Carbon-14 Analysis Validates the Biogenic Content of Biofuels

By Jordan Turner, Marketing Coordinator, SGS Beta
Special to The Digest

The global market for biofuels is expected to grow to USD 207.87 billion by 2030 as demand for clean fuels grows and regulations are implemented.¹ Keeping up with this growth and regulatory developments requires renewable bioenergy industry professionals to employ accurate, well-established scientific tools to measure and validate the biogenic fraction of their biomass-derived biofuels. Carbon-14 biogenic content testing is an invaluable method that meets these industry needs. Testing is applicable for the measurement of a wide range of renewable products including biofuels, renewable diesel, fatty acid methyl ester (FAME), used cooking oil (UCO), hydrotreated vegetable oil (HVO), and renewable naphtha, among others. The data resulting from biogenic content testing reveals the precise fraction of carbon in a given sample that originates from biogenic (biomass-derived) sources. These results can be used by biofuel manufacturers, suppliers, and distributors in the pursuit of decarbonization, for regulatory compliance, and for research and development projects focused on achieving carbon neutrality.

Carbon-14 Analysis Measures Biogenic Content

Biogenic content testing is a precise tool for validating the biogenic carbon fraction of renewable fuels. Testing takes advantage of carbon-14 (¹⁴C), or radiocarbon, analysis methodology according to international standards ASTM D6866 and EN 16640. Analysis is conducted using an Accelerator Mass Spectrometer (AMS) instrument to measure the radioactive isotope carbon-14. This is a well-known method, discovered in the 1940s by Willard Libby and originally used for archaeological and paleontological studies. Since then, the applications of carbon-14 analysis have expanded into the biofuels industry as the same principles that make it suitable for dating archaeological artifacts also allow for biogenic content to be affirmed.

The carbon-14 isotope is only found in organic and inorganic carbon of renewable origin (including plant, animal, fungal, marine, and forestry materials). It is formed in the atmosphere and enters plants and animals via photosynthesis and the food chain. The carbon uptake process ends with the death of the plant or animal, at which time the process of radioactive decay begins. Carbon-14 has a detection limit of approximately 43,500 years, after which time the detectable amount of carbon-14 has decayed. Materials that originate from fossil-derived sources are too old to contain any carbon-14 and will not be measurable. Therefore, this method is a highly accurate option for verifying the biogenic content of biomass-derived biofuels.

The results obtained from biogenic content testing reveal the fraction of biomass-derived versus fossil-fuel derived carbon in biofuels. Results are reported as a percentage of biogenic content (Figure 1). Biofuel mixtures can also be measured with the biomass portion accurately verified. Any percentage between 1-99% indicates a blend of biogenic and fossil carbon. Samples with 0% biogenic content are wholly fossil-derived and those with 100% biogenic content are completely made of biomass.

Figure 1, Biogenic testing results reveal the % fossil carbon versus the % biogenic carbon in a sample.

Applications & Regulations

Biogenic content testing is recognized in the biofuels industry as an accurate method for validating the biogenic carbon content of biofuel blends. These analytical results provide useful data and provide biofuel producers and R&D teams with a highly accurate and easy to understand verification tool with uses in a number of areas. Refineries can also benefit from undertaking biogenic content testing. The data obtained through analysis provides precise ratios of biofuel blends which can be used to identify the portion of the blend that originates from bio-oil as opposed to petroleum feedstocks.

Another area in which biogenic content testing has been found to provide vital data is for validating the biomass content of sustainable aviation fuels (SAF). Because SAF is made from renewable and waste-derived feedstocks including waste oil, animal fats, and agricultural and forestry residue, the carbon-14 method is suitable for verifying the absence of fossil material. Additionally, biogenic content testing is beneficial for SAF produced by co-processing, such as renewable diesel.

Analysis supports efforts toward decarbonization and achieving net-zero goals by verifying that biofuel formulations were developed using renewable biomass feedstocks that are carbon-neutral, thus not adding new CO₂ to the atmosphere when burned. The precise nature of the results confirms the accuracy of biofuels blends, providing an exact percentage of biomass which allows R&D teams to optimize biogenic content over time. Additionally, analysis of biofuel samples provides third-party verification that can be used to comply with regulatory requirements and qualify for tax credits. ASTM D6866 biogenic content testing via carbon-14 analysis is required or recognized by several industry regulations such as the US EPA Renewable Fuel Standard (RFS)², Canada’s Clean Fuel Regulation (CFR)³, and the California Air Resources Board Low Carbon Fuel Standard (LCFS)⁴. Additionally, global regulations such as the Renewable Energy Directive (RED)⁵ also accept biogenic content testing methodology for their certification process.

Conclusion

Carbon-14 analysis has a robust background as an analytical methodology and is well-regarded by industry professionals and a number of regulatory programs for its accuracy and wide applicability when it comes to biogenic carbon content measurement in the biofuel industry. Biogenic content testing is based on globally recognized scientific standards and provides results in the form of an easily understood and precise ratio. This analytical method is indispensable as a third-party tool that biofuel industry professionals can rely on to support their goals as their industry continues to grow and develop over the coming decades. Biogenic content analysis provides the opportunity for effective monitoring of progress toward decarbonization and carbon-neutrality goals, obtaining tax credits and incentives, and ensuring compliance with evolving regulatory program requirements.

REFERENCES

1. 2024. “Biofuels Market Size, Share & Trends Analysis Report By Feedstock (Corn, Sugarcane), By Application (Transportation, Aviation), By Form (Solid, Liquid), By Product (Biodiesel, Ethanol), By Region, And Segment Forecasts, 2024 – 2030.” Grand View Research.
2. 2024. “Overview of the Renewable Fuel Standard Program.” United States Environmental Protection Agency.
3. 2023. “Clean Fuel Regulations.” Government of Canada.
4. 2025. “Low Carbon Fuel Standard.” California Air Resources Board.
5. 2025 “Renewable Energy Directive.” European Commission.