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Prevention and control of coal spontaneous combustion are key to coal mining and storage. Existing technologies for the detection of coal spontaneous combustion have limitations, but coal spontaneous combustion creates some serious disasters in areas of the world where coal mining and/or storage exists. New technologies to detect coal …
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The major source of NOx production from nitrogen-bearing fuels such as certain coals and oil, is the conversion of fuel bound nitrogen to NOx during combustion. During combustion, the nitrogen bound in …
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Combustion of low-volatile coals requires added attention to the boiler design to achieve and sustain combustion (Hough and al, 1987). In drop-tube-furnace studies of a wide rank range of coals, Bengtsson (1986) found that a low volatile bituminous coal had poor reactivity at 800 °C, with it being only slightly more reactive than an ...
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The spontaneous combustion of coal is affected by many factors, among which the influence of water is significant and complicated. To explore the influence of water on the spontaneous combustion characteristics of goaf residual coal, coal samples with similar particle size distributions to those of goaf residual coal were prepared. After the …
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Oxy–fuel (O2/CO2) combustion technology shows great potential for carbon reduction. However, difference in the combustion atmosphere would affect coal combustion characteristics and pollutant emissions. In order to explore oxy–fuel combustion characteristics, two typical Chinese coals, sub–bituminous and lean coal, …
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1. Introduction. According to the 2020 Global Air Quality Report, 82 of the 106 countries tested failed to meet the World Health Organization air quality standards, and air pollution remains one of the major threats to environmental health in the world. 1−3 Coal combustion is the main cause of air pollution in various countries. In China, coal-fired …
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Rare earth elements (REEs) are critical and strategic materials in the defense, energy, electronics, and automotive industries. The reclamation of REEs from coal combustion fly ash has been proposed as a way to supplement REE mining. However, the typical REE contents in coal fly ash, particularly in the United States, have not been comprehensively …
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It is deduced that the combustion process is inhibited to a certain extent by water washing which implies that sodium has some catalytic effect on coal combustion. Easy combustibility and long-lasting combustion were the distinctive effects of coal cleaning on raw coals when Kok et al. [18], [34] employed sink-float tests with organic solvent ...
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Biomass is considered as an environment friendly fuel and has some advantages over fossil fuels like coal. Biomass contains little sulfur and nitrogen. Biomass co-combustion has vital positive SO 2 reductions of up to 75%. Most of nitrogen in biomass is converted to NH 3 products such as ammonia NH 3 during combustion.
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The occurrence of spontaneous combustion is not limited to coal but the phenomenon is known to take place in a number of coal-shale, pyritic black shale and coal refuse (Kim and Chaiken 1990; Onifade and Genc 2018e, f, g; Restuccia et al. 2017; Rumball et al. 1986).The principles that control spontaneous combustion are similar in …
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During combustion, the nitrogen in coal can be converted to ammonia, elemental nitrogen, or nitrogen oxides depending on the conditions of burning and the nature of the coal used. Nitrogen values could possibly be used to estimate the amount of nitrogen oxides that would be emitted upon burning of certain coals.
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Based on TGA data, burning profiles of coals were obtained and used to identify the desirable blend ratio for combustion of two or more coals. However, all the studies were carried out with the emphasis on the environmental impact of coal burning or economy of coal blending process. ... Certain physical and chemical activity such as …
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This review presents an overview of trace element chemistry in coal combustion systems with an emphasis on what has been learned over the past century …
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Coal Combustion. In coal combustion, the dominant source (as much as 80%) of NOx is the coal (fuel NOx), with secondary thermal NOx formed from the heating of atmospheric …
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Certain coal variants may be predisposed to self-heating, risking spontaneous combustion in holds where both combustible and noxious gases, inclusive of carbon monoxide, are prevalent. Moreover, specific coals can react with water, generating corrosive acids. Further, volatile and noxious gases such as hydrogen can be emitted.
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Why do certain coals burn better than others? This is a question that took a long time to be answered. ... The specific purposes for which coal combustion is directly utilised include (i) power generation, (ii) hot steam for industry, (iii) the heat for industrial furnaces for cement and ceramics production, and (iv) building heating and ...
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Also BL sample has relatively more volatile matter. Both coals have high ash fusion temperatures but BL coal ash consists of high proportion of refractory minerals e.g. SiO 2, Al 2 O 3 and TiO 2. Hence, BL coal has better amenability for easy ignition and its combustion characteristics are expected to be improved than the AH.
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Coal, containing all the elements that are present in nature and more than 200 minerals, has a complex chemical structure, making it one of the most c…
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The main gas components produced in the process of coal oxidation and spontaneous combustion include CO, CO 2, CH 4, C 2 H 4, C 2 H 6, and C 2 H 2. …
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bituminous coals range from 10,720 to 14,730 Btu/lb. 3 The heating values of subbituminous coals range from 8,300 to 11,500 Btu/lb on a wet, mineral-matter-free basis 2, and from 9,420 to 10,130 Btu/lb on an as-mined basis. 3 Formulae and tables for classifying coals are given in Reference 2. 1.1.2 Firing Practices 4
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The data show that various applications and technological problems concerning coal, such as correlation of different coals, prospecting and recovery of valuable compounds, coal preparation, combustion performance, prediction of combustion residues, slagging, abrasion, and corrosion, are related directly or indirectly to specific …
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Abstract. Underground coal gasification is an in situ coal utilization technique that has immense potential as a future clean coal technology. UCG possesses a number of advantages including the ability to use deep and unmineable coals. The most important component of UCG is the underground "cavity"—which serves as a chemical …
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The NO x produced due to combustion of certain fossil fuels (Certain Coals and Oils) that contain Nitrogen, is called Fuel NO x. Natural Sources. It's not like only human activities are responsible for NO x Emission, rather a considerable amount is produced by the nature too. For examples,
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Coal combustion, however, also produces sulfur dioxide, nitrogen oxides and a range of toxic pollutants (e.g., fluorine, arsenic, selenium, mercury, and lead) from coals mined in certain ...
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@article{osti_10125031, title = {Air toxic emissions from the combustion of coal: Identifying and quantifying hazardous air pollutants from US coals}, author = {Szpunar, C B}, abstractNote = {This report addresses the key air toxic emissions likely to emanate from continued and expanded use of domestic coal. It identifies and quantifies those …
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Coal is a remarkably complex (primarily) biologic rock. Coal is a function of three fundamental aspects, each a reflection of the origin and diagenesis/metamorphism …
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The aggregates of small amount of illite group minerals were noted in the samples obtained from fluidise combustion processes. Fly ashes from lignite coal combustion had the same mineralogical content …
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The phenomenon of coal spontaneous combustion is one of the common hazards in coal mines and also one of the important reasons for the loss of coal in piles and mines. Based on previous researches, different types of coals have different spontaneous combustion characteristics. For coal loss prevention, a measure is necessary for …
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Coal combustion is a dirty process, releasing a range of pollutants including sulphur dioxide, nitrogen oxides, carbon dioxide, volatile organic compounds, ash and a range of …
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The article reviews the main techniques employed to detect coal spontaneous combustion and their advantages and disadvantages; it also reviews the good application prospect of acoustic temperature …
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