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With the rapidly increasing world population and the need for industrialization, energy supply has become an important global problem. A significant part of the world's energy needs is provided by fossil fuels. About half of all global coal deposits are low-quality coals, including lignite. Karapınar/Konya, also the study area, has Turkiye's second richest lignite reserve. The region's lignite reserve can be used in thermal power plants for electricity generation in terms of its nature and the amount is an important opportunity to meet the energy demand for both region and country. The region contains many sinkholes, and the potential for the formation of new sinkholes makes the site selection for thermal power plants in the region an even more strategic decision. This study aims to propose the most suitable thermal power plant site for the region by using Multi-Criteria Decision Making methods and Geographic Information Systems in an integrated way. Within the scope of the study, a total of twelve sub-criteria were taken into consideration under the main criteria of Geological, Economic and Environmental. The Best-Worst Method was applied to determine the criteria weights, and by using the weights, a suitability map for the thermal power plant installation site was produced and candidate regions were determined. TOPSIS was applied to determine the most suitable location among the candidate regions. The Candidate Region in the easternmost part of Karapinar district was chosen as the most suitable site for the thermal power plant installation., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

In recent years, there has been a focus on clean power generation, and it is critical to assess the environmental impact of novel technologies used in pollution control in power generation. The study uses life cycle assessment (LCA) to assess the environmental impacts of coal-fired thermal power plants with different emission control techniques in an Indian scenario. As there are no such studies available in the Indian context, this work might provide a holistic view of the impacts of energy generation. A supercritical coal-fired plant with a capacity of 660 MW is considered in this study. The system boundary included coal extraction, transportation, power plant operation, and transmission losses of electricity with a functional unit of 1 kWh. It was observed that there was an energy penalty due to the power consumed in emission control devices, but the maximum energy penalty was due to the power used in the carbon capture system. The LCA is done from "cradle to gate", with impact indicators at the mid-point evaluated using the RECIPE (H) 2016 LCIA method. LCA results showed that power plant operation is the most significant contributor to environmental impact. Initially, in cases 1 and 2, climate change (CC) potential was a major impact category, but CC potential was reduced with carbon capture and storage, 0.27 kg CO 2 eq. in case 3 with ESP, FGD, SCR, and carbon capture and storage (CCS) and 0.263 kg CO 2 eq. in case 4 with ESP and CCS. But there was a considerable increase in the majority of the impact categories in case 4. Freshwater consumption potential increased from 3.98 E-03 m 3 in base case 1 to 4.98 E-03 m 3 in case 3 due to the amount of water used in chemical production during CCS, as CC potential is a major concern in power generation, However, compared to case 1, the potential for climate change increased in case 2, whilst in case 4, the potential for climate change is lower but has resulted in an increase in the majority of impact categories. Case 3 shows an optimal approach to reducing CO 2 emissions compared to other cases. The combination of ESP, FGD, SCR, and CCS is favourable for cleaner energy generation., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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 554 µg/kg, with an average of 175 µg/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.

We present seasonal rock magnetic data for 48 surficial soil samples collected seasonally around a coal-fired thermal power plant on the southwest coast of India to demonstrate how fly ash from the power plant is transported both spatially and seasonally. Sampling was carried out during pre-monsoon (March), early-monsoon (June), monsoon (September) and post-monsoon (December) seasons. Low- and high-frequency magnetic susceptibility (χlf and χhf), frequency-dependent magnetic susceptibility (χfd), χfd %, isothermal remanent magnetization (IRM), "hard" IRM (HIRM), saturation IRM (SIRM) and inter-parametric ratios were determined for the samples. Scanning electron microscopy (SEM) was used on limited number of samples. NOAA HYSPLIT MODEL backward trajectory analysis and principal component analysis were carried out on the data. Fly ash samples exhibit an average HIRM value (400.07 × 10(-5) Am(2) kg(-1)) that is comparable to that of soil samples. The pre- and post-monsoon samples show a consistent reduction in the concentration of magnetically "hard" minerals with increasing distance from the power plant. These data suggest that fly ash has indeed been transported from the power plant to the sampling locations. Hence, HIRM may perhaps be used as a proxy for tracking fly ash from coal-fired thermal power plants. Seasonal data show that the distribution of fly ash to the surrounding areas is minimum during monsoons. They also point to the dominance of SP magnetite in early-monsoon season, whereas magnetic depletion is documented in the monsoon season. This seasonal difference is attributable to both pedogenesis and anthropogenic activity i.e. operation of the thermal power plant.

The processing and combustion of coal in thermal power plants release anthropogenic chemicals into the environment. Baccharis trimera is a common plant used in folk medicine that grows readily in soils degraded by coal mining activities. This shrub bioaccumulates metals released into the environment, and thus its consumption may be harmful to health. The purpose of this study was to investigate the phytochemical profile, antioxidant capacity (DPPH), genotoxic (comet assay) and mutagenic potential (CBMN-cyt) in V79 cells of B. trimera aqueous extracts in the coal-mining region of Candiota (Bt-AEC), and in Bagé, a city that does not experience the effects of exposure to coal (Bt-AEB, a reference site). In the comet assay, only Bt-AEC was genotoxic at the highest doses (0.8mg/mL and 1.6mg/mL), compared to the control. For extracts from both areas, mutagenic effects were observed at higher concentrations compared to the control. The cell damage parameters were significantly high in both extracts; however, more striking values were observed for Bt-AEC, up to the dose of 0.8mg/mL. In chemical analysis, no variation was observed in the contents of flavonoids and phenolic compounds, neither the antioxidant activity, which may suggest that DNA damage observed in V79 cells was induced by the presence of coal contaminants absorbed by the plant., (Copyright © 2015 Elsevier Inc. All rights reserved.)

In order to improve the utilization rate of coal generation and reduce carbon emissions from coal-fired boilers, the operation parameters of power plant boilers should be matched with the actual burning coal. Due to the complex and high-risk blending process of multiple coal types, the actual application of coal types inconsistent with expectations may lead to low combustion efficiency of boilers, cause disturbances to the normal operation of thermal power units, increased energy waste and carbon emissions, and even lead to serious explosion accidents. Therefore, the online identification of coal types for thermal power units is of great significance. To obtain the precise type of coal online, in the present work, a data-driven coal identification method is proposed based on convolutional networks that do not necessitate additional hardware detection equipment and are easy to implement. Experimental results indicate that the proposed method exhibits superior performance in comparison to traditional methods, thus ultimately improving the performance of thermal power plant. [ABSTRACT FROM AUTHOR]

In this study, first law (energy conservation) and second law (exergy) analyzes of thermodynamics were performed for a thermal power plant. It is very important to perform energy and exergy analyzes in industrial plants. These analyzes can provide guidance on improving energy efficiency and recycling waste energy. For these analyses, coals with different contents, available in nine different countries, were considered. According to the analysis, the highest first law efficiency was determined as 53.61% in the second type of coal. The second highest law efficiency was determined as 46.67% in the 6th coal type. Environmental Destruction Index and Sustainability Index values were determined and it was seen that, the highest EDI value was obtained in the 2nd coal type and the highest SI value was obtained in the 6th coal type. According to this study, the efficiency of the 6th coal type, which has the highest second law efficiency, was observed.

In an actual thermal power plant, deep peak shaving will cause thermal power units to run under non-nominal conditions for an extended period, resulting in serious problems such as increased equipment wearing, low equipment utilization efficiency and decreased benefits. To this end, in this work, both the design and optimization method for a coal to hydrogen system which is coupled with the expected non-nominal operation of thermal power units are proposed. Aiming towards maximum profit in the context of thermal power plants, a mathematical optimization model for a coal to hydrogen system based on the multi-period operating conditions of thermal power plants is established. The corresponding optimal design scheme of the coal to hydrogen system is determined using variable operating conditions. The superiority of the integrated system compared with an independent system is explored and the feasibility of the proposed method is verified by using the case study of an actual thermal power plant. The results show that compared with the independent system, the economic benefits of the integrated system can increase by 13.56%, where the sale of hydrogen in the coal to hydrogen system accounts for 60.3% of the total benefit. The main expenditure associated with the system is the purchase cost of feedstock coal, accounting for 91.8%. Since the required power and medium-pressure steam in the coal to hydrogen process are provided by thermal power units, the minimum operating load of the thermal power plant in the integrated system increases from 40% to 60.1%, which significantly improves the utilization efficiency and service life of the generator units. In addition, the proposed integration scheme of the system is simple and controllable, which can contribute to the maintenance of the safe and stable operation of power generation and hydrogen production processes. These results are expected to provide the necessary methodological guidance for the integration and optimization of coal-fired power plants and coal to hydrogen systems. [ABSTRACT FROM AUTHOR]

Purpose. Development and verification of a method for calculating and forecasting CO2 emissions from coal combustion at thermal power plants based on proximate analysis data. Calculation of gross and specific CO2 emissions per unit of output energy and mass of coal consumed at Ukrainian thermal power plants (TPPs). Methodology. Methods of mathematical statistics were used for processing the data of ultimate and proximate analysis of 170 samples of A, L, G, and LFG coal ranks with low heat value on operating state (Qri) in the range of 17.2 to 31.0 MJ/kg and ash content on dry state (Ad) in the range of 3.8 to 38.0 % to determine relationships between carbon emission factors (kc), calorific value, and ash content. Findings. The values of emission factors (kCO2) and gross CO2 emissions for mixtures of coals of grades A and L, G and LFG at Ukrainian TPPs in 2017–2021 were calculated. For 2021, the average value of CO2 k for coals of grades G and LFG was 94,128 g/GJ, and for coals of grades A and L it was 104,987 g/GJ. Gross CO2 emissions at Ukrainian TPPs have been in the range of 38–49 million tons in recent years, and their annual reduction is due to a decrease in energy production and fuel consumption at TPPs, primarily of grades A and L. Originality. Empirical dependencies kc for steam coal of different ranks are determined in the form of kc =a+bQri +cAd. The coefficients a, b, and c are determined for grades A, L, G, and LFG and their mixtures. The relationship between the carbon content in coal and the low heat value for coal is linear: Cr K · Qri, where K is a coefficient depending on the coal grade. The values of K are determined for coal of grades A, L, G, and LFG. Practical value. Verification of the created method shows that the calculation error is less than 1.0 %. This is in line with the requirements of the Monitoring Procedure and Directive 2003/87/EC. In 2021, the specific CO2 emission per unit of output energy at TPPs in Ukraine was 1,084 g/kWh for all ranks of steam coal. The values of specific CO2 emissions per unit mass of consumed coal were 1.94 t/t for coals of all grades, 1.91 t/t for grades G and LFG, and 2.21 t/t for grades A and L. The official annual reports of the Ministry of Energy of Ukraine contain information on the amount of produced electricity, consumed coal, and forecast balances of electricity production at TPPs, therefore, the values of specific emissions established by us are convenient to use for estimating and forecasting carbon dioxide emissions. [ABSTRACT FROM AUTHOR]

In this study, first law (energy conservation) and second law (exergy) analyzes of thermodynamics were performed for a thermal power plant. It is very important to perform energy and exergy analyzes in industrial plants. These analyzes can provide guidance on improving energy efficiency and recycling waste energy. In this study, energy and exergy analyzes were made for coals with different chemical contents in nine different countries. According to the results of the analysis, the highest first-law efficiency was found in Serbian coal (second type), as 53.61%. The second highest law efficiency was determined as 46.67% in Bangladesh coal (sixth type). Environmental Destruction Index (EDI) and Sustainability Index (SI) values were determined for all coal types. According to the results of the analysis, the highest EDI value was obtained as 4.00 at the temperature of 305 K for the 2nd coal type, and the highest SI value was obtained as 1.91 at the temperature of 293 K for the 6th coal type, according to the changing reference temperature values. According to this study, the highest second law efficiency was obtained from Bangladesh coal with a carbon (C) content of 77.84%. [ABSTRACT FROM AUTHOR]

As a crucial part of cyber-physical systems, a digital twin can process data, visualize processes, and send commands to the control system, which can be used for the research on thermal power plants that are vital for providing energy for manufacturing and industry, and also daily consumptions. This article introduces the methodologies and techniques toward a web-based digital twin thermal power plant. To implement a web-based digital twin thermal power plant, the architecture, modeling, control algorithm, rule model, and physical-digital twin control are explored. The potential functionalities of the web-based digital twin including real-time monitoring, visualization and interactions, and provided services for physical thermal plants and universities are also presented. A case study has been provided to illustrate the web-based digital twin power plant. The research in this article can provide potential solutions for web-based digital twin research and education. [ABSTRACT FROM AUTHOR]

In this investigation, metals of environmental concern, Cd, Cr, Co, Pb and Cu, are identified in the feed coal of thermal power plant from eastern India. The concentrations (0.56–10.3 µg/g) of these metals are enriched (one- to twofold) in fly and bottom ash during combustion. Additionally, a noticeable presence of Cd, Cr, Co, Pb, and Cu was also observed on the surface (0.26–5.6 µg/l) and groundwater (0.12–2.65 µg/l) of the neighbouring power plant, which focuses on the contribution of combustion ashes in the water contamination of these elements. The analytical result shows that rainwater has a greater influence on the rapid transportation of these elements into the surface water than groundwater. The mobility of such metals of environmental concern from the combustion ashes into the surface and groundwater may pose a risk to the ecosystem. A regular monitoring of chemical quality of coal as well as expert dumping custom, chemical treatment before disposal and recycling of combustion residues are the essential steps for clean energy generation and safe environment. [ABSTRACT FROM AUTHOR]

Ensuring the reliable operation of the dust fuel preparation system at thermal power plants (TPP) is a topical issue since it determines the energy strategy of any country that fires coals for thermal energy production. This unit is one of the most energy-intensive units in TPP. Those systems are outdated, poorly automated and high energy-intensive. Furthermore, they must ensure efficient and safe operation of the facility while being environmentally friendly. The current work focuses on the process of grinding coals in ball drum mills for further pulverized combustion. An experimental study was performed in order to determine the main factors (rotational speed of the drum mill, the degree of loading with the grinding balls, and the velocity of the supplied air) that affect the efficiency of the fuel preparation system. The obtained experimental data and performed mathematical modeling resulted in regression equations describing the energy performance of the mill. Three regression equations for mill productivity, power consumed, and specific surface area of the final product were obtained and validated. The study reveals that the lowest specific energy consumption is achieved when the relative rotational speed of the mill is between 0.81 and 0.87; the weighted average diameter of the balls ranges from 33.5 up to 34.5 mm; the load factor of the grinding media ranges from 0.325 up to 0.335, the supplied air velocity is between 0.2 and 0.3 m/s. The proposed methodology allows adjustment of the operating parameters of the grinding process to achieve the lowest energy consumption. The power consumption for the preparation can be reduced up to 5 % for the selected operation mode of the grinding facility [ABSTRACT FROM AUTHOR]

Coal resources, in addition to oil, gas and uranium as a non-renewable and hydropotential as a renewable energy source, represent the most significant part of energy potential and an energy source of strategic importance on the Republic of Srpska. The modern pace of technological and industrial development causes a permanent increase in coal exploitation and consumption. The use of this resource must be planned and extremely rational. Coal deposits in the Republc Srpska are differed in the structure and quantities of reserves, geological and technical-economic conditions of exploitation and quality. Geological reserves of the Gacko coal deposit amount to 330 Mt. According to the current geological documentation, the balance reserves are ≈182 Mt, with an energy potential of 545 TWh. According to the processed performance indicators, the balance and mineable reserves of coal enable a long-term supply of fuel for the current and future thermal power plant under the favorable economic conditions. In order to provide the required amount of energy for operation the existing and "new" thermal power plant in Gacko, it is necessary to carry out the geological explorations in order to reproduce the mineral and raw material base. The duty of every company engaged in exploitation the coal energy resources is a continuous performance of geological explorations in order to find the new ones or transfer the existing reserves into a higher category. The future development and level of coal production from the Gacko deposit will mostly depend on the electricity production in the Gacko Thermal Power Plant. It would certainly strive for fulfillment the basic conditions, i.e. the cost of coal heat utilization, as in many other countries, be at least approximately competitive with the cost of heat from the other primary energy sources (hydro sources, imported energy, etc.).In order that the Gacko non-renewable energy resource would survive and evolve in a particular environment, it must have a clearly defined purpose of existence. This purpose of existence is primarily reduced to a multiphase process of providing and using a non-renewable energy resource in accordance with the realistic natural, economic and ecological opportunities, in relation to which there are the expressed needs in a wider or narrower environment.

• PIGE and PIXE were applied for elemental quantification of Indian coal and coal residues. • In situ current normalized PIGE was used to determine F, Na, Mg, Al and Si. • PIXE was used to determine total 22 elements, namely, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Kr, Rb, Sr, Y, Zr, Nb, Gd, and Pb. • Toxic elements like F, Cr, Mn, Ni, As and Pb were found in significant concentration. Particle Induced Gamma-ray Emission and Particle Induced X-ray Emission spectroscopies were applied for the determination of low, medium and high Z elements in coal and coal residues of Indian thermal power plants. In situ current normalized PIGE was used to determine F, Na, Mg, Al and Si concentrations in coal and coal residues. Elements namely Mg, Al and Si were found in percent level, while Na and F were found in trace concentration levels. Charged normalized PIXE was used to determine a total of 22 elements, namely, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Kr, Rb, Sr, Y, Zr, Nb, Gd and Pb in these samples. K, Ca, Ti and Fe were found in percent concentration and V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Kr, Rb, Sr, Y, Zr, Nb, Gd and Pb were found in trace concentration levels. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agriculture & Nature / Kahramanmaraş Sütçü İmam Üniversitesi Tarım & Doğa Dergisi is the property of Kahramanmaras Sutcu Imam Universitesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Disposal of fly ash produced in a large quantity is a major problem in coal fired thermal power plants. The coal quality depends upon its rank and grade. Fly ash content in Indian coal ranges from 35% to 50% consisting of a variety of toxic elements including heavy metals that damage the surrounding environment. During transportation, disposal and storage phases, the residues from coal combustion may pollute both ground and surface waters through leaching. The fly ash enriched in Ca, Ni and Fe showed greater leachability in acidic or ion exchangeable conditions. Principal mechanisms of metal leachability are the dissolution of primary solids under aggressive environment and/or precipitation sorption reactions, which are primarily dependent on pH. Fe is found to be tightly bound to the ash and does not leach easily while Ca is highly soluble and leaches out almost all the mediums. The leachabiltiy of trace elements in fly ash is time dependent and pH values of the leachant. [ABSTRACT FROM AUTHOR]

This study investigates the effect of changes in coal properties in thermal power plants (TPPs) due to the breakage behavior of coal in the grinding stage. A grinding process is carried out in a stirred mill for different periods of time to determine the specific breakage rate. Two different types of coal with different properties and similar calorific values are used to compare their breakage rates. The results of the stirred mill grinding are presented in a comparative manner. Furthermore, washing tests are performed on the coal to determine the solid fossil fuel structure. It is shown that the solid fossil fuel structure affects linear and non-linear movement that results in different breakage behaviors. [ABSTRACT FROM AUTHOR]

High demands for increasing robustness, safety, and efficiency in thermal power plants are the main motivation behind ongoing attempts to optimize combustion. This paper presents a study of modeling and control of the combustion process in a tangentially fired pulverized-coal boiler. It proposes an approach to flame geometry and position control by means of reallocation of firing. Such control ensures flame focus maintenance away from the walls of the boiler, and thus prevents many unwanted by-products of combustion. In addition, uniform heat dissipation over mills enhances the energy efficiency and reliability of the boiler. First, experimental data obtained from the 350-MW boiler of the Nikola Tesla power plant, Serbia, are analyzed in detail. This results in a model identification procedure using an adaptive parameter estimation method. Second, constrained multivariate extremum seeking (ES) is proposed in this paper, to optimally tune boiler operation in order to maintain the desired flame configuration in the furnace. Finally, the effectiveness of the ES adaptive controller in the presence of disturbances is demonstrated through simulations performed on the experimentally identified model of the boiler. [ABSTRACT FROM AUTHOR]

By burning coal in thermal power plants in Romania, results large waste quantities which can be grouped into fly ash, powdery material, collected from the flue gases through electrostatic precipitators, mainly used as additive in the cement industry and bottom ash, a mixture of slag and heavy ash which collects at the bottom of the boiler and is discharged through the transport system to the ash and slag deposits. Slag and ash develop soil deposits which generate large environmental problems, being a source of groundwater and surface pollution of soil, due to large surfaces occupied and also a source of air pollution due to the ash particles entrained by the wind. Moreover, slag and ash deposits affect biodiversity because of pollutants contained in these wastes (especially heavy metals). For these reasons, and also for natural resources preservation, through different research technologies were analyzed diverse possibilities for reusing of such thermal power plants wastes, given the physical, chemical and mineralogical characteristics. [ABSTRACT FROM AUTHOR]

Copyright of Bosanskohercegovacka Elektrotehnika is the property of Bosanskohercegovacka Elektrotehnika and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The using of the coals for the thermal energy's obtaining in the electro thermal power plants occupies an important percent in the global structure of the energy sources (thermal, hydraulic, atomic, wind etc.). In the end of the burning complex process and collecting of the formed products from the coal inert material an inert fine sandy material in natural conditions is resulting, forming important deposits that are occupying extended areas constituting local pollution sources. The structural and physical characterization is important and obligatory for different sources because the characteristics are depending on the utilized coal's nature, the burning process, transport and storage. The characteristics of the ashes collected by wet process were studied for two decades, because the resulted material was different function of the utilized coal from local and import sources, especially from Ukraine. [ABSTRACT FROM AUTHOR]

Coal blending is becoming increasingly common as more and more off-specification coals are received in coal-fired power plants, given the present coal market in China. This situation requires optimization of the operating parameters for matching the varying coal properties. The motivation for such optimization includes confirming good performance of the units regarding the security, the economy and environmental protection. However, the current adjustments to operation of the plant rely mostly on human experience because of the imperfections of existing theoretical models for coal-blend combustion. In this paper, a Case-Based Reasoning (CBR) method providing online decision-making for optimization of coal-blend combustion was investigated using cases representing successful operation of the unit for specific coal blends and loads. A case base containing a wealth of knowledge about optimal operation modes was constructed from a large number of cases. The development process for the CBR system includes case design, case evaluation, case generation, case retrieval and case reasoning. Case evaluation focused mainly on heating surface security, output capability, slagging tendency, comprehensive fuel consumption and pollutant emissions. Five indexes were introduced to quantify the above characteristics based on actual combustion parameters. A case-generating algorithm employing an evolutionary strategy was proposed in which the case base evolves while retaining new cases. Two methods for measuring case similarity - termed entirely similarity and eigenvalue similarity - were used for case retrieval. Run-time optimization strategies were recommended by the case-reasoning model based on the current operating status. The CBR system using Browser/Server framework were successfully applied to a 600-MW power plant, which provided an opportunity for coal-blend combustion optimization. [ABSTRACT FROM AUTHOR]

This work presents modern plasma technology for solid fuel ignition and combustion. It promotes more effective and environmentally friendly low-rank coal incineration. To implement this technology at coal fired thermal power plants plasma-fuel systems (PFSs) were developed. PFS is a pulverized coal burner equipped with arc plasmatron producing high temperature air stream of 4000–6000°C. Basis of technology PFS is plasma thermo-chemical preparation of coal for burning. It consists in plasma heating of air–coal mixture up to temperature of coal volatiles release and char carbon partial gasification. In PFS air–coal mixture is deficient in oxygen therefore carbon is oxidized mainly to carbon monoxide. As a result, at the PFS exit a highly reactive mixture is formed of combustible gases and partially burned char particles, together with products of combustion, while the temperature of the mixture is around 1050°C. Further mixing with air promotes intensive ignition and combustion of the prepared in the PFS fuel. PFS have been tested for boilers start up and pulverized coal flame stabilization at 30 power boilers of 75–950t/h steam productivity. The boilers were equipped with different types of pulverized coal burners: direct flow, muffle and swirl burners. At tests of the PFS power coals of all ranks (lignite, bituminous, anthracite and their mixtures) were incinerated. Volatile content of them was in range of 4–50%, ash varied from 15% to 48% and heat of combustion was from 6690 to 25100kJ/kg. To show advantages of the plasma technology of coal combustion before conventional one numerical investigation of plasma ignition, gasification and thermo-chemical preparation of air–coal mixture for incineration in a power boiler was fulfilled. The numerical modeling was performed for low-rank bituminous coal of 40% ash content incinerated at a boiler of 420t/h steam productivity. Both analysis of the numerical modeling and experience of PFS industrial use showed ecological efficiency of the plasma technology. When plasmatrons operate in the regime of plasma stabilization of pulverized coal flame, NOX emission is reduced twice and amount of unburned carbon is reduced four times. The PFSs reduce the temperature at the exit of the furnace. Tests of the PFS for the boiler BKZ-420 of Almaty TPP-2 cold startup confirmed the possibility of high-ash Ekibastuz coal ignition in the cold furnace without heating of primary air. [ABSTRACT FROM AUTHOR]

This paper presents the methods for the calculation of chemical exergies of coal, heavy fuel oil and natural gas that are used as fuel in conventional thermal power plants. Calculations have shown that the chemical composition of the fuel greatly influences the value of its chemical exergy. In case of coal in which carbon and hydrogen are not combined together, an increase in both carbon and hydrogen contents increases its chemical exergy value. In case of heavy fuel oils, hydrogen-carbon ratio is the most influencing parameter in the chemical exergy value. An increase in hydrogen-carbon ratio in the fuel tends to increase its chemical exergy. In case of natural gases, a decrease in lighter hydrocarbon gas contents and an increase in heavier hydrocarbon gas contents tend to increase the chemical exergy value of the fuel. High moisture and/or ash contents also tend to lower the value of the chemical exergy. [ABSTRACT FROM AUTHOR]

In this paper we have looked into the qualitative analysis of coals in Bosnia and Herzegovina. The analysis includes the following characteristics: moisture, ash, combustible matter and lower heating value. From the statistic parameters we have determined: absolute range, arithmetic mean, standard deviation and variations coefficient. It has been shown that the coal characteristics have normal distribution. The analysis show that there are considerable deviations of ash characteristics: moisture (36.23%), ash (34.21%), combustible matter (16.15%), and lower heating value (25.16%) from the mean value which is shown by the variations coefficient. Large oscilations of mass portions: W, A, Vg, and Hd around the mean value can adversely influence the function of a boiler plant and an electric filter plant in thermal power plants in Bosnia and Herzegovina in which the mentioned types of coal burn. Large ash oscilations (34.21%) around the mean value point out to the inability of application of dry procedures of desulphurisation of smoke gasses due to the additional quantity of ash. It has been shown that the characteristics of Bosnian types of coal do not deviate a lot from the characteristics of coal in the sur rounding countries (coals of Serbia and Montenegro). The results can be used in analysis of coal combustion in thermal power plants, optimisation of electrical-filtre, reduction of SO2 in smoke gas, and other practical problems. [ABSTRACT FROM AUTHOR]

Abstract: The rapid increase of coal fired thermal power generation in India has resulted in increased generation of fly ash and bottom ash of various properties. In this study, coal and ash samples collected from five different thermal power plants across India were characterized and quantified to determine trace element concentration so as to understand their distribution, enrichment, and partitioning behavior. Concentrations of Pb, Cu, Cd, Zn, Fe, Mn, Cr, Ni, Mg, Li, Co, Hg, and As, were estimated in fly ash, bottom ash, and coal samples. The concentrations of toxic elements, such as As, Hg, Pb, and Cd in fly ash were in the range of 0.19–0.35μg/g, 0.51–2.13μg/g, 7.6–35.3μg/g, and 0.6–0.93μg/g, respectively, whereas in bottom ash, concentrations of these toxic elements were in the range of 0.1–0.29μg/g, 0.41–1.58μg/g, 8.8–28.28μg/g, and 0.49–0.79μg/g, respectively. Cadmium and As were the lowest in both coal and ash samples, whereas Fe, Mn, and Zn were found to be the highest. The elements were classified into three groups based on their volatility. All the elements were found to be enriched more in fly ash than in bottom ash. To evaluate the influence of the elements on local environment, enrichment factor with respect to Fe was calculated for all the elements in fly ash and bottom ash. The enrichment ratio, relative enrichment index, and partitioning behavior were used to describe the differences of trace-element concentrations in coal, fly ash, and bottom ash. Among the elements, maximum enrichment was observed for Mn in both fly ash and bottom ash. [Copyright &y& Elsevier]

Abstract: In this work, the capability of laser-induced breakdown spectroscopy for process control in a thermal power plant is presented through quantitative compositional characterization of the coal used for combustion. Laser-induced emission signal of seven samples with a range of concentrations was calibrated for quantification purposes. The eighth sample was subsequently analyzed five times as unknown in order to determine the precision and accuracy of the measurements. Two modes of operation, dynamic and static and two laser wavelengths, 1064nm and 355nm were employed in this study for comparison. The results revealed that UV wavelength provided better results than IR radiation in terms of accuracy for the quantification of inorganic species in coal after the comparison with conventional atomic absorption spectrometry characterization. [Copyright &y& Elsevier]

The article presents abstracts of several studies on environmental geochemistry. Some of the abstracts presented include "Biogeochemical Cycling of Nutrients in Karstic Catchments, Southwestern China: Linkages to Changes of Eco-Environments," by Congqiang Liu and "Emerging Organic Contamination in China," by Guibin Jiang and colleagues.

The rapid increase in thermal power generating capacity in Brazil has resulted in the production of huge quantities of brown coal of high ash content. Current estimates indicate that coal ash production in Brazil is likely to reach 4 million tons per year by 2005. In view of the need to burn this type of fuel to the maximum possible extent, a rational use of coal is vitally important. However, the coal from Candiota (a coal mine in southern Brazil) contains calcium-bearing compounds that damage equipment, causing process stoppages; this coal may become cost ineffective unless the noncombustible material and its content is controlled. This article reports on the results of the comminution characteristics of coal combustion feed and of industrial tests, which demonstrate the urgent need for optimizing particle size distribution to preclude the presence of calcareous material. Hard calcium-based minerals display a crushing behavior that differs from coal particles, requiring their screening and elimination from the feed. Examples of the overall situation, screening optimization, and the beneficiation process at the Candiota power plant are discussed in terms of fragmentation, particle size analysis, type of screen, and economic benefits. [ABSTRACT FROM AUTHOR]

A field study was conducted around two thermal power plants of India to quantify the changes in foliar elemental concentrations due to emission in a low rainfall tropical area. Sulphur dioxide and particulates were at high levels which may cause serious ecological effects. Emission from the power plants has altered the elemental concentrations in the leaves of evergreen and deciduous plants. The foliar total-S and SO$\_4$$^2-$-S levels were significantly higher in all the plants growing at polluted sites. However, the organic-S content was more or less unaltered. In evergreen plants, the SO$\_4$$^2-$-S content increased gradually from summer through winter, whereas in the deciduous plants there was a higher magnitude of increase after onset of new leaves during summer. With the increasing pollution load, foliar Ca$^2+$ and K$^+$ contents increased, whereas N content decreased. The reduction in N content was greater during summer in evergreen plants and during winter in deciduous plants. The plants growing closer to the power plants accumulated more trace elements (Mn, Fe, Cd, Pb and Ni) as compared to those growing at distant sites. In deciduous plants the leaf fall during winter lowered down the trace element [ABSTRACT FROM AUTHOR]

Effects of coal-smoke pollutants and the root-knot nematode Meloidogyne incognita race 1, singly and jointly, were investigated on okra, Abelmoschus esculentus in 1988 and 1989. Plants in clay pots were placed at two sites (K1 and K2), 1 and 2 km away from the stack of a coal-fired thermal power plant, and also at the Department of Botany, AMU (control site). The mean concentrations of SO2, NO2 and suspended particulate matter (SPM) were 141, 76 and 309 μg m-3 at K1, and 184, 93 and 205 μg m-3 at K2, but the concentrations of the pollutants at the control site were very low. Okra plants at the K2 site showed browning of the leaves, whereas injury was mild at K1. The intensity of the browning and the impact of nematode disease was appreciably higher in the infected plants at the polluted sites in both the years. The plants grown at the two sites exhibited suppressions in plant growth, yield and photosynthetic pigments, particularly at K2. M. incognita at the control site also caused significant reductions, but joint effects of the nematode and coal-smoke were synergistic. Nematode reproduction was enhanced at K1, but was unaffected at K2. Egg laying was reduced by 13 and 27% at K1 and K2, respectively. The response of stomata and trichomes to air pollutants was negative and positive at the two sites, respectively, and stomatal opening was directly correlated with the percent suppressions in dry matter production, yield etc. [ABSTRACT FROM AUTHOR]