Biofuels explained Biodiesel, renewable diesel, and other biofuels

Renewable diesel is the second-most consumed biofuel after fuel ethanol

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. It can also be blended with petroleum diesel or with biodiesel in various amounts. Renewable diesel-petroleum diesel blends are labeled 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% 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, 2023, the United States had 17 operating renewable diesel production facilities in 12 states with a combined production capacity of about 3 billion gallons per year. Two of these facilities are former petroleum refineries converted to processing biofuels. In 2022, U.S. renewable diesel production was about 1.5 billion gallons and consumption was about 1.7 billion gallons, which included about 0.3 billion gallons of imports. California uses most U.S. renewable diesel fuel imports.

Biodiesel is the third-most consumed 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 have increased substantially, largely because of government incentives and requirements that have come into effect to produce, sell, and use biodiesel. In addition to the U.S. Renewable Fuel Standard Program, the Biodiesel Mixture Excise Tax Credit and the Biodiesel Income Tax Credit are important incentives for biodiesel blenders and producers. In 2022, biodiesel accounted for about 9% of total U.S. biofuels production and consumption.

Pure biodiesel has limited direct-use applications and has supply logistics challenges because of its physical properties and characteristics. Biodiesel is a good solvent, which means it 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 turns into a gel at higher temperatures than petroleum diesel, which creates problems for its use in cold temperatures. So, biodiesel cannot be stored or transported in regular petroleum liquids tanks and pipelines—it must 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). Some vehicle fleets use B100 (neat biodiesel). Much of the petroleum diesel fuel sold in the United States contains up to 1% biodiesel because biodiesel's lubrication qualities can potentially prolong the lifetime of certain engine components. Biodiesel is added to petroleum diesel at blending terminals after the petroleum diesel is loaded into tanker trucks for local distribution.

As of January 1, 2023, the United States had biodiesel production facilities in 29 states with a total production capacity of about 2.9 billion gallons per year. About 70% of the production capacity is in midwestern states (PADD 2). In 2022, U.S. biodiesel production was about 1.6 billion gallons, imports were about 25 million gallons, and exports were about 24 million gallons. About 1.7 billion gallons of biodiesel were consumed in 2022, nearly all in blends up to B20.

Other biofuels use is increasing

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 U.S. SAF production and consumption is in California. In 2022, one SAF production facility was operating in California and several were 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. EIA includes SAF in the data it publishes for Other biofuels. However, the U.S. Environmental Protection Agency's RFS RIN transaction data indicates 15.8 million gallons of SAF were generated in 2022, most of which was in California, according to California's LCFS data.

Outlook for renewable diesel and other biofuels increases

Production and consumption of renewable diesel, SAF, renewable heating oil, and other non-ethanol biofuels (excluding biodiesel) in the United States is likely to increase as 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: February 26, 2024.