MDI Emissions Reporting Guidelines for the ... - Polyurethanes

MDI Emissions Reporting Guidelines for the Polyurethanes Industry
L con = K con * n con * K mdi * t pr * 2.205 lb/kg
Lcon = the annual losses from connectors in lb/yr
ncon = the number of connectors
Kmdi = adjustment factor to the vapor pressure that is a function of MDI
concentration in the feedstock and the temperature
tpr = the total time in hours/year that the process is operating
Total emissions can then be estimated from the following expression:
E tot = L gas + L liq + L pump + L con
5.0 Calculating Emissions from Enclosed Processes (Based on Cavity Size)
To estimate emissions from enclosed processes when the volume of the mold is known or
can be determined. The emissions from the process will correspond to the total volume of
air displaced from the molding operations at the temperature of the process. A reasonable
worst case estimate of emissions can be made based on the volume of the mold cavity, the
number of pieces produced per year and the maximum process temperature.
The enclosed process losses can be estimated from the following expression:
Where:
L c = V air * (1 / 359) * (273.15 / T proc ) * (VP mdi / 760) * M w * K mdi
Lc = the emissions from the enclosed process in lb/yr
Vair = the annual volume of displaced air in ft3 /yr
Tproc = the process temperature in K. This is the maximum temperature of the MDI
tack-free time
VPmdi = the vapor pressure of MDI in mm Hg at process temperature
Mw = 250.26 (this is the molecular weight of MDI)
Kmdi = the 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
6.0 Calculating Emissions from Enclosed Processes (Based on Foam Density)
To estimate emissions from enclosed processes when the volume of the mold is not known or
when a large number of different cavity or mold sizes are filled each year. For this situation
the emissions can be estimated from:
1. The density of the cured foam.
2. The total weight of the MDI-based component in the foam.
3. The Temperature of the foam at the tack-free time during the curing process.
The enclosed process losses can be estimated from the following expression:
D-5