MDI Emissions Reporting Guidelines for the ... - Polyurethanes

Where:
Therefore:
MDI Emissions Reporting Guidelines for the Polyurethanes Industry
Ciso = the % of isocyanate feedstock in the total formulation
Fmdi = the fraction of free MDI remaining in the mold. The free MDI is assumed to
be 0.01(1% of the initial MDI remains unreacted during this step
Tso = the total time of operation in hrs/yr
359 = the molar volume of an ideal gas in ft3 /lb-mole @ 0 o
C and 1-atmosphere
60 = time, minutes/hr
Vair = 20,000 cfm*(273.15 o
K /383.15 o
K) = 14,258 acfm
ppmv = (0.03898/760)*(1,000,000) = 51.3 ppmv
MW = 250.26
Kmdi = 1.0
Ciso = (29,838lbs MDI/725,000 lbs Total feed) = .04
Fmdi = 0.0001
Tso = 8760 hrs/yr
359 = the molar volume of an ideal gas in ft3 /lb-mole @ 0 o
C and 1-atmosphere
60 = time, minutes/hour
Lmp = (14,258 acfm)*(60min/hr)*(51.3ppmv/1000000)*(250.26)*(0.04)*(1.0)*
(8760)* (0.0001)
L mp = 1.07 lbs/yr
Using the same approach for the shakeout step, the estimated emissions are:
Lso = the emissions in lb/year from the shakeout and mold pour step
Vair = the exhaust airflow rate in ft3 /min (at stack temperature)
ppmv = the saturated concentration of pure MDI in air (in ppmv) at the stack
temperature (Tst ). It is directly determined from the vapor pressure
MW = the molecular weight of MDI (250.26)
Kmdi = adjustment factor to the vapor pressure that is a function of the MDI/PMDI
ratio in the isocyanate feedstock and the temperature. The value of Kmdi is
1.00 for pure MDI
Ciso = the % of isocyanate feedstock in the total formulation
Fmdi = the fraction of free MDI remaining in the mold. The free MDI is assumed to
be 0.01 (1% of the initial MDI remains unreacted during this step)
Tso = the total time of operation in hrs/yr
359 = the molar volume of an ideal gas in ft3 /lb-mole @ 0 o
C and 1-atmosphere
60 = time, mins/hr
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