When developing your emission profiles for batch process vents as required in § 63.11925(g) , except as specified in paragraph (i) of this section, you must calculate emissions from episodes caused by vapor displacement, purging a partially filled vessel, heating, depressurization, vacuum operations, gas evolution, air drying, or empty vessel purging, using the applicable procedures in paragraphs (a) through (h) of this section.
(Eq. 1)
Where:
E = Mass of HAP emitted.
V = Volume of gas displaced from the vessel.
R = Ideal gas law constant.
T = Temperature of the vessel vapor space; absolute.
Pi = Partial pressure of the individual HAP.
MWi = Molecular weight of the individual HAP.
n = Number of HAP compounds in the emission stream.
i = Identifier for a HAP compound.
(Eq. 2)
Where:
E = Mass of HAP emitted.
V = Purge flow rate of the noncondensable gas at the temperature and pressure of the vessel vapor space.
R = Ideal gas law constant.
T = Temperature of the vessel vapor space; absolute.
Pi = Partial pressure of the individual HAP at saturated conditions.
Pj = Partial pressure of individual condensable compounds (including HAP) at saturated conditions.
PT = Pressure of the vessel vapor space.
MWi = Molecular weight of the individual HAP.
t = Time of purge.
n = Number of HAP compounds in the emission stream.
i = Identifier for a HAP compound.
j = Identifier for a condensable compound.
m = Number of condensable compounds (including HAP) in the emission stream.
Where:
Si = Saturation factor for individual condensable compounds.
Pi = Partial pressure of individual condensable compounds at saturated conditions.
PT = Pressure of the vessel vapor space.
A = Surface area of liquid.
V = Purge flow rate of the noncondensable gas.
Visat = Volumetric flow rate of individual condensable compounds at saturated vapor pressure.
Ki = Mass transfer coefficient of individual condensable compounds in the emission stream.
Ko = Mass transfer coefficient of reference compound (e.g., 0.83 cm/s for water).
Mo = Molecular weight of reference compound (e.g., 18.02 for water).
Mi = Molecular weight of individual condensable compounds in the emission stream.
n = Number of condensable compounds in the emission stream.
(Eq. 6)
Where:
E = Mass of HAP vapor displaced from the vessel being heated.
Navg = Average gas space molar volume during the heating process.
PT = Total pressure in the vessel.
Pi,1 = Partial pressure of the individual HAP compounds at initial temperature (T1).
Pi,2 = Partial pressure of the individual HAP compounds at final temperature (T2).
MWHAP = Average molecular weight of the HAP compounds calculated using Equation 13 of this section.
ni,1 = Number of moles of condensable in the vessel headspace at initial temperature (T1).
ni,2 = Number of moles of condensable in the vessel headspace at final temperature (T2).
n = Number of HAP compounds in the emission stream.
ln = Natural logarithm.
(Eq. 7)
Where:
Navg = Average gas space molar volume during the heating process.
V = Volume of free space in vessel.
PT = Total pressure in the vessel.
R = Ideal gas law constant.
T1 = Initial temperature of the vessel.
T2 = Final temperature of the vessel.
Where:
V = Volume of free space in vessel.
R = Ideal gas law constant.
T1 = Initial temperature in the vessel.
T2 = Final temperature in the vessel.
Pi,1 = Partial pressure of the individual HAP compounds at T1.
Pi,2 = Partial pressure of the individual HAP compounds at T2.
n = Number of HAP compounds in the emission stream.
Where:
E = Mass of HAP emitted.
[DELTA][ETA] = The number of moles of noncondensable displaced from the vessel, as calculated using Equation 10 of this section.
PT = Pressure in the receiver.
Pi = Partial pressure of the individual HAP determined at the exit temperature of the condenser or at the conditions of the dedicated receiver.
Pj = Partial pressure of the individual condensable (including HAP) determined at the exit temperature of the condenser or at the conditions of the dedicated receiver.
n = Number of HAP compounds in the emission stream.
i = Identifier for a HAP compound.
j = Identifier for a condensable compound.
MWHAP = The average molecular weight of HAP in vapor exiting the dedicated receiver, as calculated using Equation 11 of this section with partial pressures determined at the exit temperature and exit pressure conditions of the condenser or at the conditions of the dedicated receiver.
m = Number of condensable compounds (including HAP) in the emission stream.
Where:
[DELTA][ETA] = Number of moles of noncondensable gas displaced from the vessel.
V = Volume of free space in the vessel.
R = Ideal gas law constant.
T1 = Initial temperature of vessel contents, absolute.
T2 = Final temperature of vessel contents, absolute.
Pan = Partial pressure of noncondensable gas in the vessel headspace at initial (n = 1) and final (n = 2) temperature.
MWHAP = The average molecular weight of HAP in vapor exiting the dedicated receiver.
(Pi)Tn = Partial pressure of each HAP in the vessel headspace at initial (T1) and final (T2) temperature of the receiver.
MWi = Molecular weight of the individual HAP.
n = Number of HAP compounds in the emission stream.
i = Identifier for a HAP compound.
Where:
E = Emissions.
V = Free volume in vessel being depressurized.
R = Ideal gas law constant.
T = Temperature of the vessel, absolute.
P1 = Initial pressure in the vessel.
P2 = Final pressure in the vessel.
Pj = Partial pressure of the individual condensable compounds (including HAP).
MWi = Molecular weight of the individual HAP compounds.
n = Number of HAP compounds in the emission stream.
m = Number of condensable compounds (including HAP) in the emission stream.
i = Identifier for a HAP compound.
j = Identifier for a condensable compound.
ln = Natural logarithm.
Where:
E = Mass of HAP emitted.
PT = Absolute pressure of receiving vessel or ejector outlet conditions, if there is no receiver.
Pi = Partial pressure of the HAP at the receiver temperature or the ejector outlet conditions.
Pj = Partial pressure of condensable (including HAP) at the receiver temperature or the ejector outlet conditions.
La = Total air leak rate in the system, mass/time.
MWnc = Molecular weight of noncondensable gas.
t = Time of vacuum operation.
MWi = Molecular weight of the individual HAP in the emission stream, with HAP partial pressures calculated at the temperature of the receiver or ejector outlet, as appropriate.
Where:
E = Mass of HAP emitted.
B = Mass of dry solids.
PS1 = HAP in material entering dryer, weight percent.
PS2 = HAP in material exiting dryer, weight percent.
Where:
V = Volume of empty vessel.
R = Ideal gas law constant.
T = Temperature of the vessel vapor space; absolute.
Pi = Partial pressure of the individual HAP at the beginning of the purge.
MWi = Molecular weight of the individual HAP.
F = Flow rate of the purge gas.
t = Duration of the purge.
n = Number of HAP compounds in the emission stream.
i = Identifier for a HAP compound.
40 C.F.R. §63.11950