August 2015
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World Coal
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43
I
n today’s economic climate, it is increasingly
challenging for power plants to source easy‑handling
lump coal. Trends toward lower fuel cost and added
preparation steps have resulted in many plants
requiring the use of fine and high moisture content coal,
which is usually more difficult to handle. As a result, the
potential for material flow problems increases. Coal can
build up inside handling equipment, which can lead to
flow stoppages. This paper discusses the handling
challenges with fine and high-moisture coal through a case
study at Dominion’s Virginia City Hybrid Energy Center.
Coal handling at the plant
Dominion’s Virginia City Hybrid Energy Center is located
in Wise County, southwest Virginia, in the US. The 600 MW
plant is one of the cleanest coal-fired power plants in the
country. It uses nearly 3 million tpy of coal. The plant uses
advanced circulating fluidised bed (CFB) technology, which
is a proven clean‑coal technology that also enables the use
of ROM coal, waste coal and renewable energy sources,
such as wood waste. With modern post‑combustion
controls, the plant has low emissions of sulfur dioxide,
nitrogen oxide, particulate matter and mercury. This helps
it operate in an environmentally responsible manner, which
minimises overall impact to air, water and land resources.
The plant entered commercial operations on 10 July 2012.
One of the main fuels used by the plant is waste coal.
Waste coal is the low‑energy‑value material reclaimed
during coal mining. It is sometimes also referred to as
“culm” or “gob”. In the US, waste coal mined during
twentieth century was mostly piled and not used. Burning
waste coal offers a solution to the environmental problems
associated with the piling of waste coal over the years.
With the advanced CFB technology, Virginia City Hybrid
Energy Center is able to use such coal for power
generation.
The plant receives waste coal from various nearby
suppliers. Typically, it is brought in using trucks. These
trucks unload the coal into below ground level hoppers.
From here, coal is conveyed to the coal yard and stacked in
