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时间:2010-05-10 19:48来源:蓝天飞行翻译 作者:admin
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HC emissions per pound of chemical consumed)
i - chemical present in deicing fluid (propylene glycol, ethylene glycol, or
other organic compound)
j - deicing operation (runway or aircraft deicing)
Equation H-10: Hydrocarbon Emissions For Deicing Operations
H-24
H3.3.2 Data Sources
H3.3.2.1 Quantity of Deicing Fluid Used
Quantities should be expressed in gallons and separated into fluid used for aircraft and runway
deicing. This data requirement should not pose a problem because the two operations are usually
maintained separately. This information may be obtained from the airport operator, deicing
contractor, or base operations department.
H3.3.2.2 Density of Deicing Fluid
This information may be obtained from the maintenance section, base operations department,
fluid manufacturer, or by calculation. The density should be expressed as pounds per gallon of
fluid. To calculate the density of the deicing fluid, Equation H-11 should be applied. The
equation is performed for each component, and results are totaled to obtain the total density.
D = S [Dw x (Ck/100) x SGk]
Where:
D - density of deicing fluid (pounds per gallon)
Dw - density of water (8.345 pounds per gallon)
Ck - concentration of component k in deicing fluid (percent)
SGk - specific gravity of component k; specific gravity is a dimensionless
ratio of the weight of the chemical to the weight of water
k - components of deicing fluid (water, ethylene glycol, propylene glycol,
urea, polymer additives, etc.)
Equation H-11: Density of Deicing Fluid
The concentration of each component in the deicing fluid should be obtained from the airport
operator, deicing contractor, or fluid manufacturer. Concentrations for all fluid components,
including water, should be obtained. Therefore if a solution is given as 48% propylene glycol,
then the remainder of the solution (52%) is assumed to be water.
Specific gravity for common deicing fluid components is given in Table H-6.
Fluid Component Specific Gravity (dimensionless)
Water 1.000
Ethylene Glycol 1.119
Propylene Glycol 1.036
Urea 1.323
Table H-6 : Specific Gravity of Common Deicing Fluid Components7
7 Source: CRC Handbook of Chemistry and Physics, 63rd Edition (Reference 92).
H-25
A 50% ethylene glycol deicing fluid is considered as an example. The weight of the ethylene
glycol component, following the above equation, is 8.345 pounds/gallon x (50/100) x 1.119 =
4.669 pounds ethylene glycol per gallon of fluid. The other component of the fluid is water,
which is also 50% of the fluid by weight. The weight of the water component is 8.345
pounds/gallon x (50/100) x 1.000 = 4.173 pounds water per gallon of deicing fluid. The total
density of the deicing fluid, then, is 4.669 + 4.173 = 8.842 pounds/gallon.
H3.3.2.3 Concentration of Chemical in Deicing Fluid (By Weight)
This information should be obtained from MSDS sheets, deicing contractor, or fluid
manufacturer. Common solutions are 50% propylene glycol in water or 50% ethylene glycol in
water. In many cases, different chemical formulations are used for runway and aircraft deicing.
H3.3.2.4 Emission indices
Emission indices for an ethylene glycol solution applied to a runway and to aircraft have been
calculated (Reference 19). An emission index of 0.0067 pounds HC emissions per pound of
ethylene glycol applied should be used for runway deicing, and an emission index of 0.00011
pounds HC emissions per pound of ethylene glycol applied should be used for aircraft deicing.
One should be careful to note that emissions are given per pound of ethylene glycol rather than
per pound of deicing fluid, which also contains water. Equation H-11 takes this into account by
employing a concentration factor. The emission indices given for ethylene glycol solutions may
also be applied to propylene glycol, which is somewhat less volatile than ethylene glycol.
H3.4 Solvent Degreasers
H3.4.1 Methodology
The use of organic solvents such as chlorinated hydrocarbons, petroleum distillates, ketones and
alcohol results in the evaporation of volatile organic compounds (VOC’s) or other hydrocarbons,
which are subsequently either disposed of as waste liquids or released to the atmosphere. If
water-based alkaline wash systems are used for degreasing, no evaporation of VOC’s or other
hydrocarbons occurs.
The methodology for estimating evaporative hydrocarbon emissions from the operation of
solvent degreasers is presented here. The methodology is based on the assumption that all solvent
consumed by a solvent degreasing unit is either disposed of as waste liquid or released to the
atmosphere as hydrocarbon emissions. The emissions to the atmosphere, therefore, are estimated
 
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