METHODOLOGY,
ASSUMPTIONS,
AND
REFERENCES
PRELIMINARY
COST
ESTIMATES
FLUE
GAS
CONDITIONING
RETROFITS
INDUSTRIAL
BOILERS
By
Sikander
Khan
Environmental
Engineer,
U.
S.
EPA
OCTOBER­
NOVEMBER
2003
Preliminary
FGC
Cost
Estimates
2
PRELIMINARY
COST
ESTIMATES
FLUE
GAS
CONDITIONING
RETROFITS
INDUSTRIAL
BOILERS
1.0
METHODOLOGY
The
cost
estimates
covered
in
this
report
were
developed
as
part
of
the
investigations
conducted
for
the
proposed
Interstate
Air
Quality
Rule
(
IAQR)
for
industrial
boilers.
These
costs
are
preliminary
and
are
being
reviewed
further
by
the
EPA.

A
switch
from
a
high­
sulfur
coal
to
a
low­
sulfur
coal
is
one
option
for
reducing
SO2
emissions
associated
with
coal
burning
in
an
industrial
boiler.
However,
for
a
boiler
equipped
with
an
electrostatic
precipitator
(
ESP),
such
a
coal
switch
may
have
an
adverse
impact
on
the
ESP
performance.
The
resistivity
of
the
low­
sulfur
coal
ash
is
generally
greater
than
that
of
the
high­
sulfur
coal
ash.
Since
higher­
resistivity
ash
is
harder
to
capture
in
an
electrostatic
field,
it
would
require
a
larger
ESP
plate
area
for
the
same
ash
capture
effectiveness.
A
switch
to
a
low­
sulfur
coal,
therefore,
can
result
in
a
performance
shortfall
for
an
existing
ESP
originally
designed
to
handle
high­
sulfur
coal
ash.

Flue
gas
conditioning
(
FGC)
is
utilized
to
restore
the
ESP
performance,
affected
by
a
low­
sulfur
coal
switch.
FGC
involves
injection
of
a
suitable
chemical
into
the
flue
gas
stream
ahead
of
the
ESP,
which
lowers
the
ash
resistivity
to
levels
suitable
for
the
ESP
performance.
The
preliminary
estimates
in
this
report
were
developed
for
FGC
retrofits
on
industrial
boilers
electing
to
switch
to
low­
sulfur
coals
for
SO2
control.
These
estimates
were
developed
for
three
boiler
sizes,
with
heat
inputs
of
100,
250,
and
1,000
MMBtu/
hr.

It
is
to
be
noted
that
the
purpose
of
this
evaluation
was
to
develop
FGC
retrofit
cost
information
for
a
large
range
of
industrial
boiler
sizes.
The
decision
on
the
use
of
this
information
in
the
proposed
IAQR
will
be
made
as
part
of
the
Rule
itself.

The
methodology
can
be
divided
into
two
major
activities:
1)
Developing
design
basis
for
the
FGC
system
and
determining
its
operating
impacts
on
the
boiler
performance
and
2)
determining
capital
and
operating
costs
associated
with
FGC
retrofits.
These
two
activities,
along
with
the
associated
assumptions
and
references,
are
described
below.

2.0
DESIGN
BASIS
AND
PERFORMANCE
IMPACTS
Combustion
calculations
were
performed
to
establish
flue
gas
flow
rates
and
other
information,
using
standard
procedures(
1,2),
for
the
three
boiler
sizes
of
100,
250,
and
1,000
MMBtu/
hr.
Data
provided
in
the
EPRI
flue
gas
conditioning
manual(
3)
was
used
to
develop
the
FGC
system
design
basis
and
consumable
rates
for
each
of
the
three
boiler
sizes.
Preliminary
FGC
Cost
Estimates
3
A
variety
of
reagents(
3,4)
can
be
used
for
the
FGC
system,
including
molten
sulfur,
H2SO4,
SO2,
and
proprietary
chemicals
available
from
certain
vendors.
The
most
commonly
utilized
reagent
in
the
power
plant
industry
is
molten
sulfur(
3,4),
that
was
selected
as
a
design
basis
for
this
report.

Tables
1
summarizes
the
key
data
determined
from
the
calculations
for
the
three
boiler
sizes,
including
the
FGC
system
design
basis
and
plant
performance
impacts
3.0
CAPITAL
AND
LEVELIZED
COSTS
The
capital
costs
($/
MMBtu/
hr)
for
the
FGC
system
were
developed
using
available
industry
data(
4)
for
a
75
MW
plant.
A
scaling
factor
of
0.7
was
used
to
adjust
the
costs
to
the
boiler
sizes
used
in
this
evaluation.
A
US
Department
of
Commerce,
Bureau
of
Economic
Analysis(
5)
price
index
was
used
to
adjust
cost
basis
from
one
year
to
another.
The
costs
are
based
on
1999
dollars.

In
general,
an
EPRI
methodology(
6)
was
used
for
the
above
cost
estimates,
with
the
following
cost
factors
used
for
the
non­
process
costs:

General
Facilities:
5.0
%
of
total
direct
process
cost
Engineering
and
home
office
fees:
10%
of
total
direct
process
cost
Project
contingency:
15%
of
total
direct
process
and
the
above
two
non­
process
costs
Retrofit
factor:
10%
Preproduction
cost:
2.0%
of
total
plant
investment
with
retrofit
costs
Inventory
capital:
cost
for
a
30­
day
reagent
storage
The
capital
costs
are
summarized
in
Table
2.

The
levelized
costs
(
mills/
MMBtu/
hr)
were
calculated
using
the
estimates
of
the
capital
costs
and
increased
consumable
rates
shown
in
Table
1.
The
economic
factors
used
in
these
calculations(
3,4)
were
as
follows:

Molten
sulfur,
$/
lb
0.06
Steam,
$/
lb
0.0035
Power,
mills/
kwh
25.0
Catalyst,
$/
cu.
ft.
500
Useful
life,
years
30
Carrying
charges,
%
12.00
Levelization
factor
1.0
Maintenance
cost
(%
of
capital
cost)
2.0
The
levelized
costs
are
presented
in
Table
3.
Preliminary
FGC
Cost
Estimates
4
5.0
REFERENCES
1.
"
Steam
Its
Generation
and
Use,"
Babcock
and
Wilcox,
40th
Edition
2.
"
Power
Test
Code
 
Steam
Generating
Units,"
ASME
PTC
4.1,
1991
3.
"
A
Manual
on
the
Use
of
Flue
Gas
Conditioning
for
ESP
Performance
Enhancement,"
EPRI
CS­
4145,
Final
Report,
August
1985
4.
"
A
Novel
Approach
to
Sulfuric
Acid
Vapor
Injection
for
ESP
Flue
Gas
Conditioning,"
9th
Part.
Control
Symposium,
10/
15
to
18/
1991,
Virginia
5.
"
Implicit
Price
Deflator,"
Table
7.3.
Quantity
and
Price
Indexes,
http://
www.
bea.
doc.
gov/
bea/
dn/
nipaweb/
TableViewFixed.
asp
6.
"
Technical
Assessment
Guide,
Vol.
I:
Electricity
Suppl­
1993
(
Revision
7);
EPRI
TR­
102276s;
Electric
Power
Research
Institute
Preliminary
FGC
Cost
Estimates
5
TABLE
1
FGC
SYSTEM
DEISGN
BASIS
AND
PLANT
PERFORMANCE
IMPACTS
FGC
Design
Parameter
Boiler
 
100
MMBtu/
hr
Boiler
 
250
MMBtu/
hr
Boiler
 
1000
MMBtu/
hr
Flue
gas
flow
rate,
acfm
38,230
95,400
381,000
Flue
gas
temperature,
F
330
330
330
SO3
injection
rate,
ppmv
(
design)
40
40
40
SO3
injection
rate,
ppmv
(
normal
operation)
20
20
20
Molten
sulfur
rate,
lb/
hr
(
normal
operation)
2.5
6.3
25.1
Steam
consumption,
lb/
hr
(
normal
operation)
4.0
5.5
14.1
Power
consumption,
kW
(
normal
operation)
30.5
31.9
38.8
Catalyst
replacement,
ft3/
yr
2
2
2
Preliminary
FGC
Cost
Estimates
6
TABLE
3
TOTAL
LEVELIZED
COST
 
FGC
SYSTEM
RETROFIT
mills
/
MMBtu/
hr
Fuel
Technology
Capacity
Factor
%
100
MMBtu/
hr
250
MMBtu/
hr
1000
MMBtu/
hr
14
360
256
158
50
108
75
46
Low­
sulfur
coal
Flue
Gas
Conditioning,
Molten
Sulfur­
Based
System
83
68
47
29
TABLE
2
CAPITAL
COSTS
­
FLUE
GAS
CONDITIONING
SYSTEM
Cost
Item
Boiler
 
100
MMBtu/
hr
Boiler
 
250
MMBtu/
hr
Boiler
 
1000
MMBtu/
hr
DIRECT
COSTS
($):

Total
installed
cost
for
the
FGC
system
202,138
365,827
910,669
TOTAL
DIRECT
PROCESS
CAPITAL
($)
202,138
365,827
910,669
INDIRECT
COSTS:

GENERAL
FACILITIES
10,107
18,291
45,533
ENGINEERING
AND
HOME
OFFICE
FEES
20,214
36,583
91,067
PROCESS
CONTINGENCY
0
0
0
PROJECT
CONTINGENCY
34,869
63,105
157,090
TOTAL
PLANT
COST
(
TPC)
($):
267,328
483,806
1,204,360
CONSTRUCTION
YEARS
<
1
<
1
<
1
ALLOAWANCE
FOR
FUNDS
DURING
CONSTRUCTION
0
0
0
TOTAL
PLANT
INVESTMENT
(
TPI)
($)
267,328
483,806
1,204,360
TOTAL
PLANT
INVESTMENT
WITH
RETROFIT
FACTOR,
$
294,061
532,187
1,324,796
ROYALTY
ALLOWANCE
0
0
0
PREPRODUCTION
COST
5,881
10,644
26,496
INVENTORY
CAPITAL
109
272
1,085
INITIAL
CATALYST
AND
CHEMICALS
0
0
0
TOTAL
PLANT
REQUIREMENTS
($)
300,051
543,102
1,352,377
TOTAL
PLANT
REQUIREMENTS
($/
MMBtu)
3,001
2,172
1,352
