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Effects Of Fly Ash On Mercury Oxidation During Post Combustion Conditions
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Book Synopsis EFFECTS OF FLY ASH ON MERCURY OXIDATION DURING POST COMBUSTION CONDITIONS. by :
Download or read book EFFECTS OF FLY ASH ON MERCURY OXIDATION DURING POST COMBUSTION CONDITIONS. written by and published by . This book was released on 1999 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tests were performed in simulated flue gas streams using two fly ash samples from the electrostatic precipitators of two full-scale utility boilers. One fly ash was derived from a Powder River Basin (PRB) coal, while the other was derived from Blacksville coal (Pittsburgh No. 8 seam). The tests were performed at temperatures of 120 and 180 C under different gas compositions. Elemental mercury (Hg) streams were injected into the simulated flue gas and passed over filters (housed in a convection oven) loaded with fly ash. The Ontario Hydro method was used to determine the total amount of Hg passing through the filter as well as the percentages of elemental and oxidized Hg collected. Results indicated that substantial amounts of Hg oxidation did not occur with either fly ash, regardless of the temperature used for testing. When oxidation was observed, the magnitude of the oxidation was comparable between the two fly ashes. These results suggest that the gas matrix may be more important than the ash components with respect to the distribution of Hg species observed in gaseous effluents at coal-fired power plants.
Book Synopsis Effects of Fly Ash on the Oxidation of Mercury During Post-combustion Conditions by : Hongqun Yang
Download or read book Effects of Fly Ash on the Oxidation of Mercury During Post-combustion Conditions written by Hongqun Yang and published by . This book was released on 2002 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury emissions from coal-fired power plants pose impact on human health. The emissions will be regulated in the near future. Mercury speciation in flue gas has an important effect on the efficiency of mercury emission control devices. This study focuses on the role of fly ash on the oxidation of Hg0 in bench-scale simulated flue gas environment and in laboratory-scale coal combustion flue gas environment. The effects of flue gas matrices, temperature, fly ash mineralogy and morphology on the oxidation of Hg0 are studied. Conclusions are drawn based on the testing results: *Mercury chemistry is very complex in flue gas. *The presence of fly ash is critical for heterogeneous Hg0 oxidation. *The flue gas components, including NO2, HC1, NO and SO2, have strong effects on the potential of whole fly ashes to oxidize Hg0. *Fly ash specific surface area appears to have a determining effect on Hg0 heterogeneous oxidation.
Download or read book Fly Ash and Mercury Oxidation written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury is a known pollutant that has detrimental effect on human health and environment. The anthropogenic emissions of mercury account for 10 to 30% of worldwide mercury emissions. There is a need to control/reduce anthropogenic mercury emissions. Many mercury control technologies are available but their effectiveness is dependent on the chemical form of mercury, because different chemical forms of mercury have different physical and chemical properties. Mercury leaves the boiler in its elemental form but goes through various transformations in the post-combustion zone. There is a need to understand how fly ash and flue gas composition affect speciation, partitioning, and reactions of mercury under the full range of post-combustion zone conditions. This knowledge can then be used to predict the chemical transformation of mercury (elemental, oxidized or particulate) in the post combustion zone and thus help with the control of mercury emissions from coal-burning power plants. To accomplish this goal present study was conducted using five coal fly ashes. These ashes were characterized and their catalytic activity was compared under selected reaction conditions in a fixed bed reactor. Based on the results from these fly ash experiments, three key components (carbon, iron oxide and calcium oxide) were chosen. These three components were then used to prepare model fly ashes. Silica/alumina was used as a base for these model fly ashes. One, two or three component model fly ashes were then prepared to investigate mercury transformation reactions. The third set of experiments was performed with CuO and CuCl2 catalysts to further understand the mercury oxidation process. Based on the results of these three studies the key components were predicted for different fly ash compositions under variety of flue gas conditions. A fixed bed reactor system was used to conduct this study. In all the experiments, the inlet concentration of Hg0(g) was maintained at 35 [mu]g/m3 using a diffusion tube as the source of Hg0(g). All experiments were conducted using 4% O2 in nitrogen mix as a reaction gas, and other reactants (HCl, H2O and SO2, NO2, Br2) were added as required. The fixed bed reactor was operated over a temperature range of 200 to 400 C. In each experiment, the reactor effluent was analyzed using the modified Ontario-Hydro method. After each experiment, fly ash particles were also analyzed for mercury. The results show that the ability of fly ash to adsorb and/or oxidize mercury is primarily dependent on its carbon, iron and calcium content. There can be either one or more than one key component at a particular temperature and flue gas condition. Surface area played a secondary role in effecting the mercury transformations when compared to the concentration of the key component in the fly ash. Amount of carbon and surface area played a key important role in the adsorption of mercury. Increased concentration of gases in the flue gas other than oxygen and nitrogen caused decreased the amount of mercury adsorbed on carbon surface. Mercury adsorption by iron oxide primarily depended on the crystalline structure of iron oxide. [alpha]-Iron oxide had no effect on mercury adsorption or oxidation under most of the flue gas conditions, but?-iron oxide adsorbed mercury under most of the flue gas conditions. Bromine is a very good oxidizing agent for mercury. But in the presence of calcium oxide containing fly ashes, all the oxidized mercury would be reduced to elemental form. Among the catalysts, it was observed that presence of free lattice chlorine in the catalyst was very important for the oxidation of mercury. But instead of using the catalyst alone, using it along with carbon may better serve the purpose by providing the adsorption surface for mercury and also some extra surface area for the reaction to occur (especially for fly ashes with low surface area).
Book Synopsis Mercury Control by : Evan J. Granite
Download or read book Mercury Control written by Evan J. Granite and published by John Wiley & Sons. This book was released on 2015-01-20 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: This essential handbook and ready reference offers a detailed overview of the existing and currently researched technologies available for the control of mercury in coal-derived gas streams and that are viable for meeting the strict standards set by environmental protection agencies. Written by an internationally acclaimed author team from government agencies, academia and industry, it details US, EU, Asia-Pacific and other international perspectives, regulations and guidelines.
Book Synopsis The Effects of Carbon-in-ash on Mercury Capture from Flue Gas by : Kyung Man Kim
Download or read book The Effects of Carbon-in-ash on Mercury Capture from Flue Gas written by Kyung Man Kim and published by . This book was released on 2010 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury existing as a trace element in coal is an important pollutant because coal burning is increasing around the world for energy production and coal-fired plants are the largest anthropogenic source of mercury emission to the environment. Mercury behavior in the homogeneous conditions of cooling flue gas is characterized using equilibrium study and fundamental mercury kinetics depending on the time-temperature history. Up-to-date version of mercury oxidation based on quench rate is plotted with revised mercury mechanism. Slow quench rates show better mercury oxidation at the typical cooling rate in power plant. Mercury capture mostly occurs under heterogeneous conditions between sorbent particles and gaseous mercury, and this study is mainly devoted to understanding the role of carbon-in-ash on mercury capture from flue gas. Coal flyash samples are characterized by loss-on-ignition (LOI), surface area (BET) tests, and scanning electron microscopy (SEM). Flyash sorbents are injected using an in-flight configuration and then mercury concentration is measured by Hg CEMS. The unburned carbon is one main factor for capturing mercury. However, mercury uptake is shown to be relatively low when using flyash from high rank coal such as anthracite because of the small surface area coming from the non-porous structure. Therefore, when flyash is used as a sorbent for mercury capture, quantitative surface area should be compared and coal rank also should be considered. Non-carbon zeolite injection showed that carbon has physico-chemically favorable structure to capture mercury as well as creating high surface area with the ash. A detailed diffusion mechanism for the mercury capture process was examined using a relatively simple 1-D model. Porosity and Knudsen diffusivity are very important in intra-particle diffusion based on the investigation of sensitivity of diffusion factors. Under the conditions of this study, it appears that elemental mercury can be more readily captured than oxidized mercury because of its lower molecular weight.
Book Synopsis Control of mercury emissions from coalfired electric utility boilers interim report including errata dated 32102 by :
Download or read book Control of mercury emissions from coalfired electric utility boilers interim report including errata dated 32102 written by and published by DIANE Publishing. This book was released on with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :United States. Congress. House. Committee on Science. Subcommittee on Energy and Environment Publisher : ISBN 13 : Total Pages :1050 pages Book Rating :4.0/5 (9 download)
Book Synopsis The DOE FY 99 Budget Authorization Request, H.R. 1806, to Provide for the Consolidation of the DOE Offices of Fossil Energy, Renewable Energy, and Energy Efficiency, S. 965, to Amend Title II of the Hydrogen Future Act of 1996 by : United States. Congress. House. Committee on Science. Subcommittee on Energy and Environment
Download or read book The DOE FY 99 Budget Authorization Request, H.R. 1806, to Provide for the Consolidation of the DOE Offices of Fossil Energy, Renewable Energy, and Energy Efficiency, S. 965, to Amend Title II of the Hydrogen Future Act of 1996 written by United States. Congress. House. Committee on Science. Subcommittee on Energy and Environment and published by . This book was released on 1998 with total page 1050 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fundamental Understanding of Mercury Removal from Coal Combustion by : Erdem Sasmaz
Download or read book Fundamental Understanding of Mercury Removal from Coal Combustion written by Erdem Sasmaz and published by Stanford University. This book was released on 2011 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coal-fired power plants are a major anthropogenic source of worldwide mercury (Hg) emissions. Since mercury is considered to be one of the most toxic metals found in the environment, Hg emissions from coal-fired power plants is of major environmental concern. Mercury in coal is vaporized into its gaseous elemental form throughout the coal combustion process. Elemental Hg can be oxidized in subsequent reactions with other gaseous components (homogeneous) and solid materials (heterogeneous) in coal-fired flue gases. While oxidized Hg in coal-fired flue gases is readily controlled by its adsorption onto fly ash and/or its dissolution into existing solution-based sulfur dioxide (SO2) scrubbers, elemental Hg is not controlled. The extent of elemental Hg formed during coal combustion is difficult to predict since it is dependent on the type of coal burned, combustion conditions, and existing control technologies installed. Therefore, it is important to understand heterogeneous Hg reaction mechanisms to predict the speciation of Hg emissions from coal-fired power plants to design and effectively determine the best applicable control technologies. In this work, theoretical and experimental investigations have been performed to investigate the adsorption and in some cases the oxidation, of Hg on solid surfaces, e.g., calcium oxide (CaO), noble metals and activated carbon (AC). The objective of this research is to identify potential materials that can be used as multi-pollutant sorbents in power plants by carrying out both high-level density functional theory (DFT) electronic structure calculations and experiments to understand heterogeneous chemical pathways of Hg. This research uses a fundamental science-based approach to understand the environmental problems caused by coal-fired energy production and provides solutions to the power generation industry for emissions reductions. Understanding the mechanism associated with Hg and SO2 adsorption on CaO will help to optimize the conditions or material to limit Hg emissions from the flue gas desulfurization process. Plane-wave DFT calculations were used to investigate the binding mechanism of Hg species and SO2 on the CaO(100) surface. The binding strengths on the high-symmetry CaO adsorption sites have been investigated for elemental Hg, SO2, mercury chlorides (HgCl and HgCl2) and mercuric oxide (HgO). It has been discovered that HgCl, HgCl2, and SO2 chemisorb on the CaO(100) surface at 0.125 ML coverage. Binding energies of elemental Hg are minimal indicating a physisorption mechanism. Noble metals such as palladium (Pd), gold (Au), silver (Ag), and copper (Cu) have been proposed to capture elemental Hg. Plane-wave DFT calculations have been carried out to investigate the mercury interactions with Pd binary alloys and overlays in addition to pure Pd, Au, Ag, and Cu surfaces. It has been determined that Pd has the highest mercury binding energy in comparison to other noble metals. In addition, Pd is found to be the primary surface atom responsible for increasing the adsorption of Hg with the surface in both Pd binary alloys and overlays. Deposition of Pd overlays on Au and Ag has been found to enhance the reactivity of the surface by shifting the d-states of surface atoms up in energy. The possible binding mechanisms of elemental Hg onto virgin, brominated and sulfonated AC fiber and brominated powder AC sorbents have been investigated through packed-bed experiments in a stream of air and simulated flue gas conditions, including SO2, hydrogen chloride (HCl), nitrogen oxide (NO) nitrogen dioxide (NO2). A combination of spectroscopy and plane-wave DFT calculations was used to characterize the sorption process. X-ray photoelectron spectroscopy (XPS) and x-ray absorption fine structure (XAFS) spectroscopy were used to analyze the surface and bulk chemical compositions of brominated AC sorbents reacted with Hg0. Through XPS surface characterization studies it was found that Hg adsorption is primarily associated with halogens on the surface. Elemental Hg is oxidized on AC surfaces and the oxidation state of adsorbed Hg is found to be Hg2+. Though plane-wave DFT and density of states (DOS) calculations indicate that Hg is more stable when it is bound to the edge carbon atom interacting with a single bromine bound atop of Hg, a model that includes an interaction between the Hg and an additional Br atom matches best with experimental data obtained from extended x-ray absorption fine structure (EXAFS) spectroscopy. The flue gas species such as HCl and bromine (Br2) enhance the Hg adsorption, while SO2 is found to decrease the Hg adsorption significantly by poisoning the active sites on the AC surface. The AC sorbents represent the most market-ready technology for Hg capture and therefore have been investigated by both theory and experiment in this work. Future work will include similar characterization and bench-scale experiments to test the metal-based materials for the sorbent and oxidation performance.
Book Synopsis Fundamentals of Mercury Transformations in Coal Combustion Flue Gas by : Balaji Krishnakumar
Download or read book Fundamentals of Mercury Transformations in Coal Combustion Flue Gas written by Balaji Krishnakumar and published by . This book was released on 2008 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Effect of Fuel, Combustion Conditions, and Post-Combustion Treatment on the Environmental Impact of Fly Ash by : Indrek Külaots
Download or read book Effect of Fuel, Combustion Conditions, and Post-Combustion Treatment on the Environmental Impact of Fly Ash written by Indrek Külaots and published by . This book was released on 1998 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Oxidation of Mercury in Products of Coal Combustion by :
Download or read book Oxidation of Mercury in Products of Coal Combustion written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Laboratory measurements of mercury oxidation during selective catalytic reduction (SCR) of nitric oxide, simulation of pilot-scale measurements of mercury oxidation and adsorption by unburned carbon and fly ash, and synthesis of new materials for simultaneous oxidation and adsorption of mercury, were performed in support of the development of technology for control of mercury emissions from coal-fired boilers and furnaces. Conversion of gas-phase mercury from the elemental state to water-soluble oxidized form (HgCl2) enables removal of mercury during wet flue gas desulfurization. The increase in mercury oxidation in a monolithic V2O5-WO3/TiO2 SCR catalyst with increasing HCl at low levels of HCl (
Book Synopsis Fundamental Understanding of Mercury Removal from Coal Combustion by : Erdem Sasmaz
Download or read book Fundamental Understanding of Mercury Removal from Coal Combustion written by Erdem Sasmaz and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coal-fired power plants are a major anthropogenic source of worldwide mercury (Hg) emissions. Since mercury is considered to be one of the most toxic metals found in the environment, Hg emissions from coal-fired power plants is of major environmental concern. Mercury in coal is vaporized into its gaseous elemental form throughout the coal combustion process. Elemental Hg can be oxidized in subsequent reactions with other gaseous components (homogeneous) and solid materials (heterogeneous) in coal-fired flue gases. While oxidized Hg in coal-fired flue gases is readily controlled by its adsorption onto fly ash and/or its dissolution into existing solution-based sulfur dioxide (SO2) scrubbers, elemental Hg is not controlled. The extent of elemental Hg formed during coal combustion is difficult to predict since it is dependent on the type of coal burned, combustion conditions, and existing control technologies installed. Therefore, it is important to understand heterogeneous Hg reaction mechanisms to predict the speciation of Hg emissions from coal-fired power plants to design and effectively determine the best applicable control technologies. In this work, theoretical and experimental investigations have been performed to investigate the adsorption and in some cases the oxidation, of Hg on solid surfaces, e.g., calcium oxide (CaO), noble metals and activated carbon (AC). The objective of this research is to identify potential materials that can be used as multi-pollutant sorbents in power plants by carrying out both high-level density functional theory (DFT) electronic structure calculations and experiments to understand heterogeneous chemical pathways of Hg. This research uses a fundamental science-based approach to understand the environmental problems caused by coal-fired energy production and provides solutions to the power generation industry for emissions reductions. Understanding the mechanism associated with Hg and SO2 adsorption on CaO will help to optimize the conditions or material to limit Hg emissions from the flue gas desulfurization process. Plane-wave DFT calculations were used to investigate the binding mechanism of Hg species and SO2 on the CaO(100) surface. The binding strengths on the high-symmetry CaO adsorption sites have been investigated for elemental Hg, SO2, mercury chlorides (HgCl and HgCl2) and mercuric oxide (HgO). It has been discovered that HgCl, HgCl2, and SO2 chemisorb on the CaO(100) surface at 0.125 ML coverage. Binding energies of elemental Hg are minimal indicating a physisorption mechanism. Noble metals such as palladium (Pd), gold (Au), silver (Ag), and copper (Cu) have been proposed to capture elemental Hg. Plane-wave DFT calculations have been carried out to investigate the mercury interactions with Pd binary alloys and overlays in addition to pure Pd, Au, Ag, and Cu surfaces. It has been determined that Pd has the highest mercury binding energy in comparison to other noble metals. In addition, Pd is found to be the primary surface atom responsible for increasing the adsorption of Hg with the surface in both Pd binary alloys and overlays. Deposition of Pd overlays on Au and Ag has been found to enhance the reactivity of the surface by shifting the d-states of surface atoms up in energy. The possible binding mechanisms of elemental Hg onto virgin, brominated and sulfonated AC fiber and brominated powder AC sorbents have been investigated through packed-bed experiments in a stream of air and simulated flue gas conditions, including SO2, hydrogen chloride (HCl), nitrogen oxide (NO) nitrogen dioxide (NO2). A combination of spectroscopy and plane-wave DFT calculations was used to characterize the sorption process. X-ray photoelectron spectroscopy (XPS) and x-ray absorption fine structure (XAFS) spectroscopy were used to analyze the surface and bulk chemical compositions of brominated AC sorbents reacted with Hg0. Through XPS surface characterization studies it was found that Hg adsorption is primarily associated with halogens on the surface. Elemental Hg is oxidized on AC surfaces and the oxidation state of adsorbed Hg is found to be Hg2+. Though plane-wave DFT and density of states (DOS) calculations indicate that Hg is more stable when it is bound to the edge carbon atom interacting with a single bromine bound atop of Hg, a model that includes an interaction between the Hg and an additional Br atom matches best with experimental data obtained from extended x-ray absorption fine structure (EXAFS) spectroscopy. The flue gas species such as HCl and bromine (Br2) enhance the Hg adsorption, while SO2 is found to decrease the Hg adsorption significantly by poisoning the active sites on the AC surface. The AC sorbents represent the most market-ready technology for Hg capture and therefore have been investigated by both theory and experiment in this work. Future work will include similar characterization and bench-scale experiments to test the metal-based materials for the sorbent and oxidation performance.
Book Synopsis Materials & Components in Fossil Energy Applications by :
Download or read book Materials & Components in Fossil Energy Applications written by and published by . This book was released on with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Water Quality Impacts of the Energy-Water Nexus by : Avner Vengosh
Download or read book Water Quality Impacts of the Energy-Water Nexus written by Avner Vengosh and published by Cambridge University Press. This book was released on 2022-02-24 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy and water have been fundamental to powering the global economy and building modern society. This cross-disciplinary book provides an integrated assessment of the different scientific and policy tools around the energy-water nexus. It focuses on how water use, and wastewater and waste solids produced from fossil fuel energy production affect water quality and quantity. Summarizing cutting edge research, it describes the scientific methods for detecting contamination sources in the context of policy and regulations. The authors highlight the growing evidence that fossil fuel production, from both conventional and unconventional sources, leads to water quality degradation, while regulations for the water and energy sector remain fractured and highly variable across and within countries. This volume will be a key reference for scholars, industry professionals, environmental consultants and policy makers seeking information on the risks associated with the energy cycle and its impact on the environment, particularly water resources.
Book Synopsis Fundamentals of Mercury Oxidation in Flue Gas by :
Download or read book Fundamentals of Mercury Oxidation in Flue Gas written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this project was to understand the importance of and the contribution of gas-phase and solid-phase coal constituents in the mercury oxidation reactions. The project involved both experimental and modeling efforts. The team was comprised of the University of Utah, Reaction Engineering International, and the University of Connecticut. The objective was to determine the experimental parameters of importance in the homogeneous and heterogeneous oxidation reactions; validate models; and, improve existing models. Parameters studied include HCl, NO(subscript x), and SO2 concentrations, ash constituents, and temperature. The results suggested that homogeneous mercury oxidation is below 10% which is not consistent with previous data of others and work which was completed early in this research program. Previous data showed oxidation above 10% and up to 100%. However, the previous data are suspect due to apparent oxidation occurring within the sampling system where hypochlorite ion forms in the KCl impinger, which in turn oxidized mercury. Initial tests with entrained iron oxide particles injected into a flame reactor suggest that iron present on fly ash particle surfaces can promote heterogeneous oxidation of mercury in the presence of HCl under entrained flow conditions. Using the data generated above, with homogeneous reactions accounting for less than 10% of the oxidation, comparisons were made to pilot- and full-scale data. The results suggest that heterogeneous reactions, as with the case of iron oxide, and adsorption on solid carbon must be taking place in the full-scale system. Modeling of mercury oxidation using parameters from the literature was conducted to further study the contribution of homogeneous pathways to Hg oxidation in coal combustion systems. Calculations from the literature used rate parameters developed in different studies, in some cases using transition state theory with a range of approaches and basis sets, and in other cases using empirical approaches. To address this, rate constants for the entire 8-step homogeneous Hg oxidation sequence were developed using an internally consistent transition state approach. These rate constants when combined with the appropriate sub-mechanisms produced lower estimates of the overall extent of homogeneous oxidation, further suggesting that heterogeneous pathways play an important role in Hg oxidation in coal-fired systems.
Book Synopsis Mercury Reaction Chemistry in Combustion Flue Gases from Experiments and Theory by : Bihter Padak
Download or read book Mercury Reaction Chemistry in Combustion Flue Gases from Experiments and Theory written by Bihter Padak and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Emissions from coal combustion processes constitute a significant amount of the elemental mercury released into the atmosphere today. Coal-fired power plants in the United States, with the capacity of just over 300GW, are the greatest anthropogenic source of mercury emissions. Mercury exists in coal combustion flue gas in a variety of forms depending on the coal type and combustion conditions; i.e., elemental, oxidized and particulate. Particulate mercury in the flue gas can be removed using air pollution control devices such as electrostatic precipitators and fabric filters. Oxidized mercury is easily captured by wet flue gas desulfurization scrubbers, while gaseous elemental mercury passes through the scrubbers readily. Activated carbon, when injected into the gas stream of coal-fired boilers, is effective in capturing both elemental and oxidized mercury through adsorption processes. However, the mechanism by which mercury adsorbs on activated carbon is not exactly known and its understanding is crucial to the design and fabrication of effective capture technologies for mercury. The objective of the current study is to apply theoretical-based cluster modeling to examine the possible binding mechanism of mercury on activated carbon. The effects of activated carbon's different surface functional groups and halogens on elemental mercury adsorption have been examined. Also, a thermodynamic approach is followed to examine the binding mechanism of mercury and its oxidized species such as HgCl and HgCl2 on a simulated carbon surface with and without Cl. Energies of different possible surface complexes and possible products are compared and dominant pathways are determined relatively. Since different methods are employed to capture varying forms of mercury, understanding mercury speciation during combustion and how the transformations occur between different forms is essential to developing an effective control mechanism for removing mercury from flue gas. In this study, homogeneous oxidation of mercury via chlorine is examined experimentally in a simulated flue gas environment. Mercury and chlorine are introduced into a laminar premixed methane-air flame. Cooled flue gas is sampled and sent to a custom-built electron ionization quadrupole mass spectrometer specially designed for mercury measurement on the order of parts per billion (ppb) in flue gas. The use of a mass spectrometer allows for distinguishing between the different forms of oxidized mercury (Hg+, Hg+2). By directly measuring mercury species accurately, one can determine the actual extent of mercury oxidation in the flue gas, which will aid in further developing mercury control technologies.
Book Synopsis 21st European Symposium on Computer Aided Process Engineering by :
Download or read book 21st European Symposium on Computer Aided Process Engineering written by and published by Elsevier. This book was released on 2011-06-10 with total page 2086 pages. Available in PDF, EPUB and Kindle. Book excerpt: The European Symposium on Computer Aided Process Engineering (ESCAPE) series presents the latest innovations and achievements of leading professionals from the industrial and academic communities. The ESCAPE series serves as a forum for engineers, scientists, researchers, managers and students to present and discuss progress being made in the area of computer aided process engineering (CAPE). European industries large and small are bringing innovations into our lives, whether in the form of new technologies to address environmental problems, new products to make our homes more comfortable and energy efficient or new therapies to improve the health and well being of European citizens. Moreover, the European Industry needs to undertake research and technological initiatives in response to humanity's "Grand Challenges," described in the declaration of Lund, namely, Global Warming, Tightening Supplies of Energy, Water and Food, Ageing Societies, Public Health, Pandemics and Security. Thus, the Technical Theme of ESCAPE 21 will be "Process Systems Approaches for Addressing Grand Challenges in Energy, Environment, Health, Bioprocessing & Nanotechnologies."
