public works projects paid for by business taxes Coal is still an important feedstock for electric power plants in the United States China India and several other countries around the world COAL CHALLENGES Coal was once a prospering business relying on a steady and strong demand for its product But in the 2000s mine operators found it increasingly difficult to stay in business By June 2016 the value of coal from the Powder River basin of Wyoming had fallen to 8 80 per short ton How Much for That Coal The price for a ton of coal depends on its rank quality or type where it’s mined how it’s mined its heat content and its sulfur content High-sulfur coal creates more sulfur dioxide emissions and is generally worth less than low-sulfur coal In general coal mined underground is more expensive than coal dug at the surface because the costs of underground mining are higher Coking coal used in steel production must be low-sulfur coal that goes through extensive processing at the mine to reduce the sulfur and ash content The most important factor however is rank The US Energy Information Administration found the following average prices for the different types of coal in 2013 Sub-bituminous 14 86 per short ton 0 9 metric tons Lignite 19 96 per short ton Bituminous 60 61 per short ton Anthracite 87 82 per short ton Coking coal 157 per short ton2 Another important factor is how a buyer pays for the coal Spot prices are quoted for delivery within a year The spot price can change quickly depending on the market price of coal which changes from day to day Most power plants however buy coal through long-term contracts These may run for several years and allow the utility buying the coal a more stable guaranteed price 8
0 9 metric tons a drop of more than 19 percent since the beginning of the year 3 At these relatively low prices many mines operate at a loss Coal is losing market share to other energy sources such as natural gas The main reason is cost a power plant using natural gas is less expensive to operate In 2015 coal claimed 35 percent of the market for power generation a fall of 9 percent since 2009 4 When the price of crude oil goes down as happened in 2015 coal also loses its value Tighter regulations by governments on coal use also make it less desirable as a fuel stock for power plants Besides the economic issues coal also faces environmental challenges As miners extract coal from the ground coal mining radically transforms the surrounding area Coal mines dug at the surface devastate old-growth forests in the Appalachian Mountains of West Virginia and Kentucky The process of washing coal for shipment creates a toxic sludge that pollutes streams and lakes unless the operator safely disposes of the refuse Coal burning itself releases sulfur dioxide and nitrogen dioxide into the air These compounds react with rainwater to create acid rain which can damage building stone and is toxic to trees and wetlands A federal law known as the Clean Air Act of 1977 encouraged power companies to install special equipment to scrub these pollutants from combustion emissions But as of 2011 more than half of all coal-burning plants still lacked this equipment 5 Coal combustion also produces carbon dioxide which traps heat energy created by sunlight and in higher concentrations raises global surface temperatures Global warming is an important 9
reason many nations are trying to limit or phase out the use of coal as well as other fossil fuels such as oil and natural gas Scientists and environmentalists have warned that continued reliance on fossil fuels threatens man-made climate problems such as sea level rise and water shortages Coal’s environmental dangers combined with the collapse in the coal market are causing governments to refuse further permitting of new mines and coal-fired power plants In early 2016 for example the US government stopped issuing new leases for coal mining on publicly owned land Banks see the industry as a bad investment and some have stopped granting loans Nevertheless coal remains an essential resource around the world The coal business goes hand-in-hand with the rising demand for electricity Power plants use coal to fire immense boilers Coal in BTUs Although coal is categorized by rank another important categorization has to do with British thermal units or BTUs The BTU is a measure of heating energy one BTU generates enough heat to raise the temperature of one pound 0 45 kg of water by one degree Fahrenheit 0 6ºC The BTU scale allows the coal industry to compare the efficiency of different kinds of coal and also to compare coal with other heat sources such as natural gas and petroleum For example high-grade coal can 10 contain approximately 15,000 BTUs per pound Lignite the coal with the lowest carbon content provides 4,000 to 8,300 BTUs per pound 6 Utilities also measure efficiency by the amount of fuel it takes to generate a single kilowatt-hour of electricity For coal the average amount is 1 04 pounds 0 47 kg while for natural gas it is approximately 10 cubic feet 0 3 cu m and for petroleum 0 07 gallons 0 26 L 7
and run electric turbines When electricity use rises so does the use of coal Increasing demand for electricity especially in developing countries means steady demand for the cheap and abundant coal that fuels power plants Millions of people in developing nations such as China and India aspire to a more comfortable and convenient life This means running electric lights appliances televisions and devices such as cellphones and laptops Wind solar and biomass energy although environmentally friendly are not produced reliably enough or cheaply enough to compete with coal In the future as the market for these fuel sources grows the renewable industry will scale up production This in turn should lower costs for the end user creating even tougher competition Things Get Hotter with Coke Although most coal is mined for power plants another important end use is in steelmaking Approximately 70 percent of steel produced uses metallurgical or coking coal 8 Steel is highly refined iron ore The ore dug from the ground must be converted using high temperatures produced by coal In a process called coking steel producers heat the coal using ovens that reach approximately 1,800 degrees Fahrenheit 1,000ºC in an oxygen-free atmosphere The material is then sent to a blast furnace where it produces carbon monoxide The carbon monoxide reacts with iron ore to produce finished iron or steel for coal Syngas which can be made by superheating coal may also provide fuel for vehicles and home heating plants Manufacturing syngas however is not an environmentally friendly process as it relies on fossil fuel sources as does the manufacture of hydrogen fuel 11
