Misplaced Pages

#480519

45-412: The economy is dominated by the 1,878 MW Hongsa lignite -fired power plant adjacent to Thailand's Nan Province . The Hongsa plant accounts for around a third of Lao energy production. Almost all of its power is exported to Thailand. The plant is 80% Thai-owned, backed by nine Thai banks. Thai residents have seen negative impacts on their farms, watershed, and environment from pollution that may originate at

90-409: A carbon content around 25–35% and is considered the lowest rank of coal due to its relatively low heat content . When removed from the ground, it contains a very high amount of moisture , which partially explains its low carbon content. Lignite is mined all around the world and is used almost exclusively as a fuel for steam-electric power generation . Lignite combustion produces less heat for

135-485: A carbon content of 60–70 percent on a dry ash-free basis. However, its inherent moisture content is sometimes as high as 75 percent and its ash content ranges from 6–19 percent, compared with 6–12 percent for bituminous coal . As a result, its carbon content on the as-received basis (i.e., containing both inherent moisture and mineral matter) is typically just 25-35 percent. The energy content of lignite ranges from 10 to 20 MJ/kg (9–17 million BTU per short ton ) on

180-560: A fuel for poor people compared to higher value hard coals. In Germany, briquettes are still readily available to end consumers in home improvement stores and supermarkets. An environmentally beneficial use of lignite is in agriculture. Lignite may have value as an environmentally benign soil amendment , improving cation exchange and phosphorus availability in soils while reducing availability of heavy metals, and may be superior to commercial K humates. Lignite fly ash produced by combustion of lignite in power plants may also be valuable as

225-732: A moist, mineral-matter-free basis. The energy content of lignite consumed in the United States averages 15 MJ/kg (13 million BTU/ton), on the as-received basis. The energy content of lignite consumed in Victoria, Australia, averages 8.6 MJ/kg (8.2 million BTU/ton) on a net wet basis. Lignite has a high content of volatile matter which makes it easier to convert into gas and liquid petroleum products than higher-ranking coals. Its high moisture content and susceptibility to spontaneous combustion can cause problems in transportation and storage. Processes which remove water from brown coal reduce

270-517: A period of eight days is not considered to be hazardous. There are many factors involved, among them the type of wood and the temperature at which the charcoal was prepared. Extensive studies have been completed on the self-heating of coal. Improper storage of coal is a main cause of spontaneous combustion, as there can be a continuous oxygen supply and the oxidization of coal produces heat that doesn't dissipate. Over time, these conditions can cause self-heating. The tendency to self-heat decreases with

315-417: A pile of material that would have been safe at a low ambient temperature may spontaneously combust during hotter weather. Hay and compost piles may self-ignite because of heat produced by bacterial fermentation , which then can cause pyrolysis and oxidation that leads to thermal runaway reactions that reach autoignition temperature. Rags soaked with drying oils or varnish can oxidize rapidly due to

360-430: A result of increased temperatures and pressures underground. Lignite forms from peat that has not been subjected to deep burial and heating. It forms at temperatures below 100 °C (212 °F), primarily by biochemical degradation. This includes the process of humification, in which microorganisms extract hydrocarbons from peat and form humic acids, which decrease the rate of bacterial decay. In lignite, humification

405-413: A soil amendment and fertilizer. However, rigorous studies of the long-term benefits of lignite products in agriculture are lacking. Lignite may also be used for the cultivation and distribution of biological control microbes that suppress plant pests. The carbon increases the organic matter in the soil while the biological control microbes provide an alternative to chemical pesticides. Leonardite

450-425: A substance with a relatively low ignition temperature such as hay, straw, peat, etc., begins to release heat. This may occur in several ways, either by oxidation in the presence of moisture and air, or bacterial fermentation , which generates heat. These materials are thermal insulators that prevent the escape of heat causing the temperatures of the material to rise above its ignition point. Combustion will begin when

495-484: A sufficient oxidizer , such as oxygen, and fuel are present to maintain the reaction into thermal runaway. Thermal runaway can occur when the amount of heat produced is greater than the rate at which the heat is lost. Materials that produce a lot of heat may combust in relatively small volumes, while materials that produce very little heat may only become dangerous when well insulated or stored in large volumes. Most oxidation reactions accelerate at higher temperatures, so

SECTION 10

#1732793146481

540-600: Is a hardened, gem-like form of lignite used in various types of jewelry. Germany is the largest producer of lignite, followed by China , Russia , and United States . Lignite accounted for 8% of all U.S. coal production in 2019. – no data available Spontaneous combustion Spontaneous combustion or spontaneous ignition is a type of combustion which occurs by self-heating (increase in temperature due to exothermic internal reactions ), followed by thermal runaway (self heating which rapidly accelerates to high temperatures) and finally, autoignition . It

585-563: Is a soil conditioner rich in humic acids that is formed by natural oxidation when lignite comes in contact with air. The process can be replicated artificially on a large scale. The less matured xyloid (wood-shaped) lignite also contains high amounts of humic acid. Reaction with quaternary amine forms a product called amine-treated lignite (ATL), which is used in drilling mud to reduce fluid loss during drilling. Lignite may have potential uses as an industrial adsorbent . Experiments show that its adsorption of methylene blue falls within

630-536: Is called slacking or slackening . Most lignite is used to generate electricity. However, small amounts are used in agriculture , in industry , and even, as jet , in jewelry . Its historical use as fuel for home heating has continuously declined and is now of lower importance than its use to generate electricity. Lignite is often found in thick beds located near the surface, making it inexpensive to mine. However, because of its low energy density , tendency to crumble, and typically high moisture content, brown coal

675-536: Is distinct from (but has similar practical effects to) pyrophoricity , in which a compound needs no self-heat to ignite. The correct storage of spontaneously combustible materials is extremely important considering improper storage is the main cause of spontaneous combustion. Materials such as coal, cotton, hay, and oils should be stored at proper temperatures and moisture levels to prevent spontaneous combustion. Allegations of spontaneous human combustion are considered pseudoscience. Spontaneous combustion can occur when

720-734: Is inefficient to transport and is not traded extensively on the world market compared with higher coal grades. It is often burned in power stations near the mines, such as in Poland's Bełchatów plant and Turów plant , Australia's Latrobe Valley and Luminant 's Monticello plant and Martin Lake plant in Texas. Primarily because of latent high moisture content and low energy density of brown coal, carbon dioxide emissions from traditional brown-coal-fired plants are generally much higher per megawatt-hour generated than for comparable black-coal plants, with

765-413: Is just below the level required for germinating seed, the activity of mold fungi is a likely candidate for generating heat. This was established for flax and sunflower seeds, and soy beans. Many of the oil seeds generate oils that are self-heating. Palm kernels, rapeseed, and cotton seed have also been studied. Rags soaked in linseed oil can spontaneously ignite if improperly stored or discarded. Copra ,

810-472: Is one of a number of projects by organiser Elefantasia to conserve and raise awareness of Laos's elephant population. One of the town's monasteries, Wat Simungkhun, contains a stone platform allegedly covering a hole "leading to the end of the world". Lignite Lignite (derived from Latin lignum meaning 'wood'), often referred to as brown coal , is a soft, brown, combustible sedimentary rock formed from naturally compressed peat . It has

855-492: Is partial, coming to completion only when the coal reaches sub-bituminous rank. The most characteristic chemical change in the organic material during formation of lignite is the sharp reduction in the number of C=O and C-O-R functional groups. Lignite deposits are typically younger than higher-ranked coals, with the majority of them having formed during the Tertiary period. Lignite is often found in thick beds located near

900-596: The railway network was dependent on lignite either through steam trains or electrified lines mostly fed with lignite derived power. As per the table below, East Germany was the largest producer of lignite for much of its existence as an independent state. In 2014, about 12 percent of Germany's energy and, specifically, 27 percent of Germany's electricity came from lignite power plants, while in 2014 in Greece , lignite provided about 50 percent of its power needs. Germany has announced plans to phase out lignite by 2038 at

945-475: The Hongsa plant. The plant has been at the centre of land grab controversies, with thousands of residents reportedly losing land and receiving little compensation. The economy of Hongsa is being transformed by the Hongsa power plant. Plant construction is provided about 3,000 jobs and average local incomes have already risen sharply. Once the plant goes online, local officials anticipate further employment growth with

SECTION 20

#1732793146481

990-419: The amount of carbon dioxide and sulfur released than other ranks of coal. As a result, lignite is the most harmful coal to human health. Depending on the source, various toxic heavy metals , including naturally occurring radioactive materials , may be present in lignite and left over in the coal fly ash produced from its combustion, further increasing health risks. Lignite is brownish-black in color and has

1035-460: The amount of oxygen available in the hay. At 100 °C, wet hay absorbed twice the amount of oxygen of dry hay. There has been conjecture that the complex carbohydrates present in hay break down to simpler sugars, which are more readily fermented to ethanol. Charcoal, when freshly prepared, can self-heat and catch fire. This is separate from hot spots which may have developed from the preparation of charcoal. Charcoal that has been exposed to air for

1080-420: The area remains saturated with water, which covers dead vegetation and protects it from atmospheric oxygen. Otherwise, peat swamps are found in a variety of climates and geographical settings. Anaerobic bacteria may contribute to the degradation of peat, but this process takes a long time, particularly in acidic water. Burial by other sediments further slows biological degradation, and subsequent transformations are

1125-578: The creation of factories to export to Thailand and other ASEAN nations. The Hongsa power plant is a coal-fired plant supplying the majority of its electricity to neighbouring Thailand . The project cost is estimated at US$ 3.7 billion with completion in 2015. The plant is 80% Thai-owned, with the remaining 20% held by the Lao government. Its capacity is 1,878 megawatts, of which 1,500 MW is exported to Thailand. The plant, and associated lignite mine, will be Laos's largest. While project officials have highlighted

1170-417: The dried, white flesh of the coconut from which coconut oil is extracted, has been classed with dangerous goods due to its spontaneously combustive nature. It is identified as a Division 4.2 substance. There have been unconfirmed anecdotal reports of people spontaneously combusting. This alleged phenomenon is not considered true spontaneous combustion, as supposed cases have been largely attributed to

1215-505: The economic benefits of the plant, environmental groups have raised concerns about the impact of the project on the local people and environment. Concerns include: The annual Elephant Festival, held in February each year, has attracted increasing numbers of visitors to the province. In 2008, the festival attracted more than 50,000 visitors. The venue of the festival rotates between nearby Ban Viengkeo, Pak Lay and Sainyabuli . The festival

1260-931: The governments of Japan and Australia has begun extracting hydrogen from brown coal. The liquefied hydrogen will be shipped via the transporter Suiso Frontier to Japan. The largest lignite deposits in North America are the Gulf Coast lignites and the Fort Union lignite field. The Gulf Coast lignites are located in a band running from Texas to Alabama roughly parallel to the Gulf Coast. The Fort Union lignite field stretches from North Dakota to Saskatchewan . Both are important commercial sources of lignite. Lignite can be separated into two types: xyloid lignite or fossil wood , and compact lignite or perfect lignite. Although xyloid lignite may sometimes have

1305-474: The increasing rank of the coal. Lignite coals are more active than bituminous coals , which are more active than anthracite coals. Freshly mined coal consumes oxygen more rapidly than weathered coal, and freshly mined coal self-heats to a greater extent than weathered coal. The presence of water vapor may also be important, as the rate of heat generation accompanying the absorption of water in dry coal from saturated air can be an order of magnitude or more than

1350-881: The land has been restored to full productivity. A bond (not necessary in this form) for mine reclamation is required in the US by the Surface Mining Control and Reclamation Act of 1977 . The Latrobe Valley in Victoria , Australia , contains estimated reserves of some 65 billion tonnes of brown coal. The deposit is equivalent to 25 percent of known world reserves. The coal seams are up to 98 m (322 ft) thick, with multiple coal seams often giving virtually continuous brown coal thickness of up to 230 m (755 ft). Seams are covered by very little overburden (10 to 20 m (33 to 66 ft)). A partnership led by Kawasaki Heavy Industries and backed by

1395-708: The large surface area, and even a small pile can produce enough heat to ignite under the right conditions. Coal can ignite spontaneously when exposed to oxygen, which causes it to react and heat up when there is insufficient ventilation for cooling. Pyrite oxidation is often the cause of coal's spontaneous ignition in old mine tailings . Pistachio nuts are highly flammable when stored in large quantities, and are prone to self-heating and spontaneous combustion. Large manure piles can spontaneously combust during conditions of extreme heat. Cotton and linen can ignite when they come into contact with polyunsaturated vegetable oils (linseed, massage oils); bacteria will slowly decompose

Hongsa - Misplaced Pages Continue

1440-473: The latest. Greece has confirmed that the last coal plant will be shut in 2025 after receiving pressure from the European Union and plans to heavily invest in renewable energy . Lignite was and is used as a replacement for or in combination with firewood for home heating. It is usually pressed into briquettes for that use. Due to the smell it gives off when burned, lignite was often seen as

1485-407: The lignite is removed, restoration involves grading the mine spoil to as close an approximation as practical of the original ground surface (Approximate Original Contour or AOC). Subsoil and topsoil are restored and the land reseeded with various grasses. In North Dakota , a performance bond is held against the mining company for at least ten years after the end of mining operations to guarantee that

1530-434: The majority occurring in the fourth or fifth week. The process may begin with microbiological activity (bacteria or mold) which ferments the hay, creating ethanol. Ethanol has a flash point of 14 °C (57 °F). So with an ignition source such as static electricity, e.g. from a mouse running through the hay, combustion may occur. The temperature then increases, igniting the hay itself. Microbiological activity reduces

1575-415: The materials, producing heat. If these materials are stored in a way so the heat cannot escape, the heat buildup increases the rate of decomposition and thus the rate of heat buildup increases. Once ignition temperature is reached, combustion occurs with oxidizers present (oxygen). Nitrate film , when improperly stored, can deteriorate into an extremely flammable condition and combust. The 1937 Fox vault fire

1620-746: The range of activated carbons currently used by industry. Jet is a form of lignite that has been used as a gemstone. The earliest jet artifacts date to 10,000 BCE and jet was used extensively in necklaces and other ornamentation in Britain from the Neolithic until the end of Roman Britain . Jet experienced a brief revival in Victorian Britain . Lignite begins as partially decayed plant material, or peat. Peat tends to accumulate in areas with high moisture, slow land subsidence , and no disturbance by rivers or oceans – under these conditions,

1665-414: The risk of spontaneous combustion to the same level as black coal, increase the calorific value of brown coal to a black coal equivalent fuel, and significantly reduce the emissions profile of 'densified' brown coal to a level similar to or better than most black coals. However, removing the moisture increases the cost of the final lignite fuel. Lignite rapidly degrades when exposed to air. This process

1710-467: The risk of spontaneous combustion. A striking example of a cargo igniting spontaneously occurred on the ship Earl of Eldon in the Indian Ocean on 24 August 1834. Oil seeds and residue from oil extraction will self-heat if too moist. Typically, storage at 9–14% moisture is satisfactory, but limits are established for each individual variety of oil seed. In the presence of excess moisture that

1755-412: The same amount of dry air. Cotton too can be at great risk of spontaneous combustion. In an experimental study on the spontaneous combustion of cotton, three different types of cotton were tested at different heating rates and pressures. Different cotton varieties can have different self-heating oxidation temperature and larger reactions. Understanding what type of cotton is being stored will help reduce

1800-422: The subsurface beds. Topsoil and subsoil must be properly removed and either used to reclaim previously mined-out areas or stored for future reclamation. Excavator and truck overburden removal prepares the area for dragline overburden removal to expose the lignite beds. These are broken up using specially equipped tractors ( coal ripping ) and then loaded into bottom dump trucks using front loaders . Once

1845-409: The surface. These are inexpensive to extract using various forms of surface mining , though this can result in serious environmental damage. Regulations in the United States and other countries require that land that is surface mined must be restored to its original productivity once mining is complete. Strip mining of lignite in the United States begins with drilling to establish the extent of

Hongsa - Misplaced Pages Continue

1890-401: The tenacity and the appearance of ordinary wood, it can be seen that the combustible woody tissue has experienced a great modification. It is reducible to a fine powder by trituration , and if submitted to the action of a weak solution of potash , it yields a considerable quantity of humic acid . Leonardite is an oxidized form of lignite, which also contains high levels of humic acid. Jet

1935-501: The world's highest-emitting plant being Australia's Hazelwood Power Station until its closure in March 2017. The operation of traditional brown-coal plants, particularly in combination with strip mining , is politically contentious due to environmental concerns. The German Democratic Republic relied extensively on lignite to become energy self-sufficient , and eventually obtained 70% of its energy requirements from lignite. Lignite

1980-496: Was also an important chemical industry feedstock via Bergius process or Fischer-Tropsch synthesis in lieu of petroleum, which had to be imported for hard currency following a change in policy by the Soviet Union in the 1970s, which had previously delivered petroleum at below market rates. East German scientists even converted lignite into coke suitable for metallurgical uses ( high temperature lignite coke ) and much of

2025-506: Was caused by spontaneously combusting nitrate film. Hay is one of the most widely studied materials in spontaneous combustion. It is very difficult to establish a unified theory of what occurs in hay self-heating because of the variation in the types of grass used in hay preparation, and the different locations where it is grown. It is anticipated that dangerous heating will occur in hay that contains more than 25% moisture. The largest number of fires occur within two to six weeks of storage, with

#480519