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Biodiesel Basics

Biodiesel is a domestically produced, renewable that can be manufac- tured from new and used vegetable oils, animal , and recycled res- taurant grease. Biodiesel’s physical properties are similar to those of diesel, but it is a cleaner- burning renewable alternative. Using biodiesel in place of petroleum diesel Biodiesel works well in many applications, such as this B20 transit at the University of significantly reduces lifecycle carbon Colorado at Boulder. Photo by Pat Corkery, NREL 18103 emissions. Research shows that it also reduces emissions of toxic air pollut- ants in older on-road vehicles and in vehicles. Nearly 80% of OEMs already the Alternative Fueling Station Locator many off-road applications. approve blends up to B20 in some or all at www.afdc.energy.gov/stations. of their diesel vehicles, and some even approve the use of B100 in certain types Biodiesel blends of farm equipment. Ongoing research How well does biodiesel Biodiesel can be blended and used in aims to gain approval for the use of B20 perform? many different concentrations, includ- blends in all on-road diesel vehicles. Engines operating on B20 exhibit ing B100 (pure biodiesel), B20 (20% similar fuel consumption, horsepower, biodiesel, 80% petroleum diesel), B5 Check your OEM’s website or speak and torque to engines running on (5% biodiesel, 95% petroleum diesel), with a dealer to determine which conventional diesel. Biodiesel also has a and B2 (2% biodiesel, 98% petroleum biodiesel blend is right for your vehicle. higher (a measure of the diesel). B20 is a common biodiesel You can also find general and manu- ignition value of ) and higher blend in the United States. facturer-specific information on the lubricity (the ability to lubricate fuel website pumps and fuel injectors) than conven- (www.biodiesel.org). It is up to you to Using biodiesel in tional diesel fuel, so it combusts easier determine the right blend ratio for and lubricates the fuel system better. diesel engines your vehicle and application. B20’s energy content is between those For vehicles manufactured after of No. 1 and No. 2 diesel. 1994, biodiesel blends meeting ASTM standards can be used with minimal How can I find biodiesel? impact on operating performance. Biodiesel is available in all 50 states. Will biodiesel perform well Diesel vehicles manufactured before According to the U.S. Energy Infor- in cold weather? mation Administration, annual 1994 may include elastomers (hoses The cold-flow properties of of biodiesel in the United and ) that could break down blends vary depending on the amount States totaled more than 1.3 billion with repetitive use of blends above of biodiesel in the blend and the types gallons in 2013, and as of January 2014, B20. Higher blends should be avoided of fuel used in the blend. This issue is the country had an annual produc- in these older vehicles, or their elas- not limited to biodiesel, as diesel fuel tion capacity of more than 2.2 billion tomers should be upgraded to a exhibits the same behavior. All diesel gallons.1 The Alternative Data compatible material. and biodiesel blends can have com- Center (AFDC) website has informa- pounds that crystallize in very cold Currently, every original equipment tion on fueling sites across the country temperatures, causing operability issues manufacturer (OEM) of diesel vehicles that offer blends of B20 and higher. To if not properly monitored. However, approves blends of up to B5 in their find biodiesel stations in your area, use fuel blenders have a number of options 1 Monthly Biodiesel Production Report, February available to improve the cold-flow 2014 With Data for December 2013, Washington, properties of biodiesel blends, includ- D.C.: U.S. Energy Information Administration. ing adding flow improvers, blending in Accessed June 12, 2014: www.eia.gov/biofuels/ more No. 1 diesel, or blending in less biodiesel/production/archive/2013/2013_12/bio- diesel.pdf biodiesel. Users should consult with

VEHICLE TECHNOLOGIES OFFICE cleancities.energy.gov VEHICLE TECHNOLOGIES OFFICE • July 2014 • Page 2 their fuel provider with questions about must meet ASTM D975, which requires 5 1994 the cold weather performance of their these blends to meet the same fuel- 4 fuels. For more information about cold- quality specifications as conventional 1998 flow properties and biodiesel handling, diesel fuel, so they have the same physi- download the Biodiesel Handling and cal properties. For blends containing 3 Use Guide from www.nrel.gov/docs/ 6%–20% biodiesel, the finished blend 2002 2 fy09osti/43672.pdf. needs to meet ASTM D7467.

NOx (g/hp-hr) NOx 1 2007 (NOx=1.2) 2010 (NOx=0.2) Will biodiesel plug my Does biodiesel burn 0 vehicle filters? cleaner than diesel? 0 0.02 0.04 0.06 0.08 0.10 Biodiesel has a effect. It cleans Prior to the 2010 model year (MY), Particulate (g/hp-hr) your vehicle’s fuel system and could some studies showed contradictory Figure 1: Emission Standards for Heavy- release deposits accumulated from results for emissions of nitrogen oxides Duty Highway Engines. U.S. emissions previous diesel fuel use. The release of with B20 compared to diesel fuel. With limits for nitrogen oxides (NOx) and deposits may initially clog filters, so new emission control technologies, this particulate matter (PM) have been reduced you should be proactive in checking is no longer an issue, because diesel fuel significantly over the last 20 years. for and replacing clogged fuel filters. burns as cleanly as B20 in MY 2010 and Biodiesel’s benefits are maximized in Once the build-up is eliminated, return newer engines. In older engines, bio- engines older than MY 2010. to your regular replacement schedule. diesel blends may offer some additional This issue is less common with B20 emissions reduction benefits, particu- and lower-level blends. larly for particulate matter, carbon entiate among the various biodiesel monoxide, and unburned hydrocar- feedstocks—vegetable oils and waste bons. The amount of the benefit will fats, greases, and oils—in defining 2 Will long-term biodiesel depend on the engine’s emission control biodiesel as an advanced fuel. use affect my engine? technology, the age of the engine, the Studies of B20 and lower-level blends percent of biodiesel in the blend, and Can I use straight vegeta- in approved engines have not dem- how the vehicle is operated. As Figure 1 onstrated negative long-term effects. illustrates, the oldest engines and tech- ble oil in my ? Higher-level blends (above B20) may nologies will reap the greatest emissions No, straight is not biodiesel impact fuel system components in benefits from the use of biodiesel. and is not a legal . It doesn’t vehicles manufactured before 1994. meet biodiesel fuel specifications or The effects are lessened as the biodiesel Biodiesel also reduces greenhouse quality standards. For more informa- blend level decreases. For more infor- gas emissions on a lifecycle basis. tion, download the fact sheet, “Straight This is because the mation, visit www.biodiesel.org. Vegetable Oil as a Diesel Fuel?” at www. released during is offset nrel.gov/docs/fy14osti/54762.pdf. by the carbon dioxide sequestered Are there standards while growing the plants that are used Where can I read more? for biodiesel? to produce the fuel. Greenhouse gas emission reductions are an important For more information on biodiesel, BQ-9000 is the voluntary industry qual- component of being an advanced including production, distribution, ity assurance program, and information under the Renewable Fuel and fueling station locations, visit the can be found at bq-9000.org. Biodiesel Standard. The U.S. Environmental biodiesel section of the AFDC at www. blends should start with B100 biodiesel Protection Agency does not differ- afdc.energy.gov/afdc/fuels/biodiesel.html. that meets ASTM International Specifi- cation D6751. When blended for B5 and 2 EPA Lifecycle Analysis of from , Washington, D.C.: U.S. Environ- lower-level blends, the finished blend mental Protection Agency. Accessed June 12, 2014: www.epa.gov/otaq/renewablefuels/420f10006.pdf

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To view this and other Clean Cities publications online, visit cleancities.energy.gov/publications.

DOE/GO-102014-4420 • July 2014

Prepared by the National Laboratory (NREL), a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy; NREL is operated by the Alliance for , LLC.