Coal Plants Research Articles

Energy Consequences for Environment

The beginnings of this century sets up the dilemma of more energy or betterment of the environment. If “energy” is the capacity to do work, as often said, then it can be made profitable. If protecting the ecology of Earth is what the COP reunions of the UN aim at, then it is hardly a surprise that China and India reneged against the original formulation of phasing out coal power. Both countries use a lot of coal plants to get cheap energy for rapid economic development. This is dismal fact for COP endeavours. The efforts of the UN to create global ecology coordination will be harmed by the war in Ukraine, but how realistic is the 1.5 temperature goal anyhow?

Impact of Zeolite from Coal Fly Ash on Soil Hydrophysical Properties and Plant Growth

Zeolites can be extensively employed in agricultural activities because they improve soil properties such as infiltration rates, saturated hydraulic conductivity, water holding capacity, and cation exchange capacity. Natural and synthetic zeolites can efficiently hold water. Zeolites are also believed to have the ability to lose and gain water reversibly, without changing their crystal structure. In the present study, several laboratory tests were carried out using: (i) zeolite synthesized from coal fly ash (a waste product from burning coal in thermoelectric power plants), (ii) a silty loam soil, typically found in Southern Italy, and (iii) sunflower as a reference plant. The selected soil was amended with different percentages of zeolite (1, 2, 5, and 10%) and the effects of the synthetic mineral addition on the hydrophysical properties of the soil and plant growth were evaluated. The results indicated that soil–zeolite mixtures retained water more efficiently by pore radius modification. However, this causes a variation in the range of plant-available water towards higher soil humidity values, as the amount of added zeolite increases. These data confirm that zeolite addition modifies the selected hydrophysical properties of the soil with the effect of decreasing the soil drainage capacity, making the soil less habitable for plant growth.

The Energy to Change: A Sustainable World

The world is changing every day and with increased collective awareness of the damaging effects of fossil fuels. The Public health is a key issue in India. The air and water pollution emitted by coal and natural gas plants is linked with breathing problems, neurological damage, heart attacks, cancer, premature death, and a host of other serious problems. Most of these negative health impacts come from air and water pollution. In India Global warming Emission are extracted from the electricity sectors most of those emission come from fossil fuels like coal and natural gas. Clean energy technologies could provide a solution to this problem. The Government of India has been focusing in implementing clean energy technologies. The focus of this article is to bring to light the problems faced in India in terms of energy consumption as well as the hindrances faced by clean energy-based technologies. Government policies aimed at addressing these issues, as well as the current state of clean energy technologies in India are discussed, so as to analyse the possibility of a solution to the problems of finding a sustainable method to eradicate clean energy technologies in India. The research reveals that the Government of India has been unable to meet some of its unrealistic development goals, and in order to achieve the remaining goals it will have to take drastic steps. The Government will have to be more aggressive in the promotion of clean energy technologies in order to achieve sustainable development in India.

Enhancement of dewatering performance of vitrinite-rich and inertinite-rich coals by surfactants: Experiment and simulation

The high moisture content of fine coals, especially flotation clean coals has affected the production of coal processing plants for a very long time. The two main components of fine coals are vitrinite and inertinite. The percentage of these two macerals present in the coal has an impact on the dewatering process. In this paper, the influence of surfactants on the dewatering effect of two samples with different maceral contents is studied. The results demonstrate that non-ionic surfactants have an excellent dewatering effect on vitrinite-rich coal, and it reduced the filter cake moisture by 1.84%, while cationic surfactants have an outstanding dewatering effect on inertinite-rich coal, and it reduced the filter cake moisture by3.81%. For both the coals, surfactant adsorption reduces the hydrophobicity of the coal. The best dewatering effect corresponds to the lowest filtrate surface tension and the loosest filter cake structure. Surfactants can reduce the pressure required to remove water from the filter cake by lowering the surface tension of the filtrate. In addition, surfactants have an agglomeration effect on fine coals, which increases the porosity of the coal and facilitates a low-moisture product. This study will help engineers select the suitable filter aid for the maceral content of coal and contribute to the development of efficient filter aids.

Identifying coal plants for early retirement in India: A multidimensional analysis of technical, economic, and environmental factors

Coal-fired energy generation is the backbone of India’s power sector and considered a driver of its economic development. However, it is associated with detrimental environmental and health impacts in India and its fleet is currently struggling with overcapacity and inefficiency problems. One solution to address these challenges is the early retirement of some of India’s coal-fired power plants. In this paper, we introduce multidimensional indices that identify plants for retirement based on comprehensive criteria that include technical and economic characteristics of plants as well as their environmental impacts. We implement an ensemble approach, where we formulate 8008 indices based on all possible combination of seven relevant parameters and rank plants accordingly. This approach facilitates a comprehensive analysis of the plants’ performance on different parameters and provides a new outlook on plant retirements that differs from the common approach of retiring plants based solely on technical characteristics such as age, capacity, and heat rate. Our results show that top plants recommended for early retirement are typically 7 years older, 13% more expensive and have around 40% higher population exposure to emissions compared to an average plant in India. We estimate the potential costs saved from the retirement of the worst-performing 50 GW of generating capacity to be $21 billion resulting from shifting ownership towards a cheaper cost of capital and replacing coal by more competitive sources such as solar power.

Mechanical and Thermal Evaluation of Diatomite Doped Fly Ash Based Geopolymers

In this work, the properties of alkali silicate geopolymer type materials and diatomite as additive to fly coal ash was investigated using thermic coal plant’s fly ash in alkaline solution. The reacted products of alumino-silicate geopolymers using fly ash plus diatomite were pseudo-amorphous aluminosilicate gel and calcite and their mechanical and thermal properties were evaluated by the addition of diatomite. The compressive strength of this geopolymer is similar to that of the Portland cement mortar of PC20 (± 20 %) when cured for 28 days while the density and thermal properties are much lower that indicates the insulator properties. Alkaline solution was produced by NaOH in different concentrations to determine the least alkaline solution molarity in the range of 1 M, 3 M and 5 M. The characterization of geopolymers were done by using XRD for phase analysis, SEM for surface and morphological evaluation, compression tests for mechanical properties and transient plane source thermal analysis for thermal insulation properties. The results showed that, 1 M of NaOH alkaline solution and 10wt% diatomite addition can provide enough strength of 18 MPa which is a good candidate for constructional materials. The thermal conductivity coefficient of 10 wt.% diatomite added geopolymer was evaluated as 0.0018 W/m×K which can also be a good candidate for insulator materials to be used in green lateral wall production.

Source apportionment and ecological and health risk mapping of soil heavy metals based on PMF, SOM, and GIS methods in Hulan River Watershed, Northeastern China.

Heavy metals in agricultural soils not only affect the food security and soil security, but also endanger the human health through the food chain. Based on the incorporation of index analysis, positive matrix factorization (PMF), self-organizing map (SOM), and geostatistical methods, this research performed the assessment of source apportionment and ecological and health risks of soil heavy metals in Hulan River Watershed, Northeastern China. According to the Pollution Load Index (PLI), 83.08% of the soil samples were slightly or mildly polluted, and 1.54% of the soil samples were severely polluted. The ecological risk index (EI) showed that about 80.77% and 60.77% of the soil samples were beyond the low risk level for Hg and Cd, respectively. In this research, the non-carcinogenic and carcinogenic risk indices for children were higher than adult males and adult females. Four potential sources were revealed based on the PMF and SOM analysis including atmospheric deposition and industrial emission; transportation source; agricultural source; and a combination of agricultural, industrial, and natural sources. Considerable and high ecological risk from Hg existed in the area close to the coal steam-electric plant, and considerable and high ecological risk from Cd existed in the Hulan River estuary area. The eastern part of the study area experienced higher non-carcinogenic and carcinogenic risks for adults and children than the western part of the study area. The source apportionment and ecological and health risk mapping provide important role in reducing pollution sources. Zonal pollution control and soil restoration measures should be performed in the areas with high ecological and health risks.

Distribution, occurrence mode, and extraction potential of critical elements in coal ashes of the Chongqing Power Plant

Critical metals play an irreplaceable role in supporting the development of the global economy and emerging industries. Their short supply makes the recovery of critical metals from alternative sources, such as coal ash, a research hotspot. In this study, Chongqing Power Plant coal and its combustion products, which are rich in a variety of critical metal elements, were selected for the study. The enrichment, distribution, and occurrence mode of critical elements in the products of coal combustion was studied, and improved sequential chemical extraction procedure, and their extraction potential was proposed and discussed. The results show that the contents of the most critical elements in different coal ashes are generally high in the order of fly ash, slag, and bottom ash. The critical elements Li, Ga, Sr, Zr, Hf, Nb, Ta, and rare earth elements and yttrium (REY) are enriched in fly ash and the contents of Ga, Nb, and REY exceed their respective industrial utilization grades, which have great recovery potential. Lithium, Ga, Nb, Ta, and REY are mainly distributed in small particle sizes in non-magnetic fly ash and occur in aluminosilicate glass, followed by mullite and quartz. Three categories of extractability are proposed: easy-to-extract form, relatively easy-to-extract, and difficult-to-extract forms. Finally, future research should focus on the collaborative extraction of multiple critical elements (such as Li, Ga, Nb, and REY) from coal ash.

Potentially Economic Concentrations of Rare Earth Elements and Gold in Power Plant Coal Combustion Products (Far East, Russia)

The distribution of rare earth elements (REE) and gold (Au) in fly ash released during combustion of brown coal from the Pereyaslavskoye (Siberia) and Erkovetskoye (Far East) deposits has been investigated. Coal combustion was carried out in two locations: the boiler unit of the Blagoveshchenskaya coal-fired power plants (CFPP), equipped with an electrostatic precipitator (ESP); and at the Amur Experimental and Technological Complex (ETC) with the aim of separating the combustion products (slag, fly ash, sludge). It was found that in both processes the highest contents of REE (400 and more ppm) and Au (up to 0.29 ppm) are concentrated in fly ash. These characteristics of coals were used as the basis for the author's calculation of the predicted resources of REE and Au under the conditions of the annual operation of firstly one boiler unit, and then five, equipped with an ESP. Further research by the authors will be aimed at improving the degree of recovery of concentrates through the development of technologies at pilot plants such as ETC “Amur”.

Environmental and socio-economic implications of woody biomass co-firing at coal-fired power plants

We apply a detailed power sector model to explore the near-term role of woody biomass co-firing at existing coal facilities in the Eastern US in the decarbonization of US electricity generation. We evaluate five public policy interventions: a biomass co-firing subsidy, two carbon emissions fees, and two clean energy standards. Treating woody biomass as a carbon neutral feedstock, we find co-firing weakly supports decarbonization. However, policies subsidizing co-firing can delay retirement of coal facilities and reduce generation from nuclear, natural gas, wind and solar. Consequently, corresponding sector-wide emissions of CO2 and SO2 may increase (slightly) due to greater utilization of coal plants including relatively inefficient facilities. We assume NOX emissions increase due to generation efficiency losses, but this remains uncertain. Due to higher emissions, a biomass subsidy for co-firing yields small (near zero) economic welfare losses, while in contrast other policies advance decarbonization and yield significant welfare gains. We find justification for biomass use from a local perspective based on first-order impacts on employment and economy activity, but less so air quality.

Optimization and analysis strategy for phenol and ammonia recovery process with feeding variability: Introducing clustering and nonlinear regression

Feeding variability appears extensively in phenol and ammonia recovery process of coal chemical plant, which has caused severe problems in effluent quality. This study is aim to take the feeding variability into consideration for process optimization and analysis of the phenol and ammonia recovery process, have been not studied in previous efforts. For this purpose, this study proposed an optimization and analysis strategy for phenol and ammonia recovery process with feeding variability which introduced clustering and nonlinear regression. Firstly, 56,245 datasets were collected and preprocessed. 27 scenarios were generated by k-means clustering based method to represent the feeding variability and from which 7 typical scenarios were identified. Then, process model and costing model was established through equilibrium-stage model of extractor and Aspen Plus. Steam consumption of solvent recovery tower was estimated more accurately by nonlinear regression via BAS-BPNN. The mean relative error with the industrial value was decreased to 3.9% from 47% of the above-mentioned process model. Finally, sensitivity analysis was conducted via Sobol’ method to pick decision operating variables for lower optimization computing cost. Based on these, deterministic optimization models were individually solved at seven typical scenarios via genetic algorithm, and scenarios-between contrastive analysis suggested that the feeding variability directly affected ideal process operational policy with the maximum cost gap of 571,648 US$/a between typical scenarios. Additionally, stochastic optimization was solved and the results showed that the expected costs were 2.31%, 3.17% and 9.04% larger than the deterministic model. Obviously, the increase in the process's robustness and decrease in the likelihood of process performance deterioration under feeding variability were at the expense of cost.

Implications of Generation Efficiencies and Supply Chain Leaks for the Life Cycle Greenhouse Gas Emissions of Natural Gas-Fired Electricity in the United States.

Uncertainties in supply chain emissions raise questions about the benefits of natural gas as a bridge fuel, but recent efficiency improvements in gas-fired electricity generation remain overlooked. Our comprehensive analysis of supply chain infrastructure and electricity generation across the United States informs spatially and temporally resolved estimates of life cycle greenhouse gas emissions. Results show decreasing life cycle emissions over each year examined: 629, 574, and 525 kg CO2 eq MWh-1 in 2005, 2010, and 2015, respectively. Electricity generation contributed 86% of emissions or greater for each year. Despite concerns over uncertain methane leaks, efficiency improvements make it much more likely that natural gas electricity has an unambiguous greenhouse gas benefit relative to coal. Methane leaks would have to be 4.4 times the Environmental Protection Agency (EPA) value in 2015 to reverse these benefits over 20-year time horizons. With retiring coal plants and scrutinized supply chain emissions, our results show that natural gas can provide a lower emissions option to coal in an increasingly decarbonized power sector.

Quantifying the regional stranded asset risks from new coal plants under 1.5 °C

Momentum to phase out unabated coal use is growing globally. This transition is critical to meeting the Paris climate goals but can potentially lead to large amounts of stranded assets, especially in regions with newer and growing coal fleets. Here we combine plant-level data with a global integrated assessment model to quantify changes in global stranded asset risks from coal-fired power plants across regions and over time. With new plant proposals, cancellations, and retirements over the past five years, global net committed emissions in 2030 from existing and planned coal plants declined by 3.3 GtCO2 (25%). While these emissions are now roughly in line with initial Nationally Determined Contributions (NDCs) to the Paris Agreement, they remain far off track from longer-term climate goals. Progress made in 2021 towards no new coal can potentially avoid a 24% (503 GW) increase in capacity and a 55% ($520 billion) increase in stranded assets under 1.5 °C. Stranded asset risks fall disproportionately on emerging Asian economies with newer and growing coal fleets. Recent no new coal commitments from major coal financers can potentially reduce stranding of international investments by over 50%.

Repowering Coal Power in China by Nuclear Energy—Implementation Strategy and Potential

This article discusses a sustainable low-carbon development strategy that uses nuclear heat sources to replace coal boilers at existing coal power plants in China, to help support a resource and cost-effective low-carbon development. Based on the local situation in China, a three-stage strategy to explore the potential of repowering coal power by nuclear energy is proposed. The main focus of this study is to conduct a more detailed exploration of the 1st stage of this strategy, which includes coal plants located on the coast in regions that already have nuclear power installations. The study makes use of HTR-PM modular reactor for retrofit analysis for the types of coal units present in 1st stage of the strategy. The results show that: 1. There is a technical and economic basis for exploring nuclear power retrofit decarbonization. This conclusion is backed up by on-site transformation analysis and demonstration of the conversion of representative plant units to ensure the validity and reliability of the data. 2. This research provides a new pathway for the problem of stranded assets in China’s power sector decarbonization. The use of HTR-PM modules for retrofit can save up to 1200 billion $ as well as retaining local jobs and economic activity in areas currently hosting coal plants, which brings to society great economic and social benefits.

Regulatory framework for India's energy security and sustainability

India is enhancing domestic coal production to provide affordable electricity to its people even as it is committed to the responsible use of coal in power plants incorporating the latest clean coal technologies. However, the current regulatory framework for coal mines in India entails a multiplicity of laws, overlap of jurisdictions, duplicity of procedures and inadequate enforcement of environmental laws, which do not augur well for the sustainable development of India's energy security. Harmonization of laws, policies, procedures, and authorities engaged in mining, forest, and environmental governance of coal mines is critical to achieving India's Sustainable Development Goals. This paper examines the legal provisions related to environmental regulation of coal mines in India to identify the thorny issues in the extant regulatory framework. We then propose a comprehensive regulatory framework that includes the constitution of an independent Coal Mines Environment Authority to minimize the adverse environmental impact of coal mines through an integrated approach that will enhance the effectiveness, efficiency, and transparency in the environmental governance of coal mines. The paper outlines the composition and functioning of the proposed Authority which may provide pointers for other coal-producing countries seeking to improve the environmental regulation of their coal mines.

The Adopted Weight of Asbestos-Containing Products Versus Results of Stocktaking in the Area of Poland

Abstrakt The date assumed as the beginning of the pandemic in Poland is March 4 2020, the date of the first confirmed case of the virus. The article presents the actions undertaken by the management of underground hard coal mining plants concerning the risk of epidemic related to SARS-CoV-2. This work shows a set of implemented recommendations, guidelines and decisions which were established after the appearance of the first wave of cases in Poland. What is more, it discusses measures aiming at reducing the risk of spreading the coronavirus among the mineworkers. The suggestions for different variants of the decision-making process concerning the pandemic and which have an enormous impact on the operating expenses of the company are also made. © 2020 Polish Mineral Engineering Society. All rights reserved.

China’s withdrawal from overseas coal in context

China has played a significant role in enabling overseas coal-fired power plant development through provision of capital and construction services. Following Xi Jinping’s announcement in September 2021 that China would no longer build new coal-fired power projects abroad, the potential scope of affected capacity remains unclear. This perspective article estimates the range of potentially affected coal plants, showing that construction services without accompanying Chinese finance support more overseas coal-fired generating capacity than financial arrangements. Furthermore, this article discusses four important areas for energy transition policy focus: the outsized role of the non-Chinese private sector in supporting recent coal power development, China’s domestic coal pipeline, the need for early retirement of new coal plants, and mechanisms for a transition of foregone coal support to renewable energy.

Estimating the Employment and Fiscal Consequences of Thermal Coal Phase-Out in China

China hosts over half of global coal-fired power generation capacity and has the world’s largest coal reserves. Its 2060 carbon neutrality goal will require coal-fired electricity generation to shrink dramatically, with or without carbon capture and storage technology. Two macroeconomic areas in which the socioeconomic impact of this decline is felt are losses in jobs and tax revenues supported by thermal coal mining, transport and power generation. At the national level, under a ‘baseline’ (B) scenario consistent with China’s carbon neutrality goal, labour productivity growth in coal mining implies that significant job losses will occur nationally in the medium term, even if all coal plants continue operating as planned. Jobs supported by the coal power industry would decline from an estimated 2.7 million in 2021, to 1.44 million in 2035 and 94,000 in 2050, with jobs losses from mining alone expected to exceed 1.1 million by 2035. Tax revenues from thermal coal would total approximately CNY 300 billion annually from 2021–2030, peaking in 2023 at CNY 340 billion. This is significantly less than estimated subsidies of at least CNY 480 billion, suggesting coal is likely a net fiscal drain on China’s public finances, even without accounting for the costs of local pollution and the social cost of carbon. As coal plant retirements accelerate, from 2034 onwards, fiscal revenues begin to fall more rapidly, with rates of decline rising from 1% in the 2020s to over 10% a year by the 2040s. More aggressive climate policy and technology scenarios bring job and tax losses forward in time, while a No Transition policy, in which all currently planned coal plants are built, delays but does not ultimately prevent these losses. At the provincial level, China’s major coal-producing provinces will likely face challenges in managing the localised effects of expected job losses and finding productive alternative uses for this labour. Governments of coal-producing provinces like Inner Mongolia, with an industry highly dependent on exports to other provinces, are more exposed than others to declining tax revenues from coal, and more insulated from job losses, given their high current degree of labour efficiency. Although their provincial revenues are likely to remain stable until the early 2030s under the B scenario, the possibility of increasing policy stringency underlines the need for revenue and skill base diversification. At the firm level, China’s ‘Big Five’ state-owned power companies were responsible for over 40% of both jobs and tax revenues in 2021. The number of jobs supported by the activities of each of the largest ten firms, with one exception, will decline by 71–84% by the early 2040s, with the tax contribution of each declining by 43–69% in the same period.

Verified Integration of Differential Equations with Discrete Delay

Many dynamic system models in population dynamics, physics and control involve temporally delayed state information in such a way that the evolution of future state trajectories depends not only on the current state as the initial condition but also on some previous state. In technical systems, such phenomena result, for example, from mass transport of incompressible fluids through finitely long pipelines, the transport of combustible material such as coal in power plants via conveyor belts, or information processing delays. Under the assumption of continuous dynamics, the corresponding delays can be treated either as constant and fixed, as uncertain but bounded and fixed, or even as state-dependent. In this paper, we restrict the discussion to the first two classes and provide suggestions on how interval-based verified approaches to solving ordinary differential equations can be extended to encompass such delay differential equations. Three close-to-life examples illustrate the theory.

Occurrence, mobility, leaching, and recovery of rare earth elements and trace elements in Sohagpur Coalfield, Madhya Pradesh, India

ABSTRACT Coal and its by-product are considered a promising resource for the critical elements and rare earth elements (REEs). The study of REEs in coal is in its infancy. Many research methods have tried to recover these valuable REEs, but those methods can be complicated and difficult to apply on an industrial scale. This research work identifies the importance of REEs and its extraction from coal by leaching method. This experimental leaching method has recovered more than 50% of REEs, and for some metals, the recovery value goes up to 90%. Leachate also shows the mobility of trace elements, which can be harmful to the environment. These trace elements need to be removed after burning of coal in thermal power plants. So, this experimental method does the recovery of REEs and trace elements simultaneously.