Coal-fired Thermal Power Plants Research Articles

Investigation of concrete incorporating ultra-high volumes of ash: a case study in India

Coal-fired thermal power plant ash (CTPA) has been widely used in construction works not only as a partial replacement for conventional cementitious binders but also as a substitute for fine aggregates. However, higher volumes of CTPA in concrete typically lead to non-satisfactory performance of concrete in terms of strength and durability. This was remedied by incorporation of hyperplasticisers, which offset the negative effects of loss of workability, segregation, bleeding and strength reduction. This study describes three field studies undertaken with ultra-high volumes of CTPA in terms of class F fly ash and coarse bottom ash in M40 grade sustainable pavement-quality concrete at National Thermal Power Corporation (NTPC) Khargone, Khargone, India; NTPC Mouda, Nagpur, India; and Dhariwal Infrastructure Limited Tadali, Chandrapur, India. Core samples of 100 mm diameter and varying slenderness (H/D) ratios were drawn from cast segments at the sites after 28 days of curing, and the results in terms of compressive strength and durability characteristics were evaluated against the results of laboratory investigation. Statistical analysis was also conducted using Student’s t-test to analyse the variance in the results. The effects of the H/D ratio of core samples on the compressive strength of cores were also analysed. The results indicate a non-significant difference in the values of the means of the compressive strength of the batches for H/D = 1, indicating the field applicability of the developed mix designs for severe exposure conditions.

Long Term Planning of Macedonian Electricity Supply

In the paper alternatives for expansion of the Macedonian electricity supply system are presented. MESSAGE tool is used for modelling the system, for developing the scenarios, to analyse cost optimal energy pathways and to determine the optimal electricity generation technology mix. The calculations for the period 2020-2050 are made in a 5-year interval. Two scenarios are developed: Scenario 1 – BAU (Business as Usual) scenario, where the current energy structure prevailed, with trends like the current development. The electricity demand is satisfied by coal-fired thermal power plants, gas-fired thermal power plants, hydro power plants and renewable power plants. Scenario 2 – Green scenario, where gas-fired thermal power plants and nuclear power representative with small modular reactors are base load technologies, and also intensive construction of production capacities on renewable energy sources is forced. By making further analysis, the possibility of flexibility in the construction of new facilities within the interval, economic indicators, and appropriate impact on the environment are obtained. In order to make an economic analysis for a particular technology, calculations are made for parameters that are standard for projects, such as: net present value, benefit – cost ratio, payback period and internal rate of return. The environmental impact is analysed of aspect of CO2 emissions.

Pollution Risk Assessment in the Area of an Operating Coal-Fired Thermal Power Plant

Pollution Risk Assessment in the Area of an Operating Coal-Fired Thermal Power Plant

Estimation and forecasting of carbon dioxide emissions from coal-fired thermal power plants in Ukraine

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 170samples of A, L, G, and LFG coal ranks with low heat value on operating state 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 and gross CO2 emissions for mixtures of coals of grades A and L, G and LFG at Ukrainian TPPs in 20172021 were calculated. For 2021, the average value of 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 3849million 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 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: 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.

Design of ORC-RO system for utilizing waste heat from flue gases of coal-fired thermal power plant

Waste heat recovery is an efficient tool to reuse waste energy to provide useful energy products. This method addresses the practical solution for sustainable products, which reduces CO2 emissions. The organic Rankine cycle is the most desirable option for waste heat recovery systems as it operates with low heat source temperature, which is auspicious in designing flexible and compact systems. This paper aims to design an organic Rankine cycle coupled with reverse osmosis to drive RO system by utilizing waste heat from flue gases of the thermal power plant. The boiler feed (make-up) water has been treated using the RO system, and the concentrate from the RO system can be used to suppress coal fly ash. The recycling reverse osmosis system is designed according to the boiler feedwater input for achieving more than 80 % recovery. The RO feed water is pre-heated by condensing vapor from the ORC expander, which reduces the specific energy consumption of the RO system. Also, the flue gas characteristics are discussed, which can be utilized at above dew-point temperature to avoid corrosion. This concept design is developed for the 2 MW coal-fired thermal power plant.

Exergoeconomic and environmental performance assessment of the solar-assisted thermal power plant

At a time when global climate change is imposing a mounting challenge to the economy of the world, conventional coal-fired steam power plants are under tremendous pressure to meet severe climatic protocols for achieving the set sustainable development goals. Therefore, this research work investigates the energetic, exergetic, economical and environmental performance of a 330 MWe sub-critical coal-fired thermal power plant integrated with solar thermal energy. The results of energetic and exergetic analyses show that the highest energy efficiency of 38.04% and the highest exergy efficiency of 36.22% are attained for Option 3. The environmental analysis performed using the fuel-saving approach shows that the maximum reduction in coal consumption and CO2 emissions also corresponds to Option 3. The economic analysis showed that for all three replacement options, the levelised cost of electricity is 4.52, 4.47, and 4.63 (Cents/kWh) and the simple payback period is 3.4, 3.3 and 3.6 (years), respectively.

Optimization and analysis of combined heat and water production system based on a coal-fired power plant

The combined heat and water (CHW) system has been studied by many scholars since it was proposed, and a project has been implemented in Shandong, China in 2021. However, there have been few studies on optimization and comparisons of cases on the heat source side of CHW. Taking a coal-fired thermal power plant as an example, through the reasonable matching of steam flows and analysis of thermal economic parameters, the effect number and heat source steam temperature of a multi-effect distillation (MED) + multi-stage flash (MSF) combined heat and water production (CHWP) system were optimized. The optimal MED heat source temperature was found to be 70 °C, and the optimal MED and MSF effect numbers were 10 and 5, respectively. Finally, the waste heat in the power plant was utilized as much as possible throughout the year. Compared with two cases of the separate heat and water production (SHWP) system, the CHWP system easily achieved better water quality and economy under the condition of almost equal exergy efficiency, and it was easier to realize than the first case of the SHWP system.

Study on the Application of Fly Ash for Soil Amelioration

In this study, pot culture experiments were carried out to investigate the most suitable level of fly ash for the amelioration of soil that can enhance the management of fly ash. The fly ash recovered from the Mong Duong 2 coal-fired thermal power plant and had the main chemical composition of oxygen (43%), Si (26%), Al (15%), K (9%), and Fe (6%). The addition of fly ash to light texture soil increased some of the basic properties of the soil, such as moisture, cation exchange capacity, mechanical composition, and organic matter content. The results of the performance evaluation of an experimental crop (soybeans) showed the effects of the amended soil on the growth of the experimental plants, namely the number of fruits, number of nodules, and their dry biomass. The incorporation of manure into the sandy soil was amended with fly ash in the pot experiment as a single application of fly ash may not provide enough nutrients for plant growth despite its ameliorant effect on soil structure. The appropriate fly ash addition rate from 10-30% w/w is recommended in soil amelioration applications based on the results of this study. This research opens up an application direction for fly ash, a by-product generated from the operation of coal-fired power plants in Vietnam.

Determination of concentrations of non-volatile elements in fly ash released from coal combustion using EDXRF

ABSTRACT In this study, the concentration of thirteen non-volatile elements in coal fly ash samples obtained from the Kangal coal-fired thermal power plant located in Sivas province of Turkey was determined using an energy dispersive X-ray fluorescence (EDXRF) spectrometer. Non-volatile elements in coal fly ash samples were analysed in three groups: major (Al, Si, and Ca), rare earth (Y, La, Ce, Pr, and Nd), and other trace elements (Ga, Rb, Mo, Ba, and Hf). The average concentrations of Ca, Si and Al were found as 22.8, 10.9 and 5.4%, respectively. The average concentrations of Pr, Y and, Nd were found as 23.9, 19.1 and 78.2, respectively. La and Ce were observed below the detection limit of 2 mg/kg, except for two samples. The average concentrations of Ga, Rb, Mo, Ba and Hf were found as 18.6, 51.1, 177.3, 993.5 and 3.9 mg/kg, respectively. According to the average values of enrichment factor estimated for elements analysed in fly ash samples, Mo is found extremely enriched while Ca and Hf are significantly enriched.

HEART Hybrid Methods for Assessing Human Reliability in Coal-Fired Thermal Power Plant Process

The assessment of human reliability is crucial in serious processes and operations, such as planned maintenance, unplanned maintenance, and troubleshooting in a coal-fired thermal power plant, as the nature of these processes poses significant threats. When the literature is examined, the evaluation of human reliability in any type of power plant, especially coal-fired thermal power plants, is limited. In order to fill this gap, we systematically assessed human reliability in an accident that occurred during a repair of a tube failure in a boiler in a coal-fired thermal power plant. The HEART (human error assessment and reduction technique) method was used in a hybrid way alongside the fuzzy AHP and SWARA (step weight assessment ratio analysis) methods. Although the HEART method is a practical, understandable, and easy-to-implement human reliability assessment method, the APOE (assessment of the proportion effect) value depends on the decision of a single decision maker. This study aimed to eliminate this deficiency and compare human error possibilities using HEART–fuzzy AHP and HEART–SWARA methods. This hybrid method can be used in the operation of all coal-fired thermal power plants and provides practical contributions to minimize human error.

Development of fly ash–polymer-based paver blocks by powder metallurgy processing technique

Currently, polymer-based materials are extensively used for domestic applications due to their ease of economic production and desirable strength. However, most of the polymer materials are non-biodegradable. Hence, conservational environmental policies mandate the replacement or recycling of polymer-based domestic products and components. Besides, discarding fly ash, produced from coal-fired thermal power plants, in dumpsites aggravates environmental pollution (including groundwater resources). Hence, devising effective waste-management strategies or developing technologies for recycling wastes (polymers and fly ash) is the need of the hour. This research study focuses on the development of sintering technology to fabricate pavement blocks using polymer wastes and fly ash. The coupon-level specimens were fabricated by varying the sintering process parameters, and the following properties were evaluated: macrostructure, hardness, density, wear rate, friction coefficient and water absorption. The influence of sintering process parameters (temperature and time) on the properties of the developed specimen was analysed using hybrid polynomial–radial basis function models.

Ecological and contamination assessment of soil in the region of coal-fired thermal power plant

ABSTRACT This study was carried out to determine the heavy metal pollution and possible sources of agricultural soils in Tavşanlı district, Which energy power plant is located. Total 83 soil samples were taken and 8 (Cu, Cr, Pb, Co, Fe, Mn, Ni, and Zn) heavy metals were analyzed in soil samples The mean concentration of heavy metals were determined as Cu (32.89 mg kg−1), Cr (285.69 mg kg−1), Co (36.37 mg kg−1), Mn (860.20 mg kg−1), Ni (457.59 mg kg−1), Pb (22.14 mg kg−1), Fe (30,250 mg kg−1) and Zn (65.05 mg kg−1), were determined. The mean concentrations of Cu, Cr Co, Mn and Ni found to be higher than both the upper continental crust values and the European soil mean values. Contamination factor Co (2.1), Cr (3.10) and Ni (9.73), enrichment factor Co (2.73), Cr (3.75) and Ni (11.42) and geoaccumulation index Co (0.18), Cr (0.50) and Ni (1.98) values showed that the soils were polluted by Co, Cr, and Ni. In addition, it was determined that Ni (48.65) poses a “moderate ecological risk” in the study area. Pearson correlation anaysis and principal component analysis determined that Cr, Co and Ni have both lithogenic and anthropogenic origin.

A deep insight into state-level aerosol pollution in India: Long-term (2005–2019) characteristics, source apportionment, and future projection (2023)

The present study provides a national scenario of aerosol pollution with the long-term (2005–2019) trend, source apportionment, and future scenario (2023) for each of the Indian states. We used MODIS AOD and FRP, differential AODs from MERRA-2, and trace gases (NO2, SO2) data from OMI. Almost all the states of IGP fall under the red zone (“highly vulnerable”; AOD >0.5) whereas central, western, and a few south-Indian states fall under the orange zone (“vulnerable”; 0.4 < AOD >0.5). The most alarming feature is that most of the southern Indian states exhibit a shift from blue/green (less vulnerable/safe; AOD <0.4) to vulnerable zones in 2023 as observed using the auto-regressive integrated moving average (ARIMA) model. Principal component analysis (PCA) revealed that the coal-fired thermal power plant (TPP), vehicular, solid fuel/waste, and biomass burning are the major sources of aerosols for the vulnerable states at present and in the future. We estimated and proposed the TPP capacity (GW) that needs to be reduced to bring down the AOD to move the vulnerable zones to less vulnerable and safe zones. The present study would complement and strengthen the ongoing national missions to combat air pollution in India.

"Evaluation of Health Status and Effects of Thermal Power Plant Pollutants on the Population's Health and the Environment around the Plant"

The quality of the soil, air, and water are significantly impacted by coal-fired thermal power plants (TPPs), which negatively affects the surrounding environment and human health. The current study's goals were to detect specific heavy metals in fly ash, air, water, and soil samples, as well as to evaluate the respiratory health of the community living close to the plant. Materials and Procedures In the current cross-sectional study, 3533 adult people from two strata within a 10-kilometer radius of the TPP in the Karnataka state's Udupi district participated. Semi-structured questionnaires, spirometry, environmental air monitoring with a DustTrak aerosol monitor, water samples, and soil samples were used to obtain the data. Results: The majority of the study's participants were over 45 years old (41.4 percent). There were 70.6 percent females and 0.39 percent transgender people. There were different respiratory issues in 4.3 percent of the population. According to bivariable logistic regression, participants aged 46–65 and &gt;65 respectively had 2.91- and 4.42-times greater risks of respiratory disease than those aged 45 years. The results of multivariable logistic regression revealed a significant correlation between older age groups and subjects who had closed their windows while cooking (P 0.006). While the amounts of iron, manganese, and copper in the ground water samples were overly high, the levels of heavy metals in soil samples and particulate matter 2.5 were well within allowable limits. The results of this study have consequences for the formulation of policies that safeguard the environment and human health.

Preparation and characterization of semi-silica insulation refractory by utilizing lignite fly ash waste materials

A tremendous amount of lignite fly ash (FA) is produced as waste materials in coal-fired thermal power plants. These wastes materials contain toxic elements which are detrimental to the environment. In this study, the lignite FA waste materials are used as the primary raw material for the fabrication of semi-silica insulation refractory bricks to reduce the environmental pollutions. Lignite FA from coal-fired thermal power plant NLC India Ltd., Bikaner in northern India, ball clay, and sawdust are the main components of semi-silica insulation refractory bricks. FA and ball clay were blended in various combinations, and sawdust is used as a pore former in the refractory bricks. The prepared samples were fired in the range of 1000 °C to 1200 °C for 2 h. The resultant properties of these bricks were characterized in terms of mechanical, thermal, phase analysis, and microstructure. It was found that FA can be used as a suitable candidate in the preparation of semi-silica insulation refractory bricks. The chemical analysis, bulk density (BD), apparent porosity (AP), and thermal conductivity (TC) of the insulation refractory bricks prepared with lignite FA were observed to be similar to the commercial products. The sample FC30S, which contains 60% lignite FA, 30% ball clay, and 10% sawdust showed 44.69% AP and 0.38 W/mK thermal conductivity after sintering at 1100 °C for 2 h. Hence, the use of FA is technically feasible, economically beneficial, and can be used as thermal insulation refractory. The study indicates a sustainable technique of using fly ash for the fabrication of eco-friendly semi-silica insulation refractory.

Major trends shaping development of coal industry in the world and in Russia under conditions of low-carbon energy economy: Major trends. Part I. Coal sector development ratio and rates under the influence of major coal market countries

The Paris climate agreement and the restrictions introduced in connection with them boosted the decarbonization efforts and the global energy transition to renewable energy sources and hydrogen. For this reason, many countries have closed their coal-fired thermal power plants, switched to green energy sources and approved the concept of low-carbon development in the period up to 2050 (2060). In this regard, the domestic coal industry faced the risks of not only an accelerated reduction in coal production and exports, but also the risk of a possible complete closure of coal mines. In 2020, coal production in the world decreased by 4.9%, to 7.4 billion tons compared to the previous year. Russia remained the world&rsquo;s 6th coal producer with 401.6 million tons of coal produced, including 312.9 million tons of power-generating coal. Russia&rsquo;s share in the global coal production in 2020 was 5.5%. In connection with the introduction of cross-border carbon regulation, the burden on the Russian coal producers may reach significant proportions. Russia believes the EU&rsquo;s new crossborder carbon tax is contrary to WTO rules in terms of trying to equalize products made in the EU with minimal CO2 emissions with products from other countries that use technologies with high CO2&nbsp;emissions. However, many COP26 participants stressed that trans-carbon regulation could become the norm in the coming years and have a significant impact on hydrocarbon markets and trade flows. The analysis of these major factors and the current ratio and rates in production of power-generating coal makes the framework for the coal production prediction under conditions of low-carbon energy economy.

Вплив компонентів газових викидів на ріст мікроводоростей Chlorella vulgaris

The annual growth of environment anthropogenic impact, in particular, the increase of gaseous emissions amount leads to the need of their disposal. A promising solution for this problem may be the use of microalgae to absorb carbon dioxide and oxides of nitrogen and sulfur. It is important to determine the cultivation conditions for further establishment of rational parameters for the gaseous emissions disposal, which will increase the profitability of the process, reduce environmental pollution and obtain biomass for further use. The aim of the work is to analyze studies of the gaseous components impact on the growth and development of microalgae Chlorella vulgaris. The task is to determine the effect of oxides of carbon, nitrogen, sulfur and gaseous emissions on the growth and development of microalgae Chlorella vulgaris. The typical composition of gaseous emissions from a coal-fired thermal power plant based on water vapor, oxides of carbon, nitrogen, and sulfur, which can be assimilated by microalgae cells, is considered. Carbon dioxide in this mixture is 12±2 %, which is a rational concentration for growing biomass of adapted strains. However, when applying a high concentration of CO2 to the culture medium, it is necessary to stabilize the pH, because increasing the carbon dioxide content in the culture medium leads to acidification, while the consumption of CO2 by microalgae in photosynthesis increases the pH value. It is determined that nitrogen oxides, the main part of which is NO, in concentrations up to 100 ppm contribute to the accumulation of biomass and synthesis of nutrients in cells. It is necessary to reduce the concentration of sulfur oxides to 60–100 ppm and avoid their gradual accumulation, as this leads to acidification of the environment and cell death. When using Chlorella vulgaris to purify biogas from CO2 and H2S, the concentration of hydrogen sulfide should not exceed 100 ppm to eliminate its inhibitory effect on cell growth.

Technical possibilities of ash and sulphur oxides emission reduction at Russian coal-fired thermal power plants

The issues of the introduction of the best available technologies (BAT) at Russian coal-fired thermal power plants in accordance with the recommendations of the current information and technical handbook ITS 38-2017 are considered. It is shown that the technological indicators of ITS 38-2017 on emissions of solid fuel ash and sulphur dioxide do not solve the problem of reducing the negative impact on the environment. The analysis of the properties of burnt coals and available technologies for sulphur dioxides and ash cleaning of flue gases was carried out in order to determine new technological indicators for emissions of solid fuel ash and sulphur dioxide and the best available technologies for updating ITS 38-2017. The analysis of existing technologies for ash cleaning and desulphurization of gases was carried out and recommendations were given for areas of their effective application to meet different quantitative levels of technological indicators of emissions. New technological emission indicators for updating ITS 38 are proposed and justified. Recommendations are given to expand the list of the best available technologies recommended for implementation at Russian thermal power plants.

DeepThermal: Combustion Optimization for Thermal Power Generating Units Using Offline Reinforcement Learning

Optimizing the combustion efficiency of a thermal power generating unit (TPGU) is a highly challenging and critical task in the energy industry. We develop a new data-driven AI system, namely DeepThermal, to optimize the combustion control strategy for TPGUs. At its core, is a new model-based offline reinforcement learning (RL) framework, called MORE, which leverages historical operational data of a TGPU to solve a highly complex constrained Markov decision process problem via purely offline training. In DeepThermal, we first learn a data-driven combustion process simulator from the offline dataset. The RL agent of MORE is then trained by combining real historical data as well as carefully filtered and processed simulation data through a novel restrictive exploration scheme. DeepThermal has been successfully deployed in four large coal-fired thermal power plants in China. Real-world experiments show that DeepThermal effectively improves the combustion efficiency of TPGUs. We also report the superior performance of MORE by comparing with the state-of-the-art algorithms on the standard offline RL benchmarks.

Assessment of the Enrichment of Heavy Metals in Coal and Its Combustion Residues.

Coal-fired thermal power plants remain one of the main sources of electricity generation in Turkey. Combustion of coal creates coal ash and slag, which are often stored in landfills located near residential and agricultural fields, increasing the potential for high environmental contamination and health risks. This study investigates the content and enrichment factor (EF) of heavy metals in pulverized lignite coal and its combustion residues from the Kangal lignite coal-fired thermal power plant situated in the Central Anatolian Region of Turkey. The concentration of heavy metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Zr, Cd, Hg, and Pb) in lignite coal, slag, and fly ash samples were analyzed using an energy dispersive X-ray fluorescence technique. The concentration of Fe is highest while Hg concentration is lowest in the samples. The concentrations of heavy metals are higher in slag and fly ash samples than in lignite coal. Average values of EF (related to Earth’s crust average) revealed that extreme enrichment has been shown by arsenic and mercury in lignite coal and fly ash samples while very high enrichment has been shown in slag samples.