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Energy Today
Published in Anco S. Blazev, Global Energy Market Trends, 2021
Anthracite is a type of coal, which contains almost 100% carbon. This quality, and the fact that it is cleaner burning made it most popular at first. By the end of the century, however, bituminous coal with lower carbon content but comparable heat value, took its place as the preferred fuel. Until then more than half of the coal came from the great “Pittsburgh seam,” which lay exposed along the rivers above the city of Pittsburgh, PA.
Energy and the Environment
Published in Anco S. Blazev, Power Generation and the Environment, 2021
Anthracite is a type of coal, which contains almost 100% carbon. This quality, and the fact that it is cleaner-burning made it most popular at first. By the end of the century, however, bituminous coal with lower carbon content but comparable heat value, took its place as the preferred fuel. Until then, more than half of the coal came from the great “Pittsburgh seam,” which lay exposed along the rivers above the city.
Synthesis of Coal-based Nanocarbon Advances and Applications
Published in Paweł K. Zarzycki, Pure and Functionalized Carbon Based Nanomaterials, 2020
Carbon materials are considered one of the most promising electrode materials due to high porosity, large specific area, and low cost. Nanocarbons derived from high rank coal and coke are investigated for their novel electrochemical properties—both in pure and composite form. Anthracite has the highest energy and more carbon content among all coals. More carbon content in the source implies more carbon clusters or ions available for NCD formation. However, apart from these factors, microscopic organic components (called as macros) also play a major role. The energy storage applications in portable or remote devices, such as batteries and conventional capacitors are acquiring a major concentration of researchers. Electrochemical performance of carbon-based electrode materials are affected by the variation of specific surface area (Wang et al. 2008), structure and functional group (Xing et al. 2006), and pore size distribution (Bandaru and Prabhakar 2007). These features suggest that nanocarbon derivatives are suitable materials for polarizable electrodes. PANI-nanocarbon composite for the polyelectrolyte application is an upcoming field of research. Proper interface of polymer with nanocarbon matrix enhances the charge-discharge capacity and cyclic stability. The conductivity of such a system is heavily dependant on the percentage of polymer, reduced graphene, and the metal ions used (Pandey et al. 2019, Virginia et al. 2019). Recent studies show that anthracite-based nanocarbon products, on intercalating with Li-ion, enhance their electrochemical and optical properties.
Implication of nuclear analytical techniques for the assessment of coal quality in terms of ash content
Published in International Journal of Coal Preparation and Utilization, 2023
S. K. Samanta, V. Sharma, A. Sengupta, R. Acharya
Coal is a special kind of a combustible black sedimentary rock with high quantity of carbon and hydrocarbons. This fossil fuel is one of the nonrenewable sources of energy. Several geological and scientific investigations revealed the interesting phenomenon of formation of coal from plant remains (Orem and Finkelman 2003). During the coalification process, depending on the temperature and pressure, different grades of coal are formed, such as lignite (brown coal), sub-bituminous, bituminous and anthracite (black coal). Lignite is formed under mild temperature and pressure, whereas sub-bituminous, bituminous and anthracite coals are formed with increasing temperature and pressure (Orem and Finkelman 2003). Anthracite coal, the best quality and the highest rank of coal, carries 80–95% carbon and has highest calorific value. Bituminous coal is dark brown in nature and is used primarily as a fuel in steam electric power generation. Sub-bituminous coal contains lower percentage of carbon as compared to bituminous coal. Finally, lignite or brown coal is the lowest rank of coal, whose carbon content ranges from 65–70%.
Preparation of low silicon ultra clean coal by flotation pretreatment followed by alkali-acid leaching combined process
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Yanbo Yang, Mo Chu, Chengliang Hao, Lingmei Zhou
Anthracite, as the coal with the highest degree of coalification, has the advantages of high carbon content, high calorific value, low volatile, and smokeless combustion. It often used as industrial and civil fuel or further processed into coal-based carbon materials. However, ash content is a constraint for both fuels and coal-based materials. When the coal serves as the raw material for gasification, the pressurized gasification device has certain requirements for raw coal: the ash content of coal and ash melting point are the most important requirements. The requirement of melting point of ash residue is under 1,250°C, but the melting point of some minerals such as quartz and silicon aluminosilicate in coal are both over 1,500°C. The semi-coagulated slag blocks the slag outlet of gasifier and affects the equipment operation. However, anthracite with high carbon content is only used as fuel with low added value and further processing of anthracite into coal-based carbon materials is now a research hotspot, such as coal-based activated carbon, coal-based graphene, and carbon negative electrode material. For example, in the preparation of graphene oxide, the raw material is required to use the ultra-low ash coal. Therefore, the concept of ultra clean coal is put forward.
Experimental study on principles of isothermal dehydration of anthracite
Published in Drying Technology, 2019
Yunpei Laing, Fakai Wang, Yongjiang Luo, Han Wang, Qianting Hu
As the high-rank coal, anthracite is mainly used in metallurgy because of its advantages of having a small amount of natural moisture and a high calorific value.[1] It has more metamorphic pores and larger micropore volume than lignite because of the associated gas accumulation and the increase in porosity with the metamorphic degree. This capacity leads to a high gas content, enhanced dust inflammation, and high risk of coal and gas outbursts in anthracite coal mines.[2–4] Thus, the safe and efficient underground mining of anthracite is difficult to achieve. Moisture can change the physical and mechanical properties of coal.[5–8] High coal moisture can effectively promote the desorption process of coalbed methane, especially in high-rank coal. Several studies have indicated that the initial gas desorption velocity can be significantly reduced when coal moisture content reaches 2%. Moreover, the risk of coal and gas outburst is eliminated when coal moisture content reaches 4%.[9,10] Therefore, several types of hydraulic methods, such as coal seam water injection, hydraulic punching, and hydraulic extrusion are widely used to improve the permeability of coal seams and promote the desorption process of coalbed methane before mining.[11,12] An increase of moisture in the coal seam also limits the occurrence of coal dust explosions, spontaneous combustion, and other dynamic coal and rock disasters.[13]