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Updated Biodiesel Guide Helps Ensure Optimum Performance

Oct. 20, 2008

Those who travel the road in vehicles that run on biodiesel—as well as those who produce, blend, store, or distribute this renewable fuel—will want to obtain a copy of the new, fourth edition of the National Renewable Energy Laboratory's (NREL's) popular Biodiesel Handling and Use Guide. This edition contains new information on standards and best practices on storage stability, low-temperature blending and operability, and new biodiesel blend specifications to ensure optimum performance.

"We want to make sure that people are on the right path to using this fuel with few or no operational problems," said principal author Bob McCormick, a nationally known expert on biodiesel and biodiesel blends in NREL's Center for Transportation Technologies and Systems. "This 52-page guide is unique in that it contains a lot of technical data but also a lot of practical guidelines on how to handle and use biodiesel."

According to the technical definition, Earth-friendly biodiesel is composed of "mono-alkyl esters of long-chain fatty acids derived from vegetable or animal fats and meeting the requirements of ASTM (standard) D6751."

Biodiesel can be produced from animal fats (tallow, lard, white or yellow grease, poultry fats, or fish oils); recycled greases (used cooking and frying oils); and most commonly, plant oils (from soybeans, corn, rapeseed, sunflowers, and cottonseeds, etc.). Researchers are also investigating the use of oils from algae and other novel feedstocks to produce this fuel, which has several advantages when used for transportation purposes, as outlined in the new edition of the guide.

Biodiesel can be used as a "neat" fuel (B100, which is 100% biodiesel) or, more commonly, as a blend with petroleum-based diesel fuel. However, when blends contain more than 20% biodiesel (B20), there can be operational and storage problems. For example, B100 freezes more quickly than regular diesel. B100 is also incompatible with some standard engine and fuel-line materials. So, until future research and development resolves these and other issues, it is important to provide users with the detailed information in this guide.

"We've learned a lot since the third edition came out," said McCormick. With funding from DOE and assistance from Janet Yanowitz of Ecoengineering, Inc., and Richard Nelson of Enersol Resources, McCormick updated the guide and made sure that it was reviewed by other experts in the field.

Today, biodiesel makes up only about 1% of the total U.S. diesel market. But that number should increase; the federal Renewable Fuel Standard calls for 2% market penetration by 2012. "The goal is for biodiesel to be blended into every gallon of diesel fuel that's used," McCormick said.