Aircraft and Airport-Related Hazardous Air Pollutants: Research Needs and Analysis (2008) / Chapter Skim
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Pages 27-36
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From page 27... ...
Consideration of the emission factors, fuel flow rates, and times spent in mode indicate that the activity leading to the greatest gasphase HAP emissions (excluding particulate bound PAH species) is idling.
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From page 28... ...
. In the last few years, several emission measurement campaigns have significantly contributed to the total knowledge base of VOC emissions from commercial aircraft.
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From page 29... ...
appear to more accurately reflect true operational ground idle. 5.1.1.2 VOC Emissions Follow a Universal Scaling Law The ratio of any two VOCs in engine exhaust is approximately constant and independent of engine, power setting, fuel content, and ambient temperature.
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From page 30... ...
There are no measurements below 15°C as such knowledge of HAP emissions in cold temperatures is extremely limited. 5.1.1.4 Negligible Variation of VOC Emission Factors with Fuel Composition Variations in aromatic content and sulfur content were found to have a minimal effect on VOC emissions during APEX and are minor compared to variation with engine power and ambient temperature (Anderson, Chen et al.
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From page 31... ...
The shaded area outside of the circle represents the conservative underestimated amount, assuming a temperature of 18°C. 5.1.1.8 Reactive Aldehyde Emission Factors Due to the importance that this report and others assign to acrolein as an air toxic, a few details regarding its emission indices are included here.
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From page 32... ...
Over the course of 30 to 90 sec, the temperature of the engine reaches a stable condition and the emission indices of hydrocarbons and CO stabilize. As it pertains to total emissions accounting, any fuel that is pushed through the combustor before ignition is "unburned." The nature of these emissions will have the same speciation as evaporative emissions from the fuel stock.
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From page 33... ...
Thus at most airports the contribution to total VOC emissions is minor. There are many general aviation airports in the U.S.
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From page 34... ...
The area of each block represents the total VOC emissions from that phase of a landing take-of cycle. VOC emissions are dominated by the idle phase.
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From page 35... ...
Nevertheless, it is unclear if the off-road inventories used are appropriate for airport GSE fleets. There are few peer-reviewed publications in the literature regarding GSE emission factors.
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From page 36... ...
Although there are large variations in the size of stationary source VOC emissions in airport emission inventories, these inventories all indicate that HAP emissions are negligible and would have to be several orders of magnitude higher than currently believed for these sources to constitute a significant (>10%) source of HAPs.
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