1
MEMORANDUM
DATE:
April
23,
2004
SUBJECT:
Summary
of
Information
in
CARB
BACT
Clearinghouse
FROM:
Tanya
Parise,
Alpha­
Gamma
Technologies,
Inc.

TO:
Sims
Roy,
EPA
OAQPS
ESD
Combustion
Group
Introduction
The
CARB
BACT
Clearinghouse
database
available
at
http://
www.
arb.
ca.
gov/
bact/
bactnew/
rptpara.
htm
was
searched
for
information
regarding
emission
controls
and
emission
limits
for
engines.
The
following
source
categories
were
reviewed
for
their
BACT
determinations:

°
Compression
Ignition
<
175
HP
°
Compression
Ignition
>
=
175
HP
°
Emergency,
Compression
Ignition
°
Emergency,
Spark
Ignition
°
Fire
Pump,
Compression
Ignition
°
Fire
Pump,
Spark
Ignition
°
Landfill
or
Digester
Gas
Fired
°
Spark
Ignition,
Alternative
Fuels
°
Spark
Ignition,
Natural
Gas
Additional
determinations
obtained
from
the
old
BACT
Clearinghouse
database
available
at
http://
www.
arb.
ca.
gov/
bact/
bactsearch.
htm
were
also
reviewed.
Information
from
the
old
BACT
Clearinghouse
database
contained
the
following
source
categories:

96.
A:
I.
C.
Engine
­
Compression
Ignition,
Emergency
96.
B:
I.
C.
Engine
­
Compression
Ignition,
Fire
Pump
96.
C:
I.
C.
Engine
­
Compression
Ignition,
Non­
Emergency,
<
228
HP,
96.
D:
I.
C.
Engine
­
Compression
Ignition,
Non­
Emergency,
>
or
=
228
HP
96.2:
I.
C.
Engine
­
Landfill
or
Digester
Gas
Fired
96.3:
I.
C.
Engine
­
Spark
Ignition,
Natural
Gas
2
96.4:
I.
C.
Engine
­
Spark
Ignition,
Alternative
Fuels
The
results
from
both
Clearinghouses
were
combined
and
are
presented
under
the
source
category
headings
from
the
new
Clearinghouse
in
this
paper.
The
majority
of
determinations
were
from
the
South
Coast
Air
Quality
Management
District
(
AQMD)
and
from
the
San
Joaquin
Valley
Unified
Air
Pollution
Control
District
(
APCD).
Other
common
districts
listed
in
CARB's
BACT
Clearinghouse
were
Santa
Barbara
County
APCD
and
Bay
Area
AQMD.
Other
districts
such
as
Monterey
Bay
Unified
APCD,
San
Diego
APCD,
etc.
were
less
frequently
listed
in
the
Clearinghouse.

Summary
of
Findings
The
following
sections
present
a
summary
of
information,
such
as
the
size
of
engines,
type
of
controls,
and
emission
limits
for
each
of
the
source
categories
listed
above.

Compression
Ignition
<
175
HP
Only
one
facility
was
obtained
from
CARB's
BACT
Clearinghouse
for
this
source
category.
The
size
of
the
engine
at
this
facility
was
not
provided.
The
engine
was
listed
as
having
a
turbocharger
and
utilizes
4
degrees
of
retard
from
standard
timing
for
NOx
controls.
For
PM
controls
the
engine
was
listed
as
using
0.05
percent
sulfur
fuel
or
crankcase
control.
The
enforceable
NOx
limit
was
10.4
g/
bhp­
hr
and
the
PM
limit
was
1
g/
bhp­
hr.

Compression
Ignition
>
=
175
HP
A
total
of
28
facilities
were
obtained
from
CARB's
BACT
Clearinghouse
for
this
source
category.
The
engines
at
these
facilities
ranged
in
size
from
250
to
4,500
horsepower
(
HP).
According
to
the
Clearinghouse,
several
of
the
facilities
were
restricted
to
200
hours
of
operation
per
year
and
to
using
0.05
percent
sulfur
fuel.
Where
an
enforceable
permit
limit
was
listed
and
provided
in
g/
bhp­
hr,
it
ranged
from
1.9
to
9.5
g/
bhp­
hr
for
NOx.
A
PM
limit
was
provided
twice
and
was
shown
as
0.38
and
1
g/
bhp­
hr.
Controls
methods
listed
for
NOx
for
this
source
category
are
summarized
in
Table
1.

Table
1:
NOx
Control
Methods
for
Compression
Ignition
>
=
175
HP
Control
Method
Number
of
Facilities
Turbocharger
+
aftercooler
10
Turbocharger
+
aftercooler
+
4
degrees
of
timing
retard
3
Control
Method
Number
of
Facilities
3
Turbocharger
+
aftercooler
+
10
degrees
BTDC
for
injection
timing
1
Turbocharger
+
intercooler
+
direct
injection
1
Turbocharger
+
intake
air
cooling
+
fuel
injection
1
Turbocharger
+
intercooler
+
engine
design
to
emit
no
more
than
1670
ppm
NOx
at
3
percent
oxygen
1
Selective
catalytic
reduction
7
6
degrees
injection
retard
1
5
degrees
injection
retard
1
4
degrees
injection
retard
1
No
control
1
Total
28
Emergency,
Compression
Ignition
A
total
of
19
facilities
were
obtained
from
CARB's
BACT
Clearinghouse
for
this
source
category.
Engines
at
the
facilities
reviewed
ranged
from
68
to
2,935
HP
in
size.
The
majority
of
the
facilities
reviewed
were
restricted
to
200
hours
per
year
or
less
for
operation
during
non­
emergencies,
such
as
during
maintenance
and
testing.
A
few
facilities
were
also
listed
as
being
required
to
use
0.05
percent
sulfur
diesel
or
less.
Where
an
enforceable
permit
emission
limit
was
given
and
provided
in
g/
bhp­
hr,
it
ranged
from
6.6
to
7.2
g/
bhp­
hr
for
NOx
and
from
0.25
to
1.1
g/
bhp­
hr
for
PM.
For
most
of
the
facilities
obtained
from
CARB's
new
Clearinghouse,
where
an
enforceable
permit
limit
was
given,
it
was
the
same
for
all
facilities
at
6.9
g/
bhp­
hr
for
NOx
and
also
the
same
for
PM
at
0.38
g/
bhp­
hr,
which
may
be
more
representative
of
current
levels
than
the
range
provided
above
which
represented
values
from
both
the
new
and
old
Clearinghouse.
Control
methods
listed
for
NOx
for
engines
in
this
source
category
in
CARB's
BACT
Clearinghouse
are
shown
in
Table
2:

Table
2:
NOx
Control
Methods
for
Emergency,
Compression
Ignition
Control
Method
Number
of
Facilities
Turbocharger
+
aftercooler
8
Turbocharger
+
aftercooler
+
4
degrees
of
timing
retard
4
Control
Method
Number
of
Facilities
4
Turbocharger
+
4
degrees
of
timing
retard
2
Selective
catalytic
reduction
1
Manufacturer's
guarantee
1
No
control
1
No
information
2
Total
19
Control
methods
listed
for
PM
for
engines
in
this
source
category
in
CARB's
BACT
Clearinghouse
are
shown
in
Table
3:

Table
3:
PM
Control
Methods
for
Emergency,
Compression
Ignition
Control
Method
Number
of
Facilities
<
0.05
percent
sulfur
fuel
1
<
0.05
percent
sulfur
fuel
+
positive
crankcase
ventilation
1
<
0.05
percent
sulfur
fuel
+
positive
crankcase
ventilation
or
control
device
that
is
90
percent
efficient.
1
Turbocharger
+
aftercooler
1
Diesel
oxidation
catalyst
1
Manufacturer's
guarantee
1
Internal
controls
­
Turbocharger
1
No
information
12
Total
19
Emergency,
Spark
Ignition
Only
one
facility
was
found
in
the
CARB
BACT
Clearinghouse
for
this
source
category.
The
engine
at
this
facility
is
a
1,334
HP
engine
with
a
three­
way
catalytic
converter
for
NOx
control.
The
enforceable
NOx
permit
limit
for
this
engine
is
1.5
g/
bhp­
hr.
1The
four­
way
catalyst
system
was
developed
by
Ceryx
Inc.
and
was
the
first
to
be
permitted
in
the
South
Coast
District.
The
system
is
designed
to
reduce
air
pollution
from
diesel
engines
and
can
reduce
CO
and
HC
by
>
95%,
PM
by
90%,
and
NOx
by
30­
50%.
The
control
system
consists
of
two
catalyst
beds
in
series.
The
first
bed
contains
a
lean
NOx
catalyst
and
the
second
bed
is
an
oxidation
catalyst.
Ceryx
Inc.
declared
bankruptcy
in
2001.
The
technology
is
currently
on
hold
indefinitely.

5
Fire
Pump,
Compression
Ignition
A
total
of
five
facilities
were
found
in
CARB's
BACT
Clearinghouse
for
this
source
category.
The
engines
ranged
in
size
from
110
to
310
HP.
The
NOx
controls
for
these
facilities
were
5.5
degrees
of
fuel
injection
timing
retard
with
aftercooler,
fourway
catalyst
converter1
with
EGR
system,
turbocharger
with
aftercooler,
and
a
certified
emission
rate
of
7.2
g/
bhp­
hr
at
full
load.
One
facility
did
not
have
any
information
on
NOx
controls.
For
PM
controls,
one
facility
was
listed
with
a
four­
way
catalyst
converter
and
one
facility
was
listed
as
using
0.05
percent
sulfur
fuel
as
the
PM
control
method.
The
enforceable
NOx
limits
ranged
from
5.9
to
7.2
g/
bhp­
hr
and
the
PM
limits
ranged
from
0.22
to
0.38
g/
bhp­
hr.

Fire
Pump,
Spark
Ignition
Only
one
facility
was
returned
after
conducting
a
search
on
this
source
category
in
CARB's
BACT
Clearinghouse.
The
engine
at
this
facility
is
a
193
HP
engine
and
is
equipped
with
a
three­
way
catalytic
converter.
The
NOx
limit
is
0.15
g/
bhp­
hr,
which
is
guaranteed
by
the
catalyst
manufacturer.

Landfill
or
Digester
Gas
Fired
A
total
of
15
facilities
were
found
in
CARB's
BACT
Clearinghouse
for
this
source
category.
Engines
at
these
facilities
ranged
from
773
to
7,300
HP.
The
most
common
NOx
control
methods
listed
for
engines
at
these
facilities
were
lean
burn
combustion
technology
and/
or
prestratified
charge
and
a
turbocharger
with
aftercooling.
The
enforceable
permit
limits
for
NOx
ranged
from
0.6
to
2
g/
bhp­
hr.
Only
one
facility
was
listed
with
an
enforceable
permit
limit
for
PM
and
in
the
units
of
g/
bhp­
hr.
That
PM
limit
was
0.1
g/
bhp­
hr.

Spark
Ignition,
Alternative
Fuels
Nine
facilities
were
found
in
the
CARB
BACT
Clearinghouse
database
for
this
source
category.
The
engines
at
these
facilities
ranged
from
72
to
3,656
HP.
The
majority
of
the
engines
at
these
facilities
were
listed
as
having
a
three­
way
catalyst.
The
enforceable
NOx
permit
limits
ranged
from
0.15
to
3.7
g/
bhp­
hr.

Spark
Ignition,
Natural
Gas
6
A
total
of
32
facilities
were
found
in
CARB's
BACT
Clearinghouse
for
this
source
category.
Engines
at
the
facilities
reviewed
ranged
from
82
HP
to
4,130
HP
in
size.
Where
an
enforceable
permit
emission
limit
was
listed
and
provided
in
g/
bhp­
hr,
it
ranged
from
0.15
to
1.5
g/
bhp­
hr
for
NOx.
A
few
facilities
were
listed
as
having
no
NOx
limit.
Control
methods
listed
for
NOx
for
engines
in
this
source
category
in
CARB's
BACT
Clearinghouse
are
shown
in
Table
4.

Table
4:
NOx
Control
Methods
for
Spark
Ignition,
Natural
Gas
Control
Method
Number
of
Facilities
3­
way
catalytic
converter
18
3­
way
catalytic
converter
+
natural
gas
firing
1
Selective
catalytic
reduction
3
Selective
catalytic
reduction
+
oxidation
catalyst
1
Lean
burn
with
natural
gas
fuel
1
Lean
burn
technology
1
Natural
gas
firing
1
Lean­
burn
torch
ignition
system
incorporated
in
engine
design
1
Compressor
design
for
NOx
control
1
No
control
2
No
information
2
Total
32
