanol (ethyl alcohol) as a partial solution to our foreign oil dependence. They point out the energy independence of Brazil which uses domestic ethanol to run the vast majority of its vehicles. But there are problems with ethanol as a solution.
Most of the ethanol produced in the United States is made from the starches in corn kernels. The industry is popular in states producing large corn crops, but corn farming as it currently exists is fossil fuel dependent. Corn farming depends on chemical fertilizers that are made from natural gas and uses fossil fuel for mechanical operations. It also produces large amounts of nitrous oxide, a greenhouse gas more potent in trapping heat than carbon dioxide. Cellulosic ethanol is produced from grasses and agricultural waste products. It may be a "greener" source since less fertilizer and land is used to produced an equivalent amount of fuel. The non fermentable parts of the plant can also be used as fuel to drive the fermenting process, but the process of fermenting sugars from cellulose to make ethyl alcohol is more complex and expensive. Until advances are made in the cellulose process, we are stuck with corn. Corn's long term energy potential however, is limited. Roughly 15% of the crop is used to make ethanol, but this amount displaces only 2.3% of the gasoline we use every year. If by 2025, we used all of our corn crop for fuel with nothing left for food or animal feed, we would only displace 15% of our gasoline demand.
Considerations of ethanol as a solution must go beyond the environmental impacts of its production to the impacts of its use as vehicle fuel. Ethanol is currently mixed with gasoline in two major types, the commonly available 10% ethanol (E10) and the less available 85-74% ethanol blends (E85). E85 requires engine modifications and is used in flex fuel vehicles. Only half a percent of gas stations carry E85, mostly in the Midwest. E85 is preferable from an air quality standpoint since its combustion produces the fewest volatile organic compounds that are precursors to smog. E10 produces more volatile organics than pure gasoline. Only ethanol produced from cellulose can contribute significantly (63%-90% depending on blend) to reducing greenhouse gases because its production cycle does not require significant amounts of fossil fuel.
In the near term, drasticly increasing the efficiency of our new engines will save more oil than using corn ethanol as a fuel. No radically new technology is needed to obtain dramatic increases in fuel efficiency. But there is a government incentive for auto makers to produce flex fuel vehicles instead. The incentive assumes flex fuel cars and trucks use E85 half the time. In reality they only use E85 about 1% of the time. Automakers are getting more regulatory credits than they deserve. This loophole increased America's oil dependence by 80,000 barrels per day in 2005 and allowed automakers to avoid $1.6 billion in CAFE (Corporate Average Fuel Economy) non-compliance fines. Despite the failure of the flex fuel credit to reduce oil consumption Congress has reauthorize the credit until at least 2010. The corporate eye never waivers from the bottom line.

Thanks to Don MacKenzie at Union for Concerned Scientists