FAME versus NERD and Biodiesel's Future

Published May 13, 2008

FAME versus NERD is not the latest summer blockbuster for teens. FAME and NERD are the acronyms defining the two main forms of biodiesel—a non-petroleum renewable fuel that can theoretically run in any diesel vehicle without modification.

Why is it important to know the difference between FAME and NERD? Because they are not created equal in the eyes of automakers when certifying the use of biodiesel. Even though both methods produce a fuel to displace petroleum diesel, not every automaker gives the thumbs-up for their cars and trucks to be used with B5—a blend of 5 percent biodiesel and 95 percent petrodiesel.

Volkswagen, Mercedes-Benz and Ford generally are okay with B5, while Chrysler and GM approve B20 for some of their trucks. The other automakers have been very quiet about biodiesel—a stance that’s due to change as new diesel vehicles come to the market in the next few years.

Biodiesel advocates are pushing for warranty protection for stronger blends up to B20. Some cite the Magnuson Moss Warranty Act Engine, which holds manufacturers responsible for warranty protection, regardless of the type of fuel used—unless damage is directly caused by the fuel.

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Automakers reply that they don’t warranty fuel and they don’t single out biodiesel. The high-pressure injectors used in modern diesels demand a very clean and stable fuel, so the suppliers that make the injectors as well as the automakers are gun-shy about endorsing higher levels of biodiesel—until its quality standards are taken to a level comparable to Europe.

Understanding the differences between FAME and NERD could help put these squabbles to rest.

Defining FAME and NERD

FAME is Fatty Acid Methyl Ester. This is traditional biodiesel, produced by processing raw vegetable oil or animal fats through a chemical process called transesterification. The resulting product is chemically different from petroleum diesel, has different properties, and meets a different quality standard. The most common feedstock for FAME biodiesel in the U.S. is soybean oil, but in Europe rapeseed or canola oil is typically used. Refined and recycled restaurant vegetable oil also is used by some biodiesel producers. Most of the biodiesel available in the United States is the FAME type.

On the other hand, NERD renewable diesel has properties similar to petroleum diesel and minimizes blending issues. It has a higher cetane level (for improved ignition), a lower cloud point (for better cold weather performance), higher renewable content, greater fuel stability (for better storage), a broader choice of feedstock, and lower NOx and greenhouse gas emissions compared to FAME biodiesel.

NERD is Non-Esterified Renewable Diesel. There are several varieties of this type of biodiesel, also known as renewable diesel. The most advanced of these is produced through hydrotreating—the same process that is already used in today’s petroleum refineries. During hydrotreating, hydrogen replaces other atoms such as sulfur, oxygen, and nitrogen and converts the oil’s triglyceride molecules into paraffinic hydrocarbons. The first refinery using the NERD process to produce renewable diesel was recently opened by Neste Oil in Porvoo, Finland, in Summer 2007.

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Other methods under consideration for creating renewable diesel fuel include biomass-to-liquid (BTL) and thermal conversion process (TCP) technologies. The former converts biomass—predominantly cellulosic material such as certain grasses, waste plant materials or other plants—through high-temperature gasification into synthetic gas or “syngas.” And then uses a Fischer-Tropsch process to catalytically convert the syngas to liquid fuel. TCP processing converts biomass or other carboneous material into a “bio-oil” which is then further refined into diesel-like fuel. Both BTL and TCP offer tremendous potential to convert large volumes of cellulosic biomass into liquid fuels, but need further development and remain far from being economical for large-scale fuel production.

The progress in biodiesel production—resulting in a shift to renewable diesel—could make the tensions between automakers and biodiesel providers a thing of the past. The quality of FAME biodiesel has improved in recent years, according to the National Biodiesel Board—but the real answer to replacing petroleum diesel could lie with NERD.

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