Coal Supply Research Articles

Coal in energy balance of the Republic of Sakha (Yakutia)

In the article, the role of coal in the energy balance of the Republic of Sakha (Yakutia) is assessed by factoring in significant coal reserves, including low-quality and local coal in hard-to-reach areas. The research was carried out using system analysis methods. To this end, the retrospective dynamics of production and consumption of fuel and energy resources in retrospect and estimates were considered. The estimates were obtained by analysing reference documents, available resources for coal mining and the calculations performed by the authors. The production and consumption of fuel and energy resources of the Republic of Sakha (Yakutia) were analysed. It was shown that coal comprises one of the main resources for power and heat generation, along with gas and water resources. Its share in the consumption of primary fuel and energy resources in 2020 amounted to 34.6%. According to the calculation results, the coal production in the Republic in the future may reach 43 million tons, which will lead to the stabilisation of the export supply of coal and the demand for fuel at power plants and boiler houses in the Republic and neighbouring regions. Projects for developing the coal-fired power industry in the Republic rely on the consumption of coal from the South Yakut coal basin. In the optimal forecast balances, the share of coal generally remaining unchanged may range from 37.8 to 38.7% by 2035. It was established that the potential for coal consumption may increase from 3.5 million tons of coil, equivalent in 2020 to 4.1–4.8 million tons of coil equivalent per year. Mining opportunities significantly exceed their demand, both at present and in the future. A system analysis of the obtained results allowed the main factors affecting coal consumption in the long term to be identified. Coal mined in the South Yakut basin comprises a reliable fuel source in the zone of centralised energy supply in the future. In areas of the Republic of Sakha (Yakutia) having underdeveloped infrastructure and low population density, coal from local deposits becomes an alternative to imported fuel if their development is economically and socially justified.

Intelligent based decision-making strategy to predict fire intensity in subsurface engineering environments

The prospect of subsurface structures taking uncontrollable fire is a significant cause of stress held by people from all over the world. Mine fires and explosions have caused countless casualties and material losses for decades. A fire in a mine has the ability to rapidly contaminate the air of the entire mine, which might result in the loss of life and, in certain cases, the suspension of mining industry processes. Mine fires deplete coal supplies, release greenhouse gases and toxic chemicals, and cause ground subsidence from coal volume loss. This study aims to explore some interesting aspects of mine’s fire data using Catboost and light gradient boosting machine (LightGBM) methods in order to minimize the human fatalities and material losses during the construction of deep underground engineering projects. Firstly, 120 samples demonstrating several distinct characteristics were gathered from an underground coal mine in Turkey. The prediction framework was developed employing the training set and the appropriate configuration of hyperparameters. The findings indicate that LightGBM algorithms achieved a more comprehensive performance in comparison with Catboost, with an accuracy of 92 % and 89 %, respectively. Hence, the proposed intelligent decision-making model can be employed in preventing and warning system of fire risks in subsurface engineering projects. The suggested strategy would serve as a reliable guide for predicting fire intensity in deep underground projects to ensure safe subsurface environments. This research promotes safe, hygienic, environmentally friendly, climate-smart and sustainable development by reducing greenhouse gas emissions.

Sustainable energy policy with an environmental dimension – towards decarbonization

Purpose – The article poses a research question: Is decarbonization an alternative or a necessity? In view of the current problems with coal supplies on the one hand, and the need to take care of the environment on the other, the question posed takes on a deeper meaning. Particularly when sustainable management of natural resources and broad energy policies appear in the background. Therefore, the research hypothesis is: “decarbonization, as one of the recently imposed trends, is indicated from the point of view of sustainable management of natural resources as part of the energy policy and and as a desirable solution in order to to take care of the environment and current problems with coal supplies”. Research method – The article uses several research methods: literature studies, secondary data analysis, analysis of figures in the economic aspect or elements of comparatism. Results – The analysis shows that decarbonization is desirable (it is supported by economic and environmental considerations). Moreover, it is a necessity and follows from the adopted national energy strategy, which is influenced by the EU’s climate and energy policy, based on the pursuit of climate neutrality of the EU by 2050. Originality / value / implications / recommendations – The presented point of view, supported by a preliminary analysis of available statistical data, can be considered as the author’s opinion leading to more in-depth analyses based on more and more recent data in the future. In view of the above, the article is a voice in the discussion on the role and importance of energy policy, in the context of the concept of sustainable development, with a particular focus on one of the components of the European Green Deal. The included commentary on decarbonization, treated as one of the recently imposed trends, was intended to stimulate the reader’s thoughts and their own assessment of the changes taking place and the challenges that go along with them. The text was developed as part of the research project: SUPB.RN.21.109, Id: 538.

Supplies of coal from Sudzenka to Vladivostok in 1904-1905. by CER and Transsib

The most important problem of the naval strategy of the late XIX - early XX centuries. was to provide the fleet with fuel. Before the Russo-Japanese War, the Russian fleet in the Pacific was supplied with coal, which was delivered by sea. The continuation of this kind of supply in the event of war seemed impossible. In the spring of 1904, a project arose for the delivery of coal from the Sudzhensky mines of L. A. Mikhelson (Kuzbass) to the ports of the Pacific Ocean. After coordination with other departments, part of the coal ordered by the Maritime Ministry was sent to Vladivostok. However, due to the high cost of its delivery, the workload of the Trans-Siberian and Chinese Eastern Railways by trains with troops and the successful delivery of coal from England by sea to Vladivostok, the delivery of Sudzha coal was stopped after receiving 5% of the total ordered quantity.

Carbon Neutrality of Ukraine as a Determinant of Green Development

The article presents the research results on some aspects of achieving carbon neutrality in Ukraine. Carbon neutrality is a challenge for the whole world. In 2020, the concentration of greenhouse gases in the atmosphere reached a historical maximum. The work aims to study the features of achieving carbon neutrality in Ukraine. The tasks of the work are the analysis of the components of the transition to low-carbon development, analysis of the consumption of fossil fuels, and activities related to the preservation of forests, natural steppe, and meadow ecosystems. Interest in carbon neutrality issues grows yearly, with a particularly in 2021–2022. Most articles on carbon neutrality were published by scientists from China, the USA, Great Britain, Turkey, and Pakistan. They are mainly devoted to carbon dioxide emissions, economic growth, renewable energy, energy consumption, financial development, co-integration, dioxin emissions, etc. Positive trends regarding the achievement of carbon neutrality have been identified: the supply of natural gas, coal, and peat has decreased, while the supply of renewable energy sources has increased; the share of coal and peat decreased by 26.4%, and the percentage of energy produced from renewable sources increased to 6.6%; the use of coal and peat decreased by 8.5%, natural gas by 5%, and biofuels increased by 16%; the share of biofuel use increased to 5.8%. Expenditures for environmental protection increased by 88.5%, for preserving biodiversity and habitat – by 3.6 times, and costs for air protection and climate change problems – by 2.5 times. The share of expenditures on the protection of biodiversity and habitat increased to 3.2%, and costs on atmospheric air protection and climate change problems to 19.3%. Negative trends that restrain the development of a carbon-neutral economy were also revealed: a low share of renewable sources in the structure of supply and use. Thus, the percentage of biofuel in aggregate use remains low – only 5.8% in 2020. The area of forest loss is increasing, and the area of forest regeneration has decreased by 36%. The area of reforestation remained at the same level, but the area of afforestation decreased ten times during 2010–2020. The scientific novelty consists in the development of theoretical foundations for the identification of regularities in the formation of the energy transformation theory, which differs from the existing ones using bibliometric (VOSviewer v. 1.6.13) analysis.

Risk evaluation of China’s coal mine production logistics system under coal supply assurance

In order to scientifically and rationally assess the safety condition of coal mine production logistics system, this paper establishes a risk assessment model of coal mine production logistics system based on BWM-Vague set. On the basis of reviewing a large amount of literature and combining the main contributing factors of coal mine production safety accidents in practice, a relatively complete set of safety evaluation index system for coal mine production and logistics system was established, including 4 primary indexes of personnel safety, machine and equipment safety, environmental safety and management safety, and 16 secondary indexes such as the proportion of professional and technical personnel, and the fuzzy comprehensive evaluation method was applied to evaluate the index system. Firstly, the BWM assignment method is used to determine the weights of each index, after which Vague set theory is introduced and experts are invited to evaluate and score each index, and then the two are combined to determine the final comprehensive evaluation. Finally, the model was empirically tested in the context of a coal mine enterprise in Beijing, with a view to improving the safety of the production logistics system in coal mines.

Optimizing boiler combustion parameters based on evolution teaching-learning-based optimization algorithm for reducing NOx emission concentration.

How to reduce a boiler's NOx emission concentration is an urgent problem for thermal power plants. Therefore, in this paper, we combine an evolution teaching-learning-based optimization algorithm with extreme learning machine to optimize a boiler's combustion parameters for reducing NOx emission concentration. Evolution teaching-learning-based optimization algorithm (ETLBO) is a variant of conventional teaching-learning-based optimization algorithm, which uses a chaotic mapping function to initialize individuals' positions and employs the idea of genetic evolution into the learner phase. To verify the effectiveness of ETLBO, 20 IEEE congress on Evolutionary Computation benchmark test functions are applied to test its convergence speed and convergence accuracy. Experimental results reveal that ETLBO shows the best convergence accuracy on most functions compared to other state-of-the-art optimization algorithms. In addition, the ETLBO is used to reduce boilers' NOx emissions by optimizing combustion parameters, such as coal supply amount and the air valve. Result shows that ETLBO is well-suited to solve the boiler combustion optimization problem.

250KW Solar Power with MPPT Hybrid Power Generation Station

Abstract: Energy comes in different forms. Light is a form of energy. So is heat. So is electricity. Often, one form of energy can be turned into another. This fact is very important because it explains how we get electricity, which we use in so many ways. Electricity is used to light streets and buildings, to run computers and TVs, and to run many other machines and appliances at home, at school, and at work. One way to get electricity is to This method for making electricity is popular. But it has some problems. Our planet has only a limited supply of oil and coal .In this method details about Endless Energy, Solar Cells Galore, Energy from Sun shine , Understanding Electricity. Solar Thermal power plant use the Sun as a heat source. In order to generate a high enough temperature for a power plant, solar energy must be concentrated. In a solar thermal power plant this in normally achieved with mirrors. Estimation for global solar thermal potential indicates that it could more than provide for total global electricity needs. There are three primary solar thermal technologies based on three ways no of concentrating solar energy: solar parabolic through plants, solar tower power plants, and solar dish power plants. The mirrors used in these plants are normally constructed from glass, a although, other techniques are being explored. Power plant of these types use solar heat to heat a thermodynamics fluid such as water in order to drive a thermodynamic engine; for water this will be a stream turbine. Solar thermal power plants can have heat storage systems that allow them to generate electricity beyond daylight hours.

Identifying an over tenfold variation in carbon intensities of coal mines in China by multi-scale multi-benchmark accounting

Complete and accurate accounting of greenhouse gas (GHG) emissions from coal mines in China is a critical basis for identifying mitigation potential and making reduction strategies. Previous studies based on the emission factor method and life cycle assessment are limited in accounting scope completeness, data reliability, or result applicability at multiple scales and benchmarks. The objective of this study was to carry out a multi-scale multi-benchmark GHG accounting of Chinese coal mines to build a shared understanding and facilitate discussion on this topic. We established a complete accounting model to cover upstream indirect, direct, and downstream indirect GHG emissions related to coal mining. A total of 1151 operating coal mines were investigated to model site-level carbon emissions based on mass and energy benchmarks and then aggregated to 99 cities, 19 provinces, and the country for accounting. The results showed an over 14-fold variation in mass-based site-level accounting, with the highest uncertainty of less than 15%. This variability performed almost the same at city-level aggregating, whereas narrowed to over twofold at the provincial level. Energy-based accounting presented an over 17-fold variation at the site-level with a similar uncertainty to mass-based accounting. Such variability was narrowed to over sevenfold and approximately threefold in the city- and province-level aggregations, respectively. The national average mass- and energy-based carbon footprint of coal mining were 0.39 kg CO2-eq/kg and 0.0185 kg CO2-eq/MJ, respectively, in which approximately 36% of the total GHG emissions were omitted if mining methane escape was reported only. These results suggest improving the methane utilization rate and optimizing coal production and consumption patterns, which implicates cleaner production and sustainable development strategies for the coal industry in China. The conclusions are helpful to identify individual carbon emission gaps, clarify regional emission responsibilities, coordinate the national carbon neutrality process, and promote a low-carbon coal supply system.

Balázs Ablonczy. Ismeretlen Trianon: Az összeomlás és a békeszerződés történetei, 1918–1921 [Unknown Trianon: histories of the collapse and the peace treaty, 1918–21

Balázs Ablonczy. <i>Ismeretlen Trianon: Az összeomlás és a békeszerződés történetei, 1918–1921</i> [Unknown Trianon: histories of the collapse and the peace treaty, 1918–21

Coal Domestic Market Obligation (DMO) policy implementation in Indonesia to achieve energy security

As a country that still uses coal-fired power plants as the main electricity producer, the coal crisis that happened in 2009-2011 had a big impact on Indonesia. Therefore, to avoid disruptions in electricity productivity, the government established a coal DMO policy for coal producers in Indonesia. The implementation of this policy has succeeded in ensuring the stability of coal supply in Indonesia in the following years. However, at the end of 2021, Indonesia experienced another coal crisis despite the implementation of DMO policy. Therefore, this paper aims to explain hoe coal DMO impact security energy in Indonesia and we also try to describe the implementation of DMO policy in Indonesia. The data used in the study were obtained from literature studies from various publications related to coal DMO policy in Indonesia. The result shows that the coal crisis at the end of 2021 occurred as an impact of the supply of coal DMO that was not in accordance with the provisions (35000 MT of the total 5.1 million MT). Despite that, we also found that coal DMO plays important roles in ensuring the energy security in Indonesia.

REDESIGN PULVERIZER SHAFT UNIT 2 DI PLTU SEKTOR BUKIT ASAM 4 X 65 MW

In the operation of the Bukit Asam power plant, in all generating units there are many disturbances that can cause derating the units. Derating of the unit can occur due to decrease in the performance of the steam turbine, decrease in the reliability of the pulverizer, and also disturbances in the coal supply system and various factors. Based on the performance data of the Bukit Asam Generation Sector (Monthly disturbance report) in January 2014, there were 54 derating disturbances recorded. One of the causes of the derating was a broken Pulverizer Shaft with a loss of operating hours for 196.78 [hours] which caused an unallocated electricity loss of 12,422 [GWh]. With the realization of AFI (Action For Improvement) in this final project creation assignment, it aims to redesign the shaft pulverizer, as well as analyze the causes of the pulverizer shaft break. By redesigning the pulverizer shaft and analyzing the cause of the pulverizer shaft breaking, it was found that the cause of the fracture of the shaft made from AISI 1045 with the old design was from calculating the shear stress value of 48.44 x 107 [N/m2], this result exceeded the value of the material permit voltage of 31.8 x 107 [N/m2], so it was not safe to use and the service life was not long. The results of the redesign shaft changed the dimensions of the diameter of the shaft head which was previously 0.174 [m] in diameter to a dwelling of 0.25 [m]. The results of calculating the redesign shaft made from AISI 1045 obtained a shear stress value of 16.33 x 107 [N/m2], this result is smaller than the material clearance voltage value of 31.8 x 107 [N/m2], so it is safer with a relatively longer service life.Keywords: Derating, Pulverizer Shaft, material, Redesign, Shear Stress

The Balance and Optimization Model of Coal Supply in the Flow Representation of Domestic Production and Imports: The Ukrainian Case Study

The successful supply of an economy with coal fuel, for a country that carries out its large-scale extraction and import, is a complex production and logistics problem. Violations of the usual supply scheme in conditions of crises in the energy markets, international conflicts, etc., lead to the problem of simultaneous restructuring of the entire supply scheme. This requires changes in the directions and capacities of domestic production and imports. In this article, the above problem is solved by the economic and mathematical model of production type. The developed model includes subsystems of domestic production and import supply. The results of modeling economy supply with thermal coal for different values of demand are given. The model was used to determine the amounts of coal production for Ukraine with the structure of the coal industry of 2021 and under the condition of anthracite consumers’ transformation to the high volatile coal. Simulations have shown that eliminating the use of anthracite requires the modernization of existing coal mines. Under those conditions, the import of high volatile coal will amount to 3.751 million tons in 2030 and 11.8 million tons in 2035. The amounts of coking coal imports will be 5.46 million tons, 5.151 million tons, and 7.377 million tons in 2025, 2030, and 2035, respectively.

Situation Analysis of Provincial Power Market Based on System Dynamics Simulation

Under the background of carbon peaking and carbon neutrality goals, with the expansion of the scope of power market-oriented reform and the increase in uncertainty of social, political, and economic factors outside the market, the market environment is becoming more and more complex, and it is more difficult to analyze and control the market situation. From a macro perspective, overall modeling for the power transmission link between the generation side and the consumption side of the provincial power market is built, in which a variety of real-time elements or scenarios such as renewable energy power generation growth, carbon emission quota, coal shortage, and dual control system of total energy consumption and energy intensity are considered. The system dynamics tools are used for simulation, and the medium and long-term operation trends of the market are analyzed. In the case studies, the actual situation of the Jiangsu power market is used as background. The trend of the power market situation under the basic scenario is analyzed, and the sensitivity analysis is carried out for three factors: coal supply growth rate, carbon emission caps, and electricity demand growth rate. It is shown that diversified macro factors inside and outside the market will affect the balance of the market operation situation to varying degrees, making the key operation indicators of the market deviate from the existing stable state.

Coal production capacity allocation based on efficiency perspective—taking production mines in Shandong Province as an example

Coal remains an irreplaceable main energy source in China. This paper uses the zero-sum gain data envelopment analysis (ZSG-DEA) model, and proposes a production capacity optimization allocation plan, which provides a theoretical basis for how to ensure energy security in the context of China's dual-carbon strategy. Results show: (1) the optimal plan adjusts the production capacity by 7.32 million tons/year, accounting for 6.33% of the total production capacity; 32 mines will be increased in production capacity, and 19 mines will be reduced in production capacity. (2) Under the optimal plan, the raw coal output, income, and profit of provincial coal mines will increase by 3.5965 million tons, 2.65 billion yuan, and 0.972 billion yuan, respectively, and wages are expected to decrease by 73.5 million yuan. (3) In terms of the fairness of personnel placement, the Gini coefficient of the actual situation is 0.3082, and that of the optimal scheme is 0.2896. It suggests that engaging in the “one size fits all” campaign of marginalization and coal decoalization is unadvisable. Coal supply and market demand should be efficiently connected, and the elimination of backward production capacity and the release of advantageous production capacity should be rationally coordinated.

High-capacity coal trucks to reduce costs and emissions at South Africa's power utility

South Africa's national power utility, Eskom, is under growing pressure to increase its power generation capacity in the face of national rolling blackouts while also containing costs, increasing revenue, and reducing its environmental impact. While the entity embarks on an ambitious $ 10 billion 2050 decarbonisation plan, there are short-term opportunities to save costs and emissions in parts of its business through relatively simple interventions. In this work, we investigate the transport of coal to Eskom's power stations. We focus on the approximately 30 million tonnes transported by road, where ‘high-capacity vehicles’ (HCVs) have already demonstrated significant productivity improvements in a national pilot project in South Africa. First, the current costs and emissions associated with the current transport activity are calculated, which amount to approximately ZAR 4 billion (US$250 m) and 230,000 t of CO2 respectively per year. A case is then presented for transitioning the coal transport fleet to 74-t high-capacity vehicles, which is calculated to save Eskom up to ZAR 248 million (US$15 m) and 35,000 t of CO2 each year. In addition, we show that the more road-friendly HCV fleet would result in a reduction in road damage valued at ZAR 50 million (US$3 m) per year. Ultimately, these cost figures represent savings to the South African taxpayer, as both Eskom and the road authorities are state entities. The precise cost benefit to Eskom, however, will depend on the nature of its coal supply contracts with local mines and transporters, but it is likely that market forces will enable these savings to be realised throughout the supply chain.

Beneficiated Coal Buying Process: Investigating Industrial Buying Behavior Models

This research paper examines the buying process of beneficiated coal within coal-consuming industries, while considering different models of industrial buying behavior. Beneficiated coal refers to coal that has undergone a purification process to improve its quality and reduce impurities, making it suitable for industrial applications. The primary objective of this paper is to investigate and compare various models of industrial buying behavior in the specific context of the beneficiated coal market. This paper aims to provide valuable insights for coal suppliers and buyers to enhance their decision-making processes. The study focuses on the different stages involved in the buying process of beneficiated coal. Additionally, it explores the internal and external factors that influence industrial buyers when procuring beneficiated coal. The research analyzes each stage of the buying process, including problem recognition, information search, alternative evaluation, purchasing decision, and post-purchase evaluation. It also examines the internal and external factors influencing industrial buyers in their procurement of beneficiated coal, such as organizational considerations, market dynamics, and individual preferences. Furthermore, this research paper presents a comparative analysis of various models of industrial buying behavior, such as the Webster and Wind model and the Sheth model. The aim is to assess the applicability and effectiveness of these models in explaining the intricacies of the buying process within industries. By gaining a deeper understanding of the buying process and influential factors, coal suppliers and buyers can refine their marketing strategies, optimize their operations, and foster mutually beneficial relationships within the beneficiated coal market.

Study on a coalbed methane liquefaction system based on thermoacoustic refrigeration method

Recovery of coalbed methane (CBM) is significant for the safe production of coal mines, environmental protection, and clean energy supply. A novel CBM liquefaction process composed of a looped three-stage thermoacoustic engine and three pulse tube coolers (PTCs) is proposed. Each PTC is connected to one thermoacoustic engine unit by bypass. Potential liquefaction processes using thermoacoustically driven PTCs are proposed and studied numerically. The operating parameters of the system are globally optimized by performing genetic algorithm procedures, using specific power consumption (SPC) as the objective function. Additionally, exergy analyses are conducted on the main components of the system to reveal the potential directions for improvement. It is found that a three-stage thermoacoustically driven PTCs is an appropriate configuration considering the overall efficiency and geometric compactness of the system. The optimized SPC of the system is 0.58 kWh·Nm−3, which is comparable to that of the traditional liquefiers. The overall exergy efficiency of the system is 36.25%. Total exergy loss of the three PTCs is 4.978 kW, accounting for 80% of that of the system. Having the advantages of being driven by heat instead of electricity, safe operation, compact structure, and high efficiency, the proposed liquefaction process is promising for small-scale gas reserves, especially for CBM.

A Comprehensive Operation Status Evaluation Method for Mining XLPE Cables.

At present, the online insulation monitoring and fault diagnosis of mining cables are extensively discussed, while their operation status assessment has not been deeply studied. Considering that mining cables are closely related to the safe and stable operation of coal mine power supply systems, a comprehensive evaluation method including the Analytic Hierarchy Process (AHP), the membership cloud theory, and the D-S evidence theory is proposed in this paper in order to accurately assess the operation status of the mining XLPE cable. Firstly, the membership cloud is introduced to solve the index membership degree and the weights are calculated by an improved weight vector calculation method. Secondly, the conversion from the base layer indicator membership degree to the target layer trust degree is realized based on the D-S evidence theory. Then, the cable operation status is judged via the trust degree maximum and the distribution of conflict coefficients is further analyzed to warn the indicators with a bad status in the base layer. Finally, the feasibility of the proposed evaluation method is verified by a sufficient and detailed case analysis.

Dynamic modeling of global fossil fuel infrastructure and materials needs: Overcoming a lack of available data

The low-carbon energy transition requires a widespread change in global energy infrastructures which in turn calls for important inputs of energy and materials. While the transport and electricity sectors have been thoroughly analyzed in this regard, that of the hydrocarbon industry has not received the same attention, maybe in part due to the difficulty of access to the necessary data. To fill this gap, we assemble public-domain data from a wide variety of sources to present a stock-flow dynamic model of the fossil fuels supply chain. It is conducted from 1950 to 2050 and along scenarios from the International Energy Agency. We estimate the concrete, steel, aluminum and copper requirements for each segment, as well as the embedded energy and CO2 emissions through a dynamic material flow analysis (MFA) model. We find that (i) the material intensities of oil, gas and coal supply chains have stagnated for more than 30 years; (ii) gas is the main driver of current and future material consumption; and (iii) recycled steel from decommissioned fossil fuels infrastructures could meet the cumulative need of future low-carbon technologies and reduce its energy and environmental toll. Furthermore, we highlight that regional decommissioning strategies significantly affect the potential of material recycling and reuse. In this context, ambitious decommissioning strategies could drive a symbolic move to build future renewable technologies from past fossil fuel structures.