MDI Emissions Reporting Guidelines for the ... - Polyurethanes

MDI Emissions Reporting Guidelines for the Polyurethanes Industry
Where:
Lfd = emissions lb/yr
Vair = annual volume of displaced air in ft3 /year
Tproc = process temperature in K (maximum temperature of the MDI)
VPMDI = vapor pressure of MDI in mm Hg at process temperature
Mw = 250.26 (this is the molecular weight of MDI)
KMDI = adjustment factor to the vapor pressure that is a function of MDI concentration
in the feedstock and the temperature
359 = the molar volume of an ideal gas in ft3 /lb-mole @ 0 o C and 1-atmosphere
Step I: Calculate Annual Volume of Displaced Air (V air )
Vair = (Amount of material processed/year)/Foam Density
Vair = (1.05 x 10 +7 lbs/yr)(1/2.25 lbs/ft3 V air = 4.67 x 10 +6 ft 3 /yr
Step II: Calculate Process Temperature in K
The process temperature is 78 o F or;
T proc = 298.7 K
Step III: Determine vapor Pressure of MDI @ 298.7 K (VP MDI )
The vapor pressure @ 298.7 K is 1.072 x 10 -5 mm
Step IV: Determine Adjustment factor (K MDI )
To determine adjustment factor (KMDI ), the percent of MDI in the blend must be determined. The ratio of
polyol to MDI/PMDI is 93/100. Therefore, the percentage of MDI/PMDI is:
%MDI/PMDI = (100/(100 + 93)) * 100
%MDI/PMDI = 51.8 %
The percent MDI in the MDI/PMDI mixture is 52%. Therefore the percent MDI in the blend is equal to:
%MDI = (51.8) * (52.0)
%MDI = 26.9
Adjustment factor @ 298.7 K and 26.9% MDI is 0.35
Therefore:
Lfd Lfd =
=
Vair * (1 / 359) * (273.15 / Tproc ) * (VPMDI / 760) * Mw * KMDI (4.67 x10 +6ft3 /yr.)(1/359)(273.15 K /298.7 K)(1.072 x 10 –5 mm/760)
(250.26)(0.35)
Lfd = 0.015 lbs /yr
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