Thermal Coal Research Articles

CHEMICAL ANALYSIS OF COAL DEPOSIT FOR POWER GENERATION: A CASE STUDY OF BUKAN-KWATO IN LAFIA L.G.A OF NASARAWA STATE, NIGERIA.

Nigeria, the most populated country of Africa is reactivating her coal industry as supplementary energy source. Bukan - Kwato coal field is one of the recently discovered coal deposits in Lafia that is receiving great attention from investors and entrepreneurs of coal energy. The coal serves as prime target for power generation by the Nigerian Government, yet little is known about the basic properties of the deposit. The research seeks to achieve the objectives of collection of fresh coal samples from the mining site, so as to carry out the chemical analysis, determine the calorific value and to suggests best methods for processing of the coal. The coal samples were collected from the study area and were subjected to proximate, ultimate and calorific value determination in order to determine the intrinsic properties of the coal. Proximate analysis were carried out on pulverized samples using the Muffle furnace, carbon and hydrogen were determined using the method described in the Liebig method while nitrogen was obtained using the Kjeldahl method. Sulfur content were obtained using the ESCHKA method, oxygen content were calculated by difference on an air dried basis. Calorific value were determined using the Isoperibol calorimeter. The results obtained compared with the standard pulverized coal fire plants shows that the coal has a medium to high carbon content of 54.68%, high moisture content of (9.72%), Nitrogen (3.5%), Sulfur (24.24%) and Ash (31.74%) with a corresponding low volatile matter of 20.28%. The high ash content in the coal can be used as thermal coal for power generation.

Effect of Critical Variables on Air Dense Medium Fluidized Bed Coal Drying Efficiency and Kinetics

Calorific value, as a key component for fuel quality assessment, directly affects the thermal power plants' efficiency. While high-quality coal is consumed as metallurgical coal, low-rank coals are used by coal-fired power plants. The high moisture content of the thermal coals significantly influences their heating values. In this study, the drying performances of the fixed bed and air dense medium fluidized bed (ADMFB) dryers were investigated under the superficial air velocity of 15-18 cm/s, inlet air temperature of 55-75 oC, and up to 80 minutes of operation. Low air consumption is an intrinsic characteristic for ADMFB, while a low-temperature range for drying air was selected to address the coal-fired power plants' waste heat. It was found that an increase in air velocity and temperature favored the drying efficiency of both systems (i.e., 18 cm/s and 75 oC), with the temperature being more effective than the air velocity. The ADMFB dryer removed comparatively more moisture than the fixed bed for the shorter drying durations. For example, for 10% moisture reduction at 75 °C, the ADMFB dryer needed 5 minutes less time than the fixed bed. The fitting quality and goodness of serval well-known thin-layer models for describing fluidized bed and ADMFB coal drying kinetics were assessed by several models and statistical evaluators, respectively. It was found that the Middilli & Kucuk model best describes the fixed bed coal drying (i.e., R2=0.999, RSE=0.001, RMSE=0.008), while the Page model much properly simulates the ADMFB coal drying (i.e., R2=0.998, RSE=0.002, RMSE=0.009).

Green pivot: can Australia master the hydrogen trade?

Australia is in a bind. It is at the heart of the pivot to clean energy: it contains some of the world’s best solar irradiance and vast potential for large-scale carbon capture and storage; it showed the world the path forward with its stationary storage flexibility at the much vaunted Hornsdale power reserve facility; and it moved quickly to capitalise on low-carbon hydrogen production. Yet it remains one of the largest sources for carbon-intensive energy exports in the world. The extractive industries are still delivering thermal coal for power generation and metallurgical coal for carbon-intensive steel making in Asian markets. Even liquefied natural gas’s green credentials are being questioned. Are these two pathways compatible? The treasury and economy certainly benefit. But there is a huge opportunity to redress the source of those funds and jobs, while fulfilling the aspirations to reach net zero emissions by 2050. In our estimates, the low-carbon hydrogen economy could grow to become so substantial that 15% of all energy may be ultimately ‘carried’ by hydrogen by 2050. It is certainly needed to keep the world from breaching 2°C. Can Australia master the hydrogen trade? It is believed that it has a very good chance. Blessed with first-mover investment advantage, and tremendous solar and wind resourcing, Australia is already on a pathway to become a producer of green hydrogen below US$2/kg by 2030. How might it then construct a supply chain to compete in the international market with established trading partners and end users ready to renew old acquaintances? Its route is assessed to mastery of the hydrogen trade, analyse critical competitors for end use and compare costs with other exporters of hydrogen.

Gasification and physical-chemical characteristics of carbonaceous materials in relation to HIsarna ironmaking process

HIsarna ironmaking process is one of the emerging technologies being developed to mitigate the increasing carbon footprint from the steel making industry. This innovative process offers flexibility with the type of reductants used in the smelting reduction vessel for the conversion of iron ore to liquid hot metal. Natural gas is well known for being a relatively clean fossil fuel producing carbon black and hydrogen when it undergoes thermal decomposition. The gasification reactivity of carbon black compared to the carbonaceous materials used in HIsarna process is investigated in this work using isothermal gravimetric analysis (TGA) method at 1250 °C, 1350˚C and 1450 °C under atmospheric pressure. Furthermore, physical-chemical characteristics of the individual carbonaceous materials, which may influence the reactivity, are evaluated systematically. The experimental results show that carbon black is the least reactive followed by thermal coal and charcoal. It was found that the effect of the morphology of the carbonaceous materials on the reactivity is dominant compared to the surface area of the materials. In addition, the reactivity increases with the alkali index (AI) and the level of the amorphousness of the material’s structure. Three well-known kinetic models, i.e. the volumetric model (VM), the grain model (GM) and the random pore model (RPM) were applied to predict the gasification behaviour of the three carbonaceous materials. The random pore model best describes the gasification reaction of the selected samples due to the influence of the pore diffusion on the reaction. It is observed that the activation energy of the samples are not following the order of reactivity, this can be explained by the kinetic compensation effect.

Experimental Investigation on Geo-Polymer Concrete by Using Steel Slag at Higher Temperature

Concrete is the most durable, versatile and reliable construction material after water. Its requirement is very large so the need of ordinary portland cement is also high. Due to such large production of OPC our environment is getting polluted as carbon dioxide is emitted. Geo-polymer is the alternative to control the pollution and its an innovative construction material. It can be prepared by using fly ash, the secondary product of thermal coal and steel slag which is the by product of the production of steel in an electric arc. Another thing required to prepare the geopolymer concrete (GPC) is curing temperature. In this study mechanical properties of GPC is examined with curing temperature 70°C with a replacement of steel slag as coarse aggregate as 0%, 10%, 20%, 30% and 40%. Here the strength of GPC is increasing up to 30% replacement of steel slag as coarse aggregate.

Application of the underground natural brines for energy coal enrichment

As part of the development of coal generation in the Russian Federation, one of the important issues is the use of enrichment processes for thermal coal. There are a large number of mineral processing methods, namely: gravity processing, flotation processing, methods of magnetic and electrical processing, as well as special processing methods, from which there are: radiometric, chemical and mechanical methods of coal preparation. Based on the results of an economic evaluation of existing enrichment methods, the team of authors identifies the gravity enrichment method as the most applicable method for thermal coals in view of the low cost of the resulting coal concentrate during its implementation. Among the existing methods of gravitational enrichment, one can distinguish enrichment in a heavy medium, as the most easily implemented, and again, the cheapest of all existing methods of gravitational enrichment. In industry, magnetite and water-sand suspensions are most often used as a heavy medium. The advantage of using these difficult media is the depth of the enrichment process - the output of coal concentrate and the amount of valuable rock recovered (combustible part of the fuel). The downside is the difficulty in operation - the suspensions must be homogenized, and the contamination of the resulting coal concentrate with weighting particles (magnetite or sand), which reduces the amount of valuable rock. It is proposed to solve this problem by using sodium chloride and calcium chloride as a natural medium in underground brines. According to the results of the work, the main indicators of the enrichment processes are estimated when using brines as a dividing medium.

The Capital Market Impact of Blackrock’s Thermal Coal Divestment Announcement

This study examines how coal companies were affected by the announcement of thermal coal divestment made by Blackrock, a large institutional asset manager. Following the announcement, the largest thermal coal mining companies exhibited negative abnormal returns. However, the stock prices of other firms were not affected. Blackrock’s own share price increased following the announcement. We provide additional evidence that Blackrock protected its clients by lowering its exposure towards affected companies before the announcement. Overall, our results show that divestment has significant impacts on the companies in question and that the capital market sees divestment as value-enhancing for the divesting institution.

The Comparison of Regression Models and Artificial Neural Networks in Predicting Power Generation in a Thermal Coal Power Plant

A significant Eskom’s grid electricity is generated from the thermal coal-fired plants. The study focused on modelling the generated electricity during the “before and after” outage of a typical unit, in one of the Eskom Benson’s thermal coal power plants rated at 600 MW and mechanical conversion efficiency of 35%. The dataset for the chosen input parameters are collected from the metering cards and the generated electrical power are obtained from the installed power meters to the designated unit in the power plant. Multiple linear regression models (MLR) and Artificial Neural Networks (ANN) for both the “before and after outage” power generated are developed, tested and validated with the input parameters as the average air heater temperature, average main stream super-heater temperature, average high pressure heater’s temperature, the total mass of coal burnt, average of the condenser well pressure and temperature and the auxiliary power consumed. The MLR models and the ANNs for both the “before and after” outage power generated gave excellent correlation coefficients of over 0.950. Furthermore, it can be concluded that the ANNs gave better predictions over the counterparts MLRs model based on the correlation coefficients and the mean square errors derived from the models.

Research on the Transmission Ability of China’s Thermal Coal Price Information Based on Directed Limited Penetrable Interdependent Network

According to the criterion of the visibility graph and the irreversibility of the time series, this paper proposes a new perspective to construct the directed limited penetrable interdependent network (DLPIN) for thermal coal between the opening and closing price series after the Johansen cointegration test. The results of the statistical research and cointegration analysis show that there is a cointegration relationship between the opening and the closing price series, and the relationship between them does not follow a normal distribution. By analyzing the topological characteristic of the DLPIN, the results indicate that there is an obvious "community structure" and scale-free features, which show that there are groups and differences among the thermal coal price, and most of them have a weak transmission ability of the thermal coal price information; only a few of them have a strong transmission ability. The differences of the in-degree and out-degree show that some thermal coal prices have a weak influence on the other prices but are strongly affected by the other prices. In addition, most of the thermal coal prices are far away from the infectious source of the price information; only a few are close to the infectious source of the price information to a certain extent. Obviously, the influence of the thermal coal price has a certain range, which is closely related in a short distance. Furthermore, these results can reveal the internal laws of the main price fluctuation and information transmission for the thermal coal, and some references can be provided to reduce risk investment and improve capital return for the related investors.

Climate Policy Paralysis in Australia: Energy Security, Energy Poverty and Jobs

According to the 2020 Climate Change Performance Index, Australia was ranked as the worst-performing country on climate change policy. The country has an ambivalent record of climate policy development as well as implementation, and has been criticized for its inaction. This paper considers why the country has been locked in climate policy “paralysis” through analyzing defining attributes of such a paralysis, and the tentative connections between domestic energy policies and international trade and development. We conducted a media content analysis of 222 articles and identified media narratives in three cases of energy projects in the country involving thermal coal exports, domestic renewable energy storage, and closure of a domestic coal power station. The analysis reveals that policy paralysis in Australian climate change policy can be traced back to the countervailing arguments that have been pervasive around domestic energy security, rural employment and international energy poverty. The political establishment has struggled to develop a sustainable consensus on climate change and the citizenry remains polarized. We also discuss how a “focusing event,” such as a major natural disaster can break the impasse but this is only possible if energy security at home, energy poverty abroad and employment imperatives across the board are clearly delineated, measured and prioritized.

Rational Use of the Elemental Potential of the Pavlovsk Deposit Coal (Primorye)

X-ray diffractometry, X-ray fluorescence, and ICP-MS have been used to study the phase and elemental composition of the thermal coal from the Pavlovsk brown coal deposit and their ash-forming compounds. The results of the spectral analysis methods were combined with the data of thermal gravimetry, elemental analysis of OM, and scanning electron microscopy. The metal-bearing potential of the thermal coal from the deposit and the prospects for the associated extraction of useful components have been estimated. A set of analytical methods is proposed for the rapid assessment of the content of valuable and significant elements in solid fossil fuels for the comprehensive development of the coal deposits.

Mercury in Indian Thermal Coals.

In India, coal utilization in power generation, constitutes as the single largest source of mercury emissions. This study presents mercury content in Indian sub-bituminous and bituminous coals that are primarily used as fuel in large-scale electricity generation facilities. A total of 165 number of coal samples have been collected from the major coal producing regions of the country. Along with the mercury content, other chemical parameters like moisture, ash, volatile matter, total Sulphur and gross calorific value were also analyzed. Mercury concentrations of these coals were found to be between 3 and 554µg/kg, with an average of 175µg/kg. Variation of the mercury content with the rank parameters like volatile matter, carbon content, ash and total Sulphur were also assessed. No significant correlations were observed with the rank parameters but a general trend of increasing mercury with ash content is discernible.

Intensification of thermal coal and coke oxidation by metal oxides and their precursors

Oxidation process of bituminous coal, anthracite, and coke obtained after pyrolytic treatment of the corresponding fuels (bituminous coal and anthracite) modified with activating additives in the form of Cu(NO3)2 and Fe(NO3)2 in the amount of 5 wt% was studied. Application of the additives was carried out by incipient wetness impregnation method with preliminary dissolution of the additive in a water-alcohol solution with a volume ratio of C2H5OH/H2O=50/50. Additionally modified samples were subjected to thermal treatment at a temperature corresponding to the decomposition of the considered metal nitrates (about 220 °C) to ensure close contact between additives (metal oxides) and carbon materials. Oxidation process was performed by thermogravimetric analysis at a heating rate of 10 °C/min in the temperature range 45-1000 °C at atmospheric pressure. It has been established that application of activating additives in the form of metal oxides and their precursors helps to reduce the initial temperature of intense oxidation (Δti = 15-80 °C) and to shift the process to the low-temperature region as a whole. Mass spectrometric analysis was used to determine the qualitative composition of the gas-phase oxidation products. Decrease in the initial temperature of intense oxidation contributed to a decrease in the intensity of NOx release in the region of high temperature oxidation of the carbon residue.

Солнечный свет против угля

The article dwells on the topic of competition between coal and solar energy as types of fuel. The authors provide a comparison of the installed capacity of a virtual solar power station and an existing coal power station located within the land allotment of a coal mine. The development prospects of the coal industry in terms of thermal coal are shown.

Fundamentals of modern ground control management in Australian underground coal mines

Underground coal mining is inherently hazardous, with uncontrolled ground failure regarded as one of only several critical risks for multiple fatality events. Development, implementation and management of overarching systems and procedures for maintaining strata control is an important step to mitigating the impact of ground failure hazards at a mine site operational level. This paper summarised the typical pro-active ground control management system (PGCMS) implemented in various Australian underground coal mines. Australia produces approximately 100 million tonnes a year of metallurgical and thermal coal from approximately 30 of the world’s safest longwall mines operating in New South Wales and Queensland. The increased longwall productivity required to achieve both high levels of safety and profitability, places significant emphasis on the reliability of pro-active ground control management for longwall mining operations. Increased depths, adverse geological conditions, elevated variable stress regimes and weaker ground conditions, coupled with an industry wide need for increased development rates continue to make ground control management challenging. Ground control management is not only about ground support and pillar design though but also a structured process that requires a coordinated effort from all levels of the workforce to both minimise the occurrence of adverse geotechnical events and mitigate the potential risks when they do occur. The PGCMS presented in this paper is proven to provide both a safer and more productive mine environment through minimisation of unplanned delays. The critical elements of the method are presented in detail and demonstrate the utility and value of a ground control management system that has potential for implementation in underground coal mining globally.

Influence of igneous intrusion on coal and gas by means of element geochemistry and vitrinite reflectance method: a case from the Huainan coalfield, northern China

ABSTRACT Material composition changes of coal and gas under igneous intrusion have been one of the hot research fields in global geology. In this study, through in-depth discussion of a case from Huainan coalfield, North China, some important characteristics of thermal altered coal (TAC) are expounded by using the methods of element geochemistry and vitrinite reflectance (Rmax, Ro, and Rmin) calculation. The results show that the profile of coal reflectance/thermal metamorphic temperature (TMT) vs. distance from the intrusion indicates that the thermal aureole range reveals by the thickness of 2.4 m intrusion is approximately 3.24 m. Close to intrusion, the carbon (Cdaf) of coal increases significantly, while hydrogen (Hdaf) and oxygen (Odaf) decreases significantly, and the nitrogen (Ndaf) change is very irregular. After acid treatment, the volatile matter (VMacid) and ash yield (Ashacid) losses of coal have reached 5× and 4× of the ambient zone. The atomic ratios O/C and H/C are parallel to the changes of VMacid. Based on Rmax-Rmin diagram, the pressure effect of TAC is analyzed. In the actual geological model, the coal is mainly subjected to the bearing stress perpendicular to the contact surface instead of the vertical gravity of the magma body, and the applicable conditions of the theoretical model are proposed. Summing up the previous calculation methods of TMT, the exponential function method can be used when the Rmax is <1.0. On the contrary, the previous method can be used. The empirical formula for calculating the carbon isotope (δ 13 CCH4) of gas by using Rmax of TAC shows a negative result. The δ 13 CCH4 of the gas near the contact is relatively positive, which proves to some extent that 13 C of the thermal residual coal and 12 CH4 of the gas are subjected to carbon isotope fractionation. Here, the regression model between the Rmax of TAC and δ 13 CCH4of gas in the case can be expressed as δ 13 CCH4 = 16.777Ln(Rmax)-49.859.

Impact of international energy prices on China's industries

AbstractThis study examines how returns and volatility of future contracts for Brent crude oil (Brent), West Texas Intermediate crude oil (WTI), Henry Hub natural gas, and Newcastle thermal coal impacts industries in China. Using the firm‐level data of 3,750 stock listings across both Shanghai and Shenzhen stock exchanges, segregated into 138 subindustries under the Global Industry Classification Standard, this study finds evidence that crude oil futures have the most significant influence. Further analysis suggests that stock returns of oil‐related companies are more closely align to Brent and WTI's futures returns following China's key oil pricing reform on March 27, 2013. Overall, Chinese industries are also more exposed to global crude oil futures volatility after this event.

Climate, thermal coal and carbon

Pressure is mounting globally for the discontinuation of the use of thermal coal and other carbonbased fuels for power generation. The pressure to shift power-generating fuel sources to cleaner propositions comes from many fronts, including from financial institutions that have removed funding options for new and existing coal projects, large investment houses that have discontinued coal equity investments from their portfolios, social movements that have heightened awareness and have created industrial and societal disruptions and, notably, scientists and other researchers who have pronounced the need to reduce carbon-rich energy sources for environmental reasons. However, despite this, thermal coal continues to play an important role in power generation in many regions around the world and will continue to do so for decades to come. This is because coal is an abundant mineral, the power-conversion technology is tried and tested and, comparatively, coal power generation tends to be a more affordable option when considered against numerous alternatives. This latter point excludes the cost impacts associated with carbon taxes. This paper specifically covers the relationship between the amount of CO2 produced from the combustion of thermal coal for power generation purposes and the additional heating effect, measured in degrees Celsius, that this CO2 creates. It also provides explicit and comparative figures relating to the world’s largest thermal coal consumers and hence the largest contributors to climate change relating to the combustion of thermal coal.

Фіскальна ефективність акцизного податку як складова оптимізації системи непрямого оподаткування

The excise taxes contain a hidden reserve for raising funds for the state budget. Therefore, in the case of ensuring their high fiscal efficiency, they can serve as a significant resource for filling the revenue side of the country's budget. The purpose of the article is to analyze the dynamics and structure of excise tax receipts to the State Budget of Ukraine, to determine the main indicators that can be used to assess the fiscal efficiency of the excise tax. The information base for the study was the official data of the State Statistics Service of Ukraine, reports of the State Treasury Service on the implementation of the State budget, data from the Ministry of Energy and Coal Industry of Ukraine. The analysis of the structure and dynamics of the excise tax transferred to the state budget for the period 2014-2019 was carried out. Indicators that characterize the fiscal significance of the excise tax as part of the state budget revenues were determined. The tendencies revealed by the author of a decrease in the fiscal significance of the excise tax are, first of all, a consequence of the insufficient efficiency of administration of this tax, which follows from the imperfection of the current legislation and the ignorance of some potential sources of excise taxation. Based on the data of the State Fiscal Service and the Ministry of Energy and Coal Industry of Ukraine on the production of thermal coal in the period 2017-2019, an assessment of the potentially lost revenues of the state budget was made. These revenues would become possible with the introduction of an excise tax on thermal coal. In the context of optimizing the system of indirect taxation, it was determined that an increase in the current rates of excise tax on excisable goods will not give a tangible effect in the medium term, but will lead to an increase in the level of “shadow” (illegal) production, sale and movement of excisable goods across the customs border of Ukraine. Therefore, the legislature should pay attention to those groups of goods that are in a state monopoly, and their taxation can give significant additional funds to the state budget.

ВЛИЯНИЕ ПАНДЕМИИ COVID-19 НА МИРОВОЙ РЫНОК ЭНЕРГЕТИЧЕСКОГО УГЛЯ

The article highlights the changes in the global thermal coal market associated with the consequences of the COVID-19 pandemic, examines the dynamics of import volumes by key countries - consumers of thermal coal and export volumes by major exporting countries, as well as price changes in the main international markets. Analysis of changes in the global steam coal market caused by the consequences of the COVID-19 pandemic and a number of other objective factors demonstrates a change in the competitive positions of the largest exporting countries, which may have long-term consequences. In addition, the article examines the continuing trend of dividing the thermal coal market into the high-calorie and low-calorie thermal coal markets, which have multidirectional development prospects.