1
MEMORANDUM
SUBJECT:
Additional
Emissions
Control
Option
Considered
for
Area
Source
Glycol
Dehydrators
at
Oil
and
Natural
Gas
Production
Facilities
FROM:
Greg
Nizich
U.
S.
EPA
TO:
HQ
EPA
Docket
Docket
ID
No.
EPA­
HQ­
OAR­
2004­
0238
DATE:
December
6,
2005
Based
on
comments
received
on
the
supplemental
proposal
published
in
the
Federal
Register
on
July
8,
2005,
and
follow­
up
discussions
with
commenters,
another
option
is
being
considered
to
reduce
emissions
from
area
source
glycol
dehydrators.

The
additional
information
provided
by
commenters
has
led
us
to
believe
that
a
high
percentage
of
area
source
glycol
dehydrators
are
located
at
unmanned
facilities
that
lack
electrical
power
and
data
transmission
capabilities.
This
operational
infrastructure
is
necessary
to
meet
the
continuous
monitoring
requirements
in
the
proposed
rule.
Since
our
cost
estimate
did
not
account
for
the
absence
of
these
utilities,
our
previous
compliance
cost
estimate
would
increase
an
estimated
$
6,000
to
$
10,000
per
unit.

In
light
of
this
added
cost,
rather
than
require
continuous
monitoring,
it
may
be
more
effective
to
specify
a
design
standard
as
a
compliance
option
and
eliminate
monitoring
requirements
that
rely
on
power
availability
and
data
transmission.
We
anticipate
that
periodic
inspections
would
be
required
to
ensure
ongoing
proper
equipment
function.

We
believe
this
approach
merits
consideration
for
area
sources
since
a
properly
designed
aircooled
(
natural
draft)
condenser
achieves
a
substantial
reduction
in
emissions
of
hazardous
air
pollutants
(
HAP)
without
the
need
for
electrical
power.
In
addition,
the
presence
of
the
condenser
ensures
that
the
reduction
is
achieved,
eliminating
the
need
to
collect
data
for
verification.

The
following
is
a
list
of
criteria
being
considered
to
define
the
control
option:

°
Design,
install
and
operate
a
natural­
draft
condenser
that
achieves
a
to­
be­
determined
designated
outlet
temperature.
The
temperature
could
be
specified
as
a
maximum
above
ambient
temperature,
based
on
annual
average.
This
is
typically
referred
to
as
the
approach
temperature;
2
and
°
Specify
certain,
critical,
glycol
dehydrator
operating
parameters
(
e.
g.,
adsorber
temperature/
pressure,
flash
tank
pressure,
glycol
recirculation
pump
rating),
either
as
operational
ranges
or
minimums/
maximums,
in
addition
to
a
condenser
outlet
temperature;
and
°
Establish
the
operating
parameters
based
on
a
benzene
emission
reduction
of
90
percent
since
that
is
the
maximum
reduction
level
needed
to
achieve
the
1
ton/
year
(
tpy)
threshold
for
an
area
source
(
i.
e.
9.9
tpy
reduced
to
below
1
tpy);
and
°
Inspect
the
condenser
monthly
(
this
coincides
with
existing
requirements
in
63.771(
c)(
3)(
i)(
B)
for
bypass
device
inspection)
to
verify:
the
condenser
is
intact
per
initial
installation,
and
the
dehydrator
is
being
operated
within
the
specified
ranges
and
limitations.
Maintain
a
log
documenting
this
information;
and
°
Correct
any
malfunction
of
the
condenser
within
7
calendar
days
of
detection.
If
the
malfunction
cannot
be
repaired
within
7
calendar
days,
then
the
dehydrator
cannot
be
operated
until
the
repair
is
made;
and
°
Submit
an
annual
report
documenting
information
from
periodic
inspections
and
any
malfunction
incidents/
repairs.
