Showing papers on "Coal published in 2018"
DOI•
01 Jan 2018
TL;DR: In this paper, the updates implemented in EPA's 2020 inventory of U.S. GHG emissions and sinks for gathering and boosting (G&B) stations were discussed, and additional considerations for G&B were previously discussed in memoranda released November 2019 (Inventory of GHG Emissions and Sinks 1990-2018: Updates Under Consideration for Natural Gas Gathering & Boosting Station Emissions).
Abstract: This memorandum documents the updates implemented in EPA’s 2020 Inventory of U.S. Greenhouse Gas Emissions and Sinks (GHGI) for gathering and boosting (G&B) stations. Additional considerations for G&B were previously discussed in memoranda released November 2019 (Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2018: Updates Under Consideration for Natural Gas Gathering & Boosting Station Emissions),1 October 2018 (Inventory of U.S. GHG Emissions and Sinks 1990-2017: Updates Under Consideration for Natural Gas Gathering & Boosting Emissions),2 and April 2019 (Inventory of U.S. GHG Emissions and Sinks 1990-2017: Updates to Natural Gas Gathering & Boosting Pipeline Emissions).3
1,051 citations
TL;DR: In this article, a review of the main waste plastics valorization routes to produce syngas and H2 is presented, covering different gasification strategies and other novel alternative processes, such as pyrolysis and in-line catalytic steam reforming.
Abstract: The current review provides an assessment of the main waste plastics valorization routes to produce syngas and H2, thus covering different gasification strategies and other novel alternative processes, such as pyrolysis and in-line catalytic steam reforming The studies dealing with plastics gasification are in general scarce However, due to the knowledge acquired on biomass and coal gasification, the state of development of plastic gasification technologies is considerable and, in fact, several gasification studies have been performed at pilot scale units Air gasification is the most studied and developed strategy and pursues the production of a syngas for energy purposes In spite of the higher H2 content and heating value of the gas produced by steam gasification, this alternative faces significant challenges, such as the energy requirements of the process and the tar content in the syngas Moreover, the co-gasification of plastics with coal and biomass appears to be a promising valorization route due to the positive impact on process performance and greater process flexibility Other promising alternative is the pyrolysis and in-line reforming, which allows producing a syngas with high hydrogen content and totally free of tar
437 citations
TL;DR: In this paper, a quadratic model was proposed to correlate the independent variables for maximum ash reduction at the optimum process condition by using central composite design (CCD) method.
Abstract: Coal is the world’s most abundant energy source because of its abundance and relatively low cost. Due to the scarcity in the supply of high-grade coal, it is necessary to use low-grade coal for fulfilling energy demands of modern civilization. However, due to its high ash and moisture content, low-grade coal exerts the substantial impact on their consumption like pyrolysis, liquefaction, gasification and combustion process. The present research aimed to develop the efficient technique for the production of clean coal by optimizing the operating parameters with the help of response surface methodology. The effect of three independent variables such as hydrofluoric acid (HF) concentration (10–20% by volume), temperature (60–100 °C), and time (90–180 min), for ash reduction from the low-grade coal was investigated. A quadratic model was proposed to correlate the independent variables for maximum ash reduction at the optimum process condition by using central composite design (CCD) method. The study reveals that HF concentration was the most effective parameter for ash reduction in comparison with time and temperature. It may be due to the higher F-statistics value for HF concentration, which effects to large extent of ash reduction. The characterization of coal was evaluated by Fourier transform infrared spectroscopy (FTIR) analysis and Field-emission scanning electron microscopy with energy-dispersive X-ray (FESEM-EDX) analysis for confirmation of the ash reduction.
294 citations
TL;DR: In this paper, the authors discuss the key factors affecting zeolite synthesis, primarily from coal fly ash; the drawbacks of each approach are also analysed, and the characterization and potential applications of these materials are analyzed in detail through reference to the numerous studies published on fly ash worldwide over the last number of decades.
232 citations
TL;DR: In this paper, the authors focus on the toxic trace elements that may be released from coal combustion but also on the valuable elements that occur in the coal and associated ash, and present several factors responsible for these elevated concentrations: injection of exfiltrational solutions during peat accumulation or as part of later epigenetic activity.
Abstract: China is, and in the coming decades should continue to be, the largest producer and user of coal in the world. The high volume of coal usage in China has focused attention not only on the toxic trace elements that may be released from coal combustion but also on the valuable elements that may occur in the coal and associated ash. Valuable elements in several coals (or coal ashes) and some coal-bearing strata in China (e.g. Ge, Ga, U, rare earth elements and Y, Nb, Zr, Se, V, Re, Au, and Ag, as well as the base metal Al) occur at concentrations comparable to or even higher than those in conventional economic deposits. Several factors are responsible for these elevated concentrations: (1) injection of exfiltrational solutions during peat accumulation or as part of later epigenetic activity; (2) injection of infiltrational epigenetic solutions; (3) introduction of syngenetic alkali volcanic ashes into the peat-forming environment or into associated non-coal-forming terrestrial environments; (4) input...
184 citations
TL;DR: In this article, two damage constitutive models of coal were established by serially connecting one damage body with one or two Newton body(s), to reveal the influences of rock(s) on the mechanical behavior of coal in coal-rock samples.
179 citations
TL;DR: In this article, a series of experiments were performed for 10 coal samples collected from eastern Junggar Basin, to compare the material composition, pore structure and adsorption capacity of lignite and candle coal.
167 citations
TL;DR: In this article, a multi-index experimental system for estimating various factors during coal oxidation (heating) and combustion and analyzed the characteristic temperature, index gases, and EMR signals.
166 citations
TL;DR: In this paper, a comprehensive summary of the state of the art knowledge, underpins the science associated with gas adsorption/desorption, swelling/shrinkage in coals and discusses petrophysical properties (porosity, permeability, etc.) as functions of pressures, temperatures, moisture content and coal rank.
156 citations
TL;DR: In this article, the authors present a review of feedstock characteristics, pre-treatments, gasification methods, and future directions of this technology, and present a method for co-gasification of non-woody biomass.
Abstract: Non-woody biomass, having a lower lignin content than woody materials, is a common waste material found in agricultural processing plants and fields. Non-woody biomass is often bulky and has a comparatively low energy content. However, non-woody materials sourced from agricultural waste are abundant and cheap. Experimental studies into gasification of non-woody biomass have been conducted by various researchers. This paper reviews feedstock characteristics, pre-treatments, gasification methods, and future directions of this technology. Due to the heterogeneous nature of non-woody biomass, it is critical to apply suitable pre-treatments prior to gasification. Combining non-woody biomass with a small percentage of high grade carbon sourced from biochar or coal into fuel pellets for co-gasification has the potential to improve fuel quality. Synergistic effects of non-woody biomass-coal/charcoal co-gasification can also reduce tar formation and increase the occurrence of mineral based catalytic reactions. Factors influencing these effects are often complex and require further investigation. 15–20% of the energy content of fuel pellets may be needed to power the biomass pre-treatment process. The gasification of pelletised non-woody waste provides an attractive alternative fuel source to achieve agricultural energy self-sufficiency and off-grid operation.
151 citations
TL;DR: In this paper, the authors examined acid gas emissions of sulfur dioxide, nitrogen oxide, carbon dioxide, and hydrogen chloride from co-firing biomass (corn straw and rice husk) with either a high-sulfur bituminous coal or a low sulfur sub-bituminous coalition.
TL;DR: In this paper, the authors explored the coal seams of Chinese coal seams with high gas content and low permeability and proposed to improve coal seams' permeability to achieve maximum extraction of coalbed methane.
Abstract: Chinese coal seams are characterized by high gas content and low permeability. The permeability of coal seams should be improved to achieve maximum extraction of coalbed methane. This study explore...
TL;DR: In this article, a comprehensive review of carbon assisted water electrolysis, associated materials used and the challenges for the development of the technology at the commercial scale is presented, as well as a detailed discussion of the challenges and opportunities for the commercial development of this technology at a commercial scale.
TL;DR: In this paper, the prospective of coal used for power generation in China into 2030 by testing three interrelated factors, namely electricity demand, fuel mix and generation efficiency of coal power, was studied.
Abstract: Coal holds dominant position in China’s primary energy mix, and roughly 45% of China’s coal consumption is used for power generation. In this paper, we study the prospective of coal used for power generation in China into 2030 by testing three interrelated factors, namely electricity demand, fuel mix and generation efficiency of coal power. We find that, under the ‘new economic normal’, electricity demand growth would slow down; under the effort of low-carbon transition, coal power is expected to reach the peak at around 970 GW by 2020; and coal used for power generation will reach the peak at around 1280 million ton coal equivalent (Mtce) under the clean coal power plan declared by the Chinese government.
TL;DR: An up-to-date and high-resolution mercury emission inventory of Chinese coal-fired power plants is developed using a unit-based method that combined data from individual power plants, provincial coal characteristics, and industry removal efficiencies.
Abstract: As the largest coal consumer in China, the coal-fired power plants have come under increasing public concern in regard to atmospheric mercury pollution. This study developed an up-to-date and high-resolution mercury emission inventory of Chinese coal-fired power plants using a unit-based method that combined data from individual power plants, provincial coal characteristics, and industry removal efficiencies. National mercury emissions in 2015 were estimated at 73 tons, including 54 tons of elemental mercury, 18 tons of gaseous oxidized mercury and 1 ton of particle-bound mercury. Pulverized coal boilers emitted 65 tons, mainly in the coastal provinces and coal-electricity bases. Circulating fluidized bed boilers emitted 8 tons, mainly in Inner Mongolia and Shanxi Province. The average mercury emission intensity over the Chinese mainland was 18.3 g/GWh, which was similar to the limit for low-rank coal-fired units in the United States. The overall uncertainty of national mercury emission was estimated to b...
TL;DR: In this article, the volatilization, transformation, and emission behavior of arsenic and its removal technologies are discussed in depth, including temperature, pressure, mode of occurrence of arsenic, coal rank, mineral matter, and the sulfur and chlorine content of the fuel.
TL;DR: In this paper, the results of air-blown combustion and oxy-combustion kinetic characterization were compared with two different isoconversional methods (Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose) of different kinds of coal (from Italy, South Africa and Hungary) and biomass (pine and eucalyptus chips) by thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) together with assessment of different characteristic combustion parameters.
TL;DR: This paper highlights the advances in the surfactant-aided coal dust suppression technology by critically reviewing prior studies and suggests more focus should be on the dynamic interaction between the coal particle and water droplet in wind tunnels or well controlled onsite conditions.
TL;DR: In this paper, the behavior of nonylphenol ethoxylate with 12 ethylene oxide groups (NPEO-12) on model surface of Hatcher subbituminous coal was investigated.
TL;DR: In this article, the authors consider the enabling conditions in Great Britain and the potential for rapid fuel switching in other coal-reliant countries and find that spare generation and fuel supply chain capacity must already exist for fuel switching to deliver rapid carbon savings, and to avoid further high-carbon infrastructure lock-in.
Abstract: Great Britain’s overall carbon emissions fell by 6% in 2016, due to cleaner electricity production. This was not due to a surge in low-carbon nuclear or renewable sources; instead it was the much-overlooked impact of fuel switching from coal to natural gas generation. This Perspective considers the enabling conditions in Great Britain and the potential for rapid fuel switching in other coal-reliant countries. We find that spare generation and fuel supply-chain capacity must already exist for fuel switching to deliver rapid carbon savings, and to avoid further high-carbon infrastructure lock-in. More important is the political will to alter the marketplace and incentivize this switch, for example, through a stable and strong carbon price. With the right incentives, fuel switching in the power sector could rapidly achieve on the order of 1 GtCO2 saving per year worldwide (3% of global emissions), buying precious time to slow the growth in cumulative carbon emissions. Coal-generated electricity forms a significant contribution to global carbon emissions. This Perspective explores the factors behind Great Britain's recent rapid switch from coal power to natural gas, which brought a large decrease in emissions, and discusses savings potential for other coal-using nations.
TL;DR: This article explored the socio-technical imaginaries surrounding infrastructures of coal mining and coal combustion in Poland and examined how coal-fuelled national modernisation can support coal futures, even in the face of contradictory evidence for domestic resource depletion, poor regional air quality and global climate change.
Abstract: This paper explores the socio-technical imaginaries surrounding infrastructures of coal mining and coal combustion in Poland. Contemporary policy makers in Poland mobilise a national imaginary inherited from communist times – encapsulated in the slogan ‘Poland stands on coal’ – that fuses infrastructures of coal extraction and combustion with the fate of the nation. This socio-technical imaginary provides support for coal futures, even in the face of contradictory evidence for domestic resource depletion, poor regional air quality, and global climate change. To examine this process, the paper brings research on socio-technical imaginaries into conversation with work on resource materialities. It highlights how certain materialities of coal (abundance, accessibility, energy density, location) were integral to the emergence of a national socio-technical imaginary of modernisation via coal; and how other materialities (declining resource quality, effects of emissions on respiratory health, coal as CO2-in-waiting) now collide with the political strategies of a government determined to reassert ‘black gold’ as a bedrock of national development for years to come. The paper considers how contemporary political efforts to rehabilitate coal and secure its future in Poland draw selectively upon a socio-technical imaginary of coal-fuelled national modernisation.
TL;DR: Coal reservoirs especially deep unminable coal reservoirs, are viable geological target formations for CO2 storage to mitigate greenhouse gas emissions as discussed by the authors, and an advantage of this process is that a large...
Abstract: Coal reservoirs especially deep unminable coal reservoirs, are viable geological target formations for CO2 storage to mitigate greenhouse gas emissions. An advantage of this process is that a large...
TL;DR: In this paper, the authors highlight the hydrogen production potential from biomass through gasification technology and review the parameters effect of hydrogen production such as temperature, pressure, biomass and agent ratio, equivalence ratios, bed material, gasifying agents and catalysts effect.
TL;DR: In this paper, the authors used the life cycle assessment (LCA) method to analyze the environmental impact of coal-fired power generation in China, and the relevant cost theory was used to calculate the resource consumption cost and external environmental cost.
TL;DR: In this article, the authors provide a comprehensive literature review and analysis of the comprehensive utilization of coal-preparation by-products in China, revealing problems during processing and giving indications of potential solutions.
TL;DR: This work assessed the evolution of coal-fired power plants and associated emissions in China during 2010-2030 by using a unit-based emission projection model, which integrated the historical power plant information, turnover of the future power plant fleet, and evolution of end-of-pipe control technologies.
Abstract: As the largest energy infrastructure in China, the power sector consumed approximately half of China’s coal over the past decade and threatened air quality and greenhouse gas (GHG) abatement targets. In this work, we assessed the evolution of coal-fired power plants and associated emissions in China during 2010–2030 by using a unit-based emission projection model, which integrated the historical power plant information, turnover of the future power plant fleet, and evolution of end-of-pipe control technologies. We found that, driven by stringent environmental legislation, SO2, NOx, and PM2.5 (particulate matter less than 2.5 μm in diameter) emissions from coal-fired power plants decreased by 49%, 45%, and 24%, respectively, during 2010–2015, compared to 15% increase in CO2 emissions. In contrast to ever-increasing CO2 emissions until 2030 under current energy development planning, we found that aggressive energy development planning could curb CO2 emissions from the peak before 2030. Owing to the implemen...
TL;DR: In this article, a 15-t experimental furnace for coal spontaneous combustion and synchronous thermal analyzer coupled with Fourier transform infrared spectroscopy were employed to investigate the entire process of first and second coal combustion.
TL;DR: In this paper, a new apparatus was developed to conduct simulated experiments with different gases of CO2 and N2, and the authors analyzed the formation and transport mechanism of coal-gas flow in roadway as well as evaluate the effects of gas desorption on its development.
TL;DR: In this article, the pore structures inside a coal sample and its permeability during coal seam water infusion were analyzed using nuclear magnetic resonance (NMR) technology; the influence rule of confining pressure and pore water pressure during the test on the coal sample structure and seepage characteristics is analyzed.
Abstract: Coal seam water infusion is a universal comprehensive mine disaster prevention method practiced worldwide. The result of water infusion is determined by the structure and seepage characteristics of the coal sample around the borehole. In this paper, the structure and seepage characteristics of the coal sample under various stress and pore water pressures are measured via nuclear magnetic resonance (NMR) technology; the influence rule of confining pressure and pore water pressure during the test on the coal sample structure and seepage characteristics is analyzed. Based on fractal geometrical theory, the fractal model of permeability is created. The results show that the coal sample with water infusion has an intertwined internal fracture-pore structure and that the pore radius distribution is diverse. Through theoretical analysis and discussion, we found that there are no large changes in the pore area fractal dimension and the measured pore volume fractal dimension, but the trends of changes in these two fractal dimensions are opposite, because the pore area fractal dimension characterizes the homogeneity of the pore area distribution on the surface of a coal sample, and the measured pore volume fractal dimension characterizes the cumulative volumetric changes in the pores inside a coal sample. The changes in these two fractal dimensions validate that the pore structures inside a coal sample have similar in fractal characteristics and demonstrate that the coal seam water infusion technique will not damage the skeleton of the coal sample. The variation rules of theoretical permeability from the fractal model and the value from the liquid measurement versus confining pressure and pore water pressure are consistent, an increase in the water pressure will result in an increase in the permeability, and an increase in the confining pressure will result in a decrease in the permeability. However, because the seepage channels with a large diameter in the tested coal sample were blocked, there is a relatively large difference between the two permeabilities. Therefore, increasing the connectivity between the seepage channels with a large diameter will improve the effects of water infusion, which is implemented to prevent disasters. Through NMR experiment and theoretical analysis, this study establishes a quantitative relationship between the pore structures inside the coal sample and its permeability during coal seam water infusion process, provides an advanced experimental approach and theoretical analysis method, which will be of great importance in the improvement in the water infusion process implemented in deep working coal seams to prevent disasters and in the determination of the range of application of this process and the evaluation metrics for this process.
TL;DR: In this paper, the authors evaluate the feasibility of this strategy from the perspective of water resources, exploring and predicting outcomes from 2012 to 2050, and find that the combination of a market price adjustment mechanism and a macro total control strategy can maximize the synergic benefits between energy and water resources in China.