scholarly journals Dioxin emissions from coal combustion in domestic stove: Formation in the chimney and coal chlorine content influence

2015 ◽  
Vol 19 (1) ◽  
pp. 295-304 ◽  
Author(s):  
Bostjan Paradiz ◽  
Panagiota Dilara ◽  
Gunther Umlauf ◽  
Ivan Bajsic ◽  
Vincenc Butala
Keyword(s):  
Flue Gas ◽  
Coal Combustion ◽  
Pronounced Effect ◽  
Flue Gases ◽  
Chlorine Content ◽  
Hard Coal ◽  
Waste Incinerator ◽  
Gas Temperature ◽  
Order Of Magnitude ◽  
Domestic Stove

Combustion experiments conducted in domestic stove burning hard coal demonstrated a predominant influence of the coal chlorine content on the PCDD/F emissions, together with a pronounced effect of the flue gas temperature. PCDD/F concentrations of over 100 ng TEQ/m3, three orders of magnitude higher than in a modern waste incinerator, were measured in the flue gases of a domestic stove when combusting high chlorine coal (0.31 %). The PCDD/F concentrations in the flue gases dropped below 0,5 ng TEQ/m3, when low chlorine coal (0.07 %) was used. When low chlorine coal was impregnated with NaCl to obtain 0.38 % chlorine content, the emission of the PCDD/Fs increased by two orders of magnitude. Pronounced nonlinearity of the PCDD/F concentrations related to chlorine content in the coal was observed. The combustion of the high chlorine coal yielded PCDD/F concentrations in flue gases one order of magnitude lower in a fan cooled chimney when compared to an insulated one, thus indicating formation in the chimney. The influence of flue gas temperature on the PCDD/F emissions was less pronounced when burning low chlorine coal. The predominant pathway of the PCDD/F emissions is via flue gases, 99 % of the TEQ in the case of the high chlorine coal for insulated chimney.

scholarly journals Low-Cost Organic Adsorbents for Elemental Mercury Removal from Lignite Flue Gas

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2174
Author(s):  
Marta Marczak-Grzesik ◽  
Stanisław Budzyń ◽  
Barbara Tora ◽  
Szymon Szufa ◽  
Krzysztof Kogut ◽  
...  
Keyword(s):  
Flue Gas ◽  
Low Cost ◽  
Elemental Mercury ◽  
Mercury Content ◽  
Flue Gases ◽  
Mercury Removal ◽  
Gas Purification ◽  
Gas Temperature ◽  
Corn Straw ◽  
Flue Gas Purification

The research presented by the authors in this paper focused on understanding the behavior of mercury during coal combustion and flue gas purification operations. The goal was to determine the flue gas temperature on the mercury emissions limits for the combustion of lignites in the energy sector. The authors examined the process of sorption of mercury from flue gases using fine-grained organic materials. The main objectives of this study were to recommend a low-cost organic adsorbent such as coke dust (CD), corn straw char (CS-400), brominated corn straw char (CS-400-Br), rubber char (RC-600) or granulated rubber char (GRC-600) to efficiently substitute expensive dust-sized activated carbon. The study covered combustion of lignite from a Polish field. The experiment was conducted at temperatures reflecting conditions inside a flue gas purification installation. One of the tested sorbents—tire-derived rubber char that was obtained by pyrolysis—exhibited good potential for Hg0 into Hg2+ oxidation, resulting in enhanced mercury removal from the flue. The char characterization increased elevated bromine content (mercury oxidizing agent) in comparison to the other selected adsorbents. This paper presents the results of laboratory tests of mercury sorption from the flue gases at temperatures of 95, 125, 155 and 185 °C. The average mercury content in Polish lignite was 465 μg·kg−1. The concentration of mercury in flue gases emitted into the atmosphere was 17.8 µg·m−3. The study analyzed five low-cost sorbents with the average achieved efficiency of mercury removal from 18.3% to 96.1% for lignite combustion depending on the flue gas temperature.

NOx process inhibition and energy efficiency improvement in new swirl modification device for steel slag based on coal combustion

2018 ◽  
Vol 16 (7) ◽  
Author(s):  
Junxiang Guo ◽  
Lingling Zhang ◽  
Daqiang Cang ◽  
Liying Qi ◽  
Wenbin Dai ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Flue Gas ◽  
Coal Combustion ◽  
Steel Slag ◽  
Coal Ash ◽  
Combustion Efficiency ◽  
Gas Temperature ◽  
Staged Combustion ◽  
Energy Efficiency Improvement ◽  
Swirl Combustion

Abstract In this study, a novel swirl combustion modified device for steel slag was designed and enhanced with the objective of achieving highly efficient and clean coal combustion and also for achieving the whole elements utilization of coal. Coal ash and steel slag were melted in the combustion chamber and subsequently entered the slag chamber. The detrimental substances solidified and formed crystals, which allowed for the comprehensive utilization of the ash and slag. Our experiments mainly aimed to mitigate the formation of NOx, while using the heat and slag simultaneously during the coal combustion without a combustion efficiency penalty. The increase in the device’s energy efficiency and reduction in the NOx emissions are important requirements for industrialization. The experiments were carried out in an optimized swirling combustion device, which had a different structure and various coal feeding conditions in comparison to previously reported devices. The fuel-staged and non-staged combustion experiments were compared under different coal ratios (bitumite:anthracite). For the fuel-staged combustion experiments, the NOx concentration in the flue gas was observed to decrease significantly when the coal ratio of 1:1, an excess air coefficient of 1.2, and a fuel-staged ratio of 15:85 were used. Under these conditions, the flue gas temperature was as high as 1,620°C, while the NOx concentration was as low as 320 mg/m3 at 6 % O2. The air-surrounding-fuel structure that formed in the furnace was very beneficial in reducing the formation of NOx. In comparison to other types of coal burners, the experimental combustion device designed in this study achieved a significant reduction of NOx emissions (approximately 80 %).

scholarly journals Lab-scale evaluation of possible mercury speciation in flue gas and mercury emission from combustion of pulverised solid fuels

2019 ◽  
Vol 201 ◽  
pp. 06001
Author(s):  
Maciej Cholewiński ◽  
Wiesław Rybak
Keyword(s):  
Flue Gas ◽  
Combustion Process ◽  
Flue Gases ◽  
Solid Fuels ◽  
Hard Coal ◽  
Scale Evaluation ◽  
Gaseous Products ◽  
Scale Method ◽  
Early Validation ◽  
Solid Biomass

In this work a new lab-scale method dedicated to the evaluation of both concentration and oxidation level of mercury in flue gases from pulverised fuel fired boiler was proposed. To detect the abovementioned parameters, 2 main steps need to be evaluated. Firstly, a calorimeter bomb is utilised - by a proper implementation of mass balance of mercury within substrates and products, the quantity of oxidised mercury in gaseous products can be evaluated. Then, to simulate solid fuel fired power unit and to calculate mercury concentrations in flue gases, one of the stoichiometric mathematical models of combustion process must be applied. Early validation of the method showed considerable differences between solid fuels in mercury oxidation efficiencies and concentrations in flue gasses. Four examined fuels (lignite, hard coal and 2 types of solid biomass) was investigated. Calculated mercury concentrations in raw flue gas (>700°C) varied between 4 and 75 µg/m3ref. The lowest quantity of oxidised forms ofHg in flue gases were identified in the case of investigated lignite (27% of total Hg), while significantly higher – for selected hard coal (72%) and one type of biomass (with high chlorine concentration; up to 98%).

scholarly journals Improving the efficiency of power boilers by cooling the flue gases to the lowest possible temperature under the conditions of safe operation of reinforced concrete and brick chimneys of power plants

2018 ◽  
Vol 245 ◽  
pp. 07014 ◽  
Author(s):  
Evgeny Ibragimov ◽  
Sergei Cherkasov
Keyword(s):  
Reinforced Concrete ◽  
Power Plant ◽  
Flue Gas ◽  
Power Plants ◽  
Thermal Power ◽  
Operating Mode ◽  
Flue Gases ◽  
Technical Solution ◽  
Gas Temperature ◽  
Safe Operation

The article presents data on the calculated values of improving the efficiency of fuel use at the thermal power plant as a result of the introduction of a technical solution for cooling the flue gases of boilers to the lowest possible temperature under the conditions of safe operation of reinforced concrete and brick chimneys with a constant value of the flue gas temperature, when changing the operating mode of the boiler.

scholarly journals Effect of temperature on a free energy and equilibrium constants during dry flue gas desulphurisation chemical reactions

2002 ◽  
Vol 6 (2) ◽  
pp. 71-79 ◽  
Author(s):  
Milos Kuburovic ◽  
Slavko Djuric ◽  
Aleksandar Jovovic ◽  
Milenko Karan
Keyword(s):  
Free Energy ◽  
Chemical Reactions ◽  
Flue Gas ◽  
Equilibrium Constants ◽  
Flue Gases ◽  
Effect Of Temperature ◽  
Gas Temperature

During dry flue gas desulphurisation (FGD) dry particles of reagents are inserted (injected) in the stream of flue gas, where they bond SO2. As reagents, the most often are used compounds of calcium (CaCO3, CaO or Ca(OH)2). Knowledge of free energy and equilibrium constants of chemical reactions during dry FGD is necessary for understanding of influence of flue gas temperature to course of these chemical reactions as well as to SO2 bonding from flue gases.

Protection of Wood from Burning with Paints on Alkaline Aluminosilicates-Based

2020 ◽  
Vol 1006 ◽  
pp. 19-24
Author(s):  
Sergii G. Guzii ◽  
Ihar Bazhelka ◽  
Nataliia Svitlychna ◽  
Vasyl Lashchivskiy
Keyword(s):  
Weight Loss ◽  
Burning Rate ◽  
Flue Gas ◽  
Fire Retardant ◽  
Critical Value ◽  
Flue Gases ◽  
Fire Tests ◽  
Gas Temperature ◽  
Middle Position

The aim of the work was to determination the combustibility group of color fire retardant paints for wood. As a result of the fire tests, it was found that the developed compositions of fire-retardant mineral paints on an alkaline aluminosilicate binder in the (Na, K)2O-Al2O3-nSiO2-mH2O system are difficult to combustible and to flammable, and occupy a middle position between G1 and G2 in the combustibility group. As a result of the fire tests, the temperature of the flue gases did not exceed the critical value - above 260 [°C], the weight loss of the samples was in the range from 5.56 to 10.17 [%], and the burning rate did not exceed 0.0026 [kg/(m2s)]. Given the rather high margin of flue gas temperature, further fire tests are planned to be carried out according to EN 13823 in RICE Sweden.

Removal of Mercury from Simulated Coal Combustion Flue Gas by Iron Sulfide-AC Adsorbent

2014 ◽  
Vol 1004-1005 ◽  
pp. 603-607 ◽  
Author(s):  
Sheng Ji Wu ◽  
Wei Yang ◽  
Jie Zhou ◽  
Zheng Miao Xie
Keyword(s):  
Flue Gas ◽  
Coal Combustion ◽  
Iron Sulfide ◽  
Removal Rate ◽  
Temperature Programmed Desorption ◽  
Flue Gases ◽  
Mercury Removal ◽  
Bet Surface Area ◽  
Higher Temperature ◽  
Temperature Programmed

Iron sulfide-AC adsorbents were prepared and their mercury removal capabilities were evaluated in the simulated coal combustion flue gases. The FeS2has much higher mercury removal rate than AC although it has much lower BET surface area than AC. FeS2also shows higher mercury removal rate than FeS, which is probably due to its higher free sulfur content on the FeS2. The mercury removal capability of AC modified FeS2decreases with increasing of AC content. Temperature programmed desorption/decomposition process (TPDD) shows FeS and FeS2have more desorption peak than AC and the main peaks of FeS and FeS2are at around 240°C. The desorption peaks of AC modified FeS2are shifted to the higher temperature compared with that of FeS2and more mercury compositions are desorbed by AC modified FeS2.

Study on the Technology of Increasing Combustion Efficiency and Decreasing NOx Emission of Blending Coals

2012 ◽  
Vol 614-615 ◽  
pp. 41-44 ◽  
Author(s):  
Chun Zhi Wei ◽  
Yi Cong Wang
Keyword(s):  
Combustion Chamber ◽  
Flue Gas ◽  
Coal Combustion ◽  
Thermal Load ◽  
Load Distribution ◽  
Combustion Efficiency ◽  
Pollutant Emission ◽  
Gas Temperature ◽  
Emission Properties ◽  
Different Types

Study on the combustion behavior and pollutant emission properties of the different types and different ratio of blending coal have been done. The influence of the ratio of brown-blending coal on the combustion efficiency and NOx emission have been researched and concentrated ratio and method of pulverized coal have been get. The thermal-load distribution along the height of furnace and the control of the flue gas temperature at the exit of the combustion chamber have been discussed and the retrofit schema has been put forward. By reasonably blending coal, combustion efficiency increases and NOx emission goes down.

scholarly journals Methods to Reduce Mercury and Nitrogen Oxides Emissions from Coal Combustion Processes

2021 ◽  
Author(s):  
Maria Jędrusik ◽  
Dariusz Łuszkiewicz ◽  
Arkadiusz Świerczok
Keyword(s):  
Nitrogen Oxides ◽  
Flue Gas ◽  
Field Tests ◽  
Flue Gases ◽  
Hard Coal ◽  
Sodium Chlorite ◽  
Mercury Emissions ◽  
Pros And Cons ◽  
Injection Technology ◽  
Combustion Processes

The chapter presents the issue of reducing mercury and nitrogen oxides emissions from the flue gas of coal-fired boilers. The issue is particularly relevant due to the stricter regulations regarding exhaust gas purity. A brief review of the methods for reducing Hg and NOx emissions has been made, pointing out their pros and cons. Against this background, the results of the authors’ own research on the injection of selected oxidants into flue gases to remove both of these pollutants are presented. The injection of sodium chlorite solution into the flue gas (400 MWe lignite fired unit) upstream the wet flue gas desulphurization (WFGD) absorber contributed to the oxidation of both metallic mercury and nitric oxide and enhanced their removal efficiency. The results of tests on lignite and hard coal flue gases indicate that in order to reduce the unfavorable phenomenon of mercury re-emission from WFGD absorbers, in some cases, it is necessary to add selected chemical compounds (e.g., sulfides) to the desulfurization system. The results of field tests for flue gas from lignite (400 MWe unit) and hard coal-fired boilers (195 and 220 MWe units) confirmed the usefulness of oxidizer injection technology to reduce mercury emissions below the level required by BAT conclusions.

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