Impact of Sustainable Aviation Fuel on Particulate and Non-CO₂ Emissions from Gas Turbine Engines

This study investigates the particulate matter (PM) and gaseous emissions from aviation fuel combustion, focusing on the performance of conventional JetA1 and alternative fuels such as HEFA (Hydroprocessed Esters and Fatty Acids) and HEFA blended with SAK (Synthetic Aromatic Kerosene). The experimental analysis revealed a substantial reduction in particulate emissions with the use of HEFA and its blends. HEFA alone demonstrated a 30–50% reduction in PM mass concentration compared to JetA1, attributed to its lower aromatic content. While HEFA blends with SAK showed similar trends, the reduction diminished at higher blend ratios due to increased fuel viscosity impacting atomization and combustion efficiency. The study also highlighted variations in particle characteristics, with smaller particles produced by HEFA and its blends exhibiting higher active surface areas. This is significant, as smaller particles provide a larger surface area for a given volume fraction, potentially influencing emission reactivity and environmental impact. Further, emissions were found to decrease under full-load conditions due to enhanced combustion efficiency. Advanced measurement techniques, including ELPI (Electrical Low-Pressure Impactor) and LII (Laser-Induced Incandescence), provided complementary data, with consistent trends observed across instruments despite differences in total values. Spatial profiling of exhaust plumes identified non-uniform emission patterns linked to injector performance, underscoring the importance of optimized nozzle design and maintenance. These findings demonstrate the potential of HEFA and its blends to significantly reduce aviation emissions while revealing challenges associated with fuel viscosity and injector performance. The study offers valuable insights into sustainable aviation fuel development, contributing to cleaner aviation technologies and compliance with stringent emission regulations.