Biofuels are liquid fuels created from blending biomass feedstock. Biofuels take advantage of the energy stored in plants during photosynthesis. Throughout the 2000s biofuel advocates predicted that the fuel would bring energy independence to the United States and lower carbon emissions. These predictions have been slow to become reality, however, as the movement of biofuels from the laboratory to widespread adoption has been much slower than expected. The delay in biofuel adoption, in combination with decreased gasoline consumption, pushed the U.S. Environmental Protection Agency (EPA) to cut a biofuel goal in 2013, and delay the implementation of 2013 standards to 2015.
Types of biofuels
- Ethanol is made from sugar crops such as sugar beets and sugar cane, and starches such as corn. These crops are fermented to produce ethanol, which is combined with traditional fuel sources such as gasoline to create E10, or E15 (with the 10 and 15 indicating the percentage of ethanol present) gasoline blends.
- Biodiesel is made from natural oils taken from oil palm, algae or soybeans. These oils can be burned on their own or combined with petroleum to make biodiesel.
- Wood and other wood byproducts can be converted into liquids such as methanol, ethanol or woodgas. In its solid state, wood or chipped waste biomass can also be burned.
In 2013 there were 115 biodiesel plants across the United States, with production concentrated in the Midwest. These plants have the capacity to produce 2.2 billion gallons of biodiesel per year.
The chart below shows biodiesel production (blue) and consumption (brown) from January 2001 to November 2014 in the United States in thousands of barrels. In January 2001, 17.3 thousand barrels were produced and 17 thousand barrels were consumed. By November 2014, 2,416 thousand barrels of biodiesel were produced and 3,058 thousand barrels were consumed.
First generation biofuels
The first generation of biofuels used traditional foodstuffs such as corn and soybeans to generate liquid fuel. Eventually these methods were met with some criticism. First critics argued that the quotas created by Congress to increase the use of biofuels misallocated foodstuffs, removed food from dinner tables and put it into engines, while increasing the price of food. This argument is known as the food versus fuel debate. Biofuels were also seen as a way to decrease carbon emissions, however some research has suggested that if researchers consider the carbon emitted during the entire lifetime of the crops used in biofuels, then biofuels have a larger carbon footprint than traditional gasoline. Additionally, drivers who put gasoline with ethanol into cars that aren't built to use the blend can void their car warranties and damage their engines. The debate over these criticisms continues to this day, and as technology improves it is expected that these potential problems can be better addressed.
Second generation biofuels
Research is underway to expand the types of biomass that can be used to create biofuels. The National Renewable Energy Laboratory (NREL) is one of many research institutions experimenting with ways to transform algae into transportation fuel. These second generation biofuels have three challenges to overcome according to The Economist. First, they must be created from food waste, or biomass that has no nutritional value, thus avoiding the food versus food debate. It is more difficult to break down food waste products, such as corn stalks, grass and trees, into the simple sugars needed for fuel, which makes using food waste a technological barrier for researchers. Second, producers will have to alter their fuels to work in existing vehicles. Some of the pushback against biofuels has occurred because ethanol can damage car engines and void car warranties. Third, biofuels need to be affordable so that they are attractive option for consumers.
- U.S. Energy Information Administration, “Glossary, B” accessed January 29, 2014
- New York Department of Environmental Conservation, "How Biofuel is Made," accessed April 28, 2014
- The Economist, "What happened to biofuels," September 7, 2013
- The Washington Times, "Running on empty: EPA slashes biofuel goals because of ethanol shortage," April 23, 2014
- Biofuels Digest, "EPA abandons RFS rulemaking for 2014," November 21, 2014
- U.S. Department of Energy, "Ethanol," accessed April 28, 2014
- U.S. Energy Information Administration, "Monthly Biodiesel Production Report," February 27, 2014
- U.S. Environmental Protection Agency, "Biodiesel Overview," accessed March 18, 2015
- Forbes, "Despite Evidence, Food Vs. Fuel Fight Continues," July 11, 2013
- Popular Mechanics, "Can E15 Gasoline Really Damage Your Engine?," December 21, 2010
- USA Today, "AAA warns E15 gasoline could cause car damage," November 30, 2012
- National Center for Biotechnology Information, "The Carbon Footprint of Biofuels: Can We Shrink It Down to Size in Time?," June 2008
- National Renewable Energy Laboratory, "Biofuels Basics," July 25, 2014