POWER October 2010 - 30

TOP PLANTS
Brandon Shores Generating Station,
Pasadena, Maryland
Owner/operator: Constellation Energy
Constellation Energy recently completed a series of air quality upgrades on both
units at its Brandon Shores Generating Station that included flue gas desulfurization
(FGD), baghouse, SO3 control, and mercury reduction by activated carbon injection.
The plant's unique arrangement required long duct runs to the air quality system and
a mile-long conveyor for moving barge-delivered limestone to the plant. Treated municipal
wastewater was used as wet
FGD supply water, and effluent treatment
included first-of-its-kind nitrogen
removal before discharge to the Chesapeake
Bay watershed.
By Dr. Robert Peltier, PE
Courtesy: Constellation Energy
C
onstellation Energy can trace its roots
back to 1816 when the Baltimore City
Council approved plans for the nation's
first gas utility to light the city streets. The
Gas Light Co. of Baltimore, after a series of
consolidations and acquisitions, evolved into
Baltimore Gas & Electric, the regulated side
of Constellation Energy (CE). CE's unregulated
Power Generation Group owns about
8,900 MW of fossil and renewable generation
assets consisting of 27 facilities located
in six states and Canada.
Stringent Air Quality Rules
In 2006, the Maryland General Assembly adopted
legislation (the Maryland Healthy Air
Act, " MHAA " ) requiring significant SO2
NOx, and mercury emission reductions from
,
Maryland's coal-fired units. Although it requires
more stringent and earlier emission
reductions, the MHAA generally correlates
30
with emission reductions required by the Environmental
Protection Agency's Clean Air
Interstate Rule and Clean Air Mercury Rule.
According to the Maryland Department of
the Environment (MDE), greater and earlier
SO2
and NOx
reductions and year-round controls
were required to meet federal ambient
air quality standards for fine particulate matter
and ozone, and facility-specific mercury
reductions were necessary for greater public
health protection.
The MDE projects that its two-step reductions
will ultimately achieve reductions of
75% of NOx
by 2012, 85% of SO2
by 2013,
and 90% of mercury by 2013, all compared
to a 2002 baseline. The MHAA also prohibits
Maryland power plants from using out-ofstate
emissions allowances to avoid achieving
in-state emission reductions.
In Maryland, CE's assets include nine
power plants, including its largest coal-fired
www.powermag.com
plant: the 1,273-MW Brandon Shores Generating
Station (BSGS, Figure 1). BSGS, located
on 375 acres along the western shore
of the Patapsco River, 10 miles southeast of
Baltimore, has two nominal 680-MW coalfired
units that started commercial operation
in 1984 and 1991. To comply with the
MHAA, CE budgeted $885 million to add the
necessary air quality control system equipment
to accommodate the combustion of coal
containing up to 4% sulfur. The plant's eastern
bituminous coal supply is predominantly
Central Appalachian, but the plant also burns
Northern Appalachian coal and a variety of
foreign coals when the market conditions
are right. Coal is received by barge, which is
unloaded and transferred by a mile-long conveyor
to onsite coal storage piles.
Each of the natural circulation, balanced
draft boilers was originally supplied by Babcock
& Wilcox and included a hot-side elecPOWER
| October 2010
http://www.powermag.com
POWER October 2010

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