POWER January 2011 - 56

CARBON CAPTURE
from the flue gas. This top-level process diagram
is similar to the one used for FutureGen
2.0, although the demonstration plant is
smaller. Also, because FutureGen 2.0 burns a
much higher sulfur coal, it uses wet flue gas
desulfurization (FGD) instead of dry FGD,
and the secondary recycle is taken after the
scrubber (using the cool rather than the warm
recycle process).
Given that the demo plant was designed for
only 150 MW gross, the steam cycle selected
was subcritical at 2,400 psi and 1,050F main
and reheat steam temperatures. Located in
Wyoming, the plant employs dry condenser
5. The best of many options. On an equivalent basis, oxy-combustion offers the best
plant efficiency when compared with other CO2 capture options. For comparison, air-fired cases
are the far left group, conventional carbon capture technologies are in the middle, and future
carbon capture technology predictions are on the right. Data were taken from DOE/NETL 20071291
" Pulverized Coal Oxy-combustion Power Plants, " Rev. 2; DOE/NETL 2007-1281 " Cost and
Baseline for Fossil Energy Plants, " Rev. 1; and B&W/AL Integration study using the warm recycle
process with supercritical and ultra-supercritical steam conditions. Supercritical steam conditions
are 3,500 psi, 1,110F/1,150F; ultrasupercritical conditions are 4,000 psi, 1,350F/1,400F.
Source: Babcock & Wilcox Power Generation Group and Air Liquide
50
45
40
35
30
25
20
15
10
5
No CO2 capture
44.6
39.4
39.4
33.6
28.3
29.3
29.3
32.1
33.2
33.0
With CO2 capture
38.9
cooling that minimizes freshwater makeup.
The plant was also designed for near-zeroliquid
discharge.
Air emissions in the oxy mode come only
from the CPU vent. NOx
emissions are predicted
at 13 tons/year or less (exclusive of
start-ups). SOx
, mercury, and particulates
emissions in the oxy mode are projected to be
below current power plant continuous monitoring
accuracy. CO emissions without oxidation
were projected to be about 780 tons/
year. Approximately one million tons per
year of CO2
would be captured and stored.
About 105,445 tons/year would be released
into the atmosphere, resulting in a capture
rate of over 90%.
New Reference Plant Design
A reference plant design is useful to confirm
the technical design basis and plant costs. Because
the 150-MW gross plant just described
was not selected by the DOE, the FutureGen
2.0 200-MWe gross plant will fulfill the need
for a large-scale test facility.
The objective for FutureGen 2.0 is not
only to apply the oxy-combustion technology
at large scale but also to show that the
plant can achieve 90%+ CO2
Case 1
SC air
Case 2
USC air
DOE avg
IGCC, air
Case 3
SC air
post
Case 5
SC cryoASU
B&W
warm
recycle
SC
Case
7
SC ITM
DOE avg
IGCC
Case 4
USC-air
post
Case
6 USC
cryoASU
B&W
warm
recycle
USC
Notes:
ASU = air separation unit, avg = average, IGCC = integrated gasification combined cycle, ITM = ion transport
membrane, SC = supercritical, USC = ultrasupercritical
6. Attractive lifecycle economics. Note that the B&W/AL bars show the best improvements
in the levelized cost of electricity when using oxy-combustion. All numbers are based on
the same financial assumptions about burning the same bituminous coal and are estimated in
2007 dollars, not including owner's costs. The notes in Figure 4 also apply to this figure. Source:
Babcock & Wilcox Power Generation Group and Air Liquide
Capital
12
10
8
6
4
2
Fixed O&M
No CO2 capture
11.31
0.39
2.62
2.53
7.8
6.32
1.89
0.56
0.39
3.48
Case 1
SC air
6.43
1.66
0.52
0.39
3.86
Case 2
USC air
DOE avg
IGCC, air
Case 3
SC air
post
Case 5
SC cryoASU
B&W
warm
recycle
SC
Case
7
SC ITM
DOE avg
IGCC
Case 4
USC-air
post
Case
6 USC
cryoASU
B&W
warm
recycle
USC
Notes:
ASU = air separation unit, avg = average, IGCC = integrated gasification combined cycle, ITM = ion transport
membrane, SC = supercritical, USC = ultrasupercritical
January 2011 | POWER
www.powermag.com
7.8
6.71
6.25
5.90
6.60
5.61
6.12
5.45
1.04
0.55
0.76
0.53
2.20
0.67
0.50
10.47
0.40
9.62
0.35
Variable O&M
Fuel
Transport, storage, and monitoring
With CO2 capture
10.59
0.38
3.39
0.71
0.50
10.6
0.92
0.54
10.6
10.61
0.32
2.23
2.25
0.71
0.52
9.99
0.39
8.75
0.31
1.90
0.64
0.45
capture and
confirm other emissions data. The project
will also " confirm the cost basis for retrofitting/repowering
existing coal-fired units, "
and provide the information and experience
that will reduce costs for future larger (500to
800-MW-scale) units. For plant operators,
FutureGen 2.0 will also " establish operating
and maintenance experience for future commercial
plants. "
FutureGen 2.0 is not the end game for
the B&W/AL team. In fact, B&W, AL, and
URS Washington Group in Denver have been
working together to develop a utility-scale
reference plant of 700 MW gross (about 515
MW net). The design is based on Powder
River Basin coal using state-of-the-art supercritical
boiler technology with turbine inlet
conditions of 3,500 psi and 1,100F main and
reheat steam temperatures. Originally sited at
sea level in the Midwest, the plant was redesigned
for a Kenosha, Wisconsin, location
when the Electric Power Research Institute
partnered with the project in mid-2010. Performance
models and equipment sizing tasks
are completed and estimates of plant costs
are under development.
Preliminary results of the work predict that
the net plant efficiency with carbon capture
approaches the current coal-fired fleet average
efficiency without CCS. Projections for
air emissions in the oxy mode are very low:
for NOx
about 52 tons/year (not including
start-ups); about the same CO as for a comparable
air-fired plant (without oxidation);
and SOx
, Hg, and particulates below current
55
Levelized cost of electricity (¢/kWh)
Efficiency % (HHV)

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POWER January 2011

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