Developing a supply chain model for sustainable aviation fuel using logging residues in Georgia, United States

Abstract

Sustainable aviation fuel (SAF) as a drop-in fuel from biomass feedstocks can reduce carbon emissions and provide resiliency to the aviation sector in light of the volatile nature of conventional aviation fuel (CAF) prices. This study aims to develop a supply chain model for SAF derived from unutilized logging residues across Georgia, a prominent forestry state located in the southern region of the United States. We employed a mixed-integer linear programming (MILP) model to minimize the total discounted cost of the SAF supply chain using the Ethanol-to-Jet (ETJ) production pathway over ten years of operation. Three SAF demand scenarios were selected, i.e., meeting 20 % (high), 10 % (medium), and 5 % (low) of total SAF demand at the Hartsfield-Jackson Atlanta International Airport. Results indicate a unit production cost of US $1.92 L⁻¹, US $2.03 L⁻¹, and US $2.25 L⁻¹ for the high, medium, and low demand scenarios, respectively. Over a period of ten years, to produce 3.74, 1.87, and 0.94 billion liters of SAF in scenarios A, B, and C, respectively, 38.5, 19.2, and 9.6 million Mg of logging residues are required. The capital investment and operating cost at biorefineries accounted for an average of 77 % and 22 % of the total unit cost, respectively, across scenarios. The GHG intensity of the SAF was 767 g CO₂e L⁻¹ on average across scenarios, providing about 70 % of carbon savings relative to CAF. The supply chain model suggested 54 biomass processing units (BPUs) and 13 bio-refineries across Georgia under the high demand scenario, 27 BPUs and 7 bio-refineries under the medium scenario, and 14 BPUs and 4 bio-refineries under the low SAF demand scenario. Our study is expected to provide new insights into the emerging market of SAF in Georgia and beyond.