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GLOSSARY of TERMS |
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accessibility | in reference to coal resources (core meaning), the absence of land use restrictions and the assumption that ownership or leaseholds will be obtainable for mining (see also environmental restrictions, industrial restrictions). Many technological restrictions were traditionally applied as demonstrated reserve base criteria, but (extended meaning) with the advent of available resource studies, specific technologic restrictions may be incorporated in accessibility factors. |
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anthracite | the highest rank of coal; used primarily for residential and commercial space heating. It is a hard, brittle, and black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter. The moisture content of fresh-mined anthracite generally is less than 15 percent. The heat content of anthracite ranges
from 22 to 28 million Btu per short ton on a moist, mineral-matter-free basis. The heat content of anthracite coal consumed in the United States averages 25 million Btu per short ton, on the as-received basis (i.e., containing both inherent moisture and mineral
matter). Note: Since the 1980's, anthracite refuse or mine waste has been used for steam electric power generation. This fuel typically has a heat content of 15 million Btu per short ton or less. |
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API Gravity | the universally accepted scale adopted by the American Petroleum Institute (API) for expressing the density of liquid petroleum products. The higher the API gravity, the lighter the oil. |
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aromatics | class of hydrocarbons that have at least one benzene ring as part of their structure. Generally describes benzene and benzene derivatives. These products are used as components of unleaded gasolines and as feedstocks for petrochemicals such as cyclohexane and paraxylene, both of which are used in end products like nylons and polyesters. |
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Artificial Drives
also
Artificial Lift | techniques for producing oil after depletion or in lieu of natural drives; includes waterflooding, natural gas reinjection, inert gas injection, flue gas injection and in-situ combustion. |
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ash | impurities consisting of silica, iron, alumina, and other incombustible matter that are contained in coal. Ash increases the weight of coal, adds to the cost of handling, and can affect the burning characteristics. Ash content is measured as a percent by weight of coal on an "as received" or a "dry" (moisture-free) basis. |
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auger mine | a surface mine where coal is recovered through the use of a large-diameter drill driven into a coalbed in a hillside. It usually follows contour surface mining, particularly when the overburden is too costly to excavate. |
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available
energy | potential energy capable of doing work and being degraded in the process.
(Units: kilocalories, joules, BTUs, etc.) |
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B |
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barge | a long and large, usually flat-bottomed boat that is unpowered and towed by other boats or ships, used for transporting goods. |
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barrel | As the standard unit of measurement of liquids in the petroleum industry, it contains 42 U.S. standard gallons. Abbreviated to "bbl." |
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benzene | an aromatic hydrocarbon present to a minor degree in most crude oils. Some important products manufactured from benzene are styrene, phenol, nylon and synthetic detergents. |
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bituminous | a dense coal, usually black, sometimes dark brown, often with well-defined bands of bright and dull material, used primarily as fuel in steam-electric power generation, with substantial quantities also used for heat and power applications in manufacturing and to make coke. Bituminous coal is the most abundant coal in active U.S. mining regions. Its moisture content usually is less than 20 percent. The heat content of bituminous coal ranges from 21 to 30 million Btu per ton on a moist, mineral-matter-free basis. The heat content of bituminous coal consumed in the United States averages 24 million Btu per ton, on the as-received basis (i.e., containing both inherent moisture and mineral matter). |
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bitumen | a mixture containing hydrocarbons -- often produced by the processing of coal or oil -- used in asphalt or tar for road surfacing or waterproofing. |
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Btu
(British thermal unit) | the amount of heat needed to raise the temperature of 1 pound of water by 1 degree fahrenheit. The Btu is a convenient measure by which to compare the energy content of various fuels. |
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butane | refers usually to a mixture of isobutane and normal butane. A flammable, gaseous hydrocarbon. Used as fuel. |
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C |
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carbon | the base of all hydrocarbons; capable of combining with hydrogen in almost numberless hydrocarbon compounds. The carbon content of a hydrocarbon determines, to a degree, the hydrocarbon's burning characteristics and qualities. |
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carbon dioxide (CO2) | a colorless, odorless, incombustible gas formed during combustion in fossil-fuel electric generation plants. |
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coal | a readily combustible black or brownish-black rock whose composition, including inherent moisture, consists of more than 50 percent by weight and more than 70 percent by volume of carbonaceous material. It is formed from plant remains that have been compacted, hardened, chemically altered, and metamorphosed by heat and pressure over geologic time. |
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cogenerator | a generating facility that produces electricity and another form of useful thermal energy (such as heat or steam) used for industrial, commercial, heating, and cooling purposes. To receive status as a qualifying facility (QF) under the Public Utility Regulatory Policies Act (PURPA), the facility must produce electric energy and "another form of useful thermal energy through the sequential use of energy," and meet certain ownership, operating, and efficiency criteria established by the Federal Energy Regulatory Commission (FERC). (See the Code of Federal Regulation, Title 18, Part 292.) |
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coke | a hard, dry substance containing carbon that's produced by heating bituminous coal to a very high temperature in the absence of air.
Coke (petroleum): A residue high in carbon content and low in hydrogen that is the final product of thermal decomposition in the condensation process in cracking. This product is reported as marketable coke or catalyst coke. The conversion is 5 barrels (of 42 U.S. gallons each) per short ton. Coke from petroleum has a heating value of 6.024 million Btu per barrel. |
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conveyor | a continuous moving belt that transports large volumes of material. |
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cracking | the refinery process in which large, heavy, complex hydrocarbon molecules are broken down into simpler and lighter molecules in order to derive a variety of fuel products. |
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crude oil | a mineral oil consisting of a mixture of hydrocarbons of natural origin, yellow to black in color, of variable specific gravity and viscosity; often referred to simply as crude. |
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D |
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deep mine | type of mine created to access coal buried deep underground, characterized by a set of shafts dug straight down to the coal. |
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deep-water discovery | an offshore discovery located in at least 600 feet of water. |
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demonstrated
reserves | portion of known coal reserves that could be profitably mined and marketed (in the U.S., about 472 billion tons -- or 25% of known American reserves). |
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diesel fuel | the light oil fuel used in diesel and other compression-ignition engines. |
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distillates | the distillate or middle range of petroleum liquids produced during the processing of crude oil. Products include diesel fuel, heating oil, kerosene and turbine fuel for airplanes. |
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dragline | a large machine used in the surface mining process to remove overburden, or layers of earth and rock, covering a coal seam. |
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drift mine | type of mine created to access coal seam exposed by the slope of a mountain, characterized by an entrance that is a horizontal tunnel into the seam of coal. |
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dry hole | a well that does not find oil or gas in commercial quantities. Definitions of commercial vary according to the costs of exploration. A shallow well in the old oil patch in the United States might be commercial when it can produce less than 10 barrels of oil per day, while an offshore well might not be commercial unless it produces several thousand barrels of oil per day. |
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emergy | available energy of one kind previously required directly and indirectly to make a product or service (units: emjoules, emkilocalories, etc.). [Howard T. Odum] |
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empower | emergy flow per unit time (units: emjoules per unit time). |
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energy | the capacity for doing work as measured by the capability of doing work (potential energy) or the conversion of this capability to motion (kinetic energy). Energy has several forms, some of which are easily convertible and can be changed to another form useful for work. Most of the world's convertible energy comes from fossil fuels that are burned to produce heat that is then used as a transfer medium to mechanical or other means in order to accomplish tasks. Electrical energy is usually measured in kilowatthours, while heat energy is usually measured in British thermal units. |
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ethylene | basic chemical used in the manufacture of plastics (such as polyethylene), antifreeze and synthetic fibers. |
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exergy | exergy is the maximum amount of work that can be extracted from a material by reversible processes as it approaches thermodynamic equilibrium with its surroundings. Exergy is therefore a quantity that is not definable in absolute terms. It can only be defined in terms of a reference state, namely the environment. But exergy can be calculated for any material with reference to whatever environmental medium that material would be likely to reach thermodynamic equilibrium with, namely the atmosphere, the ocean or the surface layer of the earthís crust (topsoil or subsoil). Thus gases tend to equilibrate with the atmosphere, liquids or soluble solids with the oceans, insoluble solids with the land. (Two Paradigms of Production and Growth, Professor Robert U. Ayres, Dr. Benjamin Warr, Center for the Management of Environmental Resources (CMER), INSEAD, France) |
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fossil fuels | naturally occurring fuels of an organic nature, such as coal, crude oil, and natural gas. |
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fractionation | fhe process for breaking natural gas liquids into component parts -- methane, ethane, propane, butane, pentane and heavier hydrocarbons. |
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fuel oils | the heavy distillates from the oil refining process that are used primarily for heating, for fueling industrial processes, for fueling locomotives and ships, and for fueling power generation systems. |
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gasoline | the light fuel used to spark ignition engines in cars, motorcycles, etc. Modern gasolines are blends of petroleum liquids that are produced in several different processes and which generally contain additives. |
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greenhouse effect | a warming of the earth produced by the presence of certain gases in the atmosphere. |
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geothermal energy | energy from the internal heat of the earth, which may be residual heat, friction heat, or a result of radioactive decay. The heat is found in rocks and fluids at various depths and can be extracted by drilling and/or pumping. |
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heavy crude | crude oil of 20 degree API gravity or less; often very thick and viscous. |
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hydrocarbons | organic chemical compounds of hydrogen and carbon atoms that form the basis of all petroleum products. They may exist as solids, liquids or gases. |
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hydroelectric power | the harnessing of flowing water to produce mechanical or electrical energy. |
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K |
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kerosene | a medium-light distillate from the oil refining process; used for lighting and heating, and for the manufacture of fuel for jet and turbo-prop aircraft engines. |
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light crude | crude oil with a high API gravity due to the presence of a high proportion of light hydrocarbon fractions. |
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lignite | the lowest rank of coal, often referred to as brown coal, used almost exclusively as fuel for steam-electric power generation. It is brownish-black and has a high inherent moisture content, sometimes as high as 45 percent The heat content of lignite ranges from 9 to 17 million Btu per ton on a moist, mineral-matter-free basis. The heat content of lignite consumed in the United States averages 13 million Btu per ton, on the as-received basis (i.e., containing both inherent moisture and mineral matter). |
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Liquefied Natural Gas (LNG) | Liquefied natural Gas (LNG) is natural gas liquefied either by refrigeration or by pressure to facilitate storage or transportation. It takes A LOT of ENERGY to produce, transport, and store LNG. |
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Liquefied Petroleum Gas (LPG) | Liquefied Petroleum Gas (LPG) is a mixture of butane, propane and other light hydrocarbons derived from refining crude oil. At normal temperatures, it is a gas, but it can be cooled or subjected to pressure to facilitate storage and transportation. It takes A LOT of ENERGY to produce, transport, and store LPG. |
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longwall mining | an automated form of underground coal mining characterized by high recovery and extraction rates, feasible only in relatively flat-lying, thick, and uniform coalbeds. A high-powered cutting machine is passed across the exposed face of coal, shearing away broken coal, which is continuously hauled away by a floor-level conveyor system. Longwall mining extracts all machine-minable coal between the floor and ceiling within a contiguous block of coal, known as a panel, leaving no support pillars within the panel area. Panel dimensions vary over time and with mining conditions but currently average about 900 feet wide (coal face width) and more than 8,000 feet long (the minable extent of the panel, measured in direction of mining). Longwall mining is done under movable roof supports that are advanced as the bed is cut. The roof in the mined-out area is allowed to fall as the mining advances. |
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measured resources | coal for which estimates of the rank, quality, and quantity have been computed, within a high degree of geologic assurance, from sample analyses and measurements from closely spaced and geologically well known sample sites. Measured resources are computed from dimensions revealed in outcrops, trenches, mine workings, and drill holes. The points of observation and measurement are so closely spaced and the thickness and extent of coals are so well defined that (for older estimates) the tonnage was judged to be accurate within 20 percent of true tonnage (statistical measures of error are no longer considered reliable for most measured resources). Although the spacing of the points of observation necessary to demonstrate continuity of the coal differs from region to region according to the character of the coalbeds, the points of observation are not greater than 0.5 mile apart. Measured coal is projected to extend as a 0.25-mile-wide belt from the outcrop or points of observation or measurement. |
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methane | the principal constituent of natural gas. |
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N |
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naphtha | a colorless liquid product of petroleum distillation that is used as a manufacturing solvent, a dry-cleaning fluid and a gasoline-blending stock. |
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natural gas | a mixture of hydrocarbons and small quantities of various nonhydrocarbons existing in the gaseous phase or in solution with crude oil in under-ground reservoirs.
Natural Gas (Dry): The marketable portion of natural gas production, which is obtained by subtracting extraction losses, including natural gas liquids removed at natural gas processing plants, from total production. |
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OPEC | the Organization of Petroleum Exporting Countries, which are Algeria, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, United Arab Emirates, and Venezuela. |
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overburden | layers of earth and rock covering a coal seam. |
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P |
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peat | partially carbonized vegetable material, usually found in bogs. |
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photosynthesis | process by which green plants convert light to energy by transforming carbon dioxide and water into carbohydrates. |
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propane | a heavy gaseous hydrocarbon found in crude oil and natural gas; used as fuel and in the making of petrochemicals. |
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power | useful energy flow per unit time (units: joules per time) |
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Q |
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R |
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reclamation | the process of restoring a surface mine site to its original contour, function, and appearance, thus "reclaiming" it. |
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recoverable
reserves | portion of known demonstrated reserves (see above) that actually can be extracted from the earth and delivered to market with today's mining techniques (in the U.S., about 267 billion tons -- or 13% of known American reserves). |
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S |
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slurry | a mixture of water and any of several finely crushed solids, especially cement, clay, or coal. |
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solar energy | the radiant energy of the sun, which can be converted into other forms of energy, such as heat or electricity. |
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subbituminous | a coal whose properties range from those of lignite to those of bituminous coal and used primarily as fuel for steam-electric power generation. It may be dull, dark brown to black, soft and crumbly, at the lower end of the range, to bright, jet black, hard, and relatively strong, at the upper end. Subbituminous coal contains 20 to 30 percent inherent moisture by weight. The heat content of subbituminous coal ranges from 17 to 24 million Btu per ton on a moist, mineral-matter-free basis. The heat content of subbituminous coal consumed in the United States averages 17 to 18 million Btu per ton, on the as-received basis (i.e., containing both inherent moisture and mineral matter). |
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surface mine | type of mine created to access coal seam close to the ground's surface, characterize by a scraping away of topsoil and overburden followed by direct digging of the coal. |
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sweet crude | crude oil with a low sulfur content. |
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synthetics | Synthetic Fuels
Burnable energy fluids made from coals or other hydrocarbon- containing substances.
Synthetic Natural Gas
Gases made from coals and other hydrocarbon-containing substances.
Synthetic Oils
Liquid fuels made from hydrocarbon- containing substances, including tar sands, plus animal and vegetable oils that are used as lubricants. |
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toluene | a key petrochemical and an organic solvent; along with xylene, a key component in unleaded gasoline. |
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ton | 2,000 pounds in the United States (short ton); in the United Kingdom, a long ton is 2,240 pounds; a metric ton equals 1,000 kilograms. In most countries, oil and petroleum products are sold by weight instead of liquids quantities, e.g., a ton of oil is the equivalent of 6.8 to 8.5 barrels of oil, depending on temperature, specific gravity and other physical factors. |
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transformity | emergy per unit available energy of one kind (units: emjoule per joule). |
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turbine | a device used in the generation of electricity. It has a shaft with blades at one end and electromagnets at the other. Water or steam or some other energy source pushes the blades, which make the shaft and the magnets spin very fast. The magnet end is surrounded by heavy coils of copper wire, and the spinning magnets cause electrons in the wire to begin to move, creating electricity. |
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useful energy | available energy used to increase system production and efficiency.
(units: available joules, kilocalories, etc.) |
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W |
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watt | a unit of power; power being the rate at which energy is used to do work. The unit rate at which work is done in an electrical circuit. One watt equals one JOULE of work per second. Also equal to one ampere (amp) under a pressure of one VOLT. Analogous to horsepower or footpounds per minute of mechanical power (one horsepower is equivalent to approximately 746 watts; one kilowatt equals 1,000 watts; one megawatt equals 1,000,000 watts). A 100-watt light bulb requires 100 watts of electricity to operate. Named after the Scottish inventor James Watt.
One kilowatthour is one kilowatt of electricity produced or used in one hour. |
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well | a hole bored or drilled into the earth for the purpose of obtaining water, oil or gas, or other natural resources. |
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work | an energy transformation process which results in a change in concentration or form of energy. |
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xylene | an aromatic hydrocarbon that is the basis for many petrochemicals; along with toluene, a key ingredient in unleaded gasoline. |
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Glossary 
