Coal-based Power Stations Research Articles

Comparative study of micro - nutrients of lignite flyash and cowdung using Lampito mauritii and Perionyx excavatus earthworms

Lignite flyash is one of the major solid waste products coal based thermal power stations of India. In these waste used in cement industries, cement bricks industries, civil construction work and agricultural fields etc. The environmental problems generated by large-scale production of flyash in coal based power stations. This waste alternative using vermicomposting of flyash as good sources of nutrients. The availability of many nutrients is very low in flyash; available ranges of such nutrients must to be increase the effectiveness of cowdund and flyash as a soil amendment. In our experiment, we assessed the possibility of increasing total iron content (mg/Kg), total copper content (mg/Kg), total manganese (mg/Kg), total zinc (mg/Kg) and C/N ratio micronutrients in flyash through vermicomposting. Cowdung and fly ash was mixed with different trios at 1:1, 2:1, and 3:1 ratios (weight by weight). After the findings the 3:1 cow dung fly ash was the suitable combination for earthworm activity, the freshly acclamatized earthworms were inoculated in 15 gms/kg for Lampito mauritii for 10 -50 days. The concentration of above said micronutrient was found to increase in the earthworm-treated samples of cowdung and flyash combinations compared with the control flyash alone. The worm worked composts (vermicomposts) and worm unworked composts (control) considerable amounts of total iron, total copper, total manganese, total zinc and reduction of C/N ratio micronutrients from cowdung flyash into more soluble forms and thus resulted in increased the nutrients in the vermicompost. Among different combinations of cowdung and flyash, nutrient availability was significantly higher in the 3:1 cowdung to flyash treatment compared with the other treatments.

Numerical modelling of the coal phase-out through ammonia and biomass co-firing in a pilot-scale fluidized bed reactor

The co-firing of ammonia (NH3) with coal has raised awareness, boosting NH3 research and development on its use and deployment as a sustainable fuel. Recent advancements point towards the co-firing of coal with biomass and NH3 as a state-of-art strategy to phase-out coal from coal-based power stations. The implementation of NH3 to the coal-biomass fuel mix allows not only to decarbonize coal-fired processes but also reduces biomass exploration costs to avoid feedstock availability disruption while increasing the power station production efficiency. Moreover, such a strategy brings an alternative player into the environmentally friendly power mix portfolio, accelerating the coal phase-out from electricity production. However, the use of NH3 for power generation still presents some research gaps. Thus, this study delivers a 2D Eulerian-Lagrangian numerical model to describe the co-firing of coal with biomass and NH3 in a pilot-scale fluidized bed reactor. The numerical model is validated against experimental data on coal and biomass combustion to assess the model's accuracy. The coal, biomass, and NH3 co-firing ratios are varied to the point where coal is gradually reduced from the fuel mix, and its effect on the combustion processes is broadly investigated to determine the biomass and NH3 impact on the reactor's emissions. Overall, the use of both biomass and NH3 showed to broadly reduce carbon and NO emissions from coal-fired energy systems, emphasizing the potential addressed to biomass as an alternative to coal and NH3 as an effective carbon-neutral fuel of the future.

Equilibrium Optimizer: Insights, Balance, Diversity for Renewable Energy Resources Based Optimal Power Flow with Multiple Scenarios

ABSTRACT Today, along with renewable energy sources such as wind generation units and solar photovoltaic systems, the power grid consists of traditional generating units. An approach for solving single-objective optimal power flow problems with the combination of renewable energy resources (RER-OPF) solar and wind power with conventional coal-based power stations is recommended in the proposed paper. In the proposed work, functions of lognormal and Weibull probability distribution are used, respectively, to forecast solar and wind outcomes. The objective feature includes the underestimation service charge and the standby charge for overestimating unusual non-conventional power generation. The quantitative and comparative results show that Equilibrium optimizer (EO) outperforms compare to Harris Hawks Optimizer (HHO), Grey Wolf Optimizer (GWO), Ions Motion Optimizer (IMO) and Success-History based Adaptive Differential Evolution (SHADE), which are all well-known optimization algorithms for solving RER-OPF problem. The EO optimizer provides the optimum value of each objective function and has merits in solving IEEE-30 bus-based RER-OPF problem, according to several evaluation criteria such as best value statistical criterion.

Evaluation of Coal Bottom Ash Properties and Its Applicability as Engineering Material

Coal ash is obtained in the combustion of coal for electricity production in coal based power stations. The non-combustible by-product including bottom ash and fly ash are discarded as a landfill. Consequently, the hazardous elements contained in the ashes can adulterate the ground and surface water. This study was carried out to emphasize the engineering properties of bottom ash collected at Tanjung Bin power station. An experimental study was carried out for particle size analysis, specific gravity, shear strength, compaction and relative density. The results depict that bottom ash possess particle size distribution nearly identical to sand, low specific gravity and dry density as compared to natural soil and having higher internal friction angle closer to granular materials. Based on the results, bottom ash can be employed in roadways, embankments and filling material for retaining walls by virtue of its low specific gravity, easy to compact and good frictional characteristics.

Promising utilization of fly ash as an eco-friendly sustainable additive for enhancement in flame retardancy of composite production: A review

Fly ash as one of the industrial by-product generated from the coal-based power station will eventually recognized as an environmental pollutant due to their enrichment in potentially toxic trace elements. Hundreds of thousand tons of fly ash every year exist alone were expected from the growth in power plants that use coal as the source of fuel. The present waste is widely been used in concrete industries to replace the usage of cement which is can minimize carbon dioxide footprint, but most will go straightly to the landfill or dump that will be one of the significant matter in environmental concerns and also will soon to be costly due to long term financial burden of maintenance. An economically viable solution to this problem has been proposed by utilization of fly ash as reinforcement in polymer matrix based composite production focusing on construction industry. Several studies proposed that fly ash has great potential as flame retardant in order to develop fire proof products even though not been much examined. This paper will emphasize on reviewing about properties of fly ash with its possible composition and characteristic that can help in fire controlling.

Deposition of mullite in peatlands of southern Poland: Implications for recording large-scale industrial processes

Mullite, a pure aluminosilicate (Al6Si2O13), is a rare natural rock component, known for centuries as a very resistant ceramic material. It is also a common waste product of high-temperature coal combustion that is emitted in quantity from coal-based power stations. The occurrence of mullite in two Sphagnum-dominated peatlands located near the Upper Silesia industrial region in southern Poland is described. For the first time, a complete record of mullite deposition in the peat profiles has been obtained by XRD analyses of ashed peat samples. The mullite distribution is compared with records of Hg, Pb and Cu. While mullite is supplied during high temperature processes only, Cu, Pb and Hg show more complex pattern of distribution. Both peat profiles contain elevated amounts of mullite in the time span between ca 1950–1990 with a maximum content in ca 1980. The first appearance (∼1900) of mullite is indicative of the beginning of energy production in coal-based power plants in the region. Mullite is proposed here as an indicator of industrialization in geological records. It is resistant to post-depositional processes, emitted globally, and restricted to large-scale industry.

Potassium Carbonate Slurry-Based CO2 Capture Technology

Carbonate slurry process is considered to be one of the potential technologies for large-scale CO2 capture from coal-based power stations, as it can reduce the participation of water in stripper. In this work, constant volume method was adopted to measure the CO2 loading in aqueous potassium carbonate solutions at the temperatures of 40, 70, and 120 °C for CO2 partial pressure from 0.4 to 240 kPa. Absorption heats of CO2 in aqueous solutions of K2CO3, MEA, and MDEA were measured and compared using true heat flow method. The cyclic CO2 equilibrium loading increases with K2CO3 concentration increase, which is a benefit for CO2 capture. However, the increased viscosity leads to a decrease of the apparent absorption rate. Absorption heat depends on temperature, K2CO3 concentration, and CO2 loading. Compared to MEA, potassium carbonate solution has a lower absorption heat. Generated potassium bicarbonate crystallization can enhance CO2 absorption but also increase absorption heat. Slurry desorption can reduce ...

Life cycle assessment of sewage sludge co-incineration in a coal-based power station

A life cycle assessment was conducted to evaluate the environmental and economic effects of sewage sludge co-incineration in a coal-fired power plant. The general approach employed by a coal-fired power plant was also assessed as control. Sewage sludge co-incineration technology causes greater environmental burden than does coal-based energy production technology because of the additional electricity consumption and wastewater treatment required for the pretreatment of sewage sludge, direct emissions from sludge incineration, and incinerated ash disposal processes. However, sewage sludge co-incineration presents higher economic benefits because of electricity subsidies and the income generating potential of sludge. Environmental assessment results indicate that sewage sludge co-incineration is unsuitable for mitigating the increasing pressure brought on by sewage sludge pollution. Reducing the overall environmental effect of sludge co-incineration power stations necessitates increasing net coal consumption efficiency, incinerated ash reuse rate, dedust system efficiency, and sludge water content rate.

Feasibility Study of RNPP (Rooppur Nuclear Power Project) in Bangladesh

Bangladesh is densely populated country with a population of 16 core and small area about 1, 47,570 Square-Kilometer. Among these large population only a few section are taking the blessings of power. But now at a stage government can’t give the power even to that special section. Because day by day population is increasing and also power demands is also increasing. Governments are trying to meet up the power crisis in Bangladesh by taking various steps. Like small (10-20MW) power plants, IPP, Rental power plant etc. But these are not a permanent solution. More over these rental and IPP are mainly oil and gas based, which are very costly and not very efficient. Besides these government are going with coal based power station and small scale renewable energy. But coal based power station are required very large space, its initial cost is high and create serious environmental threat. Renewable energy is not yet developed and its efficiency is very poor. Though there are many problems and threats but Nuclear Power Plant can be a permanent solution for Bangladesh. Bangladesh government is now going for nuclear power plant and recently they have taken a project called Rooppur Nuclear Power Plant Project (RNPP) which is already approved in the cabinet meeting. The purpose of this paper is to study the feasibility of RNPP.

Consideration of Environmental Effect of Power Generation: Bangladesh Perspective

Nowadays for power generation, environment is a major consideration. The heart of power generation is power station. At present there are almost above 40(Both Government & Rental) power station in Bangladesh. Among these 80% of power station is gas based. Rest of the 20% is coal, liquid and furnace oil based. Bangladesh has only one Hydraulic power station. These gas and coal based power stations are giving adverse effect in Bangladesh. The main emissions from coal combustion at thermal power plants are carbon dioxide (CO), nitrogen oxides (NO), sulfur oxides (SO), chlorofluorocarbons (CFCs), and air- borne inorganic particles such as fly ash, soot, and other trace gas species. Carbon dioxide, methane, and chlorofluorocarbons are greenhouse gases. These emissions are considered to be responsible for heating up the atmosphere, producing a harmful global environment. It is known to all that hydro power station is a clean source of energy, but it has also some ecological and environmental effect. Dhaka is one of the top polluted city in the world. So for power generation if the environmental effect is not considered then Bangladesh will be in great trouble. The purpose of this paper is to discuss the present and future possible environmental effect of power generation in Bangladesh.

Formulation, application and evaluation of a stack emission model for coal-based power stations

Estimation of coal power plant emissions is a vital step to visualise emission trends with respect to specific policy implementations and technological interventions so that their effectiveness in terms of emission reductions and ambient air quality improvement can be quantitatively assessed. However, research work concerning stack emission estimations specifically for coal power plants in India is limited. To bridge the present gap, we present a plant-specific multi-year and multi-parameter Coal Power Stack Emission Model. This model has been developed to explore current and historical annual stack emissions from a coal-based thermal power plant taking into account essential variables such as coal characteristics, process attributes and control equipment aspects, which can significantly influence the stack emissions. This study concentrates on development of Coal Power Stack Emission model and its application for the estimation of plant and year-specific emission factors and stack emissions for a coal-based power plant at Badarpur, New Delhi, for the period of 2000–2008. The validation of Coal Power Stack Emission model has also been successfully carried out by comparing the trends of percentage change in annual emission estimates and observed ambient air concentrations of total suspended particles, PM10 and sulphur dioxide at two nearby air quality monitoring stations, namely Siri Fort and Nizamuddin.

Evaluating the impact of consumer behaviour on the performance of domestic solar water heating systems in South Africa

South Africa experienced a rapid expansion in the electric power consumer base after 1994 that was not matched by corresponding investment in the country’s generation capacity. By the dawn of 2008, the situation had reached a critical point, with regular countrywide blackouts and load shedding and is expected to persist for several years, before the proposed new base stations can come online. Currently, 92% of the country’s electricity is generated in coal-based power stations and are responsible for the country’s heavy carbon footprint. Additionally this power must crisscross the country to distant load centres via an aging transmission infrastructure and in the process massive amounts of energy are lost particularly during peak power demand. Electricity consumption in South African households accounts for approximately 35% of peak demand, with water heating constituting 40% of that. The country has abundant sunshine and solar water heating technology and offers one of the most viable compiementary solutions to the country’s energy and environmental crises. Moreover the location of the systems at the consumer end means that the need to upgrade the transmission infrastructure can also be differed.Application of technology alone however, may not necessarily result in the required energy savings particularly in cases of uninformed consumer usage. In this paper the authors evaluate the impact of consumer behaviour on the performance of domestic solar water heaters in South Africa and suggest measures that could be taken to optimize this performance.

An integrated approach for the consideration of uncertainty in decision making supported by Life Cycle Assessment

This paper presents an approach for the integrated consideration of both technical and valuation uncertainties during decision making supported by environmental performance information based on Life Cycle Assessment (LCA). Key elements of this approach include “distinguishability analysis” to determine whether the uncertainty in the performance information is likely to make it impossible to distinguish between the activities under consideration, and the use of a multivariate statistical analysis approach, called principal components analysis (PCA), which facilitates the rapid analysis of large numbers of parallel sets of results, and enables the identification of choices that lead to similar and/or opposite evaluations of activities. The integrated approach for the management of uncertainty is demonstrated for a technology selection decision for the recommissioning of a coal-based power station. The results of the case study decision suggest that stakeholder involvement in preference modelling is important, and that the “encoding” of value judgements and preferences into LCA environmental performance information is to be avoided. The approach presented in this paper provides a foundation for the consideration of the implications of diversity in values and preferences as part of an overall approach to promote effective decision making based on LCA environmental performance information. However, the approach is more universally applicable – it can be used wherever multiple criteria decision analysis is used to assist in the resolution of complex decision situations.

Mounting fly ash problems in growing coal based power stations — few pragmatic approaches towards a solution

Mounting fly ash problems in growing coal based power stations — few pragmatic approaches towards a solution

Remediation of ash problems in pulverised coal-fired boilers

This paper reports the control methods for mitigating fouling and slagging in brown coal-fired power utilities. Two control methods were investigated, i.e. wet pretreatment of coal and the use of mineral additives. By the first technique, samples of brown coal were treated with aluminium solutions to adjust the levels of Na, Al and Cl. The effect of cleaning was tested under closely controlled conditions in the range of 1000–1400°C. At a gas temperature of 1250°C, the deposition behaviour of treated and raw coals were compared using a deposition probe maintained at temperatures of 500, 600, 700 and 800°C. The second technique involved experiments with mixtures of candidate mineral additives and sodium compounds at temperatures ranging from 1000 to 1400°C.Experiments showed that both the methods were effective in reducing ash-related problems. Between 1000 and 1400°C, the quantity of condensable salts generated was found to depend only on the amount of sodium in coal. With the wet method, aluminium reduces the sodium level and thus fouling by ion exchange. The stickiness of sodium silicates from this coal was also shown to be reduced by aluminium. Deposition model calculations based on sticking probability also indicated that Al-treated coals result in less ash deposition on boiler surfaces. Experiments with mineral additives showed that sodium could be captured by clay minerals, particularly kaolin. For Victorian brown coal-based power station boilers, 10–20μm kaolin making up 2–3wt.% of the feed was estimated to effectively reduce the ash problems.

Status of environment in Chotanagpur-Santal Pargana region of Jharkhand

The Chotanagpur-Santal Pargana (CSP), the ‘Ruhr of India’ has been the cradle of mineral exploitation and mineral based industries since the dawn of 20th century. The post-Independence era witnessed a rapid growth in heavy industries and subsequent urbanisation. To cater the energy need, coal based power stations were installed in Damodar valley. Such economic ventures were concentrated mainly in the Damodar and Subernarekha river valleys. These anthropogenic activities triggered a series of environmental degradation. Large scale deforestation led to wide spread soil erosion due to which loss of valuable topsoil and lowering of water table has taken place. The preference for open cast mining practice for more mineral exploitation especially coal, iron ore and bauxite has further aggravated the problem in this fragile eco-system. The discharge of large volume of untreated or semi-treated industrial effluents has literally turned the river Damodar into an “industrial effluent channel.’ Besides being unethical and inhumane, these acts are a gross violation of environmental laws. Ironically, the major culprit industries are public sector undertakings. Even the highly polluted ambient air in the mining and associated industrial areas, especially in the Damodar valley has made the region a virtual gas chamber gradually pushing the local populace towards ‘extinction’. The vast surface water resources are trapped or are in a process to be trapped leading to submergence of large agricultural and forest area and displacement of local inhabitants which are mostly tribals. Almost all such act of ‘development’ has led to delinking of tribals from their root as well as distortion of socio-cultural fabric.

99/01595 The effects of coal based power stations on the environment in Turkey : Asmatulu, R. et al. Spec. Publ. R. Soc. Chem., 1998, 217, 5–15

99/01595 The effects of coal based power stations on the environment in Turkey : Asmatulu, R. et al. Spec. Publ. R. Soc. Chem., 1998, 217, 5–15

99/00823 Environment and energy generation through coal based power station

This paper presents a simple version of the theory of M-estimation. It is argued that the theory is immediately applicable to almost all estimation schemes employed by econometricians. It is further argued that the great overlooked benefit of the theory is that is provides almost automatic asymptotic results, e.g., probability limits and asymptotic covariances. Thus one need not be a theoretical econometrician to invent and use specially tailored estimators. To illustrate its use the theory is applied to a variety of theoretical and applied problems. Particular attention is paid to two-stage estimators.

Heavy metal distribution between soil aggregate core and surface fractions along gradients of deposition from the atmosphere

This study tests the hypothesis that heavy metals deposited from the atmosphere are bound preferentially to soil aggregate surfaces mainly in forms of higher solubility than in aggregate cores. Soil aggregates (2–20 mm in diameter) were sampled along two gradients of heavy metal deposition from the atmosphere. Near Dornach/Switzerland (DOR) heavy metal deposition originates from a brass foundry, and at the second site near Ziar nad Hronom/Slovakia (ZNH) from the coal-based power station of an aluminum smelter. The soils at the DOR-sites have a neutral to weakly acid soil reaction (pH 6–7), those at the ZNH-sites have an acid soil reaction (pH 3–4). At DOR the 0–20 cm layer and at ZNH the organic layer, A and B horizons of three soils with decreasing depositional burden, were sampled. Aggregates were divided mechanically into core and surface fractions. We sequentially extracted seven fractions of Cd, Cu, Zn (DOR and ZNH) and Ni (ZNH) from both aggregate fractions. At DOR the higher the depositional burden, the more pronounced is the enrichment of heavy metals in the aggregate surface compared with the core fractions. At the acid ZNH-sites preferential leaching of heavy metals from the aggregate surfaces dominates, resulting in depletions of Cd>Ni>Zn>Cu in the aggregate surface compared with the core fractions according to the different element mobilities. The preferential leaching is, however, compensated in part by preferential sorption of deposited heavy metals at aggregate surfaces. Thus, the higher the depositional burden, the less pronounced is the depletion. Generally, at both locations greater proportions of the total metal concentrations were found in the bioavailable metal fractions in the aggregate surface than in the core fractions. This indicates that deposited metals are mainly bound in forms of higher solubility. From these results implications for the availability of deposited heavy metals to plants and for leaching may arise.

Recent climatic change, greenhouse gas emissions and future climate: The implications for India

In this paper, we discuss past climatic trends over India, greenhouse gas emissions due to energy consumption, forest and land-use changes, climate change scenarios for the year 2050, potential consequences for agriculture and cyclone activity and the possibility that India might limit the increasing trend in its emissions. India's mean surface air temperature has increased significantly by about 0.4°C over the past ccntury. Neither monsoon nor annual rainfall shows any significant trend. On average, there has been a rise in sea levels around India over recent decades, though considerable uncertainties exist in the accuracy and interpretation of the available data. Carbon emissions from the energy sector amount to 71 MT a year, equivalent to all other sectors combined. From land-use data, a marginal net sequestration of 5.25 million tonnes of carbon occurred during 1986. Following the IPCC guidelines, methane emissions from rice and livestock are estimated at 17.4 and 12.8 Tg/year, respectively. According to recent climate model projections, India may experience a further rise in temperature of 1 °C by the year 2050, about four times the rate of warming experienced over the past 100 years. A modest increase in precipitation amounts might occur. Cereals production is estimated to decrease and the nutrition security of the population-rich but land-hungry region of India might be hampered. An increase in local tropical cyclone activity may occur over thc next century, posing added problems as large areas in the coastal regions have a dense population. About 70% of the electricity generation in India is from coal-based power stations. Altering this dependence significantly to reduce emissions would imply a substantial change in the present energy policy of India. There is great potential for improving energy efficiency and conservation. The adoption of cleaner coal-technologies should be considered, as must the development of renewable, non-conventional energy sources. In all cases, serious institulional barriers and resource limitations need to be addressed. The scope for carbon sequestration is limiled by land availabilily and other factors. It is argued that any response to global warming must be located firmly in the framework of sustainable development.