Based on the sources from ABLC 2025, there were significant discussions and insights into the progress of feedstock development for the bioeconomy. Here’s a summary of what we learned:

• Diverse Range of Feedstocks Explored: The discussions highlighted a wide array of potential feedstocks beyond traditional sources. These include:

◦ Woody Biomass: This was a prominent topic, with companies like SunGas Renewables focusing on utilizing forest residues such as sawmill residues, pre-commercial thinnings, and slash. Enen also uses mostly wood residues for their RTP process. The vast availability of woody biomass in the US was noted.

◦ Agricultural Residues: These are mentioned as a significant potential feedstock.

◦ Industrial Waste Gases: Companies like Sonata Bio are innovating by upcycling waste gases rich in carbon monoxide, CO2, and hydrogen from industrial processes into ethanol and proteins.

◦ Municipal Solid Waste (MSW): While acknowledged as a more complex feedstock, some companies like Aether Fuels are considering its use for gasification. Afne Energy also mentioned the ability to manage mixed waste with certain levels of plastics.

◦ Biogas: This is being utilized, particularly from dairy manure, as seen with the California Renewable Natural Gas project discussed by Jennifer Holmberg. Aether Fuels also lists biogas as a potential upstream carbon source.

◦Purpose-Grown Crops: Hexas is developing XanoGrass™ as a purpose-grown feedstock for various bioeconomy products.

◦ Algae and Novel Biomass: Afne Energy mentioned working with algae like sargassum. Biovers has tested a wide range of biomasses, including microalgae, sugarcane bagasse, French fry rejects, and bread waste.

◦ Manure: Oberon Fuels specifically focuses on manure-based feedstocks for producing renewable DME, methanol, and natural gas.

◦ Waste Ethanol: Oberon Fuels’ facility in Southern California uses waste ethanol from craft pulp mills.

◦ Cellulosic Feedstocks: The potential of cellulosic sugars is recognized, with companies like Jennifer Holmberg’s emphasizing a gradual transition towards them.

• Emphasis on Feedstock Flexibility and Agnosticism: Several companies, such as Biovers and Afne Energy, highlighted the feedstock flexibility of their technologies, suggesting they can utilize a broad range of biomass types. However, it was also pointed out that “no project is feedstock agnostic”.

• Addressing Feedstock Constraints: The traditional limitations and constraints associated with certain feedstocks, particularly for SAF production, were acknowledged. Biovers specifically positions itself as “SAF unconstrained” due to its unique process. The importance of securing reliable and sustainable feedstock supplies for long-term project bankability was emphasized.

Advancements in Feedstock Processing Technologies: Various technologies are being advanced to improve the utilization of diverse feedstocks:

◦ Gasification: SunGas Renewables utilizes gasification of woody biomass to produce clean syngas. Aether Fuels also includes gasification in their process for various feedstocks.

◦ Thermochemical Conversion (RTP, Cat-HTR): Ensyn employs Rapid Thermal Processing (RTP) for biomass conversion. Arbios, in collaboration with Licella, focuses on upgrading Cat-HTR™ biocrude derived from biomass.

◦ Fermentation: Biovers uses directed mixed culture fermentation for various feedstocks, including cellulosics. Sonata Bio employs gas fermentation for waste gases.

◦ Acid Hydrolysis: This technology is used by some, although concerns were raised about its novelty and cost-effectiveness.

◦ Pre-processing: Afne Energy highlighted the importance of feedstock management, including shredding, dewatering, and drying, to handle different biomass types effectively. Idaho National Laboratory (INL) is working on Wet Agricultural Value Enhanced Separations (WAVES) project to improve wet waste processing.

• Focus on “Unloved” and Underutilized Feedstocks: A recurring theme was the value of utilizing “unloved” feedstocks, such as waste gases and manure, which may have lower costs and can contribute to a circular economy.

• Regulatory Landscape and Feedstock Approval: The complexities of navigating the regulatory landscape for feedstock approval were discussed, with concerns raised about the EPA’s historical approach to woody biomass under the RFS. The importance of clearly defining sustainable harvest plans for woody biomass to qualify for renewable fuel credits was highlighted. Ensuring carbon credit availability and pathway-agnostic policies are crucial for feedstock development.

• Economic Considerations of Feedstocks: The cost of feedstocks is a critical factor for the economic viability of bioproduct production. Developing processes that can utilize low-cost, abundant feedstocks is essential. Projects that can create new revenue streams for feedstock providers, such as the dairy farmers participating in RNG production, demonstrate a positive trend.

• Integration with Existing Infrastructure: Utilizing existing infrastructure is seen as crucial for reducing costs and accelerating the deployment of bio-based technologies. This includes co-processing biocrudes in refineries and using existing pipelines for renewable natural gas.

• Need for Standardized Characterization: There’s a recognized need for developing standardized analytical methods and databases of physical properties for bio-based intermediates to facilitate their integration into refinery operations.

In summary, ABLC 2025 showcased significant progress in exploring and developing a diverse range of feedstocks for the bioeconomy. Innovations in processing technologies, a focus on underutilized resources, and efforts to navigate the regulatory landscape are key drivers in expanding the feedstock pool for renewable fuels and chemicals. The economic viability and scalability of these technologies are closely tied to the availability and cost-effectiveness of the chosen feedstocks.