Coal Power Plants Research Articles

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

Business Model Innovation of Off Grid Public Electric Vehicles Battery Swap Station with Solar Powered

Energy transition is Indonesia's national agenda to maintain energy security and realize the use of green energy. The use of electric vehicles (EVs) is one strategy to maintain primary energy security and support the reduction of carbon emissions. To support the growth of the EV ecosystem, Public Electric Vehicle Battery Swap Stations (Stasiun Penukaran Baterai Kendaraan Listrik Umum, SPBKLU) have been developed and installed in several locations. Currently, SPBKLU still uses electricity sources from the PLN (Perusahaan Listrik Negara, Indonesia’s electricity state-owned company) grid, where the majority of the PLN grid itself still relies on gas and coal power plants. Hence, this work proposed a PV-powered battery swap station and presented the Business Model Canvas and financial and SWOT analysis. Two business model schemes are proposed, the BPCOSP (Battery Provider, Cabinet Owner, Solar PV Provider) and BPCOSL (Battery Provider, Cabinet Owner, Solar PV Lease) schemes. From these two business schemes, the results of the financial feasibility analysis for the SPBKLU swap rate were obtained at IDR 18,241 for the BPCOSP scheme and IDR 21,500 for the BPCOSL scheme. From a SWOT analysis perspective, the BPCOSP and BPCOSL business schemes have the opportunity to increase the Solar PV business value chain and support government programs in achieving Net Zero Emissions. However, there are still weaknesses in terms of tariffs which are still not economical compared to the fuel costs of conventional two-wheeled vehicles and the current SPBKLU swap tariff which still uses electricity from the PLN grid.

Subbase stabilization with fly ash

Due to increased activities in civil engineering, and especially in the transport infrastructure, and thus an increase in the use of additional construction materials, innovative solutions are needed in finding alternative materials for the preservation of natural resources. One of the solutions for preserving natural building materials is the application of recycled material, which will also meet the required standards in civil engineering. In the transport infrastructure, there is a great opportunity for the use of recycled material, starting from the subbase, through the embankment and all the way to the superstructure and the concrete structures. One of the recycled materials that can be used in construction is fly ash. Fly ash is the most promising waste material when it comes to the wide range of applications in construction. Fly ash is obtained by burning coal in thermal power plants to produce electricity. Due to variations in the composition and characteristics of fly ash, several divisions and classifications have been created. One of the main classifications is according to the American standard ASTM C 618-05 where it is divided into class C and class F fly ash. This research aims to investigate the application of fly ash for subgrade stabilization and to determine the difference from a financial and environmental perspective for the application of fly ash compared to natural stone aggregate. The main research was carried out in connection with the increased use of natural stone aggregate, which appeared as a need during the rehabilitation of state road R1206, section Karpalak - Zelino. Apart from the use of large quantities of stone aggregate for the stabilization of the subgrade, it also had an impact on the financial framework for the realization of the road project. In Macedonia, an analysis of the chemical composition of 4 samples of fly ash obtained in REC Bitola was carried out. From the obtained results, it can be concluded that it belongs to the classification of F-class fly ash and with the use of an activator (lime or cement) it can be used in the stabilization of the subgrade.

Carbon Footprint Analysis on Phosphoric Acid Production Using Wet Process at PT Petrokimia Gresik

Phosphoric acid is one of the main commodities in the fertilizer industry, which is very important in agricultural countries such as Indonesia. One of the biggest players in Indonesia’s fertilizer industry is PT Petrokimia Gresik, which owns a phosphoric acid plant that produces 200,000 MT/year phosphoric acid using the hemi-dihydrate process. Phosphoric acid production can be energy intensive and involve a lot of material transport, which usually corresponds with a high carbon footprint. To date, there is no literature regarding carbon footprint of Indonesia’s phosphoric acid. Thus, a carbon footprint analysis was done on phosphoric acid production at PT Petrokimia Gresik based on the inventory from their material and energy balance data. The electricity emission factor was calculated from their coal unit power plant, while the emission factor for raw materials was estimated from literature. The carbon footprint is 1378.25 kg CO2/ton P2O5. The largest carbon footprint contribution comes from sulphuric acid (43.81%), followed by material transport (36.78%). The sensitivity analysis shows that the carbon footprint was very sensitive to sulphuric acid and sea transport emission factor.

Replacing fly ash with a natural pozzolan in normal strength concrete and ultra-high performance concrete

Fly ash is a widely-used supplementary cementitious material (SCM) in concrete. Common reasons for using fly ash in normal strength concrete (NSC) are to reduce cement consumption and mitigate alkali-silica reaction. Additionally, fly ash is being used in ultra-high performance concrete (UHPC) to reduce use of silica fume which is more expensive than fly ash. Fly ash and silica fume are important SCMs in UHPC that provide a dense microstructure, improving UHPC strength and durability. However, fly ash is becoming less available because the energy industry has been investing in renewable energy production and removing coal burning power plants from operation. Therefore, there is a need to identify sustainable SCMs to replace fly ash in NSC and UHPC mixtures. Natural pozzolans are a diverse class of siliceous or siliceous and aluminous materials that can form compounds possessing cementitious properties in the presence of water. Since natural pozzolans are easily mined, they are usually considered to be more sustainable than Portland cement and nearly as sustainable as other SCMs such as fly ash and silica fume. This experimental study evaluated the effects of a natural pozzolan (pumicite) as a potential replacement for fly ash that can produce comparable rheological and mechanical properties in NSC and UHPC mixtures. Results indicated that workability of both NSC and UHPC mixtures containing pumicite was consistent enough to achieve the targeted workability in just a few trials. Additionally, NSC mixtures with 30% pumicite had comparable compressive strength compared to NSC mixtures with 30% fly ash. Modulus of rupture (MOR) for NSC mixtures containing 30% pumicite (greater than 4.10 MPa) exceeded the MOR for specimens containing 30% fly ash. For UHPC mixtures, results showed that up to 75% of the fly ash in the control mixture could be replaced with pumicite while still producing acceptable compressive and flexural strengths. Based on these results, it appears that pumicite can be a reliable alternative for fly ash in NSC and UHPC mixtures in terms of rheological and mechanical properties.

Power Generation at Low Temperatures Using Thermoelectric Generators and Cost Analysis

Interest in thermoelectric generators (TEGs) for waste heat recovery (WHR) and geothermal energy has grown significantly in recent years due to the ability to convert low‐grade thermal energy into electricity, which is essential to reduce carbon emissions. One of the main challenges in TEG power generation is the expandability and the number of layers in TEG devices. The currently reported maximum number of layers is six. In this study, the expandable TEG devices with different number of layers, up to 20, were designed and manufactured. The field tests have been then conducted with these TEG devices using the waste heat from a coal bed methane power plant at a temperature of around 80°C. To our best knowledge, this is the lowest temperature at which TEG field tests have been implemented. At a flow rate of about 3 m3/hr, a TEG unit with a volume of about 3 m3 can generate a power of 15 kW at a temperature difference of 60°C. The power density and power per unit area of the TEG are investigated and compared to those of diesel generators and photovoltaic panels at different temperature differences. Furthermore, to offer guidance for the commercial‐scale implementation of TEG, we have estimated the fabrication and installation costs, as well as the levelized cost of electricity, across various temperature differences. The results indicate that TEG is a feasible and promising technology for large‐scale power generation and WHR.

Energy and Exergy Analyses of Supercritical Coal‐Fired Power Plant With Single Reheat and Regenerative

This paper investigates energy and exergy analyses of 660 MW capacity supercritical coal power plant with single reheat and regenerative. The fuel utilized in the plant is a combination of sub‐bituminous and lignite coal. It is found that the turbine section of the system exhibits the highest energy efficiency (around 94.17%) and exergy efficiency (around 90.73%). Also, 82.07% of the total exergy destruction is found for the boiler, and the remaining 17.93% of the irreversibility is determined for the turbine, condenser, and other components. The overall cycle energy efficiency at maximum load is computed as 40.77%, while the overall cycle exergy efficiency at maximum load is found to be 39.69%. These findings provide valuable insights into the performance of the power plant and suggest the improvements needed in performance enhancement of the boiler.

Techno-Economic Study on the Application of Reverse Osmosis Technology in the Process of Boiler Feed Water Demineralization PT Puncak Jaya Power 3x65 MW

The quality of boiler feed water in a Coal Power Plant generation (PLTU) needs to be considered to avoid corrosion and deposits (scale) on process equipment. Decreased water quality causes several disturbances as such disruption of power plant operations and also regeneration of the ion exchange unit is required quite frequently. This study aims to evaluate the performance of boiler feed water demineralization system with the addition of RO unit and the effect of implementing RO system on chemical consumption in demineralizer regeneration process, as well as determine long-term economic benefits. The research was conducted in the demineralization building area of PLTU PT Puncak Jaya Power 3x65 MW, a power plant owned by PT Freeport Indonesia, located in Amamapare Village, Timika, Papua. This research is divided into two phases: technical evaluation based on research data that will be optimized using the Water Application Value Engine® (WAVE) software, and economic evaluation. Good results are obtained by adding an RO unit to the boiler feed water demineralization unit. Its application allows reducing operating costs and implementing higher level water treatment automation. The chosen RO module configuration is 2 stages with 6 vessels, offering several advantages: % recovery = 70%, high average flux = 22.5 Liters/m2/hour, longer membrane life with the additional filter, reduced load in the first stage. The results of the economic evaluation indicate that the reduction in chemical consumption for ion exchange regenerant will yield 218% return on investment (ROI) with an amortization period of two years.

Supercritical CO2 power cycle

The article is focused on summarizing the issue of energy circuits working with supercritical carbon dioxide sCO2. Carbon dioxide is currently coming to the forefront of many research institutions with regard to its possible use in its supercritical conditions, thanks to which higher efficiency and compactness of equipment can be achieved compared to conventional steam-water cycles. The article describes the basic properties of this medium, including a description of sCO2 cycles (Brayton, Rankine, etc.). Furthermore, the possible use of energy cycles with sCO2 is discussed, especially in solar and nuclear power plants and in power plants burning fossil fuels. In the case of solar power plants, the sCO2 Brayton cycle can offer higher cycle efficiencies than using super-critical steam cycles. The use of sCO2 in nuclear or coal power plants in turn increases efficiency and reduces water consumption. In addition, the use of the sCO2 circuit in new nuclear reactors of the IV generation is currently being considered, in which the operating temperatures are in the range of 500 - 900 °C, i.e. they are generally higher than operating water-cooled reactors. Even though the use of CO2 refrigerant in power systems has been known for a long time (e.g. use in the first Czechoslovak power plant in Jaslovské Bohunice), they are still not used commercially in the energy industry. One of the reasons is the ongoing research into the behavior of materials at high temperatures in sCO2, corrosion protection, or the effect of carbon dioxide purity on behavior in the supercritical region.

Possible Options for Utilization of EU Biomass Waste: Pyrolysis Char, Calorific Value and Ash Content.

The application of biomass as a co-feed in coal power plants and in standalone biomass power plants, as well as in char production for soil remediation, is a currently important issue. This paper reports on the investigation of biochar formation from agricultural waste crops that are used for soil upgrading, but which do not meet the standards of EU crops, as well as largescale food processing waste. These were compared to test results from basket willow, which is commonly used for energy generation. Food industry waste is often produced in cities on a large scale and is generally easier to process due to lack of other stream components. The key parameters, namely, the content of volatiles, energy content of the formed biochar and the composition of the ash, were determined for a number of herbaceous materials locally available in the European Union. All of them can be used as a cheap source of biochar. A novel procedure of capturing volatiles and hence minimizing the PAH content in the biochar, as well as enabling the recovery of energy from the volatiles is presented. Knowledge of the composition and form of elements in ash is very important for designing ash management systems if co-combustion is implemented. The aim of this study was to determine if the types of biomass are better suited for biochar production or energy generation.

Investigation of Seismic Behaviour of a Construction of a Conveyor Line in a Coal Power Plant

The conveyor line that carries raw materials from storage area to inside of a facility is the main vessel of a coal power plant. Therefore, this critical line should be designed by considering the many loads likely to be exposed in the field in order for the plant to operate uninterruptedly. In this study, seismic behaviour of a construction of a conveyor line was investigated by using Finite Element Analysis. The structure of coal carrier conveyor line of a coal power plant, operating in Adana, Türkiye was considered as a case study. In the study, the parts of the conveyor line were modelled as 1-D. The modified acceleration history of Golcuk-1999 earthquake was applied on the structure on lateral direction. The results showed that the maximum stress is slightly higher than the elastic limit of the steel and less than the ultimate strength. Although the construction of the conveyor line withstands the applied loads, modification should be carried out to prevent the damage on the construction.

A novel solar tower assisted pulverized coal power system considering solar energy cascade utilization: Performance analysis and multi-objective optimization

Solar-assisted pulverized coal power systems offer higher solar energy utilization efficiency, enabling pulverized coal power plants to rapidly achieve energy-saving and emission-reduction targets. This study proposes the incorporation of two solar heaters to create a new solar tower assisted pulverized coal power (STPCP) system for the cascade utilization of solar energy. A comprehensive performance analysis, considering both power-boosting (PB) and fuel-saving (FS) operation modes, has been conducted. The multi-objective particle swarm optimization method is then applied to optimize the system from both thermal and economic perspectives. The findings demonstrate that in FS mode, annual coal consumption decreases by 24.35 × 103 tons, while in PB mode, annual power generation increases by 94.12 GWh. The optimization analysis demonstrates that the optimal cost of electricity (COE) and annual standard coal consumption rate in PB mode are 1.4 × 10−4 USD/kWh and 4.3 g/kWh lower than those in FS mode. Additionally, as the solar field cost declines, the optimal COE and annual standard coal consumption rate gradually decrease. While, increasing coal prices result in higher optimal COE, but lower optimal annual standard coal consumption rate. Based on this study, it can be inferred that the STPCP system shows promising prospects in the future.

Design and Multiobjective Dynamic Optimization of Superheaters for Load-Following Operation in Pulverized Coal Power Plants.

Pulverized coal power plants are increasingly participating in aggressive load-following markets, therefore necessitating the design and optimization of primary superheaters for flexible operations. These superheaters play a critical role in maintaining the final steam temperature of the steam turbine, but their high operating temperatures and pressures make them prone to failure. This study focuses on the optimal design of future-generation primary superheaters for a fast load-following operation. To achieve this, a detailed first-principles model of a primary superheater is developed along with submodels for stress and fatigue damage. Two single-objective optimization problems are solved: one for minimizing metal mass as a measure of capital cost and another for minimizing pressure drop on the steam side as a measure of operating cost. Since these objective functions conflict, a multiobjective optimization problem is executed using a weighted metric methodology. Results from these optimization studies show that the base case design can violate stress constraints during the aggressive load-following operation. However, by optimizing the design variables, it is possible to not only satisfy tight stress constraints but also achieve the desired number of allowable cycles and adhere to the steam outlet temperature constraint. In addition, the optimized design reduces either the metal mass or the steam-side pressure drop compared to that of the base case design. Importantly, this approach is not limited to primary superheaters alone but can also be applied to similar high-temperature heat exchangers in other applications.

Can China's regional carbon market pilots improve power plants' energy efficiency?

Power plants are facing huge climate change and policy risks. This paper identifies the effect of China's carbon emissions trading system (ETS) on plants' energy efficiency. For this purpose, we use a two-step approach. In the first stage, we apply a Meta-frontier Stochastic Frontier Analysis (MSFA) method to estimate the total-factor energy efficiency of China's large coal power plants. In the second stage, we use a bootstrapped truncated difference-in-differences (BT-DID) estimator to investigate the ETS' impact on power plants. Results show that the ETS trading policy significantly improves participating plants' energy efficiency by 0.043, compared to non-ETS plants, while the announcement policy doesn't. Besides, several other methods are introduced to solve the potential autocorrelation and heteroskedasticity problems in the second-stage regression. Further, we unveil that the trading policy improves plants' energy efficiency by reducing coal consumption without affecting power generation. Finally, the heterogeneity analysis proves that China Southern Power Grid, local plants, and plants with high carbon prices benefit more from ETS.

A breath of fresh air: Coal power plant closures and health in China

This study provides the first causal evaluation of the impact of coal power plant closures on health in China using nationally representative survey data. Based on the linkage between the staggered shutdowns of 13 coal power plants between 2000 and 2015 and the China Health and Nutrition Survey (CHNS) data, we adopt the new event study approach by Sun and Abraham (2021) to compare changes in overall health statuses for residents living downwind of coal power plants (treated) with those living upwind (control), before and after plant closures. We find that incidences of sickness are reduced by 7 percentage points or 0.2 standard deviations 5–9 years after the closure. The result is robust to a host of robustness checks. Further analyses reveal that the health benefits are concentrated on older adults, rural areas, and historically low pollution regions. By considering several potential channels, we find that plant shutdowns have decreased incidences of overweight and hypertension, increased physical activity levels, and generated a wealth effect resulting from increased housing prices.

Blue Coal Power Plants for India's Net Zero Targets - A Solution for Affordable, Reliable and Sustainable Power

Blue Coal Power Plants for India's Net Zero Targets - A Solution for Affordable, Reliable and Sustainable Power

Comparative assessment of energy efficiency indicators of a multi-fuel internal combustion vehicle and an electric vehicle

In the current discussions on the future of the automotive industry, two extreme opinions clash: electromobility or vehicles with conventional drive but powered by alternative fuels. The article discusses the issue related to modeling the energy efficiency factors of a combustion engine operating on three types of fuels (Diesel 100%, Biofuel 100%, and Hemp Oil 100%) as well as an electric drive powered by energy from a coal power plant. Analytical research was conducted based on the external characteristics of the engine's performance. The external characteristic of the Fiat Panda 1.3 JTD combustion engine was obtained on the Automex dynamometer. The engine operated on three fuels: Diesel 100%, Biofuel 100% (rapeseed), and Biofuel 100% (hemp oil). The Nissan Leaf vehicle manufacturer provided the external characteristics of the electric engine. The calculation results showed that the combustion engine consumes less energy at lower speeds than the electric one. At higher speeds, the consumption rates are at a similar level. The recipients of the research are both the demand side – that is, vehicle users, as well as future manufacturers and government institutions responsible for shaping and developing future mobility in the field of individual transport.

Effect of Coal Ash Enriched Compost on Soil Chemical Properties of Ultisols

Ultisols are soils that develop in humid tropical areas and are formed due to an intensive leaching process, resulting in the accumulation of clay in the subsoil. A decrease in the chemical-physical properties of Ultisols, such as a decrease in the levels of organic C, total N, cation exchange capacity (CEC), base saturation, and on the other hand, an increase in Al saturation and soil bulk density, can occur as a result of continuous monoculture cultivation. Improving the quality of degraded soil is usually carried out by amelioration using compost. Still, the addition of compost often only has a significant effect on improving the physical properties of the soil. Coal ash in the form of fly ash-bottom ash (FABA) is a waste product from burning coal in electric steam power plants. The amount of FABA is very abundant and its utilization is minimal. FABA has an alkaline pH and contains various nutrients in varying amounts. Therefore FABA has the potential to be used as an ameliorant to improve the chemical properties of acid soils such as Ultisols. Experiments with the spread technique of compost+FABA at a dose of 50 tons/ha and in rows technique at a dose of 25 tons/ha, 15 tons/ha, and 5 tons/ha were conducted to determine the effect of the treatment on soil chemical properties. Application of FABA-enriched compost in rows technique at a dose of 25 tons/ha had a significant effect and showed the best soil chemical properties, including increasing organic C, total N, total P, available P, exch-K, -Ca, -Mg, and -Na, CEC, base saturation, and decreased Al saturation. Utilization of FABA as a soil ameliorant combined with compost can improve soil quality more effectively.

Costs and benefits of reducing air pollutant emissions as a result of bringing coal and lignite-fired power plants into compliance with BAT LCP conclusions

Abstract The analysis carried out regarding the costs of adapting to the best available technique (BAT) conclusions in relation to the benefits achieved (external costs) showed that these benefits significantly exceed the cost of investments necessary to meet the required levels of permissible best available technique-associated emission levels (BAT-AELs). In the case of sulfur dioxide, the ratio of costs incurred to benefits obtained is only 3%, for nitrogen oxides 7%, and for dust it is less than 1%. This is primarily due to a significant increase in external costs, published in 2021 by the EEA. Nevertheless, it should be remembered that a precise assessment of external costs should be based on the analyses of individual facilities, taking into account their local specificity. The analysis showed that the most cost-effective way was to adapt the coal-fired power plant sector to the requirements related to reducing dust emissions. Significant benefits were achieved as a result of small investment outlays.

Comparative assessment of the environmental impact of nuclear power plant technology using life cycle assessment approach: A review

Nuclear power plants (NPP) are being considered as an alternative energy that could reducing greenhouse gas emissions. However, there are various challenges that need to be addressed regarding the variation of current nuclear technology such as environmental impact issues. To ensure the sustainability and effectiveness of nuclear power plants technology, a Life Cycle Assessment (LCA) approach can be used to study the environmental impacts of the nuclear power plant. LCA is a method for evaluating the environmental impact of a product or process from start to finish. By conducting a preliminary LCA study of each Nuclear Power Plant technologies, the environmental impacts of the stages of construction, operation, and management of radioactive waste can be understood. This study can also help compare the environmental impacts of nuclear power plants with other energy technologies. This preliminary study will review the environmental impact from pressurized water reactor, boiling water reactor, molten salt reactor, and compare with conventional coal power plant to provide compact summary of the technology. The results of the LCA study can help identify areas that require more attention in the development of nuclear power plants in Indonesia.