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FORM D5 — ATTACHMENT
TECHNICAL ANALYSIS IN SUPPORT OF PERMIT APPLICATION
DuPont PVF Manufacturing Facility
Potential to Emit Determination — Volatile Organic Compounds (VOC)
Typically the potential to emit ("PTE") determination is made with an assumption of the emission
source operating at its design capacity for 8,760 hours a year. However, the PTE for the PVF
Manufacturing Facility is significantly lower assuming 100% uptime than it otherwise would be,
as maintenance work accounts for roughly half or more of the yearly VOC emissions. Based on
guidance from the NC Division of Air Quality — Fayetteville Regional Office, an altered
calculation methodology, which assumes periodic maintenance cycles that increase emissions, will
be used to more accurately gauge the yearly emissions from the PVF manufacturing units.
VOC Calculations:
The VOC emissions for the PVF area are divided into four categories:
1) Slurry Flash Tank Emissions
2) Maintenance Header "Dispersion" Stack Emissions
3) Analyzer Emissions
4) Fugitive Emissions
Data was used from the April 2015 VOC Emissions Calculations spreadsheet to estimate the
average hourly emission rates for the Slurry Flash Tank and Analyzers while the plants were
operating. The Slurry Flash Tank emissions are estimated based on a mass balance of the PVF
process.
The GC Analyzer emissions are measured by flow meters. Below is the table of the Analyzer
emissions values including the flow meter tags used to calculate an average emissions rate while
in operation.
GC Analyzer Emissions: All values are in lb. VOC per hour
Flow Meter
3319FC
(lb/hr)
Flow Meter
3360FC
(lb/hr)
Flow Meter
4311FG
(ib/hr)
Total
VOC
(lb/hr)
PVF-1
0.029
0.029
0.523
0.581
PVF-2
0.019
0.017
0.163
0.199
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The Fugitive Emission hourly rate is calculated based on the number of valves, flanges, pumps,
and compressors located in the two manufacturing units that are in contact with the vinyl fluoride.
The supporting documentation for the fugitive emission rates for each manufacturing unit is
presented separately as a Form D attachment. In summary, the average fugitive emissions is
estimated to be 3.115 lb. VOC per hour for each unit, and a total of 6.23 lb. VOC per hour for the
facility.
The average hourly emissions of the Maintenance Header "Dispersion" Stack were calculated
using process data from the IP-21 data historian by selecting a time period during which each plant
was in continuous operation uninterrupted by maintenance work. This was identified by
continuous vinyl fluoride flow to the PVF Reactor indicating that operation of the plant was
ongoing (1551FC). The difference in the totalized emissions from the Dispersion Stack (5807FD)
was taken and used to calculate an hourly emission rate for while the plant was operating.
Regarding the substantial difference in emissions between the PVF-1 and PVF-2 Dispersion
Stacks, PVF-1's Dispersion Stack handles all the emissions associated with VF unloading as well
as VF transfer from the VF Storage Tanks to the process. This process of unloading VF Trailers
and decontaminating the associated equipment is performed on a regular basis.
Start
End
Difference
PVF-1 Time
4/8/2015 1:12
4/24/2015 16:13
399 hr 01 min
Emissions (lb.)
374.12
1002.14
628.02
Rate (lb/hr)
1.57
PVF-2 Time
4/1/2015 0:52
4/11/2015 9:50
248 hr 58 min
Emissions (lb.)
0
70.05
70.05
Rate (lb/hr)
0.28
Summary of Operating VOC Emissions:
PVF-1
PVF-2
Flash Tank (lb/hr)
0.55
0.71
Maintenance Stack (lb/hr)
1.57
0.28
Analyzers (lb/hr)
0.58
0.20
Fugitive Emissions (lb/hr)
1.97
1.97
Total VOC (lb/hr)
4.67
3.16
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In order to estimate the VOC potential emissions that occur, from the combination of operating
emissions and maintenance emissions, several assumptions were made based upon the plants'
operating history:
1) Each manufacturing unit undergoes 1 maintenance cycle each month.
2) Each maintenance cycle lasts approximately 2 days.
3) Each maintenance cycle results in 1500 lbs. of emissions.
These assumptions are meant to roughly reflect the maintenance work on the plant. Reactor
campaigns often run close to a month long hence the monthly maintenance cycle. Each
maintenance cycle lasts roughly two (2) days in order to accomplish the associated work. Some
variance does occur with shorter campaigns, but consequently shorter maintenance cycles as well
assuming more frequent cycles with less work dedicated to each one. The emissions estimate is
based on a rough average of the worst maintenance cycles associated with large process
decontaminations and unusual maintenance events.
The potential maintenance emissions for each manufacturing unit, both PVF-1 and PVF-2, are
determined as follows:
1,500 lb. VOC 1 maintenance cycle 12 months — 36,000 lb. VOC
maintenance cycle x month x year Year
The potential operating emissions assume 100% uptime minus the days associated with
ma- ntenance work, i.e. the two days per month for each maintenance eye' e are subtracted from the
number of days in a year, since no operating emissions would be occurring.
365 days [_2 days 12 months 341 days
year month X year year
The potential operating emissions for PVF-1 are determined as follows:
4.67 lb. VOC
hour
24 hours 341 days 38,219 lb. VOC
x day " year year
The potential operating emissions for PVF-2 are determined as follows:
3.16 lb. VOC
hour
24 hours 341 days
x day " year
25,861 lb. VOC
year
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The total potential VOC emissions for the two manufacturing units, PVF-1 and PVF-2, are the
sum of their respective potential maintenance and operating VOC emissions as shown in the
following table:
PVF-1
PVF-2
Potential Maintenance VOC Emissions
36,000 lb/yr
36,000 lb/yr
Potential Operating VOC Emissions
38,2191b/yr
25,861 lb/yr
Total Potential VOC Emissions
74,219 lb/yr
61,861 lb/yr
Total Potential VOC Emissions
37.11 ton/yr
30.93 ton/yr
The total potential VOC emissions for the DuPont Company — Fayetteville Works facility is the
sum of the potential VOC emissions from the two manufacturing units, PVF-1 and PVF-2.
Therefore, the potential facility -wide VOC emissions is 68.04 tons of VOC per year.
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