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Emissions Quantification Methodology Report: ACRP 02-80 Quantifying Emissions Reductions at Airports from the Use of Alternative Jet Fuel Emissions Quantification Methodology Report Page 6 1.0 Introduction One of the most challenging environmental issues facing the aviation industry today is the impact of jet fuel emissions on the global climate. As a result, airlines throughout the world have committed to reducing their emissions-driven climate impacts. The primary means for reducing these impacts over the long term is through use of sustainable alternative jet fuels (SAJF) produced from non-petroleum sources, which reduce life-cycle greenhouse gas (GHG) emissions. Emissions testing conducted to date shows that, in addition to reducing life-cycle GHG emissions, SAJF also impacts emissions of other pollutants. Sulfur oxides (SOx) and particulate matter (nvPM) emission reductions are particularly significant. Emissions of other air quality pollutants including carbon monoxide (CO), unburned hydrocarbons (UHC), hazardous air pollutants (HAP), and nitrogen oxides (NOx) are also reduced, to a lesser extent, or at least do not increase. These additional emissions benefits may be highly valued by airports. The air quality emissions reductions from SAJF use could become an important component of airlinesâ commitment to supporting airportsâ sustainability goals. These benefits could improve relations with airport workers and the communities near airports that may be concerned with local air quality or could give airports flexibility to grow under State Implementation Plan (SIP) constraints. For these reasons, use of SAJF to reduce aircraft emissions will become significantly more important in coming years. Capturing the air quality benefits in a way that is useful to airports requires understanding how SAJF reduce pollutant emissions, quantifying the reduction, and demonstrating the impact through an easy-to-use tool that airports can apply to their emissions inventories. This document is organized as follows. Section 2 describes the emissions impact quantification methodology. Section 3 summarizes the impact quantification factor, uncertainty functions, sample impact factors, and uncertainties at 50% SAJF blend. Section 4 describes in detail the pollutant-specific analysis used to develop the impact quantification factor and uncertainty functions. Section 5 describes the results of the airport emissions inventory impact analysis which estimates the reduction in pollutant species across airports with different characteristics in terms of size and operations mix. Section 6 provides guidance to use SAJF impact factors for emissions inventory and dispersion modeling at airports. Section 7 summarizes all available emissions data. Section 8 provides instructions to use the Alternative Jet Fuel Assessment Tool PATH TO IMPACT FACTOR QUANTIFICATION â¢ Primary metrics included engine type, engine operating condition, fuel composition, blend percentages, atmospheric conditions, etc. â¢ The tabulated data revealed that in many cases the engine specific emissions may be dependent on three primary metrics: fuel composition, engine power, and fuel type. â¢ There was insufficient data to allow the fuel composition or engine-fuel-power specific dependency to be parameterized with any statistical significance. â¢ The power complexity was addressed by developing a weighted average impact based on the ICAO LTO cycle fuel burn values. â¢ The ICAO LTO cycle was designed to capture normal aircraft/airport operations, and hence can be used to normalize typical power usage. â¢ The fuel-type and engine-type complexities were addressed by incorporating them into the uncertainty analysis accompanying the impact factor quantification.