AGGREGATE FLOTATION
A clean coal technology that involves floating finely ground coal in
water. The coal has been chemically conditioned to stick to rising air
bubbles. Through this method, nearly all of the inorganic sulfur sinks
to the bottom of the mixing tank. The result is a cleaner burning coal
that emits less sulfur dioxide.
ANTHRACITE
A hard coal, almost pure carbon, used mainly for heating homes.
ATMOSPHERIC FLUIDIZED BED COMBUSTION
A clean coal technology that uses pulverized coal mixed with limestone.
The limestone effectively absorbs sulfur from the gases resulting from
the combustion of the coal. The process reduces approximately 90 percent
of sulfur dioxide emissions and causes a moderate reduction of nitrogen
oxide emissions.
BACTERIAL CLEANING (MICROBIAL)
Any pre-combustion cleaning technique that uses biological reactions
allowing easier removal of organic sulfur from coal.
BITUMINOUS COAL
A soft coal, the most common in the United States, used to generate
electricity and to make coke for the steel industry.
BTU
British thermal unit. A measure of the energy required to raise the
temperature of one pound of water by one degree Fahrenheit.
CCT BY-PRODUCTS
Useful substances that are created from gases and liquids as a result
of removing sulfur and nitrogen from coal. These by- products are being
researched for use in the pavement of roads, building materials and other
applications.
CALCIUM-BASED SORBENTS
Calcium-based or hydrated lime additives that are mixed with coal to
absorb sulfur from coal combustion gases.
CARBONIC ACID/CARBON DIOXIDE
Coal contains carbon, which converts to a gas upon burning. When carbon
dioxide combines with atmospheric water, it forms carbonic acid, which
is absorbed as a nutrient by plants and trees.
CIRCULATING FLUIDIZED BED COMBUSTION (CFBC)
Circulating fluidized bed combustion is a clean coal technology process
that produces a mixture of coal and limestone in a liquid state by vertically
moving air. The process effectively removes sulfur and nitrogen from coal,
thus reducing sulfur dioxide and nitrogen oxide from coal-burning emissions.
CHEMICAL CLEANING
Any pre-combustion cleaning technique that creates a chemical reaction,
which changes the molecular form of organic sulfur in order for the sulfur
to be easily separated and removed.
CHIYODA THOROUGHBRED SCRUBBER
A flue gas desulfurization device that removes sulfur dioxide from
the gas generated by coal combustion. The process combines this gas with
a limestone, which reacts chemically with sulfur dioxide to absorb the
gas.
CLEAN COAL TECHNOLOGIES (CCTs)
Technologies developed to clean the coal burning emissions of sulfur
dioxide, nitrogen oxide, carbon dioxide, air toxins and particulates, while
enabling coal-burning facilities to meet or exceed emission standards.
COAL RESOURCES
Total coal deposits, regardless of whether they can be mined or recovered.
The United States may have as much as four trillion tons of coal resources,
according to the U.S. Geological Survey.
COAL SEAM
A deposit of coal.
COAL WASHING (PHYSICAL)
Removal of pyritic sulfur from coal through traditional coal preseparation
procedures of float/sink separation -- cleaning the coal with substances
that enhance combustion efficiency and reducepotential pollutants. Because
pyrite is much heavier than coal, washing coal enables coal particles to
float in the preseparation fluid, while pyritic sulfur particles sink to
the bottom of the preparation container.
DEMONSTRATED RESERVES
Coal deposits that are potentially minable on an economic basis with
existing technology. The U.S. Department of Energy estimates that there
are about 500 billion tons of demonstrated reserves in the United States.
ELECTROSTATIC PRECIPITATOR (ESP)
An electrical device for removing small particles such as fly ash from
combustion gases before release from a power plant’s stack.
EXILL
An export trading company that is a not-for-profit division of the
Illinois World Trade Center. EXILL seeks foreign buyers for Illinois coal.
FLUE GAS DESULFURIZATION
A clean coal technology consisting of a device fitted between a power
plant’s boiler and its smokestack. The device removes sulfur dioxide from
flue gases flowing up the stack during the post- combustion stage of coal
churning. See "SCRUBBER".
FLUIDIZED BED COMBUSTION
A clean coal technology process that removes sulfur from coal during
combustion. In a fluidized bed boiler, crushed coal and limestone are suspended
in the boiler by an upward stream of hot air. The coal is burned in this
ebullient, liquid-like mixture, hence the name "fluidized." As the coal
burns, sulfur gases from coal combine with limestone to form a solid compound
that is recovered with ash.
FLY ASH
The finely divided, inert particles of ash in flue gases arising from
the combustion of fuel.
GAS REBURNING-SORBENT INJECTION (GR-SI)
A coal-fired boiler can burn coal with a gas reburning-sorbent injection
clean coal technology to remove 60 percent of nitrogen oxide and 50 percent
of sulfur dioxide from emissions. The process uses a hydrated lime sorbent
to absorb noxious sulfur dioxide. Natural gas is mixed with recirculated
flue gas to reduce nitrogen oxide emissions.
HIGH SULFUR
Coal that naturally contains a large amount of sulfur that converts
into sulfur dioxide upon burning.
ILLINOIS CLEAN COAL INSTITUTE (ICCI)
The Illinois Department of Commerce and Community Affairs’ Illinois
Clean Coal Institute, located at the Illinois Coal Development Park, allocates
state funds for clean coal research projects.
ILLINOIS COAL DEVELOPMENT PARK (ICDP)
The Illinois Coal Development Park is a cooperative effort between
the Illinois Department of Commerce and Community Affairs and the Southern
Illinois University Coal Research Center At Carbondale. ICDP serves as
a focal point for the state’s clean coal technology (CCT) research projects.
IN-DUCT INJECTION
In clean coal technology known as flue gas desulfurization, in-duct
injection is the introduction of a calcium-based sorbent into the flue
stream between a boiler unit’s air preheater and its electrostatic precipitator,
thereby removing sulfur dioxide and producing a dry, environmentally safe
solid waste.
LIGNITE
The softest coal with the highest moisture content. It is being used
more and more for generating electricity in certain areas of the country
and for conversion to synthetic gas.
LIQUEFACTION
Converting coal into synthetic liquid fuel similar in nature to crude
oil and/or refined products such as gasoline.
MICRONIZED COAL
Coal can be micronized by pulverizing it to the consistency of talcum
powder. Micronized coal can be combined with micronized limestone to capture
sulfur dioxide emissions when coal is burned. Nitrogen oxide emissions
can also be reduced through this clean coal technology process.
NATIONAL ACID PRECIPITATION ASSESSMENT PROGRAM (NAPAP)
A 10-year, $570 million federal effort that investigated and assessed
the acid rain phenomenon from 1980 to 1990.
NITROGEN OXIDE EMISSIONS/NITRIC ACID
As coal is burned, nitrogen oxide is released. The nitrogen oxide combines
with atmospheric water and forms nitric acid. Nitric acid is a natural
fertilizer for plants and trees.
OFFICE OF COAL DEVELOPMENT AND MARKETING (OCDM)
A division of the Illinois Department of Commerce and Community Affairs,
the Office of Coal Development and Marketing works to actively research,
demonstrate and promote technologies providing environmentally sound power
production.
PHYSICAL CLEANING
Any pre-combustion coal cleaning method involving the grinding of coal
into powder particles to remove pyritic sulfur.
PRE-COMBUSTION CLEANING
Coal is cleaned by removing sulfur and mineral matter before combustion
to reduce the emission of sulfur dioxide from combustion gases.
POST-COMBUSTION CLEANING
Cleaning coal emissions after combustion between the boiler and the
smokestack.
PREPARATION PLANT
A facility for crushing, sizing and washing coal to prepare it for
use by a particular customer.
PRESSURIZED FLUIDIZED BED COMBUSTION
A clean coal technology that is similar to atmospheric fluidized bed
combustion (AFBC), except the boiler is pressurized up to 16 times the
atmospheric pressure. Sulfur dioxide emissions are reduced 95 percent and
nitrogen oxide is reduced moderately.
RANKS OF COAL
Classification of coal by degree of hardness, moisture and heat content.
Ranks of coal include anthracite, bituminous coal, sub- bituminous coal
and lignite.
SCRUBBER
Any of several forms of chemical/physical devices that operate to remove
sulfur compounds formed during coal combustion. These devices combine the
sulfur in gaseous emissions with another chemical medium to form inert
"sludge," which is removed for disposal or sold as a by-product.
SLAGGING COMBUSTORS
A form of furnace sorbent injection that involves a slagging combustor
chamber operating at a very high temperature, which causes the mineral
matter in coal to melt into “slag” form.
SORBENT
A sulfur-absorbing substance or material.
STEAM COAL
Coal used in power plant and industrial steam boilers to produce electricity;
generally lower in Btu content than metallurgical coal.
SUB-BITUMINOUS COAL
A coal with a heating value between bituminous and lignite with low-fixed
carbon and high percentages of volatile matter and moisture. Anthracite
has the highest Btu content followed by bituminous coal, sub-bituminous
coal and lignite.
SULFUR DIOXIDE EMISSION/SULFURIC ACID-SULFATE
Coal contains sulfur, which converts to gas upon burning. The sulfur
dioxide gas combines with atmospheric water to form sulfuric acid/sulfate.
Sulfate is a nutrient for trees and plants; however, in remote areas more
sulfur is emitted than is needed by plants.