It was formed by the decomposition of plant matter, and it is a complex substance that can be found in many forms. Coal is divided into four classes: anthracite, bituminous, subbituminous, and lignite. Elemental analysis gives empirical formulas such as C 137 H 97 O 9 NS for bituminous coal and C 240 H 90 O 4 NS for highgrade anthracite.
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THE FORMATION OF COAL What is Coal? Coal is a combustible, sedimentary, organic rock formed from ancient vegetation, which has been consolidated between other rock strata and transformed by the combined effects of microbial action, pressure and heat over a considerable time. This process is referred to as 'coalification'.
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The formation process of CNTs is as follows: coal takes pyrolysis to produce small carboncontaining molecules such as CH 4, and the small carboncontaining molecules formed CNTs through catalytic cracking under the action of catalyst. A "stepwise growth" model of CNTs was established. ... we took bituminous coal as the raw material and ...
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Lignite typically transforms to bituminous coal as it is compressed further and heated to 100°C200°C. This drives much of the water and other volatiles from the coal. Longer exposure to elevated temperature will further drive volatiles from the coal, and ... Coal formation is a continuing process (some of our newest coal is a mere 1 ...
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The formation process of CNTs is as follows: coal takes pyrolysis to produce small carboncontaining molecules such as CH4, and the small carboncontaining molecules formed CNTs through catalytic ...
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Fossil fuels are nonrenewable sources of energy formed from the organic matter of plants and microorganisms that lived millions of years ago. The natural resources that typically fall under this category are coal, oil (petroleum), and natural gas. This energy (and CO 2) was originally captured via photosynthesis by living organisms such as plants, algae, and photosynthetic bacteria.
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Bitumen is a sticky, black, and highly viscous liquid or semisolid form of petroleum. It is often confused with asphalt and tar, but they are different materials. Asphalt is a mixture of bitumen and aggregates (stone, sand, gravel), whereas tar is a thick, dark liquid derived from the distillation of coal.
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The Bergius process is a method of production of liquid hydrocarbons for use as synthetic fuel by hydrogenation of highvolatile bituminous coal at high temperature and pressure. It was first developed by Friedrich Bergius in 1913. In 1931 Bergius was awarded the Nobel Prize in Chemistry for his development of highpressure chemistry.
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Bituminous coal is the product of further coal metamorphosis and has a medium degree of coalification. It is an important boiler fuel and coking material, also used for dry distillation of oil and gas production. Bituminous coal accounts for about 80% of China's total coal resources, which is much higher than lignite (6%) and anthracite (12%).
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As for bituminous coal liquefaction technology, the RD program of the NEDOL process started in 1984. Fig. shows a flow diagram of the NEDOL process (Wasaka, 1999b; Wasaka et al., 2003). The NEDOL process liquefies coal by using a Febased catalyst and hydrotreated solvent under relatively mild reaction conditions of 430460 °C and hydrogen pressure of 1520 MPa.
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syncrude from bitumen. Figure 2 is an image of petroleum coke showing different types and sizes of coke. Figure 2. Petroleum coke [4]. Coke can also be obtained from coal. There are two types of reactions that occur in the formation of coke from coal [5]. These are: 1. the cracking reactions, which consist of the rupture of carboncarbon bonds.
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Characteristics of Bituminous Coal. Bituminous coal contains moisture of up to approximately 17%. About to 2 percent of the weight of bituminous coal is nitrogen. Its fixed carbon content ranges up to approximately 85 percent, with ash content up to 12% by weight. Bituminous coal can be categorized further by the level of volatile matter ...
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Bituminous Coal Bituminous coal is formed under more heat and pressure, and is 100 million to 300 million years old. It is named after the sticky, ... In the United States, the Surface Mining Control and Reclamation Act of 1977 regulates the process of coal mining, and is an effort to limit the harmful effects on the environment. The act ...
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Pyrolysis, as a process technology, has received considerable attention from many researchers because it is an important intermediate stage in coal conversion. Reactions parameters as the ...
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Coal rank is a quantity used to describe the degree of coal mineralization in the coal formation process. Generally, coal is divided into anthracite (highrank coal), bituminous coal (midrank ...
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Coal is a naturally occurring sedimentary carbonaceous rock composed of at least 50% organic matter by weight, and 70% carbonaceous material by volume, mostly from the diagenesis (chemical and physical alteration) of plant material in buried peat (Schopf 1956, 1966; Alpern and DeSousa 2002 ). Coal is a solid hydrocarbon .
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Experimental principle. To study the cracking characteristics induced by the SCCO 2 phase change in the microcracks of coal during SCCO 2 jet coal breaking, SEM was used to analyze the variation pattern of coal surface cracks and to determine whether a phase change fracture effect occurs in the process of SCCO 2 coal breaking. A laser particle size analyzer was used to analyze the ...
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The upgraded coal (semicoke) can be utilized in ironmaking process. Thermogravimetry and DAEM were used to analyze the combustion kinetics of bituminous coal before and after modification in this study.
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The four ranks are: Anthracite: The highest rank of coal. 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. Bituminous: Bituminous coal is a middle rank coal between subbituminous and anthracite. Bituminous coal usually has a high ...
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cracking process in coal tar [10]. Effect of temperature on feedstock pyrolysis In this research, catalytic cracking of tar was carried out to break hydrocarbon compounds with large molecular weights into hydrocarbon compounds with small molecular weight—the cracking results of coal tar at varying temperatures presented in table 2. Table 2.
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Intensive studies on volatile formation mechanisms and its molecular distributions are of great significance to regulate CH 4 content in syngas during integrated coal gasification coupling pyrolysis system. Two bituminous coals were thoroughly characterized with FTIR and solidstate 13 C NMR to afford their bond structures and then pyrolytic volatiles were in depth explored with the ...
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As one of the most important primary energy, bituminous coal has been widely applied in many fields. The combustion studies of bituminous coal have attracted a lot of attention due to the releases of hazardous emissions. This work focuses on the investigation of combustion characteristics of Shenmu bituminous pulverized coal as a representative bituminous coal in China with a combined TGMS ...
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Bituminous coal is dense and mediumgrade coal that has a higher heating value than lignite and subbituminous coal. Bituminous coal contains 4586% carbon and is between 100300 million years old. ... Coal formation is a continuous process lasting hundreds of millions of years. This is why it is known as a ˜fossil fuel™.
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Bituminous Coal Bituminous coal is formed under more heat and pressure, and is 100 million to 300 million years old. It is named after the sticky, ... In the United States, the Surface Mining Control and Reclamation Act of 1977 regulates the process of coal mining, and is an effort to limit the harmful effects on the environment. The act ...
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The amount of coal burned during 2007 was estimated at billion short tons, or quadrillion BTU's. This is an average of million BTU per short ton. In terms of heat content, this is about 57,000,000 barrels (9,100,000 m 3) of oil equivalent per day.
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Bitumen occurs as a secondary organic matter generated during catagenesis due to (1) thermal cracking of kerogen in the initial/incipient oil window (exsudatinite is likely to be the maceral ...
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It can be concluded that the pyrolysis of bituminous coal occurred with a certain delay, especially at the higher heating rates. As shown in Fig. 1 (a), the three stages for the bituminous coal pyrolysis process can be divided into dry degassing, active decomposition, and slow condensation. The first stage before 270℃ is a slow loss of mass.
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Bituminous coal decomposition has been previously considered as a threestage process, where during the first stage it undergoes cleavage of bond, melting and formation of metaplast. Meanwhile, volatile gases form bubbles within the plastic phase and the pressure generated in the bubbles causes substantial swelling.
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The maceral composition of coals is defined by many factors such as specific features of the coalification processes, the nature of the initial plant material and the conditions of its accumulation and decomposition (Epshtein et al., 2015). The carbon contain of coals varies from 65 to 95% depending on the degree of the coal metamorphism.
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A major problem associated with the burning of bituminous coal is air bituminous coal with a high sulfur content releases sulfur oxides into the air. Under certain conditions, nitrogen present in coal is also released in the form of nitrogen oxides. When moisture in the atmosphere reacts with these gases, acids such as sulfuric acid are produced and fall to Earth as wet acid ...
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Tursun et al. [56] carried out steam gasification of bituminous coal and saw dust blend at a temperature of 850 °C, The study reported that with the increase of gasification temperature, the tar yield decrease because, at higher temperature and olivine as a catalyst, the cracking and reforming reaction improved which leads to less tar ...
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The coal formation process involves the burial of peat, which is made of partly decayed plant materials, deep underground. The heat and pressure of burial alters the texture and increases the carbon content of the peat, which transforms it into coal, a type of sedimentary rock. This process takes millions of years. Types, or "ranks," of coal are determined by carbon content. There are four ...
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