With the Nation's coal-burning utilities facing the possibility of
tighter controls on mercury pollutants, the U.S. Department of Energy
is preparing to fund two projects that could offer power plant operators
better ways to reduce these emissions at much lower costs.
The department will provide just over $5.5 million to McDermott
Technology, Inc., of Alliance, OH, and ADA Environmental
Solutions, LLC, of Littleton, CO, to test full-scale advanced
mercury control methods at several of the nation's power plants. The two
firms will contribute nearly $3 million.
Mercury is known to have toxic effects on the nervous system of humans
and wildlife. Although it exists only in trace amounts in coal, mercury
is released when coal burns and can accumulate on land and in water. In
water, bacteria transform the metal into methylmercury, the most hazardous
form of the metal. Methylmercury can collect in fish and marine mammals
in concentrations hundreds of thousands times higher than the levels in
surrounding waters.
In June 2000, the National Academy of Sciences released a report reinforcing
the importance, especially for women in their child bearing years, of
heeding consumption advisories of noncommercial fish to avoid methylmercury.
The Environmental Protection Agency has until December 15 to decide whether
to regulate mercury from coal-fired utility boilers.
The challenge of reducing mercury emissions from power plants today is
that no uniform method of technology exists. Current pollution controls
were designed for other types of pollutants, and their effectiveness in
reducing mercury emissions can vary from boiler to boiler. Depending upon
the power plant, reduction levels can range from 90 percent to zero.
To provide more consistent and lower cost methods, the two companies
will demonstrate mercury control at different points in a power plant's
flue gas cleanup process. McDermott will test a technology developed jointly
with its Babcock and Wilcox partner that enhances the effectiveness of
"wet scrubbers" - the technology used by more than a quarter
of the nation's coal power plants to reduce sulfur pollutants. ADA will
test a system that works in concert with a power plant's baghouse or electrostatic
precipitator to remove dust-like solid particles from a plant's exhaust
gas.
The goal is develop technologies by 2005 that will be capable of cutting
mercury emissions 50 to 70 percent at well under one-half of today's costs.
Both projects were selected from the first of two rounds of competitions
the Energy Department began in March, 2000. In October, the department
will announce selections of more novel, less developed control systems
for testing at pilot plant scales. The deadline for these project proposals
is August 31.
McDermott Technology, Inc., in conjunction with Babcock and Wilcox
In this project, Babcock and Wilcox Company will demonstrate
a cost-effective mercury removal system with its research affiliate McDermott
Technology, Inc. The technology, expected to be applicable to coal-fired
power plants equipped with wet scrubbers, will be tested at full scale
at two sites: 1) Michigan South Central Power Agency's 55-megawatt Endicott
Station in Litchfield, Michigan, and 2) Cinergy Corporation's 1300-megawatt
Zimmer Station near Cincinnati.
The Babcock and Wilcox/McDermott technology adds very small amounts of
a liquid reagent to the scrubbing solution to attain its target of 90
percent mercury removal at costs one-half to one-fourth those of today's
commercially available activated carbon mercury removal methods.
The project is expected to begin in October and last for 18 months. It
is estimated to cost $1.75 million, with $1.2 million provided by the
Energy Department. The project team includes the two utilities that will
host the tests and the Ohio Coal Development Office. If the project proves
successful, Babcock and Wilcox will offer mercury control technology for
commercial use in both new and existing wet flue gas scrubber systems.
The technical contact is Dennis K. McDonald, (330) 860-6175, e-mail dkmcdonald@pgg.mcdermott.com.
ADA Environmental Solutions
ADA Environmental Solutions will develop a portable system that
will be moved to four different utility power plants for field testing.
Each of the plants is equipped with either electrostatic precipitators
or fabric filters to remove solid particles from the plant's flue gas.
ADA's technology will inject a dry sorbent, such as fly ash or activated
carbon, that adheres to the mercury and makes it more susceptible to capture
by the particulate control devices. A fine water mist will be sprayed
into the flue gas to cool its temperature to the range where the dry sorbent
is most effective. Because cooling the flue gas can increase the formation
of corrosive sulfur trioxide, ADA's technology also includes a reagent
injection system to control the buildup of sulfur trioxide if needed.
PG&E Generating is providing two test sites that fire bituminous
coals and are both equipped with electrostatic precipitators and carbon/ash
separation systems. Wisconsin Electric Power Company is providing a third
test site that burns Powder River Basin coal and has an electrostatic
precipitator for particulate control. A fourth plant, equipped with a
fabric filter, will be added to the test program. The 36-month
project will receive $4.5 million from the Energy Department. ADA Environmental
Solutions and an 11-organization support team will provide an additional
$2.2 million. The technical contact is Michael D. Durham, (303) 734-1727,
e-mail: miked@adaes.com |