DEQ-CFW_00087877

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DuPont - Fayetteville Works - Butacite® Date: April 28, 2005
2004 SARA Title III Report Page No. 30 of 33
2004 AIR EMISSIONS INVENTORY
PVA DISSOLVER TANK
EMISSIONS DETERMINATION
Vapor Displaced per Batch
Dissolver Tank Volume = 7500 gallons Tank Temperature = 91 °C
Displaced vapor associated with filing dissolver tank and reactor feed tank:
= 15000 gallons
Displaced vapor associated with heating the dissolver tank:
PH O at 91 °C — Ph?O at 20°C ) x Vapor Space Volume = ( 546 —17.5 ) ( 7500) = 5216 gallons
Atmospheric Pressure 760
Where: PH2O at 91 °C = Vapor pressure of water at 91 °C = 546 mmHg
PHZO at 20°C = Vapor pressure of water at 20°C = 17.5 mmHg
Vapor Space Volume = Tank Volume = 7500 gallons
Total displaced vapor per batch = 15000 gallons + 5216 gallons = 20216 gallons = 2703 ft3
Methanol (VOC) Emissions per Batch
Methanol emissions per batch are calculated based on the total moles in the displaced vapor
multiplied by the methanol concentration measure in the tank vent (1200 ppm).
Methanol concentration = 1200 ppm by volume
Mole fraction of water in the air over the dissolver tank
= 546 mmHg + 760 mmHg = 0.718 mole H2O per mole of air
Calculate the molar density in the air over the tank ( assume air is at 91°C )
= Dmole = P / RT where: P = 1 atm; R = 0.082 atm-L / mole-°K; T = 551 °K
= 0.0335 g-mole / L
= 0.0021 lb -mole / ft3
Total pound -moles emitted per batch are calculated as:
= 2703 ft3 / batch x 0.0021 lb -moles / ft3 = 5.651b-moles per batch
DEQ-CFW 00087877