Session: 03-08 Sustainable Aviation Fuels

Paper Number: 126719

126719 - Gaseous and Particulate Emissions of an Allison 250-C20B Turboshaft Engine Running on HEFA-SPK and its Jet A-1 Blends 

Aviation is widely recognized as a significant source of air pollutant emissions, encompassing gaseous byproducts such as CO2 and NOx, as well as particulate matter (PM), particularly in the form of soot.

In this study, comprehensive emission measurements were conducted on an Allison 250 C20B turboshaft engine to investigate sustainable aviation fuel (SAF) impact on emissions. Two conventional Jet A-1 fuel blends with 30 % and 50 % HEFA SPK (synthesized paraffinic kerosene derived from hydroprocessed esters and fatty acids) content together with 100 % neat HEFA SPK were tested regarding their emissions and compared against neat Jet A-1. The primary focus of the tests was on the quantification of ultrafine particulate matter in terms of both number and size distribution. The selection of distinct engine load settings was based on the thrust ratios specified in the International Civil Aviation Organization's (ICAO) Landing and Take-off-cycle (LTO-cycle).

Particulate matter emissions were characterized using multiple measurement techniques. These included the application of two distinct electrical mobility analyzers, namely the Grimm SMPS and Cambustion DMS500. To underscore the reliability of the findings an additional concentration particle counter (CPC) was utilized. For the assessment of gaseous emissions, a standard FTIR/FID system was utilized, a well-established method for measuring fundamental combustion products such as CO2, CO, unburned hydrocarbons (UHCs) and NOx.

The particle measurement systems revealed a decrease in both the number and size of particles with increasing HEFA SPK content. This decrease in particle number appeared linear for the 30% and 50% HEFA SPK blends and was more pronounced for the 100% pure HEFA SPK. Furthermore, a stronger reduction in particulate emissions was observed at lower load settings, such as Ground Idle (GI), compared to higher load settings like Take-off (TO). Detailed results of the gaseous emissions are also presented in the study.

Presenting Author: Alexander Rabl Technical University of Munich - Chair of Turbomachinery and Flight Propulsion

Presenting Author Biography: 2014-2018: Bachelor of Science in Mechanical Engineering (Technical University of Munich, Garching)
2018-2021: Master of Science in Aerospace Engineering (Technical University of Munich, Garching)
2021-now: PhD student and Munich Aerospace Scholarship holder (Technical University of Munich, Garching)

Authors:

Alexander Rabl Technical University of Munich - Chair of Turbomachinery and Flight Propulsion
Marius Rohkamp University of the Bundeswehr Munich - Institute for Aeronautical Engineering
Mohammad Reza Saraji-Bozorgzad University of the Bundeswehr Munich - Institute for Chemical and Environmental Engineering
Christian Helcig Technical University of Munich - Chair of Turbomachinery and Flight Propulsion
Reetu Sallinen Neste Corporation, Innovation
Jesse Vilja Neste Corporation, Innovation
Jan Bendl University of the Bundeswehr Munich - Institute for Chemical and Environmental Engineering
Thomas Adam University of the Bundeswehr Munich - Institute for Chemical and Environmental Engineering
Andreas Hupfer University of the Bundeswehr Munich - Institute for Aeronautical Engineering
Volker Gümmer Technical University of Munich - Chair of Turbomachinery and Flight Propulsion