EPA updates guidance on corn kernel fiber ethanol production

By Erin Voegele | September 29, 2022

The U.S. EPA on Sept. 28 released updated guidance that describes three additional ways ethanol plants that co-process corn kernel fiber and corn starch can demonstrate the resulting volume of cellulosic biofuel produced.

The new guidance supplements guidance released in May 2019 that focused on quantifying an analytical method for determining the cellulosic converted fraction of corn kernel fiber co-processed with starch. The 2019 guidance was widely criticized by the ethanol industry for stifling innovation for second generation fuels. The EPA said the updated guidance benefits from recent scientific advancements, including work conducted by the U.S. Department of Energy’s National Renewable Energy Laboratory.

“The intent of this guidance is to explain our interpretation of the regulatory requirements and to articulate clear criteria for the types of analysis and demonstrations that EPA believes can be accepted for registration under the program,” the EPA said in the guidance document, noting that the new guidance reflects NREL’s work “to develop a public method which addresses the analytical concerns identified in the 2019 guidance and includes consideration of recently released reference materials by the National Institute of Standards and Technology.”

The guidance outlines three new ways companies can satisfy Renewable Fuel Standard registration requirements for corn kernel fiber, including adoption of the DOE/NREL method; demonstration of reasonable accuracy by returning comparable cellulose values to the NIST reference materials using a non-voluntary consensus standards body (non-VCSB) method; or use of advanced analytical technologies, such as mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR), as identified by DOE/NREL in its analytical method and validation.

Growth Energy is applauding release of the updated guidance. “We’re pleased to see EPA update its guidance for cellulosic biofuel from kernel fiber, a move that provides additional flexibility for bioethanol producers and the potential to accelerate stalled registrations for cellulosic biofuels,” said Emily Skor, CEO of Growth Energy. “Approval of these registrations is important to fulfilling the goals of the Renewable Fuel Standard and to help further decarbonize the transportation sector. We look forward to further reviewing EPA’s guidance with our members.”

A full copy of the new guidance is available on the EPA website