(561f) Process Design and Economics for Production of Sustainable Aviation Fuel (SAF) from Biomass Derived Intermediate

Sustainable aviation fuel (SAF) feedstocks and production technologies play an important role in decarbonizing aviation. Depending on the feedstock and technologies used to produce it, SAF can reduce life cycle GHG emissions significantly compared to conventional jet fuel. In effort to achieve United States’ goal to have net zero emissions by 2050, it is vitally important to advance the SAF production in the coming decades. On the other hand, while the demand for high performance jet fuel in the aviation industry is currently stands at 6.95 million barrels a day and is expected to increase with the demand for flights continually growing, in 2022, only 15.8 million gallons of SAF were produced. One of the key reasons for the low yield is due to the current high cost of manufacturing SAF. To this end, it is important to understand the feasibility and key economic drivers in order to develop a comprehensive strategy for scaling up technologies to produce SAF on a commercial scale across various regions in the U.S.

In this study, we investigated the alcohol-to-jet (ATJ) manufacturing processes, developed conceptual design, and perform techno-economic analysis (TEA) and sensitivity analysis. For the base case, 95% ethanol first undergoes dehydration to produce ethylene and water. The ethylene stream then undergoes oligomerization to produce longer chain olefins while the other stream is integrated with various heat exchangers further downstream as a coolant. The resulting product stream from the oligomerization is further separated. Propene and butene can be hydrogenated to produce propane and butane for sale and ethylene can be recycled back into the oligomerization feed. The higher-molecular-weight olefins are sent to a distillation column where the distillate and bottoms streams are also hydrogenated to produce natural gasoline and jet fuel, respectively. This process was scaled to produce 11 million gallons annually assuming continuous, year-round plant operation based on the current scale of mid-size refinery, Fulcrum Bioenergy. The minimum fuel selling price and impact of feedstock cost were determined following established approaches for cost analysis using n^th-plant project costing and financing. This study also explored various strategies to further reduce operating costs. These included scenarios involving the optimization of recycling streams and oligomerization reagents, minimizing the cost of feed streams, on-site hydrogen production and storage, as well as reducing the overall cost of feed streams. Finally, this study identified opportunities to advance the SAF production by developing an improved and more efficient refining process through integrated biorefinery design.