0154­
04­
010\
process
vent
reduction
mem.
doc
1
MEMORANDUM
TO:
Randy
McDonald,
U.
S.
Environmental
Protection
Agency,
OAQPS/
Sector
Policies
and
Programs
Division,
Coatings
and
Chemicals
Group
(
C504­
04)

FROM:
Roy
Oommen
and
Danny
Greene,
ERG
DATE:
June
2006
SUBJECT:
Process
Vent
Emission
Reduction
and
Control
Cost
Estimates
1.0
INTRODUCTION
The
purpose
of
this
memorandum
is
to
present
the
analyses
used
to
estimate
the
hazardous
air
pollutant
(
HAP)
emissions,
emission
reductions,
and
costs
associated
with
controlling
uncontrolled
process
vent
streams
at
hazardous
organic
NESHAP
(
HON)
sources.

These
uncontrolled
streams
are
classified
in
the
HON
regulation
as
Group
2
process
vents.

Section
2
presents
the
data
used
to
estimate
baseline
emissions
from
uncontrolled
process
vents.

Section
3
presents
the
methodologies
used
to
estimate
emission
reductions
and
control
costs.

2.0
BASELINE
DATA
Baseline
process
vent
data
on
existing
HON
facilities
were
collected
by
the
American
Chemistry
Council
(
ACC)
through
a
voluntary
survey
and
provided
to
EPA.
The
ACC
data
contained
site­
specific
information
for
the
base
year
1999
for
104
of
the
238
existing
HON
facilities.
Information
from
all
the
facilities
was
then
combined
into
one
database.
The
data
fields
in
the
database
are
presented
in
Table
2­
1.

The
ACC
survey
requested
that
process
vent
information
be
identified
as
either
controlled
or
uncontrolled.
However,
many
respondents
did
not
provide
this
information.
Such
process
vents
were
grouped
into
a
third
category,
unspecified
process
vents.
0154­
04­
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process
vent
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mem.
doc
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3.0
EMISSION
REDUCTION
AND
CONTROL
COST
ESTIMATES
For
this
analysis,
both
uncontrolled
vent
streams
and
unspecified
vent
streams
were
categorized
as
Group
2
streams.
This
assumption
regarding
the
unspecified
streams
provides
the
most
conservative
estimate
of
costs.
Additionally,
this
analysis
was
conducted
only
for
process
vent
streams
that
contained
at
least
one
HAP
with
a
high
lifetime
cancer
risk,
as
well
as
other
specific
pollutants
of
interest.
Collectively,
these
HAP
are
referred
as
HAPs
listed
in
Table
38
of
the
proposed
rule.

Table
2­
1.
Data
Fields
in
Process
Vents
Database
Source
ID
HON
Facility
ID
Chemical
Manufacturing
Process
Unit
ID
(
CMPU_
ID)

Latitude
Longitude
Emission
Type
HAP
Name
CAS
Number
Emission
Rate
(
kg/
yr)

Stack
Height
Stack
Diameter
Stack
Velocity
Stack
Temperature
Each
process
vent
was
identified
based
on
the
process
unit
associated
with
it,
as
well
as
by
unique
longitude
and
latitude,
stack
height,
stack
diameter,
stack
velocity,
and
stack
temperature.

3.1
Emission
Reductions
Emission
reductions
were
calculated
assuming
that
each
Group
2
vent
stream
would
be
controlled
using
a
combustion
device.
This
was
the
control
method
used
in
the
HON,
and
no
other
controls
were
identified
that
would
achieve
greater
emission
reductions
than
combustion.

The
destruction
efficiency
for
combustion
devices
was
assumed
to
be
98
percent,
based
on
0154­
04­
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process
vent
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mem.
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3
analyses
done
for
the
HON.
The
annual
emissions
reductions
of
each
from
controlling
each
Group
2
stream
was
calculated
using
the
following
equation:

ER
=
(
0.98)((
EHAP)(
H)(
1/
1000)

where:

C
ER
is
the
emission
reduction
of
each
HAP
in
the
vent
stream
(
Megagrams
per
hour),

C
EHAP
is
the
process
vent
HAP
emission
rate
(
kilograms
per
hour),

C
H
is
the
hours
of
operation
per
year.

3.2
Cost
The
capital
and
annual
cost
estimates
from
controlling
Group
2
streams
were
calculated
using
the
methodology
in
the
HON,
i.
e.,
using
the
total
resource
effectiveness
(
TRE)
concept.

The
TRE
index
is
a
measure
of
how
costly
a
particular
process
vent
is
to
control
(
the
higher
the
TRE
index,
the
more
costly
the
control).
For
each
process
vent,
the
TRE
was
calculated
using
the
following
equation
from
the
HON
regulation:

where:

C
EHAP
is
the
process
vent
HAP
emission
rate
(
kilograms
per
hour),

C
Qs
is
the
volumetric
flow
rate
(
standard
cubic
meters
per
minute,
scmm)
of
the
process
vent
at
a
standard
temperature
of
20
°
C,

C
HT
is
the
net
heating
value
(
mega
Joules
per
standard
cubic
meter,
MJ/
scm)
of
the
process
vent
stream,

C
ETOC
is
the
emission
rate
(
kg/
hr)
of
total
organic
carbon
(
TOC),
minus
methane
and
ethane
of
the
process
vent,
and
C
a,
b,
c,
and
d
are
coefficients
for
nonhalogenated
and
halogenated
vent
streams
(
taken
from
table
1
of
subpart
G
of
part
63).
0154­
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process
vent
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mem.
doc
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The
volumetric
flowrate
was
not
provided
in
the
survey
responses.
However,
it
could
be
estimated
using
the
stack
diameter
and
the
stack
velocity
from
the
following
equation:

Qs
=
(
 *(
Sd)
2/
4)(
Sv)

where:

C
Sd
is
the
stack
diameter
(
meters)

C
Sv
is
the
stack
gas
velocity
(
meters/
second)

Because
sufficient
data
(
total
speciated
organic
emissions)
were
not
available
for
each
process
vent
to
estimate
heating
value,
each
vent
stream
was
assigned
an
average
heating
value,
as
provided
in
the
HON
background
information
document
(
BID)
of
14.6
mega
Joules
per
standard
cubic
meter
(
MJ/
scm).
The
TOC
emission
rate
for
each
process
vent
was
estimated
by
dividing
the
HAP
emissions
by
an
average
HAP
to
VOC
ratio
from
the
HON
BID,
0.78.
The
nonhalogenated
and
halogenated
vent
stream
coefficients
(
included
in
Attachment
A)
were
assigned
based
on
whether
the
vent
stream
contained
a
halogenated
HAP.

Using
the
TRE
values,
the
total
annual
costs
(
TAC)
of
control
were
estimated
using
the
following
equation:

TAC
=
(
HAP
emission
reduction)($
3,000/
TRE)(
TRE)

This
equation
is
based
on
TRE
value
of
1.0
corresponding
to
a
cost­
effectiveness
value
of
approximately
$
3,000
per
Mg
of
HAP
reduced,
as
discussed
in
the
HON
BID.

The
total
capital
investment
(
TCI)
was
estimated
using
the
annualized
capital
costs
and
the
capital
recovery
factor.
The
annualized
capital
costs
were
estimated
by
assuming
that
the
annualized
capital
costs
account
for
40
percent
of
the
TAC.
This
assumption
was
based
on
costs
calculated
for
model
process
vent
streams
in
the
HON
BID.
The
annualized
capital
costs
are
also
equal
to
the
TCI
multiplied
by
the
capital
recovery
factor
(
CRF).
The
capital
recovery
factor
(
0.1097)
was
calculated
using
the
following
equation:

CRF
=
(
i(
1+
i)
n)/((
1+
i)
n­
1)
0154­
04­
010\
process
vent
reduction
mem.
doc
5
where:

i
=
the
interest
rate
(
7
percent
was
used
for
this
analysis),
and
n
=
repayment
period
(
years).

For
this
analysis,
the
interest
rate
chosen
was
7
percent
and
the
repayment
period
was
15
years.

Attachment
B
presents
the
summary
of
costs
and
emission
reductions
for
process
vent
streams
with
Table
38
HAP.
Table
B­
1
contains
results
for
unspecified
process
vent
streams.
Table
B­
2
contains
results
for
uncontrolled
process
vent
streams.

4.0
REFERENCES
1.
Hazardous
Air
Pollutant
Emissions
From
Process
Units
in
the
Synthetic
Organic
Chemical
Manufacturing
Industry­
Background
Information
for
Proposed
Standards,
Volume
1C­
Model
Emission
Sources,
Emission
Standards
Division,
U.
S.
Environmental
Protection
Agency,
Office
of
Air
and
Radiation,
Office
of
Air
Quality
Planning
and
Standards,
Research
Triangle
Park,
NC,
November
1992.
0154­
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process
vent
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mem.
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6
Attachment
A
Coefficients
for
Total
Resource
Effectiveness
Nonhalogenated
and
Halogenated
Vent
Streams
Coeffecient
Halogenated
Non­
halogenated
a
3.995
1.935
b
0.052
0.366
c
­
0.001769
­
0.007687
d
0.00097
0.000733
0154­
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process
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7
Attachment
B
Emissions,
Emission
Reductions,
and
Control
Cost
Estimates
for
Uncontrolled
and
Unspecified
Process
Vents
