Coal Power Plants Research Articles

Subsidizing Grid-Based Electrolytic Hydrogen Will Increase Greenhouse Gas Emissions in Coal Dominated Power Systems.

Clean hydrogen has the potential to serve as an energy carrier and feedstock in decarbonizing energy systems, especially in "hard-to-abate" sectors. Although many countries have implemented policies to promote electrolytic hydrogen development, the impact of these measures on costs of production and greenhouse gas emissions remains unclear. Our study conducts an integrated analysis of provincial levelized costs and life cycle greenhouse gas emissions for all hydrogen production types in China. We find that subsidies are critical to accelerate low carbon electrolytic hydrogen development. Subsidies on renewable-based hydrogen provide cost-effective carbon dioxide equivalent (CO2e) emission reductions. However, subsidies on grid-based hydrogen increase CO2e emissions even compared with coal-based hydrogen because grid electricity in China still relies heavily on coal power and likely will beyond 2030. In fact, CO2e emissions from grid-based hydrogen may increase further if China continues to approve new coal power plants. The levelized costs of renewable energy-based electrolytic hydrogen vary among provinces. Transporting renewable-based hydrogen through pipelines from low- to high-cost production regions reduces the national average levelized cost of renewables-based hydrogen but may increase the risk of hydrogen leakage and the resulting indirect warming effects. Our findings emphasize that policy and economic support for nonfossil electrolytic hydrogen is critical to avoid an increase in CO2e emissions as hydrogen use rises during a clean energy transition.

Optimizing biomass supply for cofiring at power plants to minimize environmental impact: A case of oil palm empty fruit bunches in West Java

This study addresses the supply flow optimization to reduce global warming in a cofiring system, using the example of oil palm empty fruit bunches converted into pellets for use in power plants in Indonesia. Four oil palm mills, seven pellet plants and five coal power plants in the West Java Region were considered in this study to select the optimal supply chain. The study was performed using a life cycle assessment (LCA) for evaluating impact of single firing of coal and linear programming (LP) for optimizing the impact reduction of cofiring of coal and pellets. Our study indicates that the optimal environmental reduction can be achieved by constructing six of the seven pellet plants, which can substitute up to 1 % of the coal supply in five power plants. Accordingly, the emissions could be decreased by an average of 0.018 kg CO2eq/kWh for the power plants, which is equal to 0.2 Mt CO2eq/y or a 1.57 % reduction per year. By varying the emission factor of the pellet plants, our analysis showed a tolerable range in which the supply would not be affected. The sensitivity analysis at a 1 % cofiring rate showed that the increase in biomass supply from the oil palm mills had the highest reduction, whereas the reduction in transportation emissions provided much less impact. By adjusting the cofiring rate, the impact would not change after the 3 % cofiring rate because of the limited availability of Empty Fruit Bunch (EFB) feedstock. However, if sufficient supply could be provided, the environmental impact would be further reduced significantly. Furthermore, the scenario expansion indicated that only three pellet plants would be required for the minimum economic scale of production, although the environmental impact increased by 0.47 % compared to using six pellet plants. Therefore, this study can be used to determine the optimal supply chain scenarios by constructing an appropriate number of economically feasible pellet plants according to the biomass demand and cofiring rate of the power plant.

Variability in surface CO2 flux: Implication for monitoring surface emission from geothermal fields

In the last decade the international push for the development of various renewable energy and the increase of the carbon tax for emitters, has put high enthalpy geothermal on a hot seat. Anthropic geothermal emissions in volcanic areas are not negligible due to the inherent nature of their volcanic setting but are counted regardless, similarly to a gas or coal power plant, despite their non-fossil carbon origin. Natural volcanic emissions are however poorly constrained due to the lack of field scale soil CO2 flux assessments. In this study, we analyse the temporal and spatial variations of soil CO2 flux and soil temperature in the Taupō region, Taupō Volcanic Zone, New Zealand, in the light of seasonal variation, field utilisation, and seismicity. Fortnightly monitoring between 2019 and 2023 at 8 sites across the Tauhara and Wairakei geothermal fields provides insight into changes of seasonal variations and geothermal activities. To understand the broader distribution of natural degassing and to compare the CO2 flux over decades, we repeated the CO2 flux survey between 2019 and 2023 and compared to previous results at Karapiti, Wairakei geothermal field (2004, 2018), Ring of Fire, Tauhara geothermal field (2006), and Rotokawa geothermal field (2003, 2011). Similar emissions but a change in the spatial distribution at Tauhara geothermal field suggests that human surface development has affected permeability in the shallow subsurface. In contrast, a similar spatial distribution of flux, but higher emissions, at Karapiti, Wairakei indicates the recovery or modification of reservoir pressure. Finally, a decrease of total emission flux of the natural geothermal features at Rotokawa coincides with the decrease of CO2eq emissions at the power stations. This study showcases the complexity and uncertainties of natural CO2 emission calculations and provides recommendations for future monitoring studies.

Proposal and simulation of a geothermal-driven water electrolysis unit integrated with a CO2 methanation process toward a novel sustainable framework

This paper presents a novel multigeneration structure powered by geothermal energy, featuring a geothermal power plant, water electrolyzer unit, methanation reactor, fuel and utility production unit, supercritical-carbon dioxide cycle, and both high-temperature and low-temperature organic Rankine cycles. Simulated in Aspen HYSYS software and analyzed from energy, exergy, economic, and environmental (4E) perspectives, the process, under base operating conditions, is capable of producing 20,940 kW of power, 620.70 kg/h of hydrogen, 4,913 kg/h of oxygen, 12.35 kg/s of domestic hot water, 5.293 kg/s of chilled water, and 2.659 kg/s of carbon dioxide with over 99% mole purity. Efficiency assessments reveal energy, exergy, and electrical efficiencies of 10.69%, 48.53%, and 3.73%, respectively, with a total unit product cost of $3.11/GJ and a net present value of $67.40 million. The water electrolyzer unit, with an 88.94% exergy efficiency and a 10% contribution to total system irreversibility, is identified as the most efficient subsystem. The geothermal power plant accounts for the highest system irreversibility at 61%, while the combustor in the fuel and utility production unit contributes 11,250 kW of irreversibility. Environmentally, the system operates with zero emissions and significantly reduces annual CO2 emissions compared to coal, oil, biomass, and natural gas power plants by 453.14 × 106, 576.80 × 106, 111.92 × 106, and 344.10 × 106 kg, respectively.

Coal Share Reduction Options for Power Generation during the Energy Transition: A Bulgarian Perspective

The sustainable energy transition to a low-carbon and climate-neutral economy by 2050 requires a consistent increase in the share of renewable energy sources (RESs) at the expense of the share of fossil fuels. The coal power plants in the Republic of Bulgaria have provided about one third of the annually produced electric power for decades, utilizing mainly locally available sources of lignite. The present work aimed to review the progress of the energy transition, its rejection and acceptance at the national and international scene alongside the available research for cleaner coal combustion in Bulgaria, as well as discuss a Bulgarian perspective for coal share reduction options for power generation during the energy transition. A comprehensive review was carried out, based on freely accessible data such as research and open media articles, officially published field reports, legislative and strategic acts as well as validated statistical data. Three groups of critical gaps (socioeconomic, sociotechnical and cultural and political) were indicated, claimed to be capable of guiding the just transition. Key factors influencing the process dynamics were identified and categorized in the context of the critical gaps. The peculiar policy criteria for the carbon-intensive regions are as follows: the dominant energy carriers, existing infrastructure, involved actors and choice of strategy. The observations allowed us to conclude that in addition to the efforts achieved and ambitious political will, the identification of reliable technological and socioeconomic measures is needed more than ever (accompanied by interdisciplinary research involving the technical, social and environmental and policy factors), while renewables still have long way to go towards complete substitution of the fossil fuels for power generation, transport, and manufacturing. Limited literature was found for reducing the share of coal from currently operating Bulgarian coal-fired power plants (CFPPs). Herein, short- and/or medium-term measures for carbon emission reduction were discussed, capable of promoting the limited operation of existing CFPPs, thus paving the road towards a sustainable, long-term transition. These measures concerned the typically used power units in the largest CFPPs located at the Maritsa Iztok Mining Complex (MIMC). Analyses of the biomass production, supply and cost for the same type of power units were proposed, considering the use of 100% biomass. Estimated costs, unit efficiencies and power generation were discussed along with the evaluations about the land use, ensuring a given annual productivity of wood chips from fast growing plants, e.g., Paulownia.

Technical feasibility of a 1000 MWe pulverized coal power plant under ammonia co-combustion conditions

Ammonia has attracted the attention as a practical way to reach carbon free power generation. Ammonia co-combustion characteristics in 1000MWe pulverized coal power plant was simulated by using Aspen Plus and evaluated under an excess air ratio of 1.0–1.2, air of 2642–3457 ton/hr, coal of 208.2–355.5 ton/hr, ammonia of 0–186.14 ton/hr and various coals. The influence of co-combustion ratios of different coals on emission characteristics and net efficiency was compared. For carbon dioxide emission reduction, the respective CO2 intensity reduction for KPU and BG was 36.44 and 37.76% in calorific value basis, 32.51 and 31.90% in weight basis. The net efficiencies of the power cycle showed a lower decrease as the fuel was supplied on the weight basis compared to the calorific value basis. Based on the obtained results, the KPU on the weight basis showed the lowest net efficiency decrement of 3.1%, but in terms of CO2 intensity reduction, BG on calorific value basis showed most drastic reduction of 37.76%. Consequently, these results showed an effective carbon reduction with ammonia co-combustion and provides a promising solution for the pulverized coal power plants to compass a meaningful reduction of carbon emissions and conservation of combustion efficiency.

Analisis Dampak Lingkungan dan Keekonomian Pembangkit Listrik Tenaga Co-firing Biomassa dan Baru bara sebagai Upaya Bauran Energi Terbarukan

Analisis Dampak Lingkungan dan Keekonomian Pembangkit Listrik Tenaga Co-firing Biomassa dan Baru bara sebagai Upaya Bauran Energi Terbarukan

Creep Resistance and Structure of 10% Cr–3% Сo–2% W–0.29% Cu–0.17% Re Steel with Low Nitrogen and High Boron Contents for Unit Components of Coal Power Plants

Creep Resistance and Structure of 10% Cr–3% Сo–2% W–0.29% Cu–0.17% Re Steel with Low Nitrogen and High Boron Contents for Unit Components of Coal Power Plants

An Opportunity for Coal Thermal Power Plants Facing Phase-Out: Case of the Power Plant Vojany (Slovakia)

The study deals with the possibilities of using alternative types of fuels to produce electricity. Power Plant Vojany (PPV) is a thermal power plant (TPP) in eastern Slovakia, which is part of the company Slovenské elektrárne, a. s. (SE). PPV primarily used black coal to produce electricity, which had to be imported from abroad (the Russian Federation). This activity has become inefficient both economically and environmentally, due to the high price of CO2 permits and the high emission factor of this type of fuel. PPV decided to co-combust biomass and refuse-derived fuel (RDF), which resulted in much better economic conditions due to their price, economic efficiency, and partly closed CO2 cycle. The aim of the paper is to explore the possibilities related to the production of energy in the cleanest possible way and with the least possible damage to the environment in coal thermal power plants using the example of operating Power Plant Vojany located in eastern part of Slovakia and to inspire each other for the modern transformation. For the purposes of hypothesis verification, analytical methods focused on overview studies of average fuel prices, comparisons, and the balance of fuels in connection with eliminated CO2 emissions, as well as municipal waste (MW) management in the EU and V4 countries, were used. The authors also focused on the energy recovery and combustion of MW and tracking the achieved CO2 savings in connection with the development of fuel sources in PPV. The results point to the fact that PPV is one of the power plants that could use biomass and RDF as fuel, which confirms the economic advantages of this procedure. The results confirm that the potential of RDF production in Slovakia is sufficient to ensure the operation of PPV at planned, even higher volumes of electricity production. The transformation to cleaner operation of coal thermal power plants represents a significant contribution of this study.

Solar Panels Produced Electricity Impact on Electricity Network

Historically, during the creation of a unified energy system, base load power plants were constructed in Estonia (shale power plants) and Lithuania (the Ignalina nuclear power plant and the Elektrenai power plant). In Latvia, the Daugava hydropower plants were designed for peak, half-peak and emergency modes in which it is possible to relatively quickly and simply implement the sudden increase or decrease of capacity according to necessity. Neither coal nor shale power plants allow such sudden change of generation capacity due to a technologically more complex process. Latvian largest electricity supplier JSC "Latvenergo" 72% of the electricity - 3.6 TWh (2012) produced from renewable and environmentally friendly energy sources [1]. JSC “Latvenergo” uses two types of energy resources in the energy generation process: renewable energy sources in hydropower plants and in biomass and wind power plants; highly efficient cogeneration in gas-fired power plants. Latvia already is one of the greener countries in the Europe in accordance with high level of energy production from RES and future strategies for energy sector development also include RES use for heat and electricity production. The Energy Strategy 2030 sets the following objectives of the energy policy: – Competitive economy – balanced, efficient, economically, socially, and ecologically justified energy policy based on market principles ensuring further development of the economy, competitiveness in the region and world; its – Sustainable energy – reduced dependency on imported energy resources, new and efficient technologies for the use of renewable resources are encouraged, measures to implemented; improve energy efficiency are – Secure supply – stable energy supply and developed infrastructure provided to energy users.

Assessment of soil contamination by heavy metals in the vicinity of the Sahiwal coal power plant, Pakistan, employing an innovative statistical analysis approach

ABSTRACT Pollution from heavy metals has become a major issue globally. Human activities could result in lower environmental quality and higher concentration of heavy metals in the soil. The establishment of coal power plants causes a significant threat to the Environment, soil and people who consume the food crops cultivated in that area. In this study, the concentration of some heavy metals like Calcium (Ca), Cadmium (Cd), Cobalt (Co), Chromium (Cr), Lead (Pb), and Magnesium (Mg) has been determined by utilising an Atomic Absorption Spectroscopy (AAS) and 10 soil samples were collected in nearby agricultural soil in the vicinity of coal power plant in Sahiwal, Pakistan during 2021–22 for this purpose. The samples for AAS were prepared via the Wet Digestion Method (WDM). The concentrations of Ca, Co, Cd, Cr, Pb and Mg that have been found are 1.7096 ± 1.4623 mg/kg, 0.0141 ± 0.0664 mg/kg, 0.1413 ± 0.3328 mg/kg, 0.2057 ± 0.3214 mg/kg, 0.1114 ± 0.07316 mg/kg and 0.8951 ± 0.4672 mg/kg, respectively. The results indicate that none of the metals were detected to be above the authorised limits, making the soil appropriate for agricultural purposes. It has been concluded that there are no detectable adverse effects due to the operation of coal power plants in terms of the analysed concentration of heavy metals. Moreover, a statistical Neutrosophic approach has been applied to the specific problem to check the reliability and variation in the concentration of heavy metals. The results come up with extensive and clear information about the particular issue. This study delivers a scientific basis for taking proper measures and managing soil pollution in incoming future in the areas near coal power plants.

Air Pollution: A Challenge to Public Health and Healthcare Systems

Air Pollution: A Challenge to Public Health and Healthcare Systems

China's energy-water-land system co-evolution under carbon neutrality goal and climate impacts

China's 2060 carbon neutrality goal has significant implications for energy, water, and land systems. However, the multi-sector dynamics among China's energy-water-land system have rarely been examined explicitly. This study adopts an integrated assessment framework to simulate China's energy-water-land system co-evolution under alternative carbon neutrality scenarios and climate impacts. Results show that although the net zero emission target provides the incentive for the energy system to move away from fossil fuels, total water withdrawal will increase due to the deployment of nuclear, bioenergy, and coal power plants with carbon capture and storage. Diversifying the negative emission technologies, by leveraging direct air capture technology, can alleviate the potential water stress and land use conflicts, which would otherwise be exacerbated by large-scale deployment of afforestation and bioenergy with carbon capture and storage. Northwest and northeast regions of China are the hotspots experiencing water withdrawal increases, while Bohai Rim and coastal regions are identified to experience fierce land competition. This study demonstrates the potential for general applicability to carry out resource planning and policy evaluation from the multi-sector coordination perspective.

A new system for hydrogen and methane production with post-combustion amine-based carbon capturing option for better sustainability

In the present paper, a novel integrated multigeneration system is developed to produce hydrogen and methane simultaneously driven by a renewable energy source. Besides, this system captures carbon dioxide from a coal power plant through an amine-based absorber and stripper. Also, solar energy is set to provide the heat required for the system. The generated power is used for different purposes from the coupled Brayton-Rankine combined cycle. There are two methods of iron-based chemical looping with four reactors and steam methane reforming, which are integrated into the system to produce hydrogen and store it at the same time. After gaining enough heat and electricity from mixing and heating the CO2 and H2, the methane is then produced, stored or used for different purposes during the system. This system primarily utilizes solar energy to produce the required heat of the system which is suitable for sunny locations. The governing and balance equations are employed to determine the energy and exergy efficiencies, methane and hydrogen production rates and carbon capture percentage as 48 %, 32 %, 0.0048 kg/s and 0.004 kg/s and 80 % carbon capturing.

Instance transfer partial least squares for semi-supervised adaptive soft sensor

In order to deal with the unknown data drift problem caused by the change of working conditions in the process of industrial soft sensor modeling, this paper proposes a semi-supervised soft sensor modeling algorithm based on instance transfer learning, named instance transfer partial least squares. Under the framework of nonlinear partial least squares, the algorithm introduces the instance transfer inner model, and realizes the distribution adaptation of the modeling data and the data to be predicted through sample importance weighting. First, a nonlinear partial least squares model is constructed by using labeled samples in the source domain, which consists of a linear outer model and a nonlinear inner model. The linear outer model maps the original data to the hidden variable space, and the nonlinear inner model realizes the nonlinear modeling of hidden variables through kernel ridge regression. Second, a small number of labeled samples from the target domain are used to update the model weights of the nonlinear inner model, enabling adaptation of the latent variable distribution. The effectiveness of the algorithm is verified on a toy dataset, a simulation dataset and a real pulverized coal power plant dataset.

Evaluation of radiological health risk caused by the use of fly ash in cement and concrete production and its storage

ABSTRACT As a result of firing pulverized coal in thermal power plants, enormous amounts of fly ash (FA) are produced as industrial waste. The release into the atmosphere and storage of this industrial waste remains one of the major environmental problems that threaten human health by contributing to air, water, and soil pollution. The recovery and reuse of FA in the construction industry is the only economic solution to the existing problem. In this study, the potential radiological risk caused by the usage of FA in concrete and cement production as a main component and its storage in landfill sites was evaluated for people and works by estimating radiological parameters (activity concentration and alpha index, annual effective doses, and the corresponding excess lifetime cancer risks) based on activity concentrations of terrestrial radionuclides in FA. Also, the radiological risk to the workers working in the FA landfill site was evaluated using the Residual Radioactivity Onsite 7.2 code. The average activity concentrations of terrestrial radionuclides in FA samples from the Tunçbilek lignite coal-fired thermal power plant at Kütahya province of Turkey were measured as 417, 156 and 454 Bq kg−1 for 226Ra, 232Th and 40K, respectively. When using up to 35% by mass of FA in cement and concrete, the average values of the radiological parameters revealed that they were within the recommended safety limits. However, code estimations showed that a regular worker in FA storage would be exposed to a total effective dose rate greater than 3 mSv y−1.

Modeling the dependency relationship between wind speed and wind power generation: An application of copula theory

The concern with global warming and pollution has increased interest in the development of renewable energy sources, which are less aggressive to the environment. Wind energy can provide adequate solutions to the above-mentioned problems. The use of this energy eliminates unwanted waste that is harmful to health and the environment from other energy sources such as coal and nuclear power plants. This work aims to analyse the dependence relationship between wind speed and wind energy production, a rather complex relationship, so this study seeks to understand the stochastic nature of both phenomena. As a methodological tool the copula theory was used. A copula function is used as a general method, which consists of formulating multivariate distributions so that different dependency structures can be represented. That is, the study is based on the analysis and modelling of the dependence between wind speed data and electrical energy generation, for an hourly database of a wind farm in the state of Bahia, collected in the entire year of 2017. Thus, this paper proposes a study aiming the search for the copula function referring to the data in the period mentioned.

Transitioning from coal to solar: A cost-benefit analysis for sustainable power generation in Indonesia

<abstract> <p>The greenhouse gas (GHG) emissions contribution from power generation in Indonesia reaches 40% of the total (GHG) emissions in the energy sector because of the use of fossil fuels. The government aims to minimize GHG emissions in the power generation sector, one of which is the phase-out of coal power plants and replacing them with integrated photovoltaic (PV) power plants with battery energy storage systems (BESS). A cost-benefit analysis compared two development scenarios for 2023–2060. The base scenario continues developing coal power plants, and the phase-out scenario replaces coal power plants with integrated PV power plants and BESS. The analysis is solely focused on the financial costs and benefits for power plant investors. The results indicate that the present value of costs for the base scenario from 2023–2036 is initially lower compared to the phase-out scenario. However, in the long term, the costs of the phase-out scenario will gradually decrease and become more affordable. The benefit-cost ratio for the phase-out scenario is 2.36, while the base scenario is 2.12, indicating that the phase-out scenario is more prospective for future development. Additionally, the phase-out scenario has the advantage of achieving the net-zero emissions target by 2056 compared to the base scenario.</p> </abstract>

Economic and Productive Viability of the Refurbishment in Coal Power Plants Through Thermal Energy Storage Solutions

Economic and Productive Viability of the Refurbishment in Coal Power Plants Through Thermal Energy Storage Solutions

Investigation of a NO<sub>x</sub> emission from coal power plants in Texas, United States and its impact on the environment

Investigation of a NO<sub>x</sub> emission from coal power plants in Texas, United States and its impact on the environment