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Global Warming or Global Cooling: Challenges and Future Prospects
Published in Moonisa Aslam Dervash, Akhlaq Amin Wani, Climate Change Alleviation for Sustainable Progression, 2022
When man began to extract coal, and then oil and gas, he interfered with the CO2 cycle. Let's explain this with the example of coal (the burning of gas, oil products, and peat, as well as the destruction of forests, in principle, work the same way). Millions of years ago, coal was formed from plant remains. Thus, CO2 was removed from the atmosphere (during plant growth and photosynthesis) and placed underground in the form of coal. Now the person takes it back and, burning it, returns the CO2 to the atmosphere. It would seem that nothing is wrong – this is a cycle. But a person burns as much coal in a year as it was formed in hundreds of thousands and millions of years. Therefore, there is no balance, but there is an unbalanced release of CO2 into the atmosphere by natural processes.
Economic and Market Outlook
Published in Eberhard Lucke, Edgar Amaro Ronces, Leveraging Synergies Between Refining and Petrochemical Processes, 2020
Eberhard Lucke, Edgar Amaro Ronces
Coal is a solid fossil fuel that is formed from peat, which itself is formed from remains of plants in tropical wetlands that existed millions of years ago. The pressure of layers of rocks and soil that laid down on top of the peat transformed the peat into the rock formation that we know as coal. There are different kinds of coal with slight differences in composition and use: Lignite – also called brown coal; lignite is mostly used as solid fuel for electric power generationSub-bituminous coal – like lignite, sub-bituminous coal is used as solid fuel for electric power generation, but is also a source for light aromatic hydrocarbons for the chemical industryBituminous coal – bituminous coal is mostly black in color, but can be found in dark brown color as well; it’s a dense, but soft rock that breaks easily and burns quickly; bituminous coal is used as solid fuel in power plants, as heating medium in manufacturing processes, for blacksmithing and as source to make coke for the steel industryAnthracite – a hard, black rock that burns longer and is used mainly in residential and commercial space heating
Coal-Based Environmental Problems in a Low-Rainfall Tropical Region
Published in Robert F. Keefer, Kenneth S. Sajwan, Trace Elements in Coal and Coal Combustion Residues, 2020
M. Agrawal, J. Singh, A. K. Jha, J. S. Singh
Coal combustion inevitably produces large amounts of gaseous and particulate pollutants. The level of SO2 emission depends upon the sulfur content in the coal and the physical devices used for SO2 control. The conversion of S constituents to SOx is 90 to 100%. More than 98% of SOx emitted is in the form of SO2. A TPP with daily consumption of 10,000 metric tons of coal may emit 50 to 90 metric tons of SO2 daily depending upon the S content of coal.2 Sulfur dioxide emission in India was 6.76 million metric tons in 1979 and is expected to reach around 13.19 million metric tons by the year 1995.3 In China total emissions of SO2 have risen from 10.0 million metric tons in 1980 to 14.2 million metric tons in 1984.4 Coal has contributed to more than 80% of the SO2 emission in China by power stations, boilers, and heating systems.
Geochemical study of coals from Sohagpur Coalfield, India, and its implication to CBM potential
Published in International Journal of Coal Preparation and Utilization, 2023
Kaushal Kishor, Manish Kumar Srivastava, Alok K. Singh
Coal and coalbed methane (CBM) are two closely related yet distinct forms of fossil fuel in the earth’s crust. Coal is a solid fossil fuel formed from the remains of ancient vegetation that has been subjected to high pressure and temperature over millions of years. On the other hand, coalbed methane is a type of natural gas found within the coal seams and is considered a cleaner fuel. Coal is a conventional energy resource that is widely used in India and worldwide. However, the extraction and use of coal results in significant greenhouse gas emissions, which contribute to climate change. From a clean energy point of view, shifting toward unconventional resources like Shale Gas, Gas Hydrates, and Coal Bed Methane (CBM) is very much needed. CBM, also known as Coal Seam Gas (CSG), Coal Seam Natural Gas, and Coal Seam Methane (Moore 2012), can be extracted by drilling through the coal seams. For methane, coal acts as a source as well as reservoir rock (Kumara et al., 2018). CBM is primarily composed of methane (CH4), which is a colorless and odorless gas and a significant component of natural gas. CBM, on the one hand, is considered a relatively clean burning fossil fuel, whereas, on the other hand, it possesses environmental threats related to its extraction processes. Since 2007, coalbed methane has been produced in India on a commercial scale; however, the low rate of CBM production is impacted by poor infrastructure and inadequate permeability (Kamble et al., 2022).
Coal ash for removing toxic metals and phenolic contaminants from wastewater: A brief review
Published in Critical Reviews in Environmental Science and Technology, 2023
Abdelkader Labidi, Haitao Ren, Atif Sial, Hui Wang, Eric Lichtfouse, Chuanyi Wang
Coal bottom ash, also known as bottom ash, is the second product obtained from coal combustion (30 wt.%), less than coal fly ash (70 wt.%) (Rashidi & Yusup, 2016). Additionally, the world production of coal bottom ash was estimated to be 730 million tonnes (Singh et al., 2020), with Asian countries share exceeding 66 wt.%, followed by European and American countries (less than 40 wt.%) (Singh et al., 2020). In fact, there are four types of coal: bituminous, sub-bituminous, anthracite, lignite. Coal bottom ash can be classified into two major categories and can be described as a class F and class C (Rashidi & Yusup, 2016). Those belonging to the first class are materials containing high amount of silicon dioxide SiO2, aluminum oxide Al2O3, ferric oxide Fe2O3 (> 70 wt.%) and low amount of calcium oxide (CaO) (Table 1). However, class C encompasses bottom ash with high quantity of calcium oxide CaO and an amount of SiO2, Al2O3, and Fe2O3 ranging from 50 to 70 wt.% (Rashidi & Yusup, 2016).
Evolutions of Oxidation Products and Free Radicals for Coal-Gangue Samples with Various Gangue Contents
Published in Combustion Science and Technology, 2023
Yutao Zhang, Shangwen Xia, Yaqing Li, Mengru Ren, Bo Che, Xu Lu
Coal is the most abundant nonrenewable energy source in the world, accounting for 27.2% of the global structure of energy consumption (Li et al. 2022; Sun et al. 2023). As a kind of major conventional energy and strategic resource, coal is widely used in industrial production such as steel and chemical industries and residential life. Gangue, a solid waste screened out in the process of coal mining, washing, and processing, features a low calorific value, a low volatile component, and a high ash content (Querol et al. 2008; Zhang, Han, and Cheng 2022). As a byproduct of coal, gangue has an annual emission accounting for about 10%-15% of the annual production of coal, holding its position as one of the top emitters of industrial solid waste in China (Fabiańska et al. 2013; Zhang et al. 2022). According to statistics, the cumulative stockpile of gangue in China has reached 7 billion tons, with a growth rate of about 200 million tons per year (Ma et al. 2020; Yu et al. 2022). Despite such a huge gangue output, plenty of gangue is still left in goafs due to the restrictions such as mining technology (Jiang et al. 2021). Such residual gangue, together with the unrecoverable coal, poses the hazard of fires in goafs. Gangue differs significantly from coal in terms of composition, pore structure, microscopic group, etc., leading to possible interactions between the two when they coexist (Ding and Jiang 2013; Lin et al. 2015). Therefore, the low-temperature oxidation characteristics of coal coexisted with residual gangue in goafs worth attention and research.