by Sustainable aviation fuel (SAF), derived from renewable sources like biomass and agricultural waste, holds immense potential to decarbonize the aviation sector. However, its widespread adoption is yet to materialize, as it accounts for less than 1% of the aviation industry’s fuel consumption, while contributing approximately 3% to global greenhouse gas (GHG) emissions. To promote commercial use, it is essential to develop cost-effective and energy-efficient SAF production methods.
Scientists at the Argonne National Laboratory Supplies have introduced a groundbreaking technology that produces a cost-competitive SAF, potentially reducing GHG emissions in the aviation industry by up to 70%. The team employed Argonne’s life cycle and techno-economic models to analyze the environmental impacts and economic viability of the SAF.
The study, published in ACS Sustainable Chemistry & Engineering, reveals that a novel methane arrested anaerobic digestion (MAAD) technology converts high-strength organic wastewater into volatile fatty acids, which can be upgraded to SAF. Volatile fatty acids serve as crucial precursors for SAF production and can significantly contribute to decarbonizing the aviation industry.
Haoran Wu, an Argonne postdoctoral researcher, stated, “Volatile fatty acids from waste streams can make biofuel production more cost-effective and sustainable.” Argonne’s technology uses a membrane-assisted bioreactor to enhance the production of volatile fatty acids.
The research advances the goals outlined in the DOE’s Sustainable Aviation Fuel Grand Challenge, which aims to increase SAF production to three billion gallons by 2030 and meet 100% of commercial jet fuel demand by 2050.
Instead of relying on traditional feedstocks like fat, oil, and grease, scientists employed carbon-rich wastewater from breweries and dairy farms as a feedstock for their innovative technology. The technology strips organic carbon from these high-strength waste streams, making low-carbon sustainable fuel for the aviation industry.
Taemin Kim, an Argonne energy systems analyst and study author, explained, “Both wastewater streams are rich in organics, and it is carbon-intensive to treat them using traditional wastewater treatment methods. By using our technology, we are not only treating these waste streams but making low-carbon sustainable fuel for the aviation industry.”
Argonne’s technology also breaks new ground in converting waste streams to SAF. While anaerobic digestion is an established technology for converting biomass to methane and then to biofuel, the MAAD technology focuses on the production of volatile fatty acids and lactic acid. However, lactic acids limit the production of SAF from volatile fatty acids. The Argonne MAAD technology overcomes this limitation to increase volatile fatty acid yield.
In another novel innovation, scientists developed an electrochemical separation method to enhance the membrane-assisted MAAD technology. This in-situ product recovery process increases retention time in the membrane-assisted digesters, allowing resilient microbial communities with abundant butyric acid producers and increasing acid productivity and concentration, thereby decreasing acid production cost and acid toxicity.
Urgun Demirtas, a principal investigator on the research and the department manager of Sustainable Materials and Processes at Argonne, stated, “We developed an in-situ product recovery process to increase retention time in the membrane-assisted digesters, which allowed resilient microbial communities with abundant butyric acid producers and increasing acid productivity and concentration, hence decreasing acid production cost and acid toxicity.”
Using the process models, scientists conducted a techno-economic and life cycle analysis of the waste-to-SAF pathways and compared them to conventional jet fuel produced from fossil fuel. The life cycle analysis was conducted using Argonne’s R&D Greenhouse gases, Regulated Emissions, and Energy use in Technologies (R&D GREET) model to evaluate GHG impacts from production to end use.
The study reveals that the waste-to-aviation fuel pathway significantly reduces carbon emissions compared to conventional jet fuel. Additionally, it expands the use of lesser-used waste materials at a time when demand for typical bio-feedstock for SAF results in a shortage.
While research will continue, ultimately, scientists hope to commercialize the patent-pending process and scale the technology for widespread use.
Wu concluded, “Designing a membrane-assisted technology that achieves a 70% reduction in greenhouse gases at a cost comparable with conventional jet fuel is a significant advancement. We will continue working to enhance sustainability and begin exploring other feedstock materials to use with our technology.”
Pahola Thathiana Benavides Gallego, an Argonne principal energy systems analyst, also served as a principal investigator on the research.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
