PNNL

Abstract

Ethanol is a promising feedstock for sustainable aviation fuel (SAF) production; however, conventional routes face significant energy and cost challenges, particularly due to the ethanol dehydration step to ethylene. This study leverages breakthrough experimental data to perform comprehensive techno-economic and life-cycle assessments of an innovative Ethanol-to-Jet process. The process employs a single-step catalytic conversion—enabled by advanced catalysts such as multifunctional Cu-ZrO2/SBA-16 to directly upgrade ethanol into a mixed olefin stream rich in n-butene. High selectivity toward n-butene offers key advantages: it simplifies downstream oligomerization into SAF-range hydrocarbons and enables the co-production of renewable n-butene alongside SAF. The analysis estimates a minimum fuel selling price as low as $2.50 per gallon, whether using corn ethanol or cellulosic ethanol from corn stover. Life cycle greenhouse gas emissions are projected to be as low as 10.6 g CO2eq/MJ SAF, representing over 70% reduction compared to conventional petroleum-based jet fuel. This one-step ethanol upgrading approach not only facilitates SAF and n-butene co-production but also provides operational flexibility. The ability to tailor product outputs allows the Ethanol-to-Jet process to adapt to varying feedstocks, incentive programs, and market dynamics, ultimately enhancing the economic viability of SAF production.