The Dickerson Generating Station is an 853 MW electric generating plant owned by NRG Energy , located approximately two miles west of Dickerson, Maryland , on the eastern banks of the Potomac River .
93-465: The facility consists of three 182 MW coal -fired steam generating plants, two 147 MW gas and oil-fired simple cycle combustion turbines , and one 13 MW black start and peaking turbine. The three coal-fired units are base-loaded and went into operation in 1959, 1960, and 1962 respectively. Condenser cooling for these units is accomplished with once-through cooling water from the Potomac River at
186-512: A cyclothem . Cyclothems are thought to have their origin in glacial cycles that produced fluctuations in sea level , which alternately exposed and then flooded large areas of continental shelf. The woody tissue of plants is composed mainly of cellulose, hemicellulose, and lignin. Modern peat is mostly lignin, with a content of cellulose and hemicellulose ranging from 5% to 40%. Various other organic compounds, such as waxes and nitrogen- and sulfur-containing compounds, are also present. Lignin has
279-689: A 56 MW generating incineration plant that burns municipal garbage and waste , is next to the Dickerson Generating Station. This waste-to-energy plant is served by the CSX railroad line, which delivers trash from a central collection center in Derwood to the plant. The facility began operations in 1995 and is operated by the Northeast Maryland Waste Disposal Authority, a state-owned corporation . Coal Coal
372-499: A canoe and kayak training facility for the 1992 Olympic Games . In December 2009, a $ 1.1 billion emissions upgrade was completed. A new stack and cooling system reduced the amount of waste heat going into the cooling water discharge channel. In 2013, NRG filed notice that it planned to decommission the coal generators by 2017, citing state emissions requirements. In May 2015, NRG filed notice to delay deactivation until May 2019. In February 2016, NRG withdrew its de-activation notice for
465-521: A community group is actively opposing their local waste-to-energy facility, Sintana Vergara, an assistant professor in the Department of Environmental Resources Engineering at Humboldt State University in California, commented that community resistance is based on both the pollution and the fact that many of these facilities have been sited in communities without any community input, and without any benefits to
558-417: A process called carbonization . Carbonization proceeds primarily by dehydration , decarboxylation , and demethanation. Dehydration removes water molecules from the maturing coal via reactions such as Decarboxylation removes carbon dioxide from the maturing coal: while demethanation proceeds by reaction such as In these formulas, R represents the remainder of a cellulose or lignin molecule to which
651-501: A rate of up to 400 million US gallons (1,500,000 m) per day. Coal is delivered to the Dickerson Generating Station by CSX Transportation train. The two combustion turbines are General Electric Frame 7F gas turbines which went into operation in 1992 and 1993, and are normally fired with natural gas from a Consolidated Natural Gas company pipeline which traverses the Dickerson site. The generation plant's site property abuts
744-501: A substitute for natural gas. The WtE process contributes to circular economy principles by transforming waste products into valuable resources, reducing dependency on fossil fuels, and mitigating greenhouse gas emissions. However, challenges remain, particularly in ensuring that emissions from WtE plants, such as dioxins and furans , are properly managed to minimize environmental impact. Advanced pollution control technologies are essential to address these concerns and ensure WtE remains
837-527: A switch in fuels happened in London in the late sixteenth and early seventeenth centuries. Historian Ruth Goodman has traced the socioeconomic effects of that switch and its later spread throughout Britain and suggested that its importance in shaping the industrial adoption of coal has been previously underappreciated. The development of the Industrial Revolution led to the large-scale use of coal, as
930-549: A tenth. Indonesia and Australia export the most, followed by Russia . The word originally took the form col in Old English , from reconstructed Proto-Germanic * kula ( n ), from Proto-Indo-European root * g ( e ) u-lo- "live coal". Germanic cognates include the Old Frisian kole , Middle Dutch cole , Dutch kool , Old High German chol , German Kohle and Old Norse kol . Irish gual
1023-542: A thermal treatment process in Collie, Western Australia. The system will process 1.5 tonnes of organic matter per hour. Annually the facility will divert 4000 tonnes of municipal waste from landfill and source an additional 8000 tonnes of organic waste from agricultural and forestry operations. Renergi’s patented “grinding pyrolysis” process aims to converts organic materials into biochar, bio-gases and bio-oil by applying heat in an environment with limited oxygen. Another project in
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#17328695152411116-721: A third of its electricity . Some iron and steel -making and other industrial processes burn coal. The extraction and burning of coal damages the environment , causing premature death and illness, and it is the largest anthropogenic source of carbon dioxide contributing to climate change . Fourteen billion tonnes of carbon dioxide were emitted by burning coal in 2020, which is 40% of total fossil fuel emissions and over 25% of total global greenhouse gas emissions . As part of worldwide energy transition , many countries have reduced or eliminated their use of coal power . The United Nations Secretary General asked governments to stop building new coal plants by 2020. Global coal use
1209-687: A total of 93.5 MW installed capacity of waste-to-energy, with a pipeline of projects in different preparation phases together amounting to another 373MW of capacity. Biofuel Energy Corporation of Denver, Colorado, opened two new biofuel plants in Wood River, Nebraska , and Fairmont, Minnesota , in July 2008. These plants use distillation to make ethanol for use in motor vehicles and other engines. Both plants are currently reported to be working at over 90% capacity. Fulcrum BioEnergy, located in Pleasanton, California ,
1302-529: A viable, environmentally sound solution. WtE technologies present a significant opportunity to manage waste sustainably while contributing to global energy demands. They represent an essential component of integrated waste management strategies and a shift toward renewable energy systems. As technology advances, WtE may play an increasingly critical role in both reducing landfill use and enhancing energy security. Gasification and pyrolysis processes have been known and used for centuries and for coal as early as
1395-403: A weight basis. This composition reflects partly the composition of the precursor plants. The second main fraction of coal is ash, an undesirable, noncombustable mixture of inorganic minerals. The composition of ash is often discussed in terms of oxides obtained after combustion in air: Of particular interest is the sulfur content of coal, which can vary from less than 1% to as much as 4%. Most of
1488-406: A weight composition of about 54% carbon, 6% hydrogen, and 30% oxygen, while cellulose has a weight composition of about 44% carbon, 6% hydrogen, and 49% oxygen. Bituminous coal has a composition of about 84.4% carbon, 5.4% hydrogen, 6.7% oxygen, 1.7% nitrogen, and 1.8% sulfur, on a weight basis. The low oxygen content of coal shows that coalification removed most of the oxygen and much of the hydrogen
1581-526: Is direct combustion of waste to produce heat, which can then be used to generate electricity via steam turbines. This method is widely employed in many countries and offers a dual benefit: it disposes of waste while generating energy, making it an efficient process for both waste reduction and energy production. In addition to combustion, other WtE technologies focus on converting waste into fuel sources . For example, gasification and pyrolysis are processes that thermochemically decompose organic materials in
1674-506: Is a combustible black or brownish-black sedimentary rock , formed as rock strata called coal seams . Coal is mostly carbon with variable amounts of other elements , chiefly hydrogen , sulfur , oxygen , and nitrogen . Coal is a type of fossil fuel , formed when dead plant matter decays into peat which is converted into coal by the heat and pressure of deep burial over millions of years. Vast deposits of coal originate in former wetlands called coal forests that covered much of
1767-439: Is a relatively old method of WtE generation. Incineration generally entails burning waste (residual MSW, commercial, industrial and RDF) to boil water which powers steam generators that generate electric energy and heat to be used in homes, businesses, institutions and industries. One problem associated is the potential for pollutants to enter the atmosphere with the flue gases from the boiler. These pollutants can be acidic and in
1860-625: Is also a cognate via the Indo-European root. The conversion of dead vegetation into coal is called coalification . At various times in the geologic past, the Earth had dense forests in low-lying areas. In these wetlands, the process of coalification began when dead plant matter was protected from oxidation , usually by mud or acidic water, and was converted into peat . The resulting peat bogs , which trapped immense amounts of carbon, were eventually deeply buried by sediments. Then, over millions of years,
1953-478: Is an open one, as European countries which recycle the most (up to 70%) also incinerate to avoid landfilling . Incinerators have electric efficiencies of 14-28%. In order to avoid losing the rest of the energy, it can be used for e.g. district heating ( cogeneration ). The total efficiencies of cogeneration incinerators are typically higher than 80% (based on the lower heating value of the waste). The method of incineration to convert municipal solid waste (MSW)
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#17328695152412046-429: Is building a WtE plant near Reno, NV . The plant is scheduled to open in 2019 under the name of Sierra BioFuels plant. BioEnergy incorporated predicts that the plant will produce approximately 10.5 million gallons per year of ethanol from nearly 200,000 tons per year of MSW. Waste-to-energy technology includes fermentation , which can take biomass and create ethanol , using waste cellulosic or organic material. In
2139-429: Is burned in a turbine). Hot exhaust gases from the turbine are used to raise steam in a heat recovery steam generator which powers a supplemental steam turbine . The overall plant efficiency when used to provide combined heat and power can reach as much as 94%. IGCC power plants emit less local pollution than conventional pulverized coal-fueled plants. Other ways to use coal are as coal-water slurry fuel (CWS), which
2232-594: Is entirely vertical; however, metamorphism may cause lateral changes of rank, irrespective of depth. For example, some of the coal seams of the Madrid, New Mexico coal field were partially converted to anthracite by contact metamorphism from an igneous sill while the remainder of the seams remained as bituminous coal. The earliest recognized use is from the Shenyang area of China where by 4000 BC Neolithic inhabitants had begun carving ornaments from black lignite. Coal from
2325-533: Is from biogenic material. Consequently, this energy is often recognised as renewable energy according to the waste input. Several methods have been developed by the European CEN 343 working group to determine the biomass fraction of waste fuels, such as Refuse Derived Fuel /Solid Recovered Fuel. The initial two methods developed (CEN/TS 15440) were the manual sorting method and the selective dissolution method . A detailed systematic comparison of these two methods
2418-464: Is ground and melted and then pyrolyzed. Catalytic converters help in the process. The vapours are condensed with oil or fuel and accumulated in settling tanks and filtered. Fuel is obtained after homogenation and can be used for automobiles and machinery. It is commonly termed as thermofuel or energy from plastic. A new process uses a two-part catalyst, cobalt and zeolite, to convert plastics into propane . It works on polyethylene and polypropylene and
2511-455: Is made when metallurgical coal (also known as coking coal ) is baked in an oven without oxygen at temperatures as high as 1,000 °C, driving off the volatile constituents and fusing together the fixed carbon and residual ash. Metallurgical coke is used as a fuel and as a reducing agent in smelting iron ore in a blast furnace . The carbon monoxide produced by its combustion reduces hematite (an iron oxide ) to iron. Pig iron , which
2604-409: Is more abundant, and anthracite. The % carbon in coal follows the order anthracite > bituminous > lignite > brown coal. The fuel value of coal varies in the same order. Some anthracite deposits contain pure carbon in the form of graphite . For bituminous coal, the elemental composition on a dry, ash-free basis of 84.4% carbon, 5.4% hydrogen, 6.7% oxygen, 1.7% nitrogen, and 1.8% sulfur, on
2697-463: Is still the global warming potential of the landfill gas being emitted to atmosphere. For example, in the US in 1999 landfill gas emission was approximately 32% higher than the amount of CO 2 that would have been emitted by combustion. In addition, nearly all biodegradable waste is biomass . That is, it has biological origin. This material has been formed by plants using atmospheric CO 2 typically within
2790-550: Is the largest user in thermal treatment of municipal solid waste in the world, with 40 million tons. Some of the newest plants use stoker technology and others use the advanced oxygen enrichment technology. Several treatment plants exist worldwide using relatively novel processes such as direct smelting, the Ebara fluidization process and the Thermoselect JFE gasification and melting technology process. As of June 2014, Indonesia had
2883-496: Is too rich in dissolved carbon, is also produced. Waste-to-energy Waste-to-energy (WtE) or energy-from-waste (EfW) refers to a series of processes designed to convert waste materials into usable forms of energy, typically electricity or heat. As a form of energy recovery, WtE plays a crucial role in both waste management and sustainable energy production by reducing the volume of waste in landfills and providing an alternative energy source. The most common method of WtE
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2976-452: Is used as fuel. 27.6% of world energy was supplied by coal in 2017 and Asia used almost three-quarters of it. Other large-scale applications also exist. The energy density of coal is roughly 24 megajoules per kilogram (approximately 6.7 kilowatt-hours per kg). For a coal power plant with a 40% efficiency, it takes an estimated 325 kg (717 lb) of coal to power a 100 W lightbulb for one year. In 2022, 68% of global coal use
3069-691: The Bronze Age (3000–2000 BC), where it formed part of funeral pyres . In Roman Britain , with the exception of two modern fields, "the Romans were exploiting coals in all the major coalfields in England and Wales by the end of the second century AD". Evidence of trade in coal, dated to about AD 200, has been found at the Roman settlement at Heronbridge , near Chester ; and in the Fenlands of East Anglia , where coal from
3162-759: The Chesapeake and Ohio Canal National Historical Park , which follows along the Potomac River. The C&O Canal structures nearest to the plant are Lock 27 and the Monocacy Aqueduct . The Dickerson plant began service in 1959. All of the generating plants were built by the Potomac Electric Power Company , which sold them to the Southern Company in December 2000 as a result of the restructuring of
3255-512: The Fushun mine in northeastern China was used to smelt copper as early as 1000 BC. Marco Polo , the Italian who traveled to China in the 13th century, described coal as "black stones ... which burn like logs", and said coal was so plentiful, people could take three hot baths a week. In Europe, the earliest reference to the use of coal as fuel is from the geological treatise On Stones (Lap. 16) by
3348-590: The Midlands was transported via the Car Dyke for use in drying grain. Coal cinders have been found in the hearths of villas and Roman forts , particularly in Northumberland , dated to around AD 400. In the west of England, contemporary writers described the wonder of a permanent brazier of coal on the altar of Minerva at Aquae Sulis (modern day Bath ), although in fact easily accessible surface coal from what became
3441-702: The Somerset coalfield was in common use in quite lowly dwellings locally. Evidence of coal's use for iron -working in the city during the Roman period has been found. In Eschweiler , Rhineland , deposits of bituminous coal were used by the Romans for the smelting of iron ore . No evidence exists of coal being of great importance in Britain before about AD 1000, the High Middle Ages . Coal came to be referred to as "seacoal" in
3534-491: The coal gap in the Permian–Triassic extinction event , where coal is rare. Favorable geography alone does not explain the extensive Carboniferous coal beds. Other factors contributing to rapid coal deposition were high oxygen levels, above 30%, that promoted intense wildfires and formation of charcoal that was all but indigestible by decomposing organisms; high carbon dioxide levels that promoted plant growth; and
3627-444: The steam engine took over from the water wheel . In 1700, five-sixths of the world's coal was mined in Britain. Britain would have run out of suitable sites for watermills by the 1830s if coal had not been available as a source of energy. In 1947 there were some 750,000 miners in Britain, but the last deep coal mine in the UK closed in 2015. A grade between bituminous coal and anthracite
3720-407: The 13th century; the wharf where the material arrived in London was known as Seacoal Lane, so identified in a charter of King Henry III granted in 1253. Initially, the name was given because much coal was found on the shore, having fallen from the exposed coal seams on cliffs above or washed out of underwater coal outcrops, but by the time of Henry VIII , it was understood to derive from the way it
3813-788: The 18th century.... Development technologies for processing [residual solid mixed waste] has only become a focus of attention in recent years stimulated by the search for more efficient energy recovery. (2004) Incineration, the combustion of organic material such as waste with energy recovery, is the most common WtE implementation. All new WtE plants in OECD countries incinerating waste (residual MSW , commercial, industrial or RDF ) must meet strict emission standards, including those on nitrogen oxides (NO x ), sulphur dioxide (SO 2 ), heavy metals and dioxins . Hence, modern incineration plants are vastly different from old types, some of which neither recovered energy nor materials. Modern incinerators reduce
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3906-410: The 1980s were reported to cause environmental degradation by turning rain into acid rain . Modern incinerators incorporate carefully engineered primary and secondary burn chambers, and controlled burners designed to burn completely with the lowest possible emissions, eliminating, in some cases, the need for lime scrubbers and electro-static precipitators on smokestacks. By passing the smoke through
3999-578: The Carboniferous, and suggested that climatic and tectonic factors were a more plausible explanation, reconstruction of ancestral enzymes by phylogenetic analysis corroborated a hypothesis that lignin degrading enzymes appeared in fungi approximately 200 MYa. One likely tectonic factor was the Central Pangean Mountains , an enormous range running along the equator that reached its greatest elevation near this time. Climate modeling suggests that
4092-587: The Central Pangean Mountains contributed to the deposition of vast quantities of coal in the late Carboniferous. The mountains created an area of year-round heavy precipitation, with no dry season typical of a monsoon climate. This is necessary for the preservation of peat in coal swamps. Coal is known from Precambrian strata, which predate land plants. This coal is presumed to have originated from residues of algae. Sometimes coal seams (also known as coal beds) are interbedded with other sediments in
4185-410: The Dickerson plant to meet current federal wastewater standards ( effluent guidelines ) by November 2020. The plant discharges arsenic and mercury to the Potomac River according to 1980s-era standards under expired permits. Upgrading the plant's treatment systems to Maryland's current standards "could reduce discharges of toxic metals by 97 percent." The U.S. Environmental Protection Agency published
4278-407: The Earth's tropical land areas during the late Carboniferous ( Pennsylvanian ) and Permian times. Coal is used primarily as a fuel. While coal has been known and used for thousands of years, its usage was limited until the Industrial Revolution . With the invention of the steam engine , coal consumption increased. In 2020, coal supplied about a quarter of the world's primary energy and over
4371-481: The German Environmental Ministry, "because of stringent regulations, waste incineration plants are no longer significant in terms of emissions of dioxins, dust, and heavy metals". Compared with other waste to energy technologies, incineration seems to be the most attractive due to its higher power production efficiency, lower investment costs, and lower emission rates. Additionally, incineration yields
4464-563: The Greek scientist Theophrastus (c. 371–287 BC): Among the materials that are dug because they are useful, those known as anthrakes [coals] are made of earth, and, once set on fire, they burn like charcoal [anthrakes]. They are found in Liguria ;... and in Elis as one approaches Olympia by the mountain road; and they are used by those who work in metals. Outcrop coal was used in Britain during
4557-633: The Rockingham Industrial Zone, roughly 45 kilometres south of Perth will see a 29 MW plant built with capacity to power 40,000 homes from an annual feedstock of 300,000 tonnes of municipal, industrial and commercial rubbish. As well as supplying electricity to the South West Interconnected System, 25 MW of the plant’s output has already been committed under a power purchase agreement. The Reppie waste to energy plant in Ethiopia
4650-702: The United States, there is already an equivalent carbon 14 method under the standard method ASTM D6866. The second method (so-called balance method ) employs existing data on materials composition and operating conditions of the WtE plant and calculates the most probable result based on a mathematical-statistical model. Currently the balance method is installed at three Austrian and eight Danish incinerators. A comparison between both methods carried out at three full-scale incinerators in Switzerland showed that both methods came to
4743-591: The absence of oxygen to produce syngas, a synthetic gas primarily composed of hydrogen, carbon monoxide, and small amounts of carbon dioxide. This syngas can be converted into methane , methanol , ethanol , or even synthetic fuels , which can be used in various industrial processes or as alternative fuels in transportation. Furthermore, anaerobic digestion , a biological process, converts organic waste into biogas (mainly methane and carbon dioxide) through microbial action. This biogas can be harnessed for energy production or processed into biomethane , which can serve as
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#17328695152414836-534: The basic lime scrubbers, any acids that might be in the smoke are neutralized which prevents the acid from reaching the atmosphere and hurting the environment. Many other devices, such as fabric filters, reactors, and catalysts destroy or capture other regulated pollutants. According to the New York Times, modern incineration plants are so clean that "many times more dioxin is now released from home fireplaces and backyard barbecues than from incineration". According to
4929-560: The coal-fired units. In May 2020, GenOn Holdings announced it would retire the three coal generating units, citing unfavorable market conditions and increased costs associated with environmental compliance. The coal units were shut down later in 2020. In August 2016 the Maryland Department of the Environment (MDE) fined Dickerson $ 1 million for releasing illegal amounts of nitrogen into the Potomac River. In August 2018 MDE required
5022-536: The combined process self-sustaining. In thermal WtE technologies, nearly all of the carbon content in the waste is emitted as carbon dioxide (CO 2 ) to the atmosphere (when including final combustion of the products from pyrolysis and gasification; except when producing biochar for fertilizer). Municipal solid waste (MSW) contain approximately the same mass fraction of carbon as CO 2 itself (27%), so treatment of 1 metric ton (1.1 short tons) of MSW produce approximately 1 metric ton (1.1 short tons) of CO 2 . In
5115-494: The community. According to a 2019 United Nations Environment Programme report, there are 589 WtE plants in Europe and 82 in the United States. The following are some examples of WtE plants. A single plant is currently under construction: The US Air Force once tested a Transportable Plasma Waste to Energy System (TPWES) facility (PyroGenesis technology) at Hurlburt Field, Florida. The plant, which cost $ 7.4 million to construct,
5208-459: The contribution of carbon capture and storage . Power generation using plastic waste will significantly increase by 2050. Carbon must be separated during energy recovery processes. Otherwise, the fight against global warming would fail due to plastic waste. MSW to a large extent is of biological origin (biogenic), e.g. paper, cardboard, wood, cloth, food scraps. Typically half of the energy content in MSW
5301-415: The converted fuel, thereby allowing higher combustion temperatures in e.g. boilers , gas turbines , internal combustion engines , fuel cells . Some advanced technologies are able to efficiently convert the energy in the feedstocks into liquid or gaseous fuels, using heat but in the absence of oxygen, without actual combustion, by using a combination of thermal technologies. Typically, they are cleaner, as
5394-628: The electricity generating industry in Maryland . The station was included in the spin-off from the Southern Company of Mirant in April 2001. Mirant was merged into GenOn Energy in 2010, and GenOn merged into NRG in 2012. In 1991, the 900-foot (270 m)-long cooling water discharge channel from the power plant, which empties into the Potomac River, became the Dickerson Whitewater Course ,
5487-485: The event that the waste was landfilled , 1 metric ton (1.1 short tons) of MSW would produce approximately 62 cubic metres (2,200 cu ft) methane via the anaerobic decomposition of the biodegradable part of the waste. This amount of methane has more than twice the global warming potential than the 1 metric ton (1.1 short tons) of CO 2 , which would have been produced by combustion. In some countries, large amounts of landfill gas are collected. However, there
5580-430: The evolution of the first trees . But bacteria and fungi did not immediately evolve the ability to decompose lignin, so the wood did not fully decay but became buried under sediment, eventually turning into coal. About 300 million years ago, mushrooms and other fungi developed this ability, ending the main coal-formation period of earth's history. Although some authors pointed at some evidence of lignin degradation during
5673-512: The factors involved in coalification, temperature is much more important than either pressure or time of burial. Subbituminous coal can form at temperatures as low as 35 to 80 °C (95 to 176 °F) while anthracite requires a temperature of at least 180 to 245 °C (356 to 473 °F). Although coal is known from most geologic periods , 90% of all coal beds were deposited in the Carboniferous and Permian periods. Paradoxically, this
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#17328695152415766-458: The feedstock is separated prior to treatment to remove the unwanted components: Thermal treatment technologies include: Non-thermal technologies: During the 2001–2007 period, the waste-to-energy capacity increased by about four million metric tons per year. Japan and China each built several plants based on direct smelting or on fluidized bed combustion of solid waste. In China there were about 434 waste-to-energy plants in early 2016. Japan
5859-406: The fermentation process, the sugar in the waste is converted to carbon dioxide and alcohol, in the same general process that is used to make wine. Normally fermentation occurs with no air present. Esterification can also be done using waste-to-energy technologies, and the result of this process is biodiesel . The cost-effectiveness of esterification will depend on the feedstock being used, and all
5952-498: The form of iron pyrite (FeS 2 ). Being a dense mineral, it can be removed from coal by mechanical means, e.g. by froth flotation . Some sulfate occurs in coal, especially weathered samples. It is not volatilized and can be removed by washing. Minor components include: As minerals, Hg, As, and Se are not problematic to the environment, especially since they are only trace components. They become however mobile (volatile or water-soluble) when these minerals are combusted. Most coal
6045-475: The heat and pressure of deep burial caused the loss of water, methane and carbon dioxide and increased the proportion of carbon. The grade of coal produced depended on the maximum pressure and temperature reached, with lignite (also called "brown coal") produced under relatively mild conditions, and sub-bituminous coal , bituminous coal , or anthracite coal (also called "hard coal" or "black coal") produced in turn with increasing temperature and pressure. Of
6138-421: The highest amount of electricity with the highest capacity to lessen pile of wastes in landfills through direct combustion. One process that is used to convert plastic into fuel is pyrolysis , the thermal decomposition of materials at high temperatures in an inert atmosphere. It involves change of chemical composition and is mainly used for treatment of organic materials. In large scale production, plastic waste
6231-431: The increasing tendency of the anthracite to break with a conchoidal fracture , similar to the way thick glass breaks. As geological processes apply pressure to dead biotic material over time, under suitable conditions, its metamorphic grade or rank increases successively into: There are several international standards for coal. The classification of coal is generally based on the content of volatiles . However
6324-721: The information they look for when considering such proposals. A 2019 report commissioned by the Global Alliance for Incinerator Alternatives (GAIA), done by the Tishman Environment and Design Center at The New School , found that 79% of the then 73 operating waste-to-energy facilities in the U.S. are located in low-income communities and/or "communities of color", because "of historic residential, racial segregation and expulsive zoning laws that allowed whiter, wealthier communities to exclude industrial uses and people of color from their boundaries." In Chester, Pennsylvania , where
6417-611: The last growing season. If these plants are regrown the CO 2 emitted from their combustion will be taken out from the atmosphere once more. Such considerations are the main reason why several countries administrate WtE of the biomass part of waste as renewable energy . The rest—mainly plastics and other oil and gas derived products—is generally treated as non-renewables . The CO 2 emissions from plastic waste-to-energy systems are higher than those from current fossil fuel-based power systems per unit of power generated, even after considering
6510-453: The morphology and some properties of the original plant. In many coals, individual macerals can be identified visually. Some macerals include: In coalification huminite is replaced by vitreous (shiny) vitrinite . Maturation of bituminous coal is characterized by bitumenization , in which part of the coal is converted to bitumen , a hydrocarbon-rich gel. Maturation to anthracite is characterized by debitumenization (from demethanation) and
6603-405: The most important distinction is between thermal coal (also known as steam coal), which is burnt to generate electricity via steam; and metallurgical coal (also known as coking coal), which is burnt at high temperature to make steel . Hilt's law is a geological observation that (within a small area) the deeper the coal is found, the higher its rank (or grade). It applies if the thermal gradient
6696-407: The nature of Carboniferous forests, which included lycophyte trees whose determinate growth meant that carbon was not tied up in heartwood of living trees for long periods. One theory suggested that about 360 million years ago, some plants evolved the ability to produce lignin , a complex polymer that made their cellulose stems much harder and more woody. The ability to produce lignin led to
6789-455: The number of double bonds between carbon). As carbonization proceeds, aliphatic compounds convert to aromatic compounds . Similarly, aromatic rings fuse into polyaromatic compounds (linked rings of carbon atoms). The structure increasingly resembles graphene , the structural element of graphite. Chemical changes are accompanied by physical changes, such as decrease in average pore size. The macerals are coalified plant parts that retain
6882-626: The one commissioned by the Renewable Energy Association in the UK, have been published that demonstrate how the carbon 14 result can be used to calculate the biomass calorific value. The UK gas and electricity markets authority, Ofgem , released a statement in 2011 accepting the use of Carbon 14 as a way to determine the biomass energy content of waste feedstock under their administration of the Renewables Obligation. Their Fuel Measurement and Sampling (FMS) questionnaire describes
6975-414: The other relevant factors such as transportation distance, amount of oil present in the feedstock, and others. Gasification and pyrolysis by now can reach gross thermal conversion efficiencies (fuel to gas) up to 75%, however, a complete combustion is superior in terms of fuel conversion efficiency. Some pyrolysis processes need an outside heat source which may be supplied by the gasification process, making
7068-456: The pre-combustion treatment, turbine technology (e.g. supercritical steam generator ) and the age of the plant. A few integrated gasification combined cycle (IGCC) power plants have been built, which burn coal more efficiently. Instead of pulverizing the coal and burning it directly as fuel in the steam-generating boiler, the coal is gasified to create syngas , which is burned in a gas turbine to produce electricity (just like natural gas
7161-409: The propane yield is approximately 80%. There are a number of other new and emerging technologies that are able to produce energy from waste and other fuels without direct combustion. Many of these technologies have the potential to produce more electric power from the same amount of fuel than would be possible by direct combustion. This is mainly due to the separation of corrosive components (ash) from
7254-427: The reacting groups are attached. Dehydration and decarboxylation take place early in coalification, while demethanation begins only after the coal has already reached bituminous rank. The effect of decarboxylation is to reduce the percentage of oxygen, while demethanation reduces the percentage of hydrogen. Dehydration does both, and (together with demethanation) reduces the saturation of the carbon backbone (increasing
7347-543: The same results. Carbon 14 dating can determine with precision the biomass fraction of waste, and also determine the biomass calorific value . Determining the calorific value is important for green certificate programs such as the Renewable Obligation Certificate program in the United Kingdom. These programs award certificates based on the energy produced from biomass. Several research papers, including
7440-399: The sulfur and most of the nitrogen is incorporated into the organic fraction in the form of organosulfur compounds and organonitrogen compounds . This sulfur and nitrogen are strongly bound within the hydrocarbon matrix. These elements are released as SO 2 and NO x upon combustion. They cannot be removed, economically at least, otherwise. Some coals contain inorganic sulfur, mainly in
7533-465: The updated federal standards in 2015. NRG operates the combustion turbines as peaking generation. The Dickerson Generating Station is dispatched by the PJM Interconnection regional transmission organization . In 2008 the plant's flue-gas desulfurization system consumed 190,000 tons of limestone and generated 310,000 of synthetic gypsum . The Montgomery County Resource Recovery Facility,
7626-658: The volume of the original waste by 95-96 percent, depending upon composition and degree of recovery of materials such as metals from the ash for recycling. Incinerators may emit fine particulate , heavy metals, trace dioxin and acid gas , even though these emissions are relatively low from modern incinerators. Other concerns include proper management of residues: toxic fly ash , which must be handled in hazardous waste disposal installation as well as incinerator bottom ash (IBA), which must be reused properly. Critics argue that incinerators destroy valuable resources and they may reduce incentives for recycling. The question, however,
7719-415: The world's coal-generated electricity. Efforts around the world to reduce the use of coal have led some regions to switch to natural gas and renewable energy . In 2018 coal-fired power station capacity factor averaged 51%, that is they operated for about half their available operating hours. Coke is a solid carbonaceous residue that is used in manufacturing steel and other iron-containing products. Coke
7812-574: Was 8.3 billion tonnes in 2022, and is set to remain at record levels in 2023. To meet the Paris Agreement target of keeping global warming below 2 °C (3.6 °F) coal use needs to halve from 2020 to 2030, and "phasing down" coal was agreed upon in the Glasgow Climate Pact . The largest consumer and importer of coal in 2020 was China , which accounts for almost half the world's annual coal production, followed by India with about
7905-574: Was based on the trading of this commodity. Coal continues to arrive on beaches around the world from both natural erosion of exposed coal seams and windswept spills from cargo ships. Many homes in such areas gather this coal as a significant, and sometimes primary, source of home heating fuel. Coal consists mainly of a black mixture of diverse organic compounds and polymers. Of course, several kinds of coals exist, with variable dark colors and variable compositions. Young coals (brown coal, lignite) are not black. The two main black coals are bituminous, which
7998-504: Was carried to London by sea. In 1257–1259, coal from Newcastle upon Tyne was shipped to London for the smiths and lime -burners building Westminster Abbey . Seacoal Lane and Newcastle Lane, where coal was unloaded at wharves along the River Fleet , still exist. These easily accessible sources had largely become exhausted (or could not meet the growing demand) by the 13th century, when underground extraction by shaft mining or adits
8091-595: Was closed and sold at a government liquidation auction in May 2013, less than three years after its commissioning. The opening bid was $ 25. The winning bid was sealed. Besides large plants, domestic waste-to-energy incinerators also exist. For example, the Refuge de Sarenne has a domestic waste-to-energy plant. It is made by combining a wood-fired gasification boiler with a Stirling motor . Renergi will scale up their system of converting waste organic materials into liquid fuels using
8184-602: Was developed in the Soviet Union , or in an MHD topping cycle . However these are not widely used due to lack of profit. In 2017 38% of the world's electricity came from coal, the same percentage as 30 years previously. In 2018 global installed capacity was 2 TW (of which 1TW is in China) which was 30% of total electricity generation capacity. The most dependent major country is South Africa, with over 80% of its electricity generated by coal; but China alone generates more than half of
8277-408: Was developed. The alternative name was "pitcoal", because it came from mines. Cooking and home heating with coal (in addition to firewood or instead of it) has been done in various times and places throughout human history, especially in times and places where ground-surface coal was available and firewood was scarce, but a widespread reliance on coal for home hearths probably never existed until such
8370-490: Was during the Late Paleozoic icehouse , a time of global glaciation . However, the drop in global sea level accompanying the glaciation exposed continental shelves that had previously been submerged, and to these were added wide river deltas produced by increased erosion due to the drop in base level . These widespread areas of wetlands provided ideal conditions for coal formation. The rapid formation of coal ended with
8463-550: Was once known as "steam coal" as it was widely used as a fuel for steam locomotives . In this specialized use, it is sometimes known as "sea coal" in the United States. Small "steam coal", also called dry small steam nuts (DSSN), was used as a fuel for domestic water heating . Coal played an important role in industry in the 19th and 20th century. The predecessor of the European Union , the European Coal and Steel Community ,
8556-413: Was published in 2010. Since each method suffered from limitations in properly characterizing the biomass fraction, two alternative methods have been developed. The first method uses the principles of radiocarbon dating . A technical review (CEN/TR 15591:2007) outlining the carbon 14 method was published in 2007. A technical standard of the carbon dating method (CEN/TS 15747:2008) is published in 2008. In
8649-430: Was used for electricity generation. Coal burnt in coal power stations to generate electricity is called thermal coal . It is usually pulverized and then burned in a furnace with a boiler . The furnace heat converts boiler water to steam , which is then used to spin turbines which turn generators and create electricity. The thermodynamic efficiency of this process varies between about 25% and 50% depending on
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