Coal-based Thermal Power Plants Research Articles

Thermoeconomic analysis of organic Rankine cycle with different working fluids for waste heat recovery from a coal-based thermal power plant

Thermoeconomic analysis of organic Rankine cycle with different working fluids for waste heat recovery from a coal-based thermal power plant

Design Of Tangentially Fired Pulverized Coal Burner Nozzle For Enhanced Erosion Resistance

Erosion-induced failure of pulverized coal burner nozzles (PCBN) presents a significant challenge in pulverized coal-based thermal power plants. Investigations have identified multiple causative factors leading to the accelerated degradation and consequent reduced lifespan of PCBN. These factors include the erosive impact of solid fuel particles carried at high velocities and angles, as well as the high-temperature conditions within the combustion zone. To mitigate erosion, strategies often revolve around enhancing material resistance or optimizing aerodynamic profiles to minimize drag forces. This study employs Computational Fluid Dynamics (CFD) via the CFX code to model and analyze the erosion dynamics within PCBN. By adjusting the geometry of the inner plates within the PCBN, simulations indicated a notable improvement in erosion resistance. The optimized design achieved this by expanding the flow area between the innermost bifurcated plates without altering their angle, leading to a more uniform flow distribution and favorable velocity and pressure gradients. These modifications have the potential not only to prolong nozzle life but also to contribute to more efficient combustion in tangentially fired furnaces.

Evaluating the effect of fly ash on soil properties and germination of rice (Oryza sativa): A study on the utilization of thermal power plant residue

India has a power capacity of 4,02,817 MW, with over half coming from coal-based thermal power plants like the Kolaghat Thermal Power Plant (KTPP), West Bengal, India. These plants produce harmful fly ash, requiring safe disposal. KTPP alone generated 0.5921 million tons of fly ash in 2020-21, managed using ash ponds. Concerns have arisen regarding contamination of nearby agricultural fields, impacting rice cultivation. The objective of the study was to understand how fly ash affects soil and seed germination and emphasizes the importance of making careful decisions when using industrial residues in agriculture to ensure sustainable and responsible practices that prioritize environmental health and plant well-being.Samples were collected from areas near KTPP, and plant growth substrates were prepared by mixing control soil with varying fly ash concentrations. The study was conducted between 15 February and 19 May 2023 in PnaskuraBanamali College (Autonomous), Purba Medinipur, West Bengal, India. The physical and chemical properties of these substrates were analyzed, and rice seed germination studies were carried out over 30 days. The subsequent transplantation and growth assessments included measuring shoots and roots, analyzing leaf chlorophyll and carotenoids, and conducting statistical evaluations. The experiments were triplicated, and statistical analyses using SPSS 16 indicated statistical significance at p less than 0.05.The study helps to understand how fly ash affects soil and seed germination, revealing both positive and negative effects on soil properties and plant growth. It emphasizes the need for careful decision-making when using industrial residues in agriculture to ensure sustainable and responsible practices that prioritize both environmental health and plant well-being.

Development of sustainable water-resistant binder with FGD gypsum & fly ash, and its environmental impact evaluation via carbon footprint and energy consumption analysis

A sustainable water-resistant binder was developed utilizing flue gas desulphurized (FGD) gypsum and fly ash (FA), which are byproducts of coal-based thermal power plants. FGD gypsum was subjected to calcination, resulting in the formation of β-hemihydrate plaster. Various trial mixes of binders were then formulated, incorporating different proportions of β-hemihydrate (50–75%) and fly ash (15–40%), along with a fixed amount of OPC (10%) and activators. The physio-chemical and mechanical properties of the sustainable binders were evaluated, leading to the recommendation of a binder mix (P4) containing 30% fly ash and 60% β-hemihydrate plaster due to its favorable cost-effectiveness. Binder mixes P4 exhibited a compressive strength of 10.25 MPa after 28 days, with a water absorption rate of 9.25%. To assess the durability of the binders, they were subjected to extreme weather conditions, evaluating their strength under hot and cold temperatures. The binder mixes displayed low thermal conductivities (0.140–0.153 W/m.K), making them suitable for insulation applications. Furthermore, the binders achieved a Class 1 classification based on fire test analysis according to BS 476–1997. The development of these binders serves the dual purpose of waste management by utilizing byproducts and providing an economical alternative to the cement industry for both internal and external applications. It propels the construction industry toward a future characterized by reduced carbon emissions.

Fractographic Investigations of the Failure Low Pressure Turbine Blade in a Coal-Based Thermal Power Plant

Fractographic Investigations of the Failure Low Pressure Turbine Blade in a Coal-Based Thermal Power Plant

Heavy metal, salinity and azo dye tolerant, Cr (VI) reducing, plant growth-promoting Pseudomonas aeruginosa R32 reverses Cr (VI) biotoxic effects in Vigna mungo

Hexavalent chromium [Cr (VI)], derived from various industries, including fly ash from coal-based Thermal Power Plants, can be a source of toxic pollution of land and water bodies. This study aimed to bioremediation of such pollutant dump sites using bacteria capable of both Cr(VI) reduction and plant growth-enhancing substance production. The bacteria were isolated from the rhizospheric fly ash of a Thermal Power Plant, Kanpur. One of the rhizospheric isolate, Pseudomonas aeruginosa R32 showed high minimum inhibitory concentration (MIC) for Cr(VI) (1250 µg/ml), heavy metal tolerance (ZnCl2, CdCl2, Pb(NO3)2) up to 100 µg/ml, Acid Red 249 (AR) tolerance and halotolerance (6% NaCl). The isolate R32 also produces plant growth-promoting (PGP) hormones in the absence or presence of Cr (VI). R32 could completely reduce Cr(VI) at a tested dose of 100 and 500 μg/ml after 24h and 72h, respectively. However, decolorization of AR was observed after 48 hours at an initial concentration of 100 µg/ml and confirmed by Fourier transform infrared spectroscopy analysis. Vigna mungo seed inoculation with isolate R32 showed increased rootling growth compared to shoot after 7 d treatment with 0, 100, 500, and 1000 μg/ml of Cr(VI) concentrations, respectively. Root length tolerance index in Cr(VI) treated V. mungo seedlings was reduced to 56%, 35%, and 29%, respectively, when treated with 100, 500, and 1000 μg/ml Cr(VI) in comparison to control. Cr(VI) sub-MIC concentrations can affect the plant growth-promoting properties of rhizospheric bacteria. Herein, we report the isolation of rhizospheric bacteria P. aeruginosa R32 showing concurrent PGP substance production and Cr(VI) bioreduction capabilities in the presence of PGP inhibitory Cr(VI) concentrations.

Studies on hydrometallurgical recovery of rare earth elements as mixed fluoride compound from coal fly ash using environmentally friendly organic acid

ABSTRACT Coal fly ash (CFA) emerged as one of the potential secondary source of rare earth elements (REEs). This paper discusses development of a process scheme for the recovery of REE from a CFA sample, assaying total REE of about 0.2% using environmentally benign lactic acid (LA) as leachant. The CFA is generated at a lignite coal-based thermal power plant. The REE occurs dominantly in an ion-exchangeable form and also as bound to iron oxides. Nearly 25% of total REE is constituted of heavy rare earth elements (HREEs). About 89% of REE values were found leachable with LA at 80°C in 2 h of reaction time at 10% solids content. Kinetic analysis of leaching process shows that the reaction between CFA and LA is chemical reaction controlled with activation energy of 42–45 kJ/mol. The dissolved REE values were extracted quantitatively from leachate using D2EHPA solvent diluted in kerosene and stripped back with 6 N HCl. The REE in strip liquor was precipitated as mixed REE-fluoride concentrate of purity 86% with precipitation efficiency of 98%. A scheme for quantitative recovery of LA from barren stream was developed for its recycle in leaching circuit.

Exergy analysis of modified-supercritical power plant with solar assisted feedwater heating and CO<SUB align="right">2 capture

Solar energy is the most readily available energy in India, which can be utilised in coal-fired thermal power plants for feedwater heating and Monoethanolamine (MEA) for MEA regeneration in post-combustion CO2 capture unit. The present study deals with 4-E (energy, exergy, environment, and economic) analysis of a 500 MWe Supercritical (SupC) coal-based thermal power plant with solar-assisted feedwater heating and MEA regeneration in CO2 capture unit. Results show that the plant efficiency is improved by 8.2% points, and the coal consumption rate is reduced by 18%. The levelised cost of electricity (LCoE) generation is increased to INR 6, and the cost for CO2 avoided is INR 3607 per tonne of CO2.

THE EFFECT OF THERMİC POWER PLANT WASTE FLY ASH ON PROPERTİES OF PORTLAND CEMENT

Today, increasing environmental awareness, national and international environmental policies are in parallel and getting stricter. The Concrete sector is criticized and under spotlight for consuming a billion tons natural resources and large amount of energy and high emissions from cement production - especially CO2. These criticisms are tried to be resolved with alternative ways. Fly ash in concrete and cement production, with the use of industrial wastes with pozzolanic properties such as blast furnace slag and silica fume, more sustainable and more durable end products can be obtained. The Fly ash, which is wastage of coal-based thermal power plants, it is easily accessible and it is one of the most used cement substitute materials due to its suitable fineness and chemical structure. With the appropriate use of fly ash, sufficient or even superior performance can be achieved in concrete.
 In this thesis study, the fly ash supplied from the thermal power plant will be substituted in CEM I 42.5 R cement at the rates of 0%-10%-20%-30% and will be subjected to various analysis studies determined in accordance with Turkish standards in the cement industry quality control laboratory.
 In this study, the physical, chemical and mechanical effects of fly ash on Portland cement were investigated by using fly ash from the Thermal Power Plant and CEM I 42.5 R cement together.

CFD Modeling for the Influence of Fly Ash Particle Size on the Different Properties of High Concentrated Slurry Transportation in Horizontal Pipe

The disposal of fly ash from thermal power plants is becoming a serious concern for environmental engineers. This article attempts to study the influence of particle size of the fly ash on the various properties of high concentrated slurry (50 - 70 % by weight) flow through a horizontal pipe with the help of a commercial CFD code ANSYS FLUENT. Modified Herschel-Bulkley model and SST k-ω turbulence model is used for computational analysis, and the computational outcomes are validated with the available literature. In the present study, the fly ash samples were procured from different coal-based thermal power plants. Various properties: physical and rheological are obtained experimentally. The specific gravity of particles and the static settling concentration (SSC) of the slurry increases with the decrease in the particle size. The rheological properties increase as the concentration increases, and the slurry behaves like a non-Newtonian fluid at a high concentration. In addition, the particle size and concentration intensively impact on the skin friction coefficient and velocity distribution. However, no significant impact on the velocity profile at 70 % concentration (by weight).
 HIGHLIGHTS
 
 The rheological properties increase as the concentration increases, and the slurry behaves like a non-Newtonian fluid at a high concentration
 CFD modelling of the slurry flow at high concentration with modified Herschel-Bulkley model and SST k-ω turbulence model
 The particle size and concentration intensively impact on the skin friction coefficient
 
 GRAPHICAL ABSTRACT

Status of Coal-Based Thermal Power Plants, Coal Fly Ash Production, Utilization in India and Their Emerging Applications

Both fossil and renewable fuel sources are used widely to produce electricity around the globe. The dependency on fossil fuels for energy leads to the depletion of reserves and various forms of pollution. Coal fly ash (CFA) is one of the most burning issues in the whole world due to its large amount of production in thermal power plants. Every year a million tons (MTs) of CFA are generated globally of which almost half is utilized in various forms, while the remaining half remains unused, leading to various types of pollution. Hence, there is an immediate requirement for CFA management approaches for the efficient and sustainable use of fly ash. In the present review, the authors emphasize the status of energy and its supply and demand. A detailed description of coal fly ash-based thermal power plants, fly ash production, and utilization is provided. Moreover, the current and emerging applications of CFA are also provided.

Analysis of Air and Soil Quality around Thermal Power Plants and Coal Mines of Singrauli Region, India.

Singrauli region is known as the energy capital of India, as it generates nearly 21 GW of electricity, supplied to various parts of the northern India. Many coal-based Thermal Power Plants (TPPs) using coal from several nearby coal mines, and numerous industries are set up in this region which has made it as one of the highly polluted regions of India. In the present study, detailed temporal analysis and forecast of carbon dioxide (CO2), nitrogen dioxide (NO2), sulfur dioxide (SO2), and methane (CH4) concentrations retrieved from satellite data have been carried out for the periods 2005–2020. Based on the classical multiplicative model and using linear regression, the maximum concentration of CO2, NO2, SO2, and CH4 in the year 2025 is found to be 422.59 ppm, 29.28 ppm, 0.23 DU, and 1901.35 ppbv, respectively. Detailed analysis shows that carbon dioxide has a 95% correlation with all other trace gases. We have also carried out the geo-accumulation index for the presence of various contaminants in the soil of this region. The geo-accumulation index shows that soil in and around thermal power plants and coal mines is contaminated by heavy metals. The cumulative index shows that soil around Hindalco industries, Bina coal mines, Khadia coal mines, and coal-based TPPs (Anpara and Vindhayachal) are highly polluted and a threat to human population living in the region.

Spatiotemporal changes in tropospheric nitrogen dioxide hotspot due to emission switch-off condition in the view of lockdown emergency in India

The COVID-19 outbreak has elicited forced lockdown conditions for all anthropogenic emissions across the globe. It has brought an opportunity for the researchers to sort out the relative contribution of the environmental pollutants which are emerged from the coal-based thermal power plants and other industrial sectors. In countries like India, some industrial sectors and thermal power plants coexist; henceforth, they mutually produce NO2 concentration canopy in the upper atmosphere in raised form. Focusing on this issue, the present work intends to explore the NO2 emission hot-spots’ foci using switch-off conditions in consequence of emergency lockdown. Our results indicate that stable {(CV}_{mathrm{low};}mathrm{and;NO}{2 }_{mathrm{;max}}) and large NO2 concentration canopy is noticeable in the inter-state border areas among Chhattisgarh, Bihar, Madhya Pradesh, and Jharkhand (around “Govind Ballabh Part Sagar” reservoir) where a cluster of thermal power plant is located. The “OFF” situation also proposes a close correspondence between the NO2 richness column and installed capacity (R2 value > 0.7 with 0.0002 p value). States that are situated in the eastern part of the country and megacities like Delhi and Kolkata represent a crucial role in NO2 emission while in certain regions of south India are more or less safe from NO2 emission. As a consequence, the lockdown has created a temporary pollution baseline for tropospheric NO2 that offers research prospects to think of alternate sources of energy that can maintain environmental health as well as human well-being.

Nexus between potentially toxic elements’ accumulation and seasonal/anthropogenic influences on mangrove sediments and ecological risk in Sundarbans, Bangladesh: An approach from GIS, self-organizing map, conditional inference tree and random forest models

Mangroves play a vital role in protecting the coastal community from the climate change effect and in the restoration of the coastal ecosystem. This research has been designed to determine the spatial and seasonal changes of potentially toxic elements’ (PTEs) concentration in sediments and their potential source contribution among the different human-driven processes in Sundarbans, Bangladesh. Different pollution evaluation indices, random forest (RF) model, conditional inference tree (CIT), self-organizing map (SOM), geographical information system (GIS), and principal component analysis (PCA) were used for the interpretation of sources and risk assessment of PTEs. The mean concentration of PTEs both in winter and monsoon seasons has fallen below the threshold effect level but exceeded the rare effect level of marine sediments quality standards. Results showed that the PTEs were significantly enriched (EF > 1.00 < 70.00) in sediments, whereas the Cd enrichment (7.00% samples) was very alarming (EF = 60–70). Except for Zn and Cd, other PTEs were enriched in 30–60% samples. The highest geoaccumulation and contamination factors for Cd were observed in 46–72% of samples. The ecological risk (ER) factors showed similar results where Cd showed strong to very strong factors (ER = 110–2218) in 80% of samples. The CIT explained the natural/geogenic and anthropogenic sources of pollution, where the higher CIT values for Cd indicated industrial, aquaculture, and coal-based thermal powerplant. The RF model provided that shrimp firms, power plants, industry, and seaport were recognized as the influential sources for Zn, Pb, Cr, Cd, and As in sediments. Though Pb and As were found as the most significant pollutants, Cd was identified as a severe threat to ecology and public health. Based on CIT, RF, SOM and PCA the order of PTEs in mangroves sediment were:industrial/urban > aquaculture/shrimpfirm > powerplant > seaportoperation > tourism > geogenic/natural. The present study will help the policymakers for effective and sustainable management of the mangrove ecosystem.

Biochar production from crop residues, its characterization and utilization for electricity generation in India

Post COP-15, the push is to reduce coal dependence for electricity generation and GHG emissions from the national electrical grid. Phasing out coal-based thermal power plants (TPPs) does not favour India's economic and social interests. Therefore, it becomes imperative to make coal-based power plants clean. Biochar derived from crop residues has been considered a clean fuel and an economical substitute for coal. The present study investigated the biochar potential of crop residues from rice, wheat, maize and sugarcane cultivation, accounting for 89% of total agro production, for coal replacement in TPPs using primary & secondary data and ArcGIS for mapping agro-residue collection point and TPP. Results show that biochar produced from the identified agro resources in the temperature range of 400 °C–500 °C are suitable for cofiring with coal. 121 MT surplus residues of the selected crops could produce 40 MT biochar having 90 TWh electricity generation potential. Biochar produced from surplus residues is equivalent to 69 MT of coal, about 11% of coal consumed annually in Indian TPPs. Also, biochar cofiring could reduce 165 MT annual CO2 emissions from coal-burning in TPPs, about 14% of CO2 emissions by the energy sector and 7% of overall CO2 emissions by India. Techno-economic analysis showed that the infrastructure development & operation cost for the biochar conversion facility is in the range of 2–3 USD/MWh, which is significantly lower than that of the new biomass to electricity generation facility (43–53 USD/MWh). The results would provide baseline data for policy decisions to avoid net GHG emissions from TPPs, and site identification for additional infrastructure to develop alternative clean fuels for India's coal-based TPPs.

Improvements in SO2 pollution in India: role of technology and environmental regulations.

India relies heavily on coal-based thermal power plants to meet its energy demands. Sulphur dioxide (SO2) emitted from these plants and industries is a major air pollutant. Analysis of spatial and temporal changes in SO2 using accurate and continuous observations is required to formulate mitigation strategies to curb the increasing air pollution in India. Here, we present the temporal changes in SO2 concentrations over India in the past four decades (1980–2020). Our analysis shows that the Central and East India, and Indo-Gangetic Plain (IGP) are the hotspots of SO2, as these regions house a cluster of thermal power plants, petroleum refineries, steel manufacturing units, and cement Industries. Thermal power plants (51%), and manufacturing and construction industries (29%) are the main sources of anthropogenic SO2 in India. Its concentration over India is higher in winter (December–February) and lower in pre-monsoon (March–May) seasons. The temporal analyses reveal that SO2 concentrations in India increased between 1980 and 2010 due to high coal burning and lack of novel technology to contain the emissions during the period. However, SO2 shows a decreasing trend in recent decade (2010–2020) because of the environmental regulations and implementation of effective control technologies such as the flue gas desulphurisation (FGD) and scrubber. Since 2010, India's renewable energy production has also been increased substantially when India adopted a sustainable development policy. Therefore, the shift in energy production from conventional coal to renewable sources, solid environmental regulation, better inventory, and effective technology would help to curb SO2 pollution in India. Both economic growth and air pollution control can be performed hand-in-hand by adopting new technology to reduce SO2 and GHG emissions.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-022-21319-2.

The Effects of Laser Cladding Surface Treatment on Surface Degradation Properties :a Review

Surface degradation due to hot corrosion and erosion in thermal power plants and gas turbines, is one of the primary concerns for many researchers, scientists and surface engineers. Hot corrosion is considered as a serious problem in coal-based thermal power plants which fulfill approximately 58.3% of the total electricity demand of India. The practice of using low-grade fuels at high functional temperatures is the overriding reason for accelerated hot corrosion. A case study stated that approximately 56% of boiler failures occur due to hot corrosion that may lead to reduced economical efficiency of the thermal power plants. Fortunately, this problem can be controlled by some preventive measures, and surface modification is one of the effective methods to enhance the lifespan of boiler components. Surface modification can be done through different surface coating processes like plasma spray, HVOF and D-gun etc. In this paper, we will discuss the effects of Laser cladding surface coating process to develop the corrosion resistance surface properties of different substrate materials

Ecological and human health risks from pseudo-total and bio-accessible metals in street dusts.

Street dust samples were collected from industrial and commercial cities (Jamshedpur and Ranchi during monsoon and post-monsoon seasons) for detecting the levels of Cr, Cd, Cu, Ni, Pb, Zn, As, Co, Al, and Mn. The industrial city recorded higher metal concentrations compared to commercial. Similar trend of pseudo-total metal concentrations was observed in both the seasons at industrial city (Al > Mn > Zn > Cr > Pb > Cu > Ni > Cd) and only monsoon season at commercial city (Al > Mn > Zn > Cu > Cr > Pb > Ni > Cd). Zn > Cd was the most bioaccessible metal throughout the cities (monsoon and post-monsoon). The geochemical parameters (Igeo, EF, CF) were highest for Cd and lowest for Ni (both cities for the two seasons). Pollution Load Indices (PLI zone) were highest during the post-monsoon season in the industrial city. The highest carcinogenic risk was posed by Cr ranging from 1.87E-05 to 4.80E-05, in both the cities through ingestion and inhalation pathways. Children were found at higher risks, while the bioaccessible fractions posed neither carcinogenic nor non-carcinogenic threats to the population. Principal component analysis and correlation analysis indicated the influence of vehicular and industrial emissions, especially steel industry and coal-based thermal power plants as the major source of metals in street-dust. The outcomes of this work will be useful in providing baseline information of pollution along with their consequent environmental and human health risks of Jharkhand state.

Mineral admixtures utilization in different areas: A review

Nowadays, the electricity required in the developing countries are mostly dependent on Coal-Based thermal Power plants. During the course of production of electricity, the solid waste residue namely Fly Ash (FA), which is left behind causes serious impact to the environment. On the other hand, another residue, Ground Granulated Blast Furnace Slag (GGBS) which is produced from the molten iron slag is also disposed on the land surface, resulting which several bad impacts occur on the heath of the environment. Apart from these mineral admixtures, one more such ash namely Rice Husk Ash (RHA) is also produced by the processes of burning of the rice husk itself. Some of the ashes which are directly produced by the burning of hard Bituminous coal together with hard Anthracite give rise to the mineral admixture to be often known as Silica Fume. Metakolin is also another type of Mineral Admixture which is produced by the burning of kaolin clay. In some countries, the production of Palm Tree is so high that electricity is generated there by burning of Palm shell and husk. During production, the residue, which is equally harmful to the environment, is known as Palm Oil Fly Ash (POFA). The problem does not lie with alone; the major issues is of storage of all these mineral admixtures. In most of the countries these solid waste mineral admixtures are placed on a large open area of the land. Such mineral admixtures are toxically associated with heavy metals which cause to leach the ground water and the soil as well. But researchers have found that these mineral admixtures being considered as solid waste, are, in fact, very useful materials and have also proven their worth over a period of time. This paper aims at focusing on the various ways of utilizing the different Mineral Admixtures in various areas of Civil Engineering. Also in the paper, there is strategical focus on the proper management of mineral admixtures to make use of these solid wastes, in order to save our Environment.

A review on life cycle assessment approach on thermal power generation

The global population is predicted to reach 9.9 billion people in 2050, with 80% of the population living in developing countries. As the world's population grows, the demand for electricity also increases. In most developing nations, coal is the most important source of energy. The environmental impacts of coal-based electricity generation are a key concern for long-term sustainability and hence an intensively studied topic in many nations. The life cycle assessment (LCA) method has been widely used around the world to assess the environmental impact of electricity generation. Because the results of LCA are generally dependent on geographical location, they must be carried out for a specific location. In the Indian context, there are still gaps to be addressed in this area. This review is part of the baseline research for a comprehensive LCA analysis of India's coal-fired power facilities. A literature analysis of a variety of worldwide studies is conducted with a focus on understanding the LCA technique and environmental assessment. The findings of the analysis demonstrate that, while prior LCA studies have proven useful, no comprehensive LCA on coal-fired power plants in India has yet been completed. As a result, the objective of this research is to undertake a systematic review of LCA studies conducted on coal-based thermal power plant operations, emissions mitigation strategies, and transmission and distribution. The paper also discusses the methodology adopted by the researchers and the results of the LCA of thermal power plants in the Indian context.