MDI Emissions Reporting Guidelines for the ... - Polyurethanes

MDI Emissions Reporting Guidelines for the Polyurethanes Industry
The enclosed process losses can be estimated from the following expression:
Where:
L fd = V air * (1 / 359) * (273.15 / T proc ) * (VP MDI / 760) * M w * K MDI
Lfd = emissions lb/yr
Vair = annual volume of displaced air in ft3 /yr
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 )
V air = (Amount of Material Processed/year)/Foam Density
V air = (6.0 x 10 +6 lbs/yr)/(1.9 lbs./ft 3 )
V air = 3.2 x 10 +6 ft 3 /yr
Step II: Calculate Process Temperature in K
The process temperature is of 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 (K MDI ), the percent of MDI in the blend must be
determined. The ratio of Polyol to MDI/PMDI is 1/1. Therefore, the percentage of
MDI/PMDI is:
%MDI/PMDI = (1/(1+1) * 100
%MDI/PMDI = 50 %
The percent MDI in the MDI/PMDI mixture is 52%. Therefore the percent MDI in the
blend is equal to
%MDI = (51.8) * (50.0)
5-50