scholarly journals Cyclone furnace as a way for mercury removal from lignite

2018 ◽  
Vol 240 ◽  
pp. 05037 ◽  
Author(s):  
Robert Zarzycki ◽  
Michał Wichliński
Keyword(s):  
Heat Treatment ◽  
Numerical Modelling ◽  
Power Plants ◽  
Coal Dust ◽  
Mercury Removal ◽  
Hard Coal ◽  
Heating Fuel ◽  
Cyclone Furnace ◽  
Methods Of Operation ◽  
Fuel Stream

The power plants will have to meet the requirements regarding permissible Hg emission levels by 2021. A particularly unfavourable situation is observed for front of lignite, which contains more mercury than hard coal, and in addition its combustion also causes more CO2 emissions. The paper presents the proposal to use the cyclone furnace in the process of heat treatment for the process of the release of mercury from lignites. The structure and methods of operation of the cyclone furnace were presented. The paper also discusses the methodology of the process of numerical modelling of combustion and gasification of coal dust. The results showed that changing a fuel stream fed to the cyclone furnace allows for controlling the temperature and degree of fuel devolatilization. This leads to heating of the fuel to the desired temperature due to the expected level of mercury removal from the fuel. This is very important especially in the case of fuels containing significant amounts of moisture, such as lignite. The experiments performed in the study confirmed the results of numerical calculations for heating fuel and showed the possibility of over 90% removal of mercury from the fuel. The results confirmed the laboratory workplace rotary kiln.

scholarly journals Preliminary assessment of the possibility of mercury removal from hard coal with the use of air concentrating tables

2017 ◽  
Vol 33 (4) ◽  
pp. 125-141 ◽  
Author(s):  
Tadeusz Dziok ◽  
Andrzej Strugała
Keyword(s):  
Organic Matter ◽  
Power Plants ◽  
Mercury Content ◽  
Mercury Removal ◽  
Hard Coal ◽  
Thermal Pretreatment ◽  
Potential Threat ◽  
Clean Coal ◽  
Mercury Emissions ◽  
Inorganic Constituents

Abstract Mercury is characterized by highly toxic properties. The natural biogeochemical cycle of mercury occurs in the environment, which results in the fact that even a small amount of mercury emitted to the environment is a potential threat to human health. The process of coal combustion is one of the main sources of anthropogenic mercury emissions. For this reason, on 31 July 2017 the European Commission has adopted the mercury emission standards for large combustion plants. The issue of mercury emissions is particularly important for Poland. Forecasts concerning energy consumption in Poland show that coal will be the main source for energy production in the coming decades. Therefore, actions enabling the reduction of mercury emissions from coal-fired power plants will have to be implemented. The mercury emissions from coal-fired power plants may be reduced through the application of a number of methods. These methods can be divided into two main groups: the post-combustion methods which allow for mercury removal from flue gases, and the pre-combustion methods which allow for mercury removal from coal before its combustion. The effectiveness of mercury removal from coal is determined by the mode of its occurrence in coal. In the case of mercury occurrence in the adventitious inorganic constituents of coal, high effectiveness will be obtained in the coal cleaning processes. In the case of mercury occurrence in the organic matter as well as in the inherent inorganic constituents of coal, the effectiveness of this method will be low. Mercury could be removed from such coals through the process of thermal pretreatment at the temperature of 200-400°C (mild pyrolysis). In the paper, the possibility of mercury removal from hard coal through the process of dry deshaling on an air concentrating table was examined. Six raw coals (coal feed), clean coals and the rejects derived from their dry deshaling were analyzed. The mercury content was measured in the examined samples. The content of mercury in raw coals and clean coals were compared. Additionally, the effectiveness of mercury removal from coal with rejects was determined. For the analyzed coals, the effectiveness of mercury removal from coal in the process of dry deshaling on an air concentrating table ranged from 9 to 96%. This effectiveness is similar to the effectiveness of mercury removal from coal in the processes of coal washing. It should be mentioned that, when compared to the coal washing processes, the dry deshaling process is characterized by lower investment and operating costs. Therefore, the dry deshaling process on an air concentrating table should be considered as a competitive method for the coal washing processes. There is also a possibility of an increase in the mercury removal efficiency from coal in the process of dry deshaling as a result of the thermal pretreatment of clean coal derived from dry deshaling. This solution is only recommended for coals in which mercury occurs in the organic matter as well as in the inorganic constituents characterized by a relatively low temperature of mercury release.It should be emphasized that the dry deshaling process allowed for a decrease of mercury content is not suitable for every coal. Although for five of the analyzed coals the mercury content in clean coal was lower in the range from 11 to 53%, for one coal the mercury content was higher by 19%. The effect of decreasing the mercury content in coal is more evident when it is related to the amount of energy contained in coal (i.e. for example to the lower heating value). For five of the analyzed coals mercury content expressed in such a way decreased in the range from 11 to 53 %, and for one coal the mercury content was, however, higher. Nevertheless, the difference was not very significant (ca. 5%).

Features of antibodies against benzo[a]pyrene formation in workers of coal mines and thermal power plants

2019 ◽  
pp. 9-14
Author(s):  
Ye. G. Polenok ◽  
S. A. Mun ◽  
L. A. Gordeeva ◽  
A. A. Glushkov ◽  
M. V. Kostyanko ◽  
...  
Keyword(s):  
Power Plant ◽  
Thermal Power Plant ◽  
Power Plants ◽  
Reference Group ◽  
Coal Dust ◽  
Thermal Power ◽  
Coal Mines ◽  
Serum Levels ◽  
Thermal Power Plants ◽  
Immune Reactions

Introduction.Coal dust and coal fi ring products contain large amounts of carcinogenic chemicals (specifically benz[a]pyrene) that are different in influence on workers of coal mines and thermal power plants. Specific immune reactions to benz[a]pyrene therefore in these categories of workers can have specific features.Objective.To reveal features of antibodies specifi c to benz[a]pyrene formation in workers of coal mines and thermal power plants.Materials and methods.The study covered A and G class antibodies against benz[a]pyrene (IgA-Bp and IgG-Bp) in serum of 705 males: 213 donors of Kemerovo blood transfusion center (group 1, reference); 293 miners(group 2) and 199 thermal power plant workers (group 3). Benz[a]pyrene conjugate with bovine serum albumin as an adsorbed antigen was subjected to immune-enzyme assay.Results.IgA-Bp levels in the miners (Me = 2.7) did not differ from those in the reference group (Me = 2.9), but in the thermal power plant workers (Me = 3.7) were reliably higher than those in healthy men and in the miners (p<0.0001). Levels of IgG-Bp in the miners (Me = 5.0) appeared to be lower than those in the reference group (Me = 6.4; (p = 0.05). IgG-Bb level in the thermal power plantworkers (Me = 7.4) exceeded the parameters in the healthy donors and the miners (p<0.0001). Non-industrial factors (age and smoking) appeared tohave no influence on specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers.Conclusions.Specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers are characterized by peculiarities: the miners demonstrate lower levels of class A serum antibodies to benz[a]pyrene; the thermal power plant workers present increased serum levels of class G antibodies to benz[a]pyrene. These peculiarities result from only the occupational features, but do not depend on such factors as age, smoking and length of service at hazardous production. It is expedient to study specific immune reactions to benz[a]pyrene in workers of coal mines and thermal power plants, to evaluate individual oncologic risk and if malignancies occur.

scholarly journals Investigating Theoretical PV Energy Generation Patterns with Their Relation to the Power Load Curve in Poland

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Jakub Jurasz ◽  
Jerzy Mikulik
Keyword(s):  
Energy Consumption ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Daily Basis ◽  
Hard Coal ◽  
The European Union ◽  
Load Curve ◽  
Fuel Feed ◽  
Power Load ◽  
Gross Energy

Polish energy sector is (almost from its origin) dominated by fossil fuel feed power. This situation results from an abundance of relatively cheap coal (hard and lignite). Brown coal due to its nature is the cheapest energy source in Poland. However, hard coal which fuels 60% of polish power plants is picking up on prices and is susceptible to the coal imported from neighboring countries. Forced by the European Union (EU) regulations, Poland is struggling at achieving its goal of reaching 15% of energy consumption from renewable energy sources (RES) by 2020. Over the year 2015, RES covered 11.3% of gross energy consumption but this generation was dominated by solid biomass (over 80%). The aim of this paper was to answer the following research questions: What is the relation of irradiation values to the power load on a yearly and daily basis? and how should photovoltaics (PV) be integrated in the polish power system? Conducted analysis allowed us to state that there exists a negative correlation between power demand and irradiation values on a yearly basis, but this is likely to change in the future. Secondly, on average, daily values of irradiation tend to follow power load curve over the first hours of the day.

scholarly journals The reduction of atmospheric emissions after the implementation of first Polish nuclear power plant

2018 ◽  
Vol 177 ◽  
pp. 01001 ◽  
Author(s):  
Maciej Cholewiński
Keyword(s):  
Power Plant ◽  
Solid Fuel ◽  
Nuclear Power ◽  
Power Plants ◽  
Environmental Benefits ◽  
Combustion Model ◽  
Hard Coal ◽  
Atmospheric Emissions ◽  
Solid Biomass ◽  
Representative Samples

In this work the environmental benefits in the atmospheric emissions after the implementation of 3,000 MW nuclear power plants were assessed and presented. To determine the quantity of avoided emissions of CO2, NOx, SO2 and Hg compounds, harmonised stoichiometric combustion model dedicated to solid fuel fired power plant was created. To increase the credibility of the studies, future strict emission standards (Directive 2010/75/EU, BAT documents for LCP) were included as well. In conducted studies, representative samples of 3 different Polish solid fuels were examined (by comprehensive proximate and ultimate analysis) and used in assessment. It was proven that by the replacement of thermal solid fuel power plant by nuclear unit (with annual production rate of 22.4 TWh net) up to 16.4 million tonnes of lignite, 8.9 million tonnes of hard coal or 13.1 million tonnes of solid biomass can be saved. Further, for the case of lignite, the emission, at least, of 21.29 million tonnes of CO2 (6.9% of all Polish emission in 2015), 1,610 tonnes of dust (0.4%), 16,102 tonnes of NOx (2.2%), 16,102 tonnes of SO2 (2.0%) and 564 kg of mercury (5.9%) can be avoided. For selected hard coal, calculated emission savings were equal to 17.60 million tonnes of CO2 (5.7%), 1,357 tonnes of dust (0.4%), 13,566 tonnes of NOx (1.9%), 13,566 tonnes of SO2 (1.7%), 271 kg of mercury (2.9%), and for biomass - equal to 20.04 million tonnes of CO2 (6.5%), 1,471 tonnes of dust (0.4%), 14,712 tonnes of NOx (2.0%), 14,712 tonnes of SO2 (1.8%) and 294 kg of mercury (3.1%).

scholarly journals Improving the reliability, as well as energy and environmental efficiency of gas cleaning systems at TPP

2019 ◽  
Vol 11 (4) ◽  
pp. 288-293 ◽  
Author(s):  
A. T. Zamalieva ◽  
M. G. Ziganshin
Keyword(s):  
Power Plants ◽  
Stokes Equations ◽  
Coal Dust ◽  
Thermal Power ◽  
Primary Energy ◽  
Navier Stokes ◽  
Thermal Power Plants ◽  
Industrial Emissions ◽  
Gas Treatment ◽  
Gas Cleaning

Energy is the basic sector of the economy and the largest consumer of primary energy resources of any country, which is why the development of world energy is accompanied by global pressure on the environment. The issues are considered of reducing the atmospheric impact of emissions of thermal power plants, improving the reliability and working life of their units, systems, and plants as a whole. The principles are presented of development and improvement of technologies for processing industrial emissions of thermal power plants, the neutralization of which is currently relevant on a regional and global scale. Analysis is carried out of existing methods of cyclone and filtration treatment. An improved design of a cyclone filter is proposed, which allows to increase the reliability of gas turbine and steam-gas units of TPP, while ensuring the efficiency of separation of the suspended part of the flow at the gas treatment point (GTP) of TPP. Similar devices can also be used to increase the degree of cleaning atmospheric emissions released by the TPP coal dust preparation and flue gas systems at coal generation from fi ne particles of PM10 and PM2,5 classes (coal dust and ash), owing to reduction of the size of caught particles from average values for cyclones and wet scrubbers of the order of 5–10 μm to 0.5 μm. The design of the cyclone filter is improved as a result of research of cyclone filtration by methods of Computational Fluid Dynamics (CFD). A system of Reynolds-averaged equations of a single-phase Navier-Stokes flow is used for mathematical modeling of motion in the cyclone filter. To determine the efficiency of separation of the suspended part of the flow in the cyclone filter, the Rercomplex is used obtained by reducing a set comprising the Navier-Stokes equations and the equation of particle motion based on Newton's law to a dimensionless form. Numerical characteristics of the suspension sedimentation from a multiphase flow in a cyclone separator of specified dimensions are found by means of the Rercomplex. The results of bench tests of the proposed design of the cyclone filter are given. 

Physical and numerical modelling of sediment guiding walls in an alpine river

2021 ◽  
Author(s):  
Jakob Siedersleben ◽  
Marco Schuster ◽  
Dennis Ties ◽  
Benjamin Zwick ◽  
Markus Aufleger ◽  
...  
Keyword(s):  
Numerical Model ◽  
Numerical Modelling ◽  
Power Plants ◽  
Sediment Management ◽  
Design Flow ◽  
Scale Model ◽  
Surface Measurement ◽  
Management Options ◽  
Erosion And Deposition ◽  
Alpine River

&lt;p&gt;The presented work is part of the optimization of the sediment management at the hydroelectric powerplants in Reutte/H&amp;#246;fen in Austria. The weirs of the two powerplants are situated at the alpine river Lech, located about 3 km upstream of the Lechaschau gauge (A=1012.2 km&amp;#178;). Totally five sluice gates and a fixed overflow weir are controlling the upstream reservoir, being subjected to high rates of coarse bed load material. In frame of a coupled approach of physical and numerical modelling, different options to (i) avoid/minimize sediment deposition and (ii) allow improved sediment flushing were tested and optimized. Besides a lowering of energy losses (reduced spilling times) the reduction of depositions downstream close to the turbine outlet were considered.&lt;/p&gt;&lt;p&gt;The physical model covers the hydropower and weir system of both power plants within a stretch of 400m / 150m using a model scale of 1:25. Investigated situations covered periods of reservoir sedimentation, flushing of the reservoir and typical flood flow situations (e.g. HQ1 and an unsteady HQ5 event). For model parametrization, sediment samples to quantify size distribution were taken in the field. Sediment inputs to the model were realized dynamically and were required (due to scaling effects) to exclude cohesive fractions having a minimum particle size of 0.5 mm. The full-area surface measurement of the river bed was made by means of airborne laser bathymetry and echo sounding.&lt;/p&gt;&lt;p&gt;As part of an optimization of the overall sediment management strategy, the focus of the presented research is on the western located runoff power plant H&amp;#246;fen. Via a lateral water intake, a maximum design flow of 15&amp;#160;m&amp;#179;/s is withdrawn causing that the intake structure is subjected to sediment depositions. Within the described scale model (1:25) and a partial scale model (1:15) covering the western side, several management options and configurations of sediment guiding walls were tested. Erosion and deposition as well as the transported material are assessed by 3D laser scanning and permanent monitoring of transported sediment load entering and leaving the scale model.&lt;/p&gt;&lt;p&gt;Complementary, a 2D hydro numerical model using a layer based multi fraction approach for sediment transport is set up for an extended area to simulate the morpho-dynamic behavior. The numerical model covers the whole weir system and 750 m of the upstream part of the Lech. The simulations made were realized at nature scale and allowed to mimic the erosion and deposition pattern obtained within the physical modelling for different tested options. Regardless of a chosen guiding wall setup, the results showed that each one is compromise between sediment defense and the effectiveness of the subsequent flushing processes.&lt;/p&gt;

scholarly journals Experimental review of thermal analysis of dissimilar welds of High-Strength Steel

2019 ◽  
Vol 58 (1) ◽  
pp. 38-49 ◽  
Author(s):  
Francois Njock Bayock ◽  
Paul Kah ◽  
Belinga Mvola ◽  
Pavel Layus
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Heat Input ◽  
Power Plants ◽  
Welding Process ◽  
Postweld Heat Treatment ◽  
High Strength ◽  
Dissimilar Welding ◽  
Dissimilar Welds ◽  
Wide Range

Abstract Dissimilar welding offers exiting benefits for a wide range of engineering applications, such as automotive bodies, piping systems of nuclear power plants, health equipment. The main advantages of dissimilarwelding applications areweight reductions, lower costs, unique properties combinations, and improved energy-efficiency. The properties of dissimilar weld depend on the type of welding process used, the accuracy of the process parameters control, the characteristics of the base metal and the heat treatment procedures. The current study reviews the scientific literature on the topic of thermal analysis of dissimilar high-strength steels (HSS) welding. The review of experimental data was carried out to analyze the variable heat input effect on dissimilar welds. The results indicate the welds mechanical properties irregularity and reduction in toughness and tensile strength due to uneven changes in the microstructure. Furthermore, postweld heat treatment (PWHT) often resulted in the formation of intermetallic compounds whose properties are dependent on the duration of treatment. The research results can be used to optimize the heat input of the HSS welding process.

scholarly journals Identification of Mechanical Properties for Titanium Alloy Ti-6Al-4V Produced Using LENS Technology

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 886 ◽  
Author(s):  
Aleksandra Szafrańska ◽  
Anna Antolak-Dudka ◽  
Paweł Baranowski ◽  
Paweł Bogusz ◽  
Dariusz Zasada ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Numerical Modelling ◽  
Optical Measurement ◽  
Electron Backscatter Diffraction ◽  
Material Behavior ◽  
Material Data ◽  
Loading Direction ◽  
Electron Microscopes ◽  
Net Shaping

This paper presents a characterization study of specimens manufactured from Ti-6Al-4V powder with the use of laser engineered net shaping technology (LENS). Two different orientations of the specimens were considered to analyze the loading direction influence on the material mechanical properties. Moreover, two sets of specimens, as-built (without heat treatment) and after heat treatment, were used. An optical measurement system was also adopted for determining deformation of the specimen, areas of minimum and the maximum principal strain, and an effective plastic strain value at failure. The loading direction dependence on the material properties was observed with a significant influence of the orientation on the stress and strain level. Microstructure characterization was examined with the use of optical and scanning electron microscopes (SEM); in addition, the electron backscatter diffraction (EBSD) was also used. The fracture mechanism was discussed based on the fractography analysis. The presented comprehensive methodology proved to be effective and it could be implemented for different materials in additive technologies. The material data was used to obtain parameters for the selected constitutive model to simulate the energy absorbing structures manufactured with LENS technology. Therefore, a brief discussion related to numerical modelling of the LENS Ti-6Al-4V alloy was also included in the paper. The numerical modelling confirmed the correctness of the acquired material data resulting in a reasonable reproduction of the material behavior during the cellular structure deformation process.

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