Biodiesel is the second-most used and produced biofuel in the United States
Only small amounts of biodiesel were consumed and produced in the United States until the early 2000s. Since then, U.S. biodiesel consumption and production increased substantially, largely because of the availability over time of various government incentives and requirements to produce, sell, and use biodiesel. In addition to its use in recent years to meet targets for advanced biofuels use under the U.S. Renewable Fuel Standard Program, important incentives to biodiesel blenders and producers are the Biodiesel Mixture Excise Tax Credit and the Biodiesel Income Tax Credit. In 2020, biodiesel was second to fuel ethanol as the most produced and consumed biofuel in the United States, and accounted for about 11% and 12% of total U.S. biofuels production and consumption respectively.
Pure biodiesel has limited direct-use applications and faces supply logistics challenges because of its physical properties and characteristics. Biodiesel is a good solvent that can degrade rubber in fuel lines and loosen or dissolve varnish and sediments in petroleum diesel fuel tanks, pipelines, and in engine fuel systems, which can clog engine fuel filters. Biodiesel gels at higher temperatures than petroleum diesel, which creates problems for its use in cold temperatures. Therefore, biodiesel cannot be stored or transported in regular petroleum liquids tanks and pipelines and it has to be transported by rail, vessel and barge, or truck.
Biodiesel is approved for blending with petroleum diesel/distillate under the American Society for Testing and Materials specification ASTM D6751. Most U.S. biodiesel is consumed as blends with petroleum diesel in ratios of 2% (referred to as B2), 5% (B5), or 20% (B20). There are some vehicle fleets that use B100 (neat biodiesel). Much of petroleum diesel fuel sold in the United States actually contains up to 1% biodiesel because of biodiesel's lubrication qualities that potentially prolong the lifetime of certain engine components. Biodiesel is added to petroleum diesel only at blending terminals into tanker trucks for local distribution.
As of January 1, 2021, there were 75 U.S. biodiesel production facilities with a total production capacity of about 2.4 billion gallons per year. About 62% of the production capacity is located in midwestern states (PADD 2). In 2020, U.S. biodiesel production equaled about 1.8 billion gallons, imports equaled about 197 million gallons, and exports equaled about 145 million gallons. About 1.9 billion gallons of biodiesel were consumed in 2020 nearly all in blends up to B20.
A bus powered by soybean oil
Source: Stock photography (copyrighted)
Use of renewable diesel and other biofuels is small is increasing
Because renewable diesel is chemically the same as petroleum diesel, it may be used in its pure form—called R100—as a drop-in fuel, or it can be blended with petroleum diesel and/or with biodiesel in various amounts. Renewable diesel-petroleum diesel blends are labelled with an R followed by the percentage (by volume) of the renewable diesel content. For example, a blend of 20% renewable diesel and 80% petroleum diesel is called R20. A blend of 20% biodiesel and 80% of renewable diesel is called B20R80 to make a 100% biofuel. A blend of 20% biodiesel, 20% renewable diesel, and 60% petroleum diesel is called B20R20.
According to the U.S. Renewable Diesel Fuel and Other Biofuels Plant Production Capacity report, as of January 1, 2021, there were six operating U.S. renewable diesel production facilities with a combined total production capacity of about 791 million gallons per year. Two of these facilities are former petroleum refineries converted to processing biofuels. In 2021, U.S. renewable diesel production equaled about 815 million gallons (0.82 billion gallons) and consumption equaled about 1,163 million gallons (1.16 billion gallons), which included about 392 million gallons of imports. California uses most of U.S. renewable diesel fuel imports.
Sustainable aviation fuel (SAF)—also called alternative jet fuel (AJF) or biojet under California's Low Carbon Fuel Standard (LCFS)—includes non-petroleum synthesized jet fuel components produced to the definitions in ASTM D7566. SAF/AJF blended with conventional jet fuel meets ASTM D1655 for use in existing aircraft and fueling infrastructure.
Most of U.S. SAF production and consumption is in California. In 2020, there was one SAF production facility operating in California and several are under construction or planned. The U.S. began importing SAF in late 2020, mostly for use in California. Los Angeles International Airport has used SAF since 2016 and San Francisco International Airport since late 2020. The U.S. Energy Information Administration (EIA) includes SAF in the data it publishes for Other biofuels. However, the U.S. Environmental Protection Agency's RFS RIN transaction data indicates generation of 4.6 million gallons of SAF in 2020, all of which has been consumed in California, according to California's LCFS data.
In 2021, use and production of renewable diesel, SAF, renewable heating oil, and other non-ethanol biofuels (excluding biodiesel) in the United States was relatively small but could increase, if announced and developing projects are completed. Much of the planned capacity could be used to produce renewable diesel or SAF. How much of that capacity is used to produce each type of biofuel will depend on market factors and how national and state biofuels policies evolve over the next few years.
Last updated: June 29, 2022, with most recent annual data for 2021 available at the time of update.