POWER August 2015 - 32

PLANT OF THE YEAR
11. Steam synergy. In a unique sort of combined heat and power scheme, extraction
steam from the turbine is sent to the carbon capture building to supply the reboilers, an integral
part of the carbon capture process. Source: POWER/Gail Reitenbach
ewan, is controlled with overfire and underfire
air and low-NOx burners, which has
dropped emissions 50%. NOx " is not a friend
of amine-based systems, " Bruce noted.
Mercury is not controlled at BDPS, although
activated carbon injection is used
at the nearby SaskPower Shand and Poplar
River stations.
As for particulate matter from Unit 3, the
flue gas is washed at least seven times after
the precipitator, so it's at virtually zero after
the capture process, Bye noted.
12. Waste incineration. A small wastewater stream from the carbon capture facility is
sent to the boilers for safe disposal via combustion. Source: POWER/Gail Reitenbach
Staffing and Control
Initially, SaskPower intended that the CC
facility would be unmanned and controlled
from Unit 3's control room. As the project
progressed and the CC water treatment plant
was added, however, plant managers decided
it would be better to staff the CC system like
a power plant, with three to four operators
and a shift supervisor. The idea was to crosstrain
the CC and Unit 3 control room staff.
However, that plan was further revised. The
CC plant has five shifts in rotation with six
personnel per shift: a shift supervisor, two
process operators in the control room, one
water treatment plant operator, and two facility
operators on the floor.
Bye noted that each operator had at least
40 hours of simulator training before the
CC facility came online. Trax International
(a subcontractor of ABB) provided the digital
simulator as part of the control system
(Figure 13), though a senior operator who
was very involved in the factory acceptance
test in Lynchburg, Va., conducted the actual
training.
SNC-Lavalin had suggested hiring process
to the power plant and incinerate it safely in
any or all of three boilers (Figure 12).
Based on the life of the existing equipment,
and the opportunities to take advantage
of efficiency improvements that have become
mainstream since the plant was originally
built, extensive work was undertaken to integrate
all improvements that could be made
cost-effectively. A dedicated heat integration
engineer focused on delivery of an integrated
design that maximized unit output based
on capital construction and operating costs.
Heat integration studies required many iterations
between the owner's engineer (Stantec)
and technical experts from Hitachi, Babcock
& Wilcox, and Babcock Borsig Service to
32
achieve the final solution.
With a unit gross output increase from 150
MW to 161 MW in noncapture mode and
full net output in capture mode (including all
design margins) that is very conservatively
pegged at 110 MW (early performance results
indicate that final net output performance
should be around 120 MW), the results far
exceed the expectations at the project's inception,
Bruce said.
Emissions Control. Aside from the CO2
and SO2, which are captured in the new facility,
other traditional emissions from Unit
3 are managed both according to regulation
and capture process needs.
NOx, which is not regulated in Saskatchwww.powermag.com
or
chemical engineers, as they have been used
at previous Cansolv gas sweetening plants,
but SaskPower went with power engineers
(in part because it was considering crosstraining
between power and capture plant
operators). Those power engineers received
about 400 hours per person of specialized
classroom training on process chemistry and
the processes involved at the BD3 plant. Bye
said, " I still believe that power engineers are
the best qualified to run the [capture] plant. "
Though Units 3 and 4 share a control
room, they do not share control stations. Unit
4 continues to use its original equipment,
while Unit 3 got a complete digital upgrade
(Figure 14).
The plant's maintenance staff, rather than
the EPC, did the commissioning work, which
gave everyone from mechanics and electricians
to instrument techs hands-on initial
troubleshooting experience.
Unit 3 can operate if the capture facility
trips offline for any reason, ensuring continued,
reliable power delivery. The only thing
POWER | August 2015

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POWER August 2015

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