Biodiesel: High Standards for A Premium Product

Dec 14, 2023 | Biodiesel, Focus Story, Product Type, Technical


By Scott Fenwick, Technical Director at Clean Fuels Alliance America
Published in Kentucky Petroleum Marketers Association Magazine | Winter 2023 Issue

As the world grapples with environmental challenges and seeks sustainable alternatives to traditional fossil fuels, biodiesel has emerged as a promising solution. Biodiesel, derived from renewable sources such as vegetable oil and animal fat, is a drop-in fuel that slashes emissions, often in heavy-duty vehicles that don’t have a realistic option to convert to electric.

The American Society for Testing and Materials (ASTM International) first published specifications for biodiesel in 2002. In the 21 years since it was first published, the ASTM specs have been revised and republished 29 times. This reflects the biodiesel industry’s commitment to revising and tightening fuel specifications for top performance in today’s engines.

In fact, the standards for biodiesel quality are more stringent than petroleum diesel fuel quality. Currently, 23 parameters need to be tested against the biodiesel specs from ASTM versus only 15 parameters that need to be tested and confirmed for petroleum diesel. These parameters include fuel performance, cetane number and residual compounds such as monoglycerides, diglycerides and triglycerides that are left over from the production process. These high standards keep biodiesel a clean and reliable product.

To ensure the safe and effective use of biodiesel, the National Renewable Energy Laboratory (NREL) has continuously updated and improved its Biodiesel Handling and Use Guide. NREL recently released the sixth edition of the guide, highlighting key updates and environmental benefits while further establishing the role it plays in biodiesel use.

Before delving into the guide’s details, it’s essential for consumers to understand the significance of biodiesel in today’s energy landscape. Biodiesel is a renewable fuel that can be blended with conventional diesel fuel or used in pure form (B100) for both transportation applications and home heating systems. This guide refers to biodiesel that meets the most current ASTM International Standard D6751, a new low metals grade.

Biodiesel is high-quality. Recent studies have found that biodiesel and petroleum diesel are almost indistinguishable in terms of use and performance. After testing that included 1,000 hours of accelerated aging on diesel engines, the ash and other emissions produced by biodiesel in an engine were comparable to or less than that of petroleum diesel and can be easily removed by the emissions after-treatment systems.

Using biodiesel does not affect an engine’s warranty. Biodiesel, and all biodiesel blends, are legally registered with the EPA and can be used in today’s engines. Of course, specific conditions of use can impact the performance of any fuel.

Biodiesel significantly reduces carbon dioxide emissions compared to traditional diesel fuel, making it an essential tool in mitigating climate change and improving air quality. Numerous health benefits have been studied when switching to 100% biodiesel including reduced asthma attacks, fewer cancer cases and premature deaths and an overall reduction in health care costs by reducing particulate matter emissions.

Domestically produced using a variety of feedstocks, biodiesel decreases our reliance on imported fossil fuels enhancing energy security and creating opportunities for rural communities and agriculture. Biodiesel can be used in existing diesel engines with little to no modification, making it a seamless transition for vehicle and equipment fleets.

NREL, a leader in renewable energy research and development, has been instrumental in advancing the adoption of biodiesel. The Biodiesel Handling and Use Guide is a comprehensive resource that has undergone several iterations to keep pace with technological advancements, regulatory changes and industry developments. The sixth edition of the guide is a testament to NREL’s commitment to providing factual information on biodiesel as a clean and sustainable fuel option.

The most current guide brings a host of updates and improvements, reflecting the latest knowledge and best practices in biodiesel handling and utilization. Some of the key updates in this edition include:

  • Regulatory Compliance: The guide provides up-to-date information on federal and state regulations governing biodiesel, ensuring users know the latest compliance requirements.
  • Fuel Quality Assurance: Biodiesel quality is essential for proper engine performance and emissions control. The guide offers fuel quality guidelines, including recommendations for storage and handling.
  • Best Practices for Biodiesel Blending: As biodiesel is often blended with conventional diesel, the guide offers insights into proper blending techniques to achieve the desired blend ratio and maintain fuel stability.
  • Cold Weather Operations: Biodiesel can have different cold flow properties than traditional diesel, and the guide offers strategies for handling and using biodiesel in cold climates.
  • Fuel Infrastructure: For those involved in fuel distribution and storage, the guide covers the design, operation, and maintenance of biodiesel storage and dispensing facilities.
  • Fleet Management: Fleet managers will find valuable information on the integration of biodiesel into their operations, including maintenance practices and engine compatibility considerations.

The guide serves as a crucial tool in promoting biodiesel across various sectors, including transportation, agriculture and industrial applications. By offering comprehensive information and guidance, it addresses many of the common concerns and challenges associated with biodiesel use, making it easier for individuals and organizations to make the transition to this sustainable fuel source.

One of the guide’s most significant contributions is its emphasis on safety. Handling and storing biodiesel require specific precautions due to its unique properties. The guide provides detailed safety recommendations to ensure users can safely and effectively work with biodiesel.

NREL’s Biodiesel Handling and Use Guide, now in its sixth edition, stands as a vital resource for anyone interested in the sustainable use of biodiesel. With its comprehensive updates, the guide addresses the evolving landscape of biodiesel regulations, technology and best practices. By providing safety, quality and efficiency in biodiesel handling and utilization, NREL plays a pivotal role in advancing the acceptance of this renewable fuel source. As we continue to seek environmentally friendly alternatives to traditional fossil fuels, the guide remains a beacon of knowledge and a catalyst for a more sustainable energy future.

Like any fuel, the quality of biodiesel depends on the entire supply chain. Biodiesel is a premium product and is held to high standards. These standards ensure top performance and lower emissions in today’s engines.

Materials supported by United Soybean Board, soybean farmers and their checkoffs.


Made from an increasingly diverse mix of resources such as recycled cooking oil, soybean oil, and animal fats, the clean fuels industry is a proven, integral part of America’s clean energy future. Clean Fuels Alliance America is the U.S. trade association representing the entire biodiesel, renewable diesel and sustainable aviation fuel supply chain, including producers, feedstock suppliers and fuel distributors. Clean Fuels receives funding from a broad mix of private companies and associations, including the United Soybean Board and state checkoff organizations.