10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
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CAAFCER: Particle Number Emission Factors from In-Flight Aircraft Fueled with Jet A1 and Biofuel Mixtures
STEVEN TRAN, Jason S. Olfert, Anthony Brown, Fred J. Ghatala, University of Alberta
Abstract Number: 380 Working Group: Combustion
Abstract The aviation sector has begun using biofuels to reduce greenhouse gas (GHG) emissions in an effort to fight climate change. The use of biofuels also has impacts on aircraft particle emissions. The Civil Aviation Alternate Fuel Contrail and Emission Research (CAAFCER) project was designed to investigate the emission performance of high blend Hydrotreated Esthers and Fatty Acids (HEFA) biojet and conventional Jet A1 fuel in a real environment via flight emissions monitoring and fuel analysis from passenger airlines under contrail conditions. While the particle emissions of biofuels have been studied extensively in laboratory conditions (with emissions sampled from engines or stationary aircrafts on the ground), few studies have been undertaken with aircraft emissions sampled in the air during commercial (revenue) flights.
In CAAFCER, the source of emissions came from Air Canada A320 series aircrafts with NRC's CT-133 trailing behind to collect contrail data. The Air Canada flights were travelling between Toronto and Montreal. The Montreal-Toronto flights used the biofuel blend while the Toronto-Montreal flights used Jet A1 fuel. The CT-133 flew in and out of the contrails in order to capture contrail and background data. The NRC CT-133 was equipped with the necessary equipment to collect contrail and emissions measurements such as a TSI 3776 ultrafine particle counter (lower limit of 2.5 nm), TSI 7610 particle counter (lower limit of 10 nm), Thermo 42I NOx Analyzer, LII300 black carbon sensor, FSSP-100 ice particle sensor and LiCor 840A CO2 and water vapour sensor. A thermal denuder (Catalytic Instruments) with a bypass was installed upstream of the 3776 CPC. The thermal denuder allowed for the measurement of non-volatile particles and was only installed in-line to the 3776 CPC.
Particle number emission indices for particles greater than 2.5 nm (3776 CPC) and greater than 10 nm (7610 CPC) were calculated to evaluate the emission performance of Jet A1 and biofuel using the Fuel Flow Method 2 developed by Boeing. This method relates fuel flow to emission indices which are both publicly available. NOx emissions were used as a tracer to determine the dilution ratio of the contrail between the source aircraft and the CT-133 measurement aircraft. The dilution ratio was then applied to the concentration of particles measured by the particle counters to estimate the total number of particles emitted by the source aircraft.
Final results will include emission indices for both the 3776 CPC and 7610 CPC. The emission indices for total particles (volatile and non-volatile) greater than 10 nm will be calculated for the biofuel blend and Jet A1 fuel. The emission indices for particles greater than 2.5 nm will be calculated for both types of fuel as well as total and non-volatile samples for each type of fuel.