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Sustainable Development
Published in Kyoung Hee Kim, Microalgae Building Enclosures, 2022
Methane, a secondary anthropogenic greenhouse gas, is emitted from activities such as burning fossil fuels, agriculture (e.g., livestock and rice paddies), and biogas from solid waste landfills. Atmospheric methane has more than doubled from 700 ppb (parts per billion) in 1750 to 1,900 ppb in 2019.34 Nitrous oxide (N2O) known as “laughing gas” is mostly caused by agricultural activities (e.g., nitrogenous fertilizer) as well as during combustion and human waste disposal.35 The CO2 equivalent is a way to normalize the effect of trapping heat for a specific length of period compared with CO2 as a reference gas. One Methane, for example, has an approximate 30 CO2 equivalent over a 100-year timescale, meaning it has 30 times more warming potential than CO2. Nitrous oxide has around a 300 CO2 equivalent for a 100-year timescale. The measurement unit for methane and nitrous oxide is ppb, one-thousandth of ppm, but small increases in emissions from such gases have detrimental environmental impacts.
Paris Agreement on Climate Change
Published in Larry E. Erickson, Gary Brase, Reducing Greenhouse Gas Emissions and Improving Air Quality, 2019
Nitrous oxide concentration was 0.33 ppm in 2017, which is 122% of pre-industrial values (i.e. before 1750). Atmospheric methane reached a new record high of 1.86 ppm in 2017, which is 257% of pre-industrial values. The value of 405 ppm for carbon dioxide is 146% of pre-industrial values. Most of the contribution to radiative forcing is due to carbon dioxide; however, methane contributes 17% and nitrous oxide contributes 6% (WMO, 2018). Finding ways to reduce methane emissions should also be a high priority because methane has a much greater impact than carbon dioxide on radiative forcing and climate change per mole of gas.
Natural Gas
Published in Anco S. Blazev, Energy Security for The 21st Century, 2021
The lifetime of atmospheric methane in the atmosphere is relatively short, as compared to carbon dioxide, but it is much more efficient at trapping heat in the atmosphere while it’s up there. One unit of methane has 62 times the global-warming potential of the same unit of CO2 when calculated over a 20-year period, 20 times over a 100-year period, and over 8 times during a 500-year period.
Application of Inorganic Solidified Foam to Control the Coexistence of Unusual Methane Emission and Spontaneous Combustion of Coal in the Luwa Coal Mine, China
Published in Combustion Science and Technology, 2020
Zhaojun Tian, Yi Lu, Shimin Liu, Shiliang Shi, He Li, Qing Ye
Methane associated with coal seams are formed as a result of the coalification process (Zuo et al., 2008; Li et al., 2019). The methane found in coal seams poses a hazard when encountered in sufficient quantities in the coal seam. Large amounts of methane are released in the mine working faces gradually as mining progresses. (Ye et al., 2018) Since methane in mines can cause a variety of problems ranging from asphyxiation (the concentrations of carbon dioxide above 1–2% in air have a major detrimental physiological effects) and burning to violent explosions (explosive range of 5–15%), (Davis et al., 2015; Hao et al., 2018; Liu et al., 2019) the maximum allowable concentration of methane in the atmosphere in China coal mines is 1%. (Zhou et al., 2014) The methane explosion in the Sun Jiawan coal mine was caused by abnormal methane emission and aggregation in the 3316 air return roadway. (Lu et al., 2014) On the other hand, atmospheric methane is the second most important greenhouse gas next to carbon dioxide, accounting for >15% of the global warming. (Su et al., 2015; Thompson et al., 2015) The methane emission sources can be divided into coal wall ahead of the working face, goaf behind the working face, the nearby goaf, and the lower slicing coal seam. All of these sources apply methane by the fractured channels induced by coal mining. Although extensive research has been carried out to control unusual methane emissions in coal mines, the common practice has been to improve mine safety by sealing the mining fractures.
Coal mine gas: a new fuel utilization technique for India
Published in International Journal of Green Energy, 2018
Atmospheric methane is an integral component of the greenhouse effect, second only to CO2 as a contributor to the total anthropogenic greenhouse gas. The global warming potential of methane is known to be 21 times more than that of carbon dioxide. The emission of methane is related to various human activities like agriculture, land use changes, burning of biomass and fossil fuels, coal mining, oil and natural gas systems, industrial processes and land-fills. Anthropogenic activities account for about 60% of total methane emissions. Although the growth in emissions is loosely correlated with increase in population, presently the global concentration of methane is increasing by about 1% per annum. Coal mining was estimated to account for about 8% of all human-related methane emissions (USEPA 2003, 1993).