The Bush Plan--more
Mercury
Bismarck Tribune
By LAUREN DONOVAN
Sunday, August 10, 2003
GRAND FORKS ‹ Any kid who ever kiped mercury from a
high school science class knows it's rightly named from the Greek
for quicksilver.
Let it out of the glass vial, and it slips away before you
know it.
It isn't easy to hold on to mercury in its pure form, as
anyone knows who's ever tried to put it back into the vial before
the teacher knows it's missing.
It isn't easy to grab it in any form, but in the not too
distant future, the coal burning industry is going to have to
figure out a way to grab the mercurial substance before it hits
the atmosphere.
The coal industry's challenge will be vastly different from
trying to gather up slippery silvery drops. The industry is
dealing with mercury contained in coal that leaves the power
plants as an invisible vapor, falls to earth and gets into the
flesh of fish in lakes and oceans. On a national scope, it's
estimated that capturing mercury will cost an easy $6
billion.
That size investment has the coal industry nervously eying the
horizon because the cleanup mandate is looming while the
technology to get the job done isn't fully developed.
The Environmental Protection Agency plans to impose a standard
that would have the coal industry reduce mercury emissions 90
percent by 2007. The Bush administration is countering with the
Clear Skies Act. It's kinder and gentler on the industry, calling
for a 46 percent reduction by 2010 and a 70 percent reduction by
2018. Under the act, mercury polluters could make beneficial
tradeoffs among themselves.
For this story about mercury it'd be helpful to get
reacquainted with that old high school devil of memorization, the
periodic table of elements, arranged from the lightest substance
on earth to the heaviest.
The symbol for mercury is Hg, from the Greek hydrargyrum. It's
number 80 in the table, ranging toward the heavy end of elements.
On one side is gold, with the symbol Au. On the other side is
thallium, symbol Tl.
Everyone knows what gold is, but thallium?
In another brief high school detour, anyone who remembers when
their science teacher still had mercury lying around might
remember thallium. It's a silvery white metallic substance once
used to treat ringworm. Thallium isn't used medically anymore
because it's toxic, and the margin between prescription and
poison is too narrow for comfort.
Mercury, its elemental neighbor, is toxic, too.
Not only is it toxic in minuscule amounts, it has the rare
ability to cross the blood-brain barrier in the human body as
methyl mercury. Children under age 14 and women of child-bearing
age are most at risk in eating mercury contaminated fish because
of the potential for neurological brain related impairments to
young children and fetuses.
That's why the federal government has mercury in its cross
hairs.
Whether it's the EPA's more stringent standard, or Bush's less
stringent approach, the clock is ticking. The boom is about to
come down on coal burners.
It's coming down even though mercury from coal accounts for a
small share of the mercury swirling around the atmosphere in
what's called the global pool.
There are 2,000 tons of mercury in the global pool, roughly
the same as 20 railroad cars loaded with wheat. Of the 2,000
tons, some 48 tons are attributable to coal burning plants in the
United States.
There's a good chance that the mercury that accounted for fish
advisories posted on 941 Minnesota lakes last year actually came
from power plants in Asia, which pumps about 150 tons into that
swirling global mercury pool.
North Dakota posts its advisories by sized fish, not lake. The
higher up the predatory food chain and the bigger the fish, the
less of it young people and childbearing-aged women should
consume.
State Health Officer Terry Dwelle said mercury intoxication is
not a reportable event, but he did survey physicians with 100
years of clinical experience among them and none diagnosed so
much as a single case in North Dakota.
Despite the U.S. coal industry's relatively small contribution
to the global problem, the mandate to reduce mercury is coming
like a train to the station. The challenge now is in figuring out
how to get the job done before the train gets in.
Across the country, there's a scramble in research labs and at
power plants to test the best means for reducing mercury.
A significant player in the research field is the Energy and
Environmental Research Center in Grand Forks. Mercury research
accounts for 25 percent of the EERC's $20 million budget, a
proportion that will get closer to 40 percent over the next
couple of years.
Steve Benson heads up the mercury research program at EERC.
When he talks about the issue, he unloads reams of paper and
studies to demonstrate his point.
He already knows this much: "Meeting the EPA's 2007 timeframe
will be next to impossible. Under the Clear Skies Act, there's a
chance."
Some of the research at EERC and elsewhere looks
promising.
Generally, it's divided into two methods.
One method involves spraying a reactive substance into the
plant's flue gas ‹ the stream that ends up going out the
tall stack ‹ to either oxidize or cause a reaction with
mercury and trap it with other small particles.
Experiments involve spraying the flue gas with different
substances, called sorbents, such as activated carbons and forms
of chlorine. The list of experimental sorbents is long and
complex. Some are described as chemical formulas.
"I used to say we've looked at everything but dirt, and now
we've looked at dirt," Benson said. "Dirt didn't work."
A second method involves running the flue gas over sorbent
beds, basically surfaces coated with a cling-on substance like
gold, which amalgamates with mercury.
Other experiments are looking at where in the plants'
pollution equipment ‹ filter houses or scrubbers ‹
mercury controls should be installed.
No method has been field tested long enough to know how
effective it is over time.
Great River Energy, with North Dakota plants in Underwood and
Stanton, is a leader in mercury experimentation.
Mark Strohfus analyzes environmental policy for his company.
He said Great River has a hyper-awareness because it's
headquartered in Minnesota, where mercury has for years been a
political hot button.
Right now, Great River is experimenting with activated carbon,
oxidation and gold-plated sorbent bed technology at its Stanton
and Underwood plants.
Coal burned at Great River is typical of North Dakota lignite.
It contains about 100 parts mercury per billion raw and about 10
parts per billion after the boiler. That's a minuscule enough
amount, but it adds up. North Dakota plants contribute about 1.3
tons to the global mercury pool.
A mercury study done in 2002 used a hypothetical example to
highlight the coal industry's challenge. It calculated the
Houston Astrodome could hold 30 billion ping pong balls and 30 of
the balls contained mercury, the same ratio of mercury in coal.
To get to 90 percent reduction, the industry will have to get 27
balls out of the "dome."
North Dakota power plant operators will have a bigger
handicap. The mercury that leaves power plant stacks here and in
the Powder River Basin to the west is elemental mercury, unlike
from eastern coal where the mercury is already oxidized and
easier to capture.
Strohfus said despite his company's aggressive approach, it's
early in the game. He sees significant problems in being ready to
meet the coming standard.
"We don't have a slam-dunk technology that we can apply now,"
Strohfus said. "Could we install (this) next year and could we be
confident that it would meet the standard? Absolutely not."
There are some practical concerns ahead of that.
Installing mercury controls will require a plant shutdown. In
Great River's case, it may have to install filters, or bag
houses, which will cost millions.
"Everything is millions," Strohfus said.
Just like those drug ads on television, the mercury cure won't
come without side effects.
Great River sells a lot of fly ash ‹ a powdery
substance left after coal is burned ‹ for everything from
a concrete additive to an ingredient in cosmetics. Those sales
will be at risk if the fly ash is contaminated with activated
carbons that were added to the process to capture mercury.
Scott Renninger is a project manager for the Department of
Energy's energy laboratory. Besides the unintended consequences
of such things as fouled fly ash, Renninger said mercury captures
will affect pollution control equipment, either plugging it up,
or just plain causing it to wear out faster.
"We just don't know what the side effects might be," he
said.
The federal government, states like North Dakota with its
research funded through the Lignite Research Council and the
energy industry are spending millions of dollars now. They will
spend millions more to get mercury controls out of the laboratory
and into the field as quickly as possibly.
It'll take a commitment.
In the end it may mean that plant operators have to install
multiple controls, especially if the most stringent reduction
carries the political day, because it may take several forms of
control to grab all or most of the mercury.
Renninger said finding the mercury fix will also take
something elusive, something beyond the realm of cold hard
science.
"It's not like hitting the Powerball, but we need to be kind
of lucky in the next couple of years," he said.
(Reach reporter Lauren Donovan at 888-303-5511, or
scoop@ndonline.com.)
© Bismarck Tribune 2003
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