The battle lines are forming over a plan to move the ethanol "blend wall" from 10 percent gasoline content to 15 percent. Forces pushing for 15 percent include farmers unions, Midwest members of Congress, some environmental groups, and state legislatures whose Renewable Energy Standards may fail without mandated biofuels. With ethanol production now over 10 billion gallons/year, supply is exceeding mandated demand.

At 15 percent ethanol, the annual need for corn for ethanol would increase from the current approximately 5 billion bushels to around 7.5 billion bushels. Total U.S. corn production has ranged from 10 to 13 billion bushels in recent years. This new demand would create a need for at least 12 million more corn acres, since cellulose ethanol is still years from volume production. Some of this extra crop land would be from conservation set-aside acres and from areas requiring irrigation.

A recent study, led by University of Minnesota professor Sangwon Suh, showed that to produce a gallon of corn ethanol in the United States requires an average of 142 gallons of fresh water. In high-irrigation states like Kansas and Nebraska, the average rises to 500 water gallons. In low-irrigation states like Iowa and Minnesota, water use is 9 to 19 gallons per ethanol gallon. The additional fertilizer for more corn sends phosphorus and nitrogen into the Mississippi River — encouraging algae growth, fostering those dead zones in the Delta and the Gulf of Mexico.

Defending the 10 percent wall are the American Petroleum Institute (API), auto manufacturers (AAM), and outdoor power equipment suppliers (OPEI), etc. Ethanol (ethyl alcohol) is a solvent, and there is concern about engine damage in engines not modified for higher ethanol content. In Australia, where 15 percent ethanol is under way, tests are also showing that car engine control systems are having problems. This is supported by a preliminary Department of Energy (DOE) test showing 13 of 25 vehicles tested with similar control problems. Additional tests are proceeding. If those new tests are satisfactory, the Environmental Protection Agency (EPA) indicates it would be in a position to "approve E-15 blends for 2001 and newer vehicles in a mid-2010 timeframe."

For 2001 and later vehicles
Meanwhile, the EPA indicates it will work to prepare appropriate retail pump labeling so that consumers will be able to select appropriate fuel blends for their vehicles and off-road equipment. According to professor Robert Wisner, an energy economist at Iowa State University, there are strong implications that if E-15 is approved, it will be only for 2001-and-newer motor vehicles. DOE publications and Wisner's reports provided some of the data for this article.

The complications for retailers having to provide multiple gasoline blends — E-10, E-15, E-85 — are enormous. In some cases, lack of land will prevent adding another storage tank. In other cases, the added investment funds may not be available, or the station may be on leased land that does not allow additional tanks to be installed. Refiners have indicated that additional refinery blends will be needed to allow varying quantities of ethanol to be added at local terminals. Raising the ethanol blend to 15 percent increases gasoline's vapor pressure, risking "vapor lock" in warm and high-altitude areas.

Kris Kiser, OPEI president, says that more than 500 million outdoor engines designed to run on fuels with 10 percent ethanol could fail at higher levels. "What's needed is more robust testing and data," he said. And most U.S. cars are warranted only for gas with 10 percent ethanol.

Potential effect on gas emissions
Growth Energy, a biofuels industry group, contended to the EPA, which is charged with the decision, that a 15 percent blend wall would reduce U.S. greenhouse gas emissions by 20 million tons/year and create 136,000 jobs.

The EPA has also received comments from several states, other environment groups, and the U.S. Coast Guard. According to Coleman Jones, biofuels manager for General Motors, "Those comments all counseled that EPA needs to wait and do a more thorough job of testing."
   
The EPA is considering a partial increase in the ethanol limit to 12 percent while tests continue. Stay tuned.

Rolf Westgard, of St. Paul, is a professional member of the Geological Society of America and a guest faculty member, University of Minnesota.