scholarly journals Justification of the Reduction Possibility of Sulfur Oxides and Fly Ash Emissions during Co-Combustion of Coal and Waste from Woodworking Enterprises

2021 ◽  
Vol 11 (24) ◽  
pp. 11719
Author(s):  
Stanislav Yankovsky ◽  
Anton Tolokol’nikov ◽  
Alexander Gorshkov ◽  
Albina Misyukova ◽  
Geniy Kuznetsov
Keyword(s):  
Thermal Decomposition ◽  
Fly Ash ◽  
Flue Gases ◽  
Continuous Recording ◽  
Sulfur Oxides ◽  
Gas Emissions ◽  
Mixed Fuel ◽  
Pine Sawdust ◽  
Wood Component ◽  
Blended Fuel

In this work, we experimentally investigated the effect of widespread biomass (woodworking waste—pine sawdust) in the composition of mixed fuel, formed also using the widespread steam coals metalignitous (D) and lean (T), on the concentration of sulfur, nitrogen and carbon oxides in flue gases. Investigations of composite fuels with a mass of at least 5 g were carried out in a reactor with continuous recording of the composition of the flue gases formed during the thermal decomposition of the investigated fuels. Thermal decomposition of fuels was carried out in the temperature range from 293 K to 873 K. It was found that an increase in the proportion of wood components in mixed fuels based on two different coals from 10% to 50% leads to a significant decrease in the concentration of sulfur oxides from 11% to 95.8% relative to the concentration of the formation of sulfur oxides in a homogeneous coal, respectively. It was found that an increase in the proportion of the wood component in the mixture with grade D coal up to 50% leads to a significant increase in the content of calcium sulfates (45.1%) and aluminum (43.2%) in the blended fuel. The increase in the content of these salts in the ash of mixed fuels based on T coal and wood is 35.1% and 38.6%, respectively. The obtained research results allowed us to conclude that woodworking wastes are an effective addition to the coals of various deposits, which would help to reduce anthropogenic-induced gas emissions when they are co-combusting in the furnaces of power boilers.

scholarly journals Additives to Coal-Based Fuel Pellets for the Intensification of Combustion and Reduction in Anthropogenic Gas Emissions

2020 ◽  
Vol 10 (19) ◽  
pp. 6689
Author(s):  
Dmitriy Klepikov ◽  
Tereza Kudelova ◽  
Kristina Paushkina ◽  
Pavel Strizhak
Keyword(s):  
Coal Dust ◽  
Polymer Particle ◽  
Porous Polymer ◽  
Flue Gases ◽  
Sulfur Oxides ◽  
Fuel Composition ◽  
Material Particle ◽  
Wood Sawdust ◽  
Fuel Pellets ◽  
Ignition And Combustion

Cylinder-shaped fuel pellets that were 3 mm in diameter and 3 mm in height, with a mass of 20 mg, were produced by compressing dry coal processing waste under the pressure of 5 MPa. The first group of pellets from coal dust with a particle size less than 140 µm did not contain any additives. The pellets of the second group of fuel compositions contained an oil-impregnated porous polymer material particle with a size of 0.5 mm in the central part of the experimental sample. The particle was surrounded by coal dust from all sides. The ratio of components was 90:10% for coal dust: polymer particle. The latter value almost completely corresponds to the fraction of oil in the fuel composition, since the mass of a porous polymer material particle is negligible. The third group of compositions was a 70:30% mixture of coal dust with wood sawdust with a particle size less than 45 µm, or 45–100, 100–200 and 200–500 µm. The ignition and combustion of single fuel pellets were studied under radiant heating in an air medium while varying the temperature from 800 to 1000 °C. The processes during the fuel combustion were recorded by a high-speed video camera, and the concentrations of the main anthropogenic emissions in flue gases were measured by a gas analyzer. The main characteristics were established—ignition delay times (2–8 s) and duration of burnout (40–90 s)—at different heating temperatures. A difference was established in the combustion mechanisms of the pellets, when adding various components to the fuel mixture composition. This has a direct influence on the induction period duration and combustion time, other conditions being equal, as well as on the concentration of nitrogen and sulfur oxides in the flue gases. Adding an oil-impregnated porous polymer particle to the fuel composition intensifies ignition and combustion, since the times of ignition delay and complete burnout of fuel pellets under threshold conditions decrease by 70%, whereas adding wood sawdust reduces the content of nitrogen and sulfur oxides in the flue gases by 30% and 25%, respectively.

Hg Emission Modeling for a Blended Coal Particle

2006 ◽  
Author(s):  
Madhu B Puchayakala ◽  
Kalyan Annamalai
Keyword(s):  
Coal Particle ◽  
Elemental Mercury ◽  
Flue Gases ◽  
Air Emissions ◽  
Gas Temperature ◽  
Transient Model ◽  
Coal Blend ◽  
Blended Coal ◽  
Blended Fuel ◽  
Different Gases

The largest source of human-caused mercury air emissions in the U.S principle is from combustion coal, a dominant fuel used for power generation. The coal chlorine content and ash composition, gas temperature, residence time and presence of different gases will decide the speciation of Hg into Hg° (elemental form) and HgCl2 (oxidized form). The extent of oxidation depends on the concentration of chlorine in flue gases. In order to predict the % of oxidized Hg, a transient model for combustion of a coal particle is formulated including Hg reactions. The model assumes that mercury and chlorine are released as a part of volatiles in the form of elemental mercury and HCl. A three step reaction is implemented for the oxidation of mercury. The model investigates the effect of coal blend with feedlot biomass (FB or Cattle manure), ambient temperature, and particle size on the extent of mercury oxidization. Mercury oxidation (HgCl2) increased with increase in diameter of particle and FB % in blended fuel.

Thermal Decomposition Mechanism of Desilication Coal Fly Ash by Low-Lime Sinter Method for Alumina Extraction

2015 ◽  
Vol 486 (1) ◽  
pp. 143-155 ◽  
Author(s):  
Zhouqing Jiang ◽  
Hongwen Ma ◽  
Jing Yang ◽  
Xi Ma ◽  
Jiangyan Yuan
Keyword(s):  
Thermal Decomposition ◽  
Fly Ash ◽  
Coal Fly Ash ◽  
Decomposition Mechanism ◽  
Thermal Decomposition Mechanism ◽  
Sinter Method

scholarly journals Acoustic Agglomeration of Power Plant Fly Ash for Environmental and Hot Gas Clean-up

1988 ◽  
Vol 110 (4) ◽  
pp. 552-557 ◽  
Author(s):  
G. Reethof
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Pollution Control ◽  
Flue Gases ◽  
Analytical Models ◽  
Particle Removal ◽  
Air Pollution Control ◽  
Hot Gas ◽  
History Of ◽  
Viable Method

Acoustic agglomeration of power plant fly ash is an intermediate treatment of the flue gases to increase the size of the small micron (1–5) and submicron (0.1–1) particulates to large micron sizes (5–10) so that the conventional particle removal devices such as bag houses, electrostatic precipitators, and scrubbers can operate more efficiently. This paper provides a brief history of the topic, introduces some of the fundamental issues and gives some recent results of analytical models of the processes. The experimental facility is briefly described and some analytical results are shown which compare well with the experimental results. Most important of all, the paper shows that acoustic agglomeration is a technically and potentially economically viable method to improve air pollution control.

scholarly journals The influence of wood processing waste on the technical and energy characteristics of the Maikuben coal-based mixed fuels

2021 ◽  
Vol 2057 (1) ◽  
pp. 012128
Author(s):  
G V Kuznetsov ◽  
I V Cherednik ◽  
A A Galaktionova ◽  
S A Yankovsky
Keyword(s):  
Experimental Studies ◽  
Calorific Value ◽  
Wood Biomass ◽  
Processing Waste ◽  
Energy Characteristics ◽  
Mixed Fuel ◽  
Pine Sawdust ◽  
Wood Processing ◽  
Moderate Reduction ◽  
The Republic

Abstract The manuscript presents the results of experimental studies of the energy and technical characteristics of mixed fuels based on lignite from the Maikuben basin of the Republic of Kazakhstan and wood processing waste, pine sawdust from the Tomsk LPC. The addition of wood biomass to coal is found to result in a significant reduction in the ash content of the mixed fuel (by 73.1 %) with a wood fraction equal to 50 % and a moderate reduction in calorific value (by 8.2 %) with the same concentration of biomass in the mixed fuel.

scholarly journals Modified Fly Ash-Based Adsorbents (MFA) for Mercury and Carbon Dioxide Removal from Coal-Fired Flue Gases

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7101
Author(s):  
Marta Marczak-Grzesik ◽  
Piotr Piersa ◽  
Mateusz Karczewski ◽  
Szymon Szufa ◽  
Hilal Ünyay ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Particle Size ◽  
Fly Ash ◽  
Chemical Composition ◽  
Solid Waste ◽  
Flue Gas ◽  
Flue Gases ◽  
Co2 Removal ◽  
Fly Ashes ◽  
Modified Fly Ash

One of the solid waste produced during the combustion of coal are fly ashes. Disposal challenges and environmental consequences are the results of significant process yield and atmospheric emission of fly ashes. The exact chemical composition of FA depends mainly on the type of utilised fuel and combustion conditions. It consists mainly of chemically stable metal oxides, such as Al2O3, Fe2O3, SiO2, CaO, MgO, K2O, Na2O and TiO2, but its toxicity is related to the possible presence of some trace elements, such as As, Hg, Cd, Se and Cr. The chemical and physical properties of fly ash (e.g., particle size distribution, porosity, and surface area) make it suitable as an adsorbent to remove various impurities from process flows such as flue gas stream. Its suitability for capturing mercury from flue gas was experimentally confirmed due to its abundant supply, particle size, bulk density, porosity, chemical composition and low cost. Hence, the use of fly ash as adsorbents and precursors for the production of heavy metal adsorbents is of great practical importance, as it reduces the cost of mercury capture and alleviates the problems associated with the disposal of solid waste. Studies showed that the chemical components present in fly ash additives could stimulate catalytic oxidative capacity, which increases the adsorption of Hg0 oxidation and adsorption of both Hg and CO2. The presented study analysed fly ashes from different zones of the electrostatic precipitator and verified their suitability for removing impurities from flue gases, i.e., mercury and carbon dioxide. The results outlined modified fly ash as having good Hg and CO2 removal capabilities. The adsorption efficiency of Hg reached 92% for Hg and 66% for CO2, while untreated fly ash reached 67% for Hg and 59% for CO2.

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