Beta Analytic director, Thierry Sam Tamers, submitted a public comment to the U.S. EPA advocating the use of ASTM D6866 to determine the biomass fraction of all heterogeneous fuels, not only for municipal solid waste. ASTM D6866 is a viable and accurate method that can be used for any type of sample whether solid, liquid, or gas.
Beta Public Comment (in its entirety):
In several sections of the proposed greenhouse gas reporting protocol, the EPA solicits comments on how to better quantify the biomass fraction of fuels. There is a readily available method called ASTM D6866 that can precisely and accurately quantify the biomass fraction of any type of fuel or material (gas, liquids, or solids).
This method is already adopted in the current reporting rule under the Tier 4 sampling protocol for municipal solid waste (pages 16636 to 16639). The EPA should broaden the use of this method for all fuels and materials since municipal solid waste is in essence a heterogeneous fuel / material.
The ASTM D6866 method is a standardized version for industrial use of radiocarbon dating, an analytical technique that was developed in the 1950s. Radiocarbon dating has been used for decades for dating archaeological artifacts. The same principles of dating (i.e. analysis of the carbon-14 atom) can also be used to measure the biomass component of fuels and materials. Biomass contains a well-characterized amount of carbon-14 that is easily distinguished from other materials such as fossil fuels that do not contain any carbon-14. Since the amount of carbon-14 in biomass is well known, a percentage of biogenic carbon (or in the case of a gas sample, biogenic CO2) can be calculated easily from the overall carbon atoms (or CO2) in the sample.
Although ASTM D6866 is now used throughout the world to measure biomass carbon / CO2, the origins of the method are American. It was written at the request of the USDA to satisfy legislation requiring federal agencies to prefer procurement from manufacturers using the greatest amount of biomass in their products (per the Farm Security and Rural Investment act of 2002). It was quickly established that radiocarbon dating was the only viable and accurate technique to make the determination of the biomass percentage. A working standard of radiocarbon dating for industrial use was completed in 2004 and is now cited in US Federal Law (7 CFR part 2902).
We believe that the ASTM D6866 method should be allowed for all heterogeneous fuels (i.e. those that contain a biomass fraction), not just municipal solid waste as cited in the current EPA greenhouse gas reporting rule. The EPA should expand the use of ASTM D6866 to include all heterogeneous and alternative fuels, including those referenced in Table C-2 on page 16640 of the EPA protocol.
Current regional protocols in the US, such as California’s AB 32 and the Western Climate Initiative, allow the use of ASTM D6866 for heterogeneous fuels. Below are two links where ASTM D6866 is cited for heterogeneous fuels in these two protocols:
California’s AB32: (Operator advised to use ASTM D6866 to determine CO2 emissions from the combustion of biomass, municipal solid waste, or waste-derived fuels with biomass.) Page 93, http://www.arb.ca.gov/regact/2007/ghg2007/frofinoal.pdf
Western Climate Initiative: (Operators who combust waste-derived fuels that are not pure biomass fuels shall determine the biomass fuel portion of CO2 emissions using ASTM D6866.) Page 56.
The European Union also allows the use of carbon-14 for measuring heterogeneous fuels, particularly for solid recovered fuels (SRF) and refuse-derived fuels (RDF). A carbon-14 method called CEN/TS 15747:2008 was developed for these types of fuels. It is almost identical to ASTM D6866. In fact, CEN/TS 15747:2008 cites ASTM D6866 as the premise for the method.
In 2007, the European Union published a FAQ for the EU Emissions Trading Scheme. On pages 16 and 17, carbon-14 is cited as an acceptable method for determining the biogenic fraction of heterogeneous fuels. Both ASTM D6866 and CEN/TR 15991:2007 (precursor to CEN/TS 15747:2008) are cited as acceptable carbon-14 methods.
Of course, it must be noted that Europe, California, and the Western Climate Initiative are not the only entities advocating the use of carbon-14 for heterogeneous fuels. Australia has also advocated its use, particularly for blended fuels. More information on the Australian protocol can be found here (see pages 117 to 119): https://www.betalabservices.com/wp-content/uploads/2018/08/22643921-Australia-NGER-Measurement-Technical-Guidelines-2009.pdf
Lastly, we would like to add that The Climate Registry’s Greenhouse Gas Reporting Protocol (please see page 65) also advocates the use of ASTM D6866 for biomass derived fuels. More information can be found at this link: http://www.theclimateregistry.org/wp-content/uploads/2014/11/TCR_GRP_Version_2.0-1.pdf
In light of the acceptance of the ASTM D6866 method for all heterogeneous fuels, we believe that the method should be allowed for all fuel types (i.e. gas, liquids or solids). The method works equally well for any material. Under certain circumstances (e.g. plant operators without CEMS), sampling the liquid or solid fuel itself might make more sense.
Of course, it is better to sample the final CO2 emission to determine the biogenic fraction from the combustion. Nonetheless, there are situations where analyzing the liquid or solid fuel is more economical, particularly if a representative sample can be submitted to the laboratory. This is often the case for the cement industry that is concurrently doing a host of other tests on their solid fuels. In that regard, the CEN/TS 15747:2008 method was created in Europe because the cement and paper/pulp industries are important users of SRF/RDF. They perform a host of tests on the SRF/RDF itself, along with the biogenic fraction determination.
On that note, the EU ETS FAQ cited before contains sampling recommendations on page 17 for liquid and solid fuels.
We would like to mention that the ASTM D6866 method would address perfectly the concerns cited in Section V, Subpart MM (pages 16569 to 16575). The method can determine unambiguously the biomass fraction of any fuel mix. For example, synthetic ethanol made from fossil fuels is chemically indistinguishable from bioethanol made from a biomass feedstock. ASTM D6866 is the only method that can determine precisely the percentage of biocarbon in the fuel mix. In a similar light, the ASTM D6866 can help resolve biocarbon fraction ambiguities in complex fuel mixes such as Hydrogenation-Derived Renewable Diesel (HDRD).
Lastly, we would like to suggest that the Tier 4 calculation allow the use of ASTM D6866 to calculate the biogenic CO2 fraction of any waste fuel or material, not just municipal solid waste. Since the ASTM D6866 method works equally well for any waste materials that contain a biomass fraction, the EPA protocol should include along with municipal solid waste, the use of ASTM D6866 for any waste materials, waste fuels, tires and alternative fuels in the Tier 4 biogenic calculation protocol.
In summary, we are advocating through this public comment that the EPA should allow the use of ASTM D6866 for all heterogeneous/alternative fuels (i.e. those that contain a biomass fraction) to determine the biogenic percentage. We are also advocating that plant operators be allowed to use the ASTM D6866 method to determine the biogenic fraction on the fuel itself when gas sampling is difficult. Contrary to emission factors or other methods (e.g. manual sorting), the carbon-14 method can accurately determine the biogenic fraction on any type of fuel (gas, liquid, or solid).
As can be seen with the national and international GHG protocols cited in this comment, the ASTM D6866 method has been accepted widely throughout the world for the measurement of the biogenic fraction of heterogeneous fuels. It is important that the EPA GHG protocol adopt similar reporting methods to ensure that CO2 emissions calculated in the United States are the same as the CO2 emissions calculated with these other protocols.
Beta’s public comment can be found in Regulations.gov Document ID EPA-HQ-OAR-2008-0508-2278.