Impact of Alternative Fuels on Emissions Characteristics of a Gas Turbine Engine – Part 1: Gaseous and Particulate Matter Emissions

Abstract

Growing concern over emissions from increased airport operations has resulted in a need to assess the impact of aviation related activities on local air quality in and around airports, and to develop strategies to mitigate these effects. One such strategy being investigated is the use of alternative fuels in aircraft engines and auxiliary power units (APUs) as a means to diversify fuel supplies and reduce emissions. This paper summarizes the results of a study to characterize the emissions of an APU, a small gas turbine engine, burning conventional Jet A-1, a fully synthetic jet fuel, and other alternative fuels with varying compositions. Gas phase emissions were measured at the engine exit plane while PM emissions were recorded at the exit plane as well as 10 m downstream of the engine. Five percent reduction in NO(x) emissions and 5-10% reduction in CO emissions were observed for the alternative fuels. Significant reductions in PM emissions at the engine exit plane were achieved with the alternative fuels. However, as the exhaust plume expanded and cooled, organic species were found to condense on the PM. This increase in organic PM elevated the PM mass but had little impact on PM number.

Challenges and Solutions for Utilization of Bioliquids in Microturbines

“…HEFA process includes the production of HRJ (Hydrotreated Renewable Jet fuel), already used in commercial flights as drop-in fuel. The use of HRJ as fuel for APU-or small scale gas turbine was largely studied in literature [22,[33][34][35], with no significant modifications to commercial technologies. The sustainability of advanced biofuels is strictly related to net GHG reduction across each "value chain" (the specific combination of sustainable feedstock, conversion process and final products), with no "negative effect" on biodiversity or land use.…”

PM emissions measurements of in-service commercial aircraft engines during the Delta-Atlanta Hartsfield Study

“…Missouri University of Science and Technology (Missouri S&T) has developed a mobile laboratory optimized for aircraft engine exhaust PM characterization using extractive sampling techniques, which have been used in a number of field measurement campaigns (Lobo et al, 2007(Lobo et al, , 2011(Lobo et al, , 2012a. The instrumentation onboard the Missouri S&T mobile laboratory included the Cambustion DMS500, a fast particulate spectrometer (Reavell et al, 2002) relying on electrical mobility for particle sizing (Biskos et al, 2005), to gather real-time size distribution information and total particle number concentration of engine exhaust PM over the particle size spectrum from 5 nm to 1000 nm.…”

Demonstration of a Regulatory Method for Aircraft Engine Nonvolatile PM Emissions Measurements with Conventional and Isoparaffinic Kerosene fuels

“…Sasol's IPK is used to blend semi-synthetic jet fuel approved for use by both United Kingdom Ministry of Defence's DEF STAN 91-91 [7] and ASTM D1655 [8]. Aircraft engines burning alternative fuels have shown a dramatic reduction in their PM emissions [9][10][11][12][13][14]. The impact of using alternative fuels in mixed turbofan engines <26.7kN rated thrust on nvPM emissions employing the standardized measurement system has not been previously explored.…”