Biofuels

What are Biofuels?

The Department of Energy* defines biofuels as “liquid fuels produced from renewable biological sources,” & in this infographic we’ll take a look at two different kinds: Biodiesel and renewable diesel.

Similarities Between Biodiesel and Renewable Diesel

Usage: Like petroleum diesel, both can be used to fuel compression-ignition engines.

Feed Stocks: Both are derived from biological sources such as vegetable oils, animal fats, recycled greases, etc.

Emissions: Both have lower greenhouse gas emissions compared to petroleum diesel.

Differences Between Biodiesel and Renewable Diesel

Energy Content: Biodiesel energy content is lower than petroleum diesel by approximately 8.5%, while renewable diesel energy content is lower than petroleum diesel by approximately 4.6%.

Usage: Biodiesel is typically blended with petroleum diesel (up to 20%, which is identified as B20) while renewable diesel can be used on its own, blended with petroleum diesel, or blended with biodiesel due to the greater flexibility afforded by its chemical structure.

Cold Weather Performance: Biodiesel tends to gel at lower temperatures, while renewable diesel has similar cold flow behavior as petroleum diesel.

Chemically: Biodiesel contains Fatty Acid Methyl Esters, with a different chemical structure than petroleum diesel. Renewable diesel is chemically nearly identical to petroleum diesel, meeting the ASTM D975 specification for petroleum diesel in the United States.

Creation Process: While both use the same basic feedstocks, different technologies are used to convert the feedstocks into fuels. Biodiesel utilizes transesterification, while renewable diesel goes through hydrotreating.

Market Outlook

The U.S. production capacity for renewable diesel is expected to increase by approximately 70% by 2025, and the U.S. production of renewable diesel (3 billion gallons in 2023) has surpassed biodiesel. Availability of renewable diesel is improving, but the current price is considerably higher than petroleum diesel or bio-blends.

*Biofuels basics. Energy.gov (n.d.). http://www.energy.gov/eere/bioenergy/biofuel-basics