Ethanol Tries to Ditch Bad Rep
There was a time when renewable fuels like ethanol were considered by environmentalists to be the wave of the future, giving us a literal breath of fresh air. But as the alternative energy scene has evolved in recent years, ethanol has taken a beating. In a cover story, Consumer Reports called it a sham, and studies have been released that offer, at best, contradictory assessments of ethanol. Some of those reports claim it actually requires more energy to derive a gallon of ethanol than the energy that gallon of fuel provides. Meanwhile, some of those who had purchased flex-fuel cars discovered to their disappointment that they were getting fewer miles per tankful, while at the same time, their fuel was costing them more.
This is not to say that ethanol has not had its supporters. In fact, the governors of the Corn Belt states are nearly unanimous in their support of ethanol, and they have been joined by General Motors, which has led the charge for ethanol amidst the auto manufacturers. The past several years have also spawned a number of companies looking to capitalize on the trend to renewable fuels. And though ethanol has taken its shots recently, these companies remain enthusiastic about ethanol’s overall future. Many of them are especially high on cellulosic ethanol production based on nonfood feedstock, and they seek to set the record straight on ethanol’s current and future states, as they see them. Here are some facts and comments on those issues based on information provided by one of those companies, Gulf Ethanol:
- How much ethanol is produced in the U.S.? According to the Renewable Fuels Association, the U.S. produced 5.4 billion gallons of ethanol in 2007. As of March 2008, U.S. ethanol production capacity was at 7.2 billion gallons, with an additional 6.2 billion gallons of capacity under construction.
- Will I get lower gas mileage with ethanol-blended fuels than with traditional gasoline? The ethanol blends used today have little impact on fuel economy or vehicle performance. Ethanol has the highest octane rating of any commonly used fuel, but on a gallon-for-gallon basis, ethanol delivers less energy than gasoline. Today's vehicles that are designed to run on gasoline blended with ethanol in small amounts (up to 10 percent) will likely see no perceptible effect on fuel economy. Flex-fuel vehicles designed to run on higher ethanol blends like 85-percent-ethanol E85 experience reduced miles per gallon when using the blended fuel, but these engines can be tuned to minimize the detrimental effects ethanol has on fuel economy by making better use of ethanol’s higher octane rating.
- Does the U.S. have enough biomass resources to displace petroleum with biofuels without negative impacts to the food supply? A joint study conducted by the Departments of Energy and Agriculture, the Billion Ton Study, estimates that 1.3 billion tons of biomass feedstock is potentially available in the U.S. for the production of biofuels. This is enough biomass feedstock to displace approximately 30 percent of current gasoline consumption on a sustainable basis. The development of technologies to convert cellulosic feedstock (in other words resources neither based on grain nor used for food purposes, such as sorghum, switchgrass, agricultural residues and wood) will make it possible to produce biofuels at levels that could displace 30 percent of gasoline use based on the use of feedstock that is not part of the food chain.
- Does ethanol require more energy to produce than it delivers as a fuel? Each gallon of corn ethanol produced today delivers as much as 67 percent more energy than is used to produce the ethanol. The amount of energy used to produce corn ethanol has decreased significantly over the last two decades due to improved farming techniques, more efficient use of fertilizers and pesticides, higher-yielding crops, and advances in conversion technologies. Cellulosic ethanol has an even higher energy balance than corn ethanol, delivering four to six times as much energy as is necessary to produce it.
- Does ethanol result in more or less greenhouse gas emissions than gasoline? Ethanol results in fewer greenhouse gas emissions than gasoline. The higher the amount of ethanol blended with gasoline, the lower the resulting greenhouse gas emissions. Cellulosic ethanol has the potential to reduce such emissions by up to 86 percent. Use of ethanol can, however, increase the emissions of some air pollutants due to the fossil energy used for farming and biofuels production. These emissions can be reduced by using improved farming methods and renewable power in the production process.