Download or read book Catalyst Additives to Enhance Mercury Oxidation and Capture written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Catalyst Additives to Enhance Mercury Oxidation and Capture written by Thomas K. Gale and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalysis is the key fundamental ingredient to convert elemental mercury in coal-fired power stations into its oxidized forms that are more easily captured by sorbents, ESPs, baghouses, and wet scrubbers, whether the catalyst be unburned carbon (UBC) in the ash or vanadium pentoxide in SCR catalysts. This project has investigated several different types of catalysts that enhance mercury oxidation in several different ways. The stated objective of this project in the Statement of Objectives included testing duct-injection catalysts, catalyst-sorbent hybrids, and coated low-pressure-drop screens. Several different types of catalysts were considered for duct injection, including different forms of iron and carbon. Duct-injection catalysts would have to be inexpensive catalysts, as they would not be recycled. Iron and calcium had been shown to catalyze mercury oxidation in published bench-scale tests. However, as determined from results of an on-going EPRI/EPA project at Southern Research, while iron and calcium did catalyze mercury oxidation, the activity of these catalysts was orders of magnitude below that of carbon and had little impact in the short residence times available for duct-injected catalysts or catalyst-sorbent hybrids. In fact, the only catalyst found to be effective enough for duct injection was carbon, which is also used to capture mercury and remove it from the flue gas. It was discovered that carbon itself is an effective catalyst-sorbent hybrid. Bench-scale carbon-catalyst tests were conducted, to obtain kinetic rates of mercury adsorption (a key step in the catalytic oxidation of mercury by carbon) for different forms of carbon. All carbon types investigated behaved in a similar manner with respect to mercury sorption, including the effect of temperature and chlorine concentration. Activated carbon was more effective at adsorbing mercury than carbon black and unburned carbon (UBC), because their internal surface area of activated carbon was greater. Catalyst coating of low-pressure-drop screens was of particular interest as this project was being developed. However, it was discovered that URS was already heavily involved in the pursuit of this same technology, being funded by DOE, and reporting significant success. Hence, testing of SCR catalysts became a major focus of the project. Three different commercial SCR catalysts were examined for their ability to oxidize mercury in simulated flue-gas. Similar performance was observed from each of the three commercial catalysts, both in terms of mercury oxidation and SO{sub 3} generation. Ammonia injection hindered mercury oxidation at low HCl concentrations (i.e., {approx}2 ppmv), yet had little impact on mercury oxidation at higher HCl concentrations. On the other hand, SO{sub 2} oxidation was significantly reduced by the presence of ammonia at both low and high concentrations of HCl.

Download or read book Catalyst Additives to Enhance Mercury Oxidation and Capture written by Thomas K. Gale and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Preliminary research has shown that SCR catalysts employed for nitrogen-oxide reduction can effectively oxidize mercury. This report discusses initial results from fundamental investigations into the behavior of mercury species in the presence of SCR catalysts at Southern Research Institute. Three different SCR catalysts are being studied. These are honeycomb-type, plate-type, and a hybrid-type catalyst. The catalysts are manufactured and supplied by Cormetech Inc., Hitachi America Ltd., and Haldor-Topsoe Inc., respectively. Test methods and experimental procedures were developed for current and future testing. The methods and procedures equalize factors influencing mercury adsorption and oxidation (surface area, catalyst activity, and pore structure) that normally differ for each catalyst type. Initial testing was performed to determine the time necessary for each catalyst to reach surface-adsorption equilibrium. In addition, the fraction of Hg oxidized by each of the SCR catalyst types is being investigated, for a given amount of catalyst and flow rate of mercury and flue gas. The next major effort will be to examine the kinetics of mercury oxidation across the SCR catalysts with respect to changes in mercury concentration and with respect to HCl concentration. Hg-sorption equilibrium times will also be investigated with respect to ammonia concentration in the simulated flue gas.

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.

Download or read book Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This final report presents and discusses results from a mercury control process development project entitled ''Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems''. The objective of this project was to demonstrate at pilot scale a mercury control technology that uses solid honeycomb catalysts to promote the oxidation of elemental mercury in the flue gas from coal combustion. Oxidized mercury is removed in downstream wet flue gas desulfurization (FGD) absorbers and leaves with the FGD byproducts. The goal of the project was to achieve 90% oxidation of elemental mercury in the flue gas and 90% overall mercury capture with the downstream wet FGD system. The project was co-funded by EPRI and the U.S. Department of Energy's National Energy Technology Laboratory (DOE NETL) under Cooperative Agreement DE-FC26-01NT41185. Great River Energy (GRE) and City Public Service (now CPS Energy) of San Antonio were also project co-funders and provided host sites. URS Group, Inc. was the prime contractor. Longer-term pilot-scale tests were conducted at two sites to provide catalyst life data. GRE provided the first site, at their Coal Creek Station (CCS), which fires North Dakota lignite, and CPS Energy provided the second site, at their Spruce Plant, which fires Powder River Basin (PRB) coal. Mercury oxidation catalyst testing began at CCS in October 2002 and continued through the end of June 2004, representing nearly 21 months of catalyst operation. An important finding was that, even though the mercury oxidation catalyst pilot unit was installed downstream of a high-efficiency ESP, fly ash buildup began to plug flue gas flow through the horizontal catalyst cells. Sonic horns were installed in each catalyst compartment and appeared to limit fly ash buildup. A palladium-based catalyst showed initial elemental mercury oxidation percentages of 95% across the catalyst, declining to 67% after 21 months in service. A carbon-based catalyst began with almost 98% elemental mercury oxidation across the catalyst, but declined to 79% oxidation after nearly 13 months in service. The other two catalysts, an SCR-type catalyst (titanium/vanadium) and an experimental fly-ash-based catalyst, were significantly less active. The palladium-based and SCR-type catalysts were effectively regenerated at the end of the long-term test by flowing heated air through the catalyst overnight. The carbon-based catalyst was not observed to regenerate, and no regeneration tests were conducted on the fourth, fly-ash-based catalyst. Preliminary process economics were developed for the palladium and carbon-based catalysts for a scrubbed, North Dakota lignite application. As described above, the pilot-scale results showed the catalysts could not sustain 90% or greater oxidation of elemental mercury in the flue gas for a period of two years. Consequently, the economics were based on performance criteria in a later DOE NETL solicitation, which required candidate mercury control technologies to achieve at least a 55% increase in mercury capture for plants that fire lignite. These economics show that if the catalysts must be replaced every two years, the catalytic oxidation process can be 30 to 40% less costly than conventional (not chemically treated) activated carbon injection if the plant currently sells their fly ash and would lose those sales with carbon injection. If the plant does not sell their fly ash, activated carbon injection was estimated to be slightly less costly. There was little difference in the estimated cost for palladium versus the carbon-based catalysts. If the palladium-based catalyst can be regenerated to double its life to four years, catalytic oxidation process economics are greatly improved. With regeneration, the catalytic oxidation process shows over a 50% reduction in mercury control cost compared to conventional activated carbon injection for a case where the plant sells its fly ash. At Spruce Plant, mercury oxidation catalyst testing began in September 2003 and continued through the end of April 2005, interrupted only by a host unit outage in late February/early March 2005. With a baghouse upstream of the catalysts, sonic horns did not appear to be necessary and were never installed. Pressure drop across the four catalysts remained low. Catalyst activity for elemental mercury oxidation was difficult to evaluate at this site. It was found that the baghouse effectively oxidized elemental mercury in the flue gas, with the baghouse outlet flue gas averaging 81% mercury oxidation. This oxidation resulted in little elemental mercury remaining in the flue gas going to the oxidation catalyst pilot unit. In many instances, catalyst outlet elemental mercury concentrations were near detection limits for the measurement methods employed, so mercury oxidation percentages across the catalyst were uncertain.

Download or read book Advanced Power Plant Materials Design and Technology written by Dermot Roddy and published by Elsevier. This book was released on 2010-05-24 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fossil-fuel power plants account for the majority of worldwide power generation. Increasing global energy demands, coupled with issues of ageing and inefficient power plants, have led to new power plant construction programmes. As cheaper fossil fuel resources are exhausted and emissions criteria are tightened, utilities are turning to power plants designed with performance in mind to satisfy requirements for improved capacity, efficiency, and environmental characteristics.Advanced power plant materials, design and technology provides a comprehensive reference on the state of the art of gas-fired and coal-fired power plants, their major components and performance improvement options. Part one critically reviews advanced power plant designs which target both higher efficiency and flexible operation, including reviews of combined cycle technology and materials performance issues.Part two reviews major plant components for improved operation, including advanced membrane technology for both hydrogen (H2) and carbon dioxide (CO2) separation, as well as flue gas handling technologies for improved emissions control of sulphur oxides (SOx), nitrogen oxides (NOx), mercury, ash and particulates. The section concludes with coverage of high-temperature sensors, and monitoring and control technology that are essential to power plant operation and performance optimisation.Part three begins with coverage of low-rank coal upgrading and biomass resource utilisation for improved power plant fuel flexibility. Routes to improve the environmental impact are also reviewed, with chapters detailing the integration of underground coal gasification and the application of carbon dioxide (CO2) capture and storage. Finally, improved generation performance is reviewed with coverage of syngas and hydrogen (H2) production from fossil-fuel feedstocks.With its distinguished international team of contributors, Advanced power plant materials, design and technology is a standard reference for all power plant engineers and operators, as well as to academics and researchers in this field. - Provides a comprehensive reference on the state-of-the-art gas-fired and coal-fired power plants, their major components and performance improvement options - Examines major plant components for improved operation as well as flue gas handling technologies for improved emissions control - Routes to improve environmental impact are discussed with chapters detailing the integration of underground coal gasification

Download or read book High Temperature Mercury Oxidation Kinetics Via Bromine Mechanisms written by Terumi Okano and published by . This book was released on 2009 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: As the foremost production of electricity in the United State comes from coal-fired plants, there is much more to learn on the topic of mercury which is a common component in coal. The speciation of mercury in the flue gas determines the best control technology for a given system. Because of the difficulty in measuring mercury at different stages of the process, it is practical to use mercury reaction kinetics to theoretically determine mercury speciation based upon coal composition, plant equipment and operating conditions. Elemental mercury cannot be captured in wet scrubbers; however, its oxidized forms can. Chlorine is a reasonable oxidizing agent and is naturally found in bituminous coal, but bromine is an even better oxidizing agent because of its larger size, it has stronger London dispersion force interactions with mercury. Bromine additive technologies have recently been implemented in several companies to enhance mercury oxidation. Because capture technologies are highly dependent upon the form of mercury that is present, investigations into their speciation are extremely important. Though there have been numerous efforts to study mercury compounds as relevant to atmospheric studies, there is little data currently available for mercury compounds found in combustion flue gases. It would be particularly beneficial to obtain kinetic rate constants at various high temperature and pressure conditions typical for a combustion system. Prevalent species of mercury containing bromine in coal combustion flue gases were studied using density functional theory (DFT) and a broad range of ab initio methods. Reaction enthalpies, equilibrium bond distances, and vibrational frequencies were all predicted using DFT as well as coupled cluster (CC) methods. All electronic calculations were carried out using the Gaussian03 or MOLPRO software programs. Kinetic predictions of three first-stage and three second-stage oxidation reactions involving the formation of oxidized mercury via bromine containing compounds are presented. Understanding the speciation of mercury in the flue gases of coal combustion is paramount in developing efficient technologies to ensure its capture.

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:

Download or read book The Homogeneous Forcing of Mercury Oxidation to Provide Low Cost Capture written by John C. Kramlich and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Oxidized mercury formed in combustors (e.g., HgCl{sub 2}) is much more easily captured in existing pollution control equipment (e.g., wet scrubbers for SO{sub 2}) than elemental mercury. This is principally due to the high solubility of the oxidized form in water. Work over the last several years in our laboratory and elsewhere has identified the general outlines of the homogeneous chemistry of oxidation. The goal of the work reported here is to make use of this knowledge of the oxidation mechanism to devise simple and inexpensive ways to promote the oxidation. The hypothesis is that simple fuels such as hydrogen or CO can promote oxidation via the free radicals they generate during their decomposition. These free radicals then promote the formation of Cl from HCl via reactions such as OH+HCl {yields} H{sub 2}O+Cl. The Cl (and Cl{sub 2} derived from Cl recombination) are considered the principal oxidizing species. In our studies, mercury vapor is exposed to HCl under isothermal conditions in a gas containing N{sub 2}, O{sub 2}, and H{sub 2}O. The experiments systematically explore the influence of reaction temperature, HCl concentration, and H{sub 2}O concentration. These baseline conditions are then perturbed by the addition of varying amounts of H{sub 2}, CO, and H{sub 2}/CO added jointly. The following report presents the results of a literature review associated with the dissertation of the student supported by the program. This outlines the state-of-the-art in mercury behavior. It then describes the experimental facilities and the results of tests involving the promotion of the oxidation reaction by H{sub 2}, CO, and H{sub 2}/CO combinations. These results indicate a substantial enhancement of oxidation under isothermal conditions at 900-1000 K, while the additives inhibit oxidation at 1200 K. The next step is to determine whether the existing chemical kinetic models of mercury oxidation are capable of reproducing this behavior. These models can then be used to extrapolate the findings to nonisothermal conditions typical of boiler environments. This would provide guidance on where to inject the oxidation promoters in a practical boiler, and how much promoter is required.

Download or read book The Forcing of Mercury Oxidation as a Means of Promoting Low Cost Capture written by John C. Kramlich and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Trace amounts of mercury are found in all coals. During combustion this mercury is vaporized and can be released to the atmosphere. This has been a cause for concern for a number of years, and has resulted in a determination by the EPA to regulate and control these emissions. Present technology does not, however, provide inexpensive ways to capture or remove mercury from flue gases. The mercury that exits the furnace in the oxidized form (HgCl{sub 2}) is known to much more easily captured in existing wet pollution control equipment (e.g., wet FGD for SO{sub 2}), principally due to its high solubility in water. Until recently, however, nobody knew what caused this oxidation, or how to promote it. Recent DOE-funded research in our group, along with work by others, has identified the gas phase mechanism responsible for this oxidation. The scenario is as follows. In the flame the mercury is quantitatively vaporized as elemental mercury. Also, the chlorine in the fuel is released as HCl. The direct reaction Hg+HCl is, however, far too slow to be of practical consequence in oxidation. The high temperature region does supports a small concentration of atomic chlorine due to disassociation of HCl. As the gases cool (either in the furnace convective passes, in the quench prior to cold gas cleanup, or within a sample probe), the decay in Cl atom is constrained by the slowness of the principal recombination reaction, Cl+Cl+M {yields} Cl{sub 2}+M. This allows chlorine atom to hold a temporary, local superequilibrium concentration. Once the gases drop below about 550 C, the mercury equilibrium shifts to favor HgCl{sub 2} over Hg, and this superequilibrium chlorine atom promotes oxidation via the fast reactions Hg+Cl+M {yields} HgCl+M, HgCl+Cl+M {yields} HgCl{sub 2}+M, and HgCl+Cl{sub 2} {yields} HgCl{sub 2}+Cl. Thus, the high temperature region provides the Cl needed for the reaction, while the quench region allows the Cl to persist and oxidize the mercury in the absence of decomposition reactions that would destroy the HgCl{sub 2}. Promoting mercury oxidation is one means of getting high-efficiency, ''free'' mercury capture when wet gas cleanup systems are already in place. The chemical kinetic model we developed to describe the oxidation process suggests that oxidation can be promoted by introducing trace amounts of H{sub 2} and/or CO within the quench region. The reaction of these fuels leads to free radicals that promote the selective conversion of HCl to Cl, which can then subsequently react with Hg. The work reported here from our Phase I Innovative Concept grant demonstrated this phenomenon, but it also showed that the process must be applied carefully to avoid promoting the recombination of Cl back to HCl. For example, addition of H{sub 2} at too high a temperature is predicted to actually decrease Cl concentrations via Cl+H{sub 2} {yields} HCl+H. At lower temperatures this reaction is slowed due to its activation energy. Thus, within the correct window, the process becomes selective for Cl promotion. Key parameters are the injection temperature of the promoter, the amount of the fuel added. A successful process based on this research will add a powerful tool to the mercury control arsenal. Presently, fractional oxidation in flue gases varies widely, but averages about 50%. The amounts of promoter needed to obtain quantitative oxidation are predicted to be small ({approx}50 ppm). The H{sub 2}/CO could be supplied by conventional natural gas reformer on site, and the low expected fuel concentration would require only a relatively trivial amount of natural gas, even for a large power plant. For example, a 600 MW{sub e} plant would require the order of only 1 MW thermal equivalent of natural gas. If the mercury in the stream approaching a FGD system is highly oxidized, then high captures could be achieved without any additional cost, even for fuels of low chlorine.

Download or read book Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems written by Gary M. Blythe and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This document summarizes progress on Cooperative Agreement DE-FC26-04NT41992, ''Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems'', during the time-period January 1 through March 31, 2006. The objective of this project is to demonstrate at pilot scale the use of solid honeycomb catalysts to promote the oxidation of elemental mercury in flue gas from coal combustion, and the use of a wet flue gas desulfurization (FGD) system downstream to remove the oxidized mercury at high efficiency. The project is being co-funded by the U.S. DOE National Energy Technology Laboratory, EPRI, Great River Energy (GRE), TXU Generation Company LP, the Southern Company, and Duke Energy. URS Group is the prime contractor. The mercury control process under development uses honeycomb catalysts to promote the oxidation of elemental mercury in the flue gas from coal-fired power plants that have wet lime or limestone FGD systems. Oxidized mercury is removed in the wet FGD absorbers and leaves with the byproducts from the FGD system. The current project is testing previously identified catalyst materials at pilot scale and in a commercial form to provide engineering data for future full-scale designs. The pilot-scale tests will continue for approximately 14 months or longer at each of two sites to provide longer-term catalyst life data. Pilot-scale wet FGD tests are being conducted periodically at each site to confirm the ability to scrub the catalytically oxidized mercury at high efficiency. This is the ninth reporting period for the subject Cooperative Agreement. During this period, project efforts primarily consisted of operating the catalyst pilot units at the TXU Generation Company LP's Monticello Steam Electric Station and at Georgia Power's Plant Yates. Two catalyst activity measurement trips were made to Plant Yates during the quarter. This Technical Progress Report presents catalyst activity results from the oxidation catalyst pilot unit at Plant Yates and discusses the status of the pilot unit at Monticello.

Download or read book Combustion Engineering Issues for Solid Fuel Systems written by Bruce G. Miller and published by Academic Press. This book was released on 2008-07-02 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: Design, construct and utilize fuel systems using this comprehensive reference work. Combustion Engineering Issues for Solid Fuel Systems combines modeling, policy/regulation and fuel properties with cutting edge breakthroughs in solid fuel combustion for electricity generation and industrial applications. This book moves beyond theory to provide readers with real-life experiences and tips for addressing the various technical, operational and regulatory issues that are associated with the use of fuels. With the latest information on CFD modeling and emission control technologies, Combustion Engineering Issues for Solid Fuel Systems is the book practicing engineers as well as managers and policy makers have been waiting for. - Provides the latest information on CFD modeling and emission control technologies - Comprehensive coverage of combustion systems and fuel types - Addresses policy and regulatory concerns at a technical level - Tackles various technical and operational issues

Download or read book Mercury study report to Congress Vol 8 written by and published by DIANE Publishing. This book was released on with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mercury study report to Congress written by and published by DIANE Publishing. This book was released on with total page 1811 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book PILOT AND FULL SCALE DEMONSTRATION OF ADVANCED MERCURY CONTROL TECHNOLOGIES FOR LIGNITE FIRED POWER PLANTS written by and published by . This book was released on 2005 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective of the project was to develop advanced innovative mercury control technologies to reduce mercury emissions by 50%-90% in flue gases typically found in North Dakota lignite-fired power plants at costs from one-half to three-quarters of current estimated costs. Power plants firing North Dakota lignite produce flue gases that contain>85% elemental mercury, which is difficult to collect. The specific objectives were focused on determining the feasibility of the following technologies: Hg oxidation for increased Hg capture in dry scrubbers, incorporation of additives and technologies that enhance Hg sorbent effectiveness in electrostatic precipitators (ESPs) and baghouses, the use of amended silicates in lignite-derived flue gases for Hg capture, and the use of Hg adsorbents within a baghouse. The approach to developing Hg control technologies for North Dakota lignites involved examining the feasibility of the following technologies: Hg capture upstream of an ESP using sorbent enhancement, Hg oxidation and control using dry scrubbers, enhanced oxidation at a full-scale power plant using tire-derived fuel and oxidizing catalysts, and testing of Hg control technologies in the Advanced Hybrid{trademark} filter.

Download or read book New Trends in Coal Conversion written by Isabel Suarez-Ruiz and published by Woodhead Publishing. This book was released on 2018-08-30 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: New Trends in Coal Conversion: Combustion, Gasification, Emissions, and Coking covers the latest advancements in coal utilization, including coal conversion processes and mitigation of environmental impacts, providing an up-to-date source of information for a cleaner and more environmentally friendly use of coal, with a particular emphasis on the two biggest users of coal—utilities and the steel industry. Coverage includes recent advances in combustion co-firing, gasification, and on the minimization of trace element and CO2 emissions that is ideal for plant engineers, researchers, and quality control engineers in electric utilities and steelmaking. Other sections cover new advances in clean coal technologies for the steel industry, technological advances in conventional by-products, the heat-recovery/non-recovering cokemaking process, and the increasing use of low-quality coals in coking blends. Readers will learn how to make more effective use of coal resources, deliver higher productivity, save energy and reduce the environmental impact of their coal utilization. - Provides the current state-of-the-art and ongoing activities within coal conversion processes, with an emphasis on emerging technologies for the reduction of CO2 and trace elements - Discusses innovations in cokemaking for improved efficiency, energy savings and reduced environmental impact - Include case studies and examples throughout the book

Download or read book Highwood Generation Station written by and published by . This book was released on 2006 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt: