(656c) Adsorptive Denitrogenation to Enable Sustainable Aviation Fuel Production

This study explores a critical separations process aimed at removing nitrogen compounds that act as pollutants and barriers in sustainable aviation fuel (SAF) production. Expected future SAF standards may require nitrogen levels below 2 ppm, presenting a significant challenge. Biomass-derived liquid fuels, such as biocrude from hydrothermal liquefaction, contain protein remnants that convert to nitrogen-containing compounds, leading to high nitrogen levels exceeding 10,000 ppm. Even after initial hydrotreatment, the jet fraction often retains over 1000 ppm of nitrogen. Four carefully selected adsorbents (Amberlyst 36 resin, Silica Gel, Zeolite Beta, and Activated Carbon) were evaluated for their nitrogen removal efficiency and recovery. Insights into adsorption mechanisms and rates were gained using first and second-order kinetic models, revealing a remarkable 99% removal efficiency for nitrogen-containing compounds. Silica gel demonstrated strong regeneration capabilities through solvent extraction or post-calcination methods. By analyzing adsorption isotherms and kinetics in batch and continuous flow modes, the study aimed to understand their commercial potential. Breakthrough testing and a technoeconomic analysis were conducted to determine a minimum selling price for fuels at $3.5/gge and a 70% reduction in greenhouse gas emissions compared to conventional production methods.