Comparison of PM Emissions from a Commercial Jet Engine Burning Conventional, Biomass, and Fischer–Tropsch Fuels

Abstract

Rising fuel costs, an increasing desire to enhance security of energy supply, and potential environmental benefits have driven research into alternative renewable fuels for commercial aviation applications. This paper reports the results of the first measurements of particulate matter (PM) emissions from a CFM56-7B commercial jet engine burning conventional and alternative biomass- and, Fischer-Tropsch (F-T)-based fuels. PM emissions reductions are observed with all fuels and blends when compared to the emissions from a reference conventional fuel, Jet A1, and are attributed to fuel properties associated with the fuels and blends studied. Although the alternative fuel candidates studied in this campaign offer the potential for large PM emissions reductions, with the exception of the 50% blend of F-T fuel, they do not meet current standards for aviation fuel and thus cannot be considered as certified replacement fuels. Over the ICAO Landing Takeoff Cycle, which is intended to simulate aircraft engine operations that affect local air quality, the overall PM number-based emissions for the 50% blend of F-T fuel were reduced by 34 ± 7%, and the mass-based emissions were reduced by 39 ± 7%.

Evaluation of Non-volatile Particulate Matter Emission Characteristics of an Aircraft Auxiliary Power Unit with Varying Alternative Jet Fuel Blend Ratios

“…In all cases, the size distributions were observed to be lognormal, and the geometric mean diameter (GMD) varied from 22.5nm to 49nm and the geometric standard deviation (GSD) ranged 1.58 -1.99. These results are consistent with those reported for other gas turbine engines burning conventional and alternative fuels [8,13,23,30,31]. For the three APU operating conditions, GMD decreased linearly with increasing fuel hydrogen content.…”

“…The reduction in EIm is greater than EIn for the corresponding fuel hydrogen content. This trend has also been observed for larger gas turbine engines at high thrust conditions [8,14] and a turboshaft engine [13] For a 50:50 blend of UCO-HEFA and Jet A-1, which would meet current ASTM specifications, the average reduction in nvPM number-based emissions was ~35%, while that for mass-based emissions was ~60%. However, the 2% and 5% UCO-HEFA fuel blend ratios are also of interest since they are representative of possible near to midterm 'real world' situation under a flightpath 2020 comingled supply scenario.…”

“…The potential to reduce both the impact of airport operations on local air quality [8] and aviation related GHG emissions on a life cycle basis [9,10] has provided additional impetus for the development of alternative jet fuels. Studies investigating the emissions of aircraft engines burning either neat FT fuels or 50:50 blends of FT and HEFA fuels with conventional jet fuel have shown that non-volatile particulate matter (nvPM) and sulfur oxides are dramatically reduced [8,[11][12][13][14][15].…”

“…Studies investigating the emissions of aircraft engines burning either neat FT fuels or 50:50 blends of FT and HEFA fuels with conventional jet fuel have shown that non-volatile particulate matter (nvPM) and sulfur oxides are dramatically reduced [8,[11][12][13][14][15]. However, the systematic evaluation of incremental variations in fuel composition of a single synthetic fuel on the production of nvPM emissions has not been explored.…”

Composition and Sources of the Organic Particle Emissions from Aircraft Engines

“…Motivated by these environmental concerns, researchers have performed studies to advance the current state of knowledge of gas turbine engine NO X Wormhoudt et al 2007;Wood et al 2008;Timko et al 2010a; Lee et al 2011;Santoni et al 2011), volatile organic compounds (Spicer et al 1994;Herndon et al 2006Herndon et al , 2009Knighton et al 2007;Yelvington et al 2007;Timko et al 2010c;Beyersdorf et al 2012), and PM emissions (Herndon et al 2005bLobo et al 2007Lobo et al , 2011Hagen et al 2009;Onasch et al 2009;Bulzan et al 2010;Timko et al 2010b). Partly because the knowledge base was limited and partly due to the potential impacts, particular emphasis has been placed on characterizing turbine engine PM emissions.…”