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Sample records for coal combustion systems

  1. Coal combustion system

    DOEpatents

    Wilkes, Colin; Mongia, Hukam C.; Tramm, Peter C.

    1988-01-01

    In a coal combustion system suitable for a gas turbine engine, pulverized coal is transported to a rich zone combustor and burned at an equivalence ratio exceeding 1 at a temperature above the slagging temperature of the coal so that combustible hot gas and molten slag issue from the rich zone combustor. A coolant screen of water stretches across a throat of a quench stage and cools the combustible gas and molten slag to below the slagging temperature of the coal so that the slag freezes and shatters into small pellets. The pelletized slag is separated from the combustible gas in a first inertia separator. Residual ash is separated from the combustible gas in a second inertia separator. The combustible gas is mixed with secondary air in a lean zone combustor and burned at an equivalence ratio of less than 1 to produce hot gas motive at temperature above the coal slagging temperature. The motive fluid is cooled in a dilution stage to an acceptable turbine inlet temperature before being transported to the turbine.

  2. Pulverized coal torch combustion in a furnace with plasma-coal system

    NASA Astrophysics Data System (ADS)

    Messerle, V. E.; Ustimenko, A. B.; Askarova, A. S.; Nagibin, A. O.

    2010-09-01

    Combustion of a pulverized coal torch has been numerically simulated on the basis of the equations of multicomponent turbulent two-phase flows. The results of three-dimensional simulation of conventional and plasma activated coal combustion in a furnace are presented. Computer code Cinar ICE was verified at coal combustion in the experimental furnace with thermal power of 3 MW that was equipped with plasma-fuel system. Operation of the furnace has been studied at the conventional combustion mode and with plasma activation of coal combustion. Influence of plasma activation of combustion on thermotechnical characteristics of the torch and decrease of carbon loss and nitrogen oxides concentration at the furnace outlet has been revealed.

  3. Improved low NOx firing systems for pulverized coal combustion

    SciTech Connect

    McCarthy, K.; Laux, S.; Grusha, J.; Rosin, T.; Hausman, G.L.

    1999-07-01

    More stringent emission limits or the addition of post combustion NOx control create the need for improvements of NOx emissions from pulverized coal boilers. Many boilers retrofitted with Low NOx technology during Phase 1 and Phase 2 of the CAAA fail or marginally meet their requirements. Technical solutions range from addition of overfire air and state-of-the-art low NOx burners to low cost additions of combustion enhancements. Regardless of the combustion NOx control method used, stoichiometries local to the burners must be maintained at the designed values at all times to provide high NOx performance at low efficiency loss due to unburned fuel. This paper describes Foster Wheeler's approach to NOx emission improvements for existing low NOx firing systems. The technology to measure air and coal flow individually for each burner and to control the parameters for optimum combustion are presented and discussed. Field experience shows the installation and advantages of the technology.

  4. Mercury in coal and the impact of coal quality on mercury emissions from combustion systems

    USGS Publications Warehouse

    Kolker, A.; Senior, C.L.; Quick, J.C.

    2006-01-01

    The proportion of Hg in coal feedstock that is emitted by stack gases of utility power stations is a complex function of coal chemistry and properties, combustion conditions, and the positioning and type of air pollution control devices employed. Mercury in bituminous coal is found primarily within Fe-sulfides, whereas lower rank coal tends to have a greater proportion of organic-bound Hg. Preparation of bituminous coal to reduce S generally reduces input Hg relative to in-ground concentrations, but the amount of this reduction varies according to the fraction of Hg in sulfides and the efficiency of sulfide removal. The mode of occurrence of Hg in coal does not directly affect the speciation of Hg in the combustion flue gas. However, other constituents in the coal, notably Cl and S, and the combustion characteristics of the coal, influence the species of Hg that are formed in the flue gas and enter air pollution control devices. The formation of gaseous oxidized Hg or particulate-bound Hg occurs post-combustion; these forms of Hg can be in part captured in the air pollution control devices that exist on coal-fired boilers, without modification. For a given coal type, the capture efficiency of Hg by pollution control systems varies according to type of device and the conditions of its deployment. For bituminous coal, on average, more than 60% of Hg in flue gas is captured by fabric filter (FF) and flue-gas desulfurization (FGD) systems. Key variables affecting performance for Hg control include Cl and S content of the coal, the positioning (hot side vs. cold side) of the system, and the amount of unburned C in coal ash. Knowledge of coal quality parameters and their effect on the performance of air pollution control devices allows optimization of Hg capture co-benefit. ?? 2006 Elsevier Ltd. All rights reserved.

  5. Coal combustion science

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Fletcher, T.H.; Mitchell, R.E.

    1990-11-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: coal devolatilization, coal char combustion, and fate of mineral matter during coal combustion. 91 refs., 40 figs., 9 tabs.

  6. Prediction of ash deposition in pulverized coal combustion systems

    SciTech Connect

    Lee, F.C.C.; Riley, G.S.; Lockwood, F.C.

    1996-12-31

    A predictive scheme based on CCSEM flyash data and Computational Fluid Dynamics (CFD) has been developed to study the slagging propensity of coals. The model has been applied to predict the deposition potential of three UK coals; Bentinck, Daw Mill and Silverdale, in a pilot scale single burner ash deposition test facility and an utility size multi-burner front wall-fired furnace. The project is part of a collaborative research program sponsored by the UK Department of Trade and Industry and involved various industrial organizations and universities. The objective of the project is to understand the fundamental aspects of slagging in pulverized coal-fired combustion systems. This paper is a sequel to the poster paper entitled: The Prediction of Ash Deposition in a Coal Fired Axi-symmetric Furnace, presented in the last Engineering Foundation Conference. The present model predicts the relative slagging propensity of the three coals correctly. The predicted deposition patterns are also consistent with the observations. The results from the model indicate a preferential deposition of iron during the initial stage of ash deposition. The average compositions of the deposits become closer to that of the bulk ash when the accumulation of ash deposits is taken into account.

  7. Coal combustion products

    USGS Publications Warehouse

    Kalyoncu, R.S.; Olson, D.W.

    2001-01-01

    Coal-burning powerplants, which supply more than half of U.S. electricity, also generate coal combustion products, which can be both a resource and a disposal problem. The U.S. Geological Survey collaborates with the American Coal Ash Association in preparing its annual report on coal combustion products. This Fact Sheet answers questions about present and potential uses of coal combustion products.

  8. Coal Combustion Science

    SciTech Connect

    Hardesty, D.R.; Fletcher, T.H.; Hurt, R.H.; Baxter, L.L. )

    1991-08-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. Specific tasks for this activity include: (1) coal devolatilization - the objective of this risk is to characterize the physical and chemical processes that constitute the early devolatilization phase of coal combustion as a function of coal type, heating rate, particle size and temperature, and gas phase temperature and oxidizer concentration; (2) coal char combustion -the objective of this task is to characterize the physical and chemical processes involved during coal char combustion as a function of coal type, particle size and temperature, and gas phase temperature and oxygen concentration; (3) fate of mineral matter during coal combustion - the objective of this task is to establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of mineral matter in coal combustion environments as a function of coal type, particle size and temperature, the initial forms and distribution of mineral species in the unreacted coal, and the local gas temperature and composition.

  9. Fuel cycle analysis for fossil energy systems: Coal combustion

    NASA Astrophysics Data System (ADS)

    Greenstreet, W. L.; Carmichael, R. L.

    1981-02-01

    Elements of the fuel cycle for coal combustion in power generation are examined; and information on economics, technological status, energy efficiencies, and environmental issues is reviewed. Overall background information is provided for guidance in identifying issues and establishing needs and priorities for engineering research, development, and demonstration. The elements treated include mining, transportation, coal preparation, direct combustion, and environmental control technology. The treatment used differs from that of usual compendiums in its emphasis on integrated examination and presentation directed primarily toward providing bases for general assessment and for guidance in program development. Emphasis is on program identification as opposed to advocacy.

  10. TENORM: Coal Combustion Residuals

    EPA Pesticide Factsheets

    Burning coal in boilers to create steam for power generation and industrial applications produces a number of combustion residuals. Naturally radioactive materials that were in the coal mostly end up in fly ash, bottom ash and boiler slag.

  11. Fluidized coal combustion

    NASA Technical Reports Server (NTRS)

    Moynihan, P. I.; Young, D. L.

    1979-01-01

    Fluidized-bed coal combustion process, in which pulverized coal and limestone are burned in presence of forced air, may lead to efficient, reliable boilers with low sulfur dioxide and nitrogen dioxide emissions.

  12. Transformations of inorganic coal constituents in combustion systems

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. ); Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. ); Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L. ); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. (Kentucky Univ., Lexingt

    1992-11-01

    The inorganic constituents or ash contained in pulverized coal significantly increase the environmental and economic costs of coal utilization. For example, ash particles produced during combustion may deposit on heat transfer surfaces, decreasing heat transfer rates and increasing maintenance costs. The minimization of particulate emissions often requires the installation of cleanup devices such as electrostatic precipitators, also adding to the expense of coal utilization. Despite these costly problems, a comprehensive assessment of the ash formation and had never been attempted. At the start of this program, it was hypothesized that ash deposition and ash particle emissions both depended upon the size and chemical composition of individual ash particles. Questions such as: What determines the size of individual ash particles What determines their composition Whether or not particles deposit How combustion conditions, including reactor size, affect these processes remained to be answered. In this 6-year multidisciplinary study, these issues were addressed in detail. The ambitious overall goal was the development of a comprehensive model to predict the size and chemical composition distributions of ash produced during pulverized coal combustion. Results are described.

  13. Transformations of inorganic coal constituents in combustion systems

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. ); Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. ); Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L. ); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. (Kentucky Univ., Lexingt

    1992-11-01

    Results from an experimental investigation of the mechanisms governing the ash aerosol size segregated composition resulting from the combustion of pulverized coal in a laboratory scale down-flow combustor are described. The results of modeling activities used to interpret the results of the experiments conducted under his subtask are also described in this section. Although results from the entire program are included, Phase II studies which emphasized: (1) alkali behavior, including a study of the interrelationship between potassium vaporization and sodium vaporization; and (2) iron behavior, including an examination of the extent of iron-aluminosilicate interactions, are highlighted. Idealized combustion determination of ash particle formation and surface stickiness are also described.

  14. Efficient volatile metal removal from low rank coal in gasification, combustion, and processing systems and methods

    DOEpatents

    Bland, Alan E.; Sellakumar, Kumar Muthusami; Newcomer, Jesse D.

    2017-03-21

    Efficient coal pre-processing systems (69) integrated with gasification, oxy-combustion, and power plant systems include a drying chamber (28), a volatile metal removal chamber (30), recirculated gases, including recycled carbon dioxide (21), nitrogen (6), and gaseous exhaust (60) for increasing the efficiencies and lowering emissions in various coal processing systems.

  15. Selenium sampling and analysis in coal combustion systems

    SciTech Connect

    DeVito, M.S.; Carlson, R.J.

    1995-12-31

    The Clean Air Act Amendments of 1990 (CAAA) identified 189 elements and compounds that are classified by the U.S. EPA as hazardous air pollutants (HAPs). Among these are eleven inorganic trace elements found in coal. A provision of the CAAA required EPA to conduct a study of the health and environmental impacts of HAP emissions from electric utility generating units. EPA has completed a number of draft documents in compliance with this mandate. For trace element emission estimates, they have relied on a number of field tests which were conducted by a variety of organizations including the U.S. Department of Energy (DOE). The DOE program utilized the EPA Method 29 sampling train to measure the emissions of trace elements including Se. EPA Method 29 is validated for municipal waste combustor sampling but not for coal-fired combustion sources.

  16. Transformations of inorganic coal constituents in combustion systems

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. ); Kang, Shim-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. ); Peterson, T.W.; Wendt, O.L.; Gallagher, N.B.; Bool, L. ); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. (Kentucky Univ., Lexington

    1992-11-01

    This report contains the computer codes developed for the coal combustion project. In Subsection B.1 the FORTRAN code developed for the percolative fragmentation model (or the discrete model, since a char is expressed as a collection of discrete elements in a discrete space) is presented. In Subsection B.2 the code for the continuum model (thus named because mineral inclusions are distributed in a continuum space) is presented. A stereological model code developed to obtain the pore size distribution from a two-dimensional data is presented in Subsection B.3.

  17. Advanced coal-fueled gas turbine systems: Subscale combustion testing. Topical report, Task 3.1

    SciTech Connect

    Not Available

    1993-05-01

    This is the final report on the Subscale Combustor Testing performed at Textron Defense Systems` (TDS) Haverhill Combustion Laboratories for the Advanced Coal-Fueled Gas Turbine System Program of the Westinghouse Electric Corp. This program was initiated by the Department of Energy in 1986 as an R&D effort to establish the technology base for the commercial application of direct coal-fired gas turbines. The combustion system under consideration incorporates a modular staged, rich-lean-quench, Toroidal Vortex Slogging Combustor (TVC) concept. Fuel-rich conditions in the first stage inhibit NO{sub x} formation from fuel-bound nitrogen; molten coal ash and sulfated sorbent are removed, tapped and quenched from the combustion gases by inertial separation in the second stage. Final oxidation of the fuel-rich gases, and dilution to achieve the desired turbine inlet conditions are accomplished in the third stage, which is maintained sufficiently lean so that here, too, NO{sub x} formation is inhibited. The primary objective of this work was to verify the feasibility of a direct coal-fueled combustion system for combustion turbine applications. This has been accomplished by the design, fabrication, testing and operation of a subscale development-type coal-fired combustor. Because this was a complete departure from present-day turbine combustors and fuels, it was considered necessary to make a thorough evaluation of this design, and its operation in subscale, before applying it in commercial combustion turbine power systems.

  18. Environmentally conscious coal combustion

    SciTech Connect

    Hickmott, D.D.; Brown, L.F.; Currier, R.P.

    1997-08-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project was to evaluate the environmental impacts of home-scale coal combustion on the Navajo Reservation and develop strategies to reduce adverse health effects associated with home-scale coal combustion. Principal accomplishments of this project were: (1) determination of the metal and gaseous emissions of a representative stove on the Navajo Reservation; (2) recognition of cyclic gaseous emissions in combustion in home-scale combustors; (3) `back of the envelope` calculation that home-scale coal combustion may impact Navajo health; and (4) identification that improved coal stoves require the ability to burn diverse feedstocks (coal, wood, biomass). Ultimately the results of Navajo home-scale coal combustion studies will be extended to the Developing World, particularly China, where a significant number (> 150 million) of households continue to heat their homes with low-grade coal.

  19. Fiber optic sensing system for temperature and gas monitoring in coal waste pile combustion environments

    NASA Astrophysics Data System (ADS)

    Viveiros, D.; Ribeiro, J.; Ferreira, J.; Lopez-Albada, A.; Pinto, A. M. R.; Perez-Herrera, R. A.; Diaz, S.; Lopez-Gil, A.; Dominguez-Lopez, A.; Esteban, O.; Martin-Lopez, S.; Auguste, J.-L.; Jamier, R.; Rougier, S.; Silva, S. O.; Frazão, O.; Santos, J. L.; Flores, D.; Roy, P.; Gonzalez-Herraez, M.; Lopez-Amo, M.; Baptista, J. M.

    2015-09-01

    It is presented an optical fiber sensing system projected to operate in the demanding conditions associated with coal waste piles in combustion. Distributed temperature measurement and spot gas sensing are requirements for such a system. A field prototype has been installed and is continuously gathering data, which will input a geological model of the coal waste piles in combustion aiming to understand their dynamics and evolution. Results are presented on distributed temperature and ammonia measurement, being noticed any significant methane emission in the short time period considered. Carbon dioxide is also a targeted gas for measurement, with validated results available soon. The assessment of this technology as an effective and reliable tool to address the problem of monitoring coal waste piles in combustion opens the possibility of its widespread application in view of the worldwide presence of coal related fires.

  20. Coal combustion research

    SciTech Connect

    Daw, C.S.

    1996-06-01

    This section describes research and development related to coal combustion being performed for the Fossil Energy Program under the direction of the Morgantown Energy Technology Center. The key activity involves the application of chaos theory for the diagnosis and control of fossil energy processes.

  1. Toxic emissions from coal combustion

    SciTech Connect

    Senior, C.L.; Bool, L.E. III; Morency, J.R.

    1998-12-31

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Of the 189 substances identified as HAPs by Title III of the 1990 Clean Air Act Amendments (CAAA), 37 species, including 11 metals, have been detected by the Electric Power Research Institute (EPRI) in the flue gases of pulverized coal-fired utility boilers. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. Over the past decade, a large database identifying the partitioning and emitted concentrations of several of these species has been developed. Laboratory data have also been generated to help define the general behavior of several elements in combustion systems. These data have been used to develop empirical and probabilistic models to predict species emissions. While useful for providing average emissions of toxic species, these empirically based models fail when extrapolated beyond their supporting database. To ensure that coal-fired power generation proceeds in an environmentally benign fashion, methods for the prediction and control of toxic species in a broad range of coal fired systems must be developed. A team of researchers are conducting a detailed research program with three major objectives: (1) to elucidate the important mechanisms of toxics formation and partitioning; (2) to develop submodels for the appropriate trace toxic species transformations; and (3) to incorporate these mechanisms into an Engineering Model to predict trace toxic formation, partitioning, and fate based upon coal and combustion parameters. In the two-year Phase 1 program described here, preliminary experiments were performed to decide upon the relevant mechanisms for trace element transformations. The three-year Phase 2 program which has recently begun will contain more detailed

  2. Development and testing of commercial-scale, coal-fired combustion systems, Phase 3

    SciTech Connect

    Not Available

    1990-01-01

    The US Department of Energy's Pittsburgh Energy Technology Center (PETC) is actively pursuing the development and testing of coal-fired combustion systems for residential, commercial, and industrial market sectors. In response, MTCI initiated the development of a new combustor technology based on the principle of pulse combustion under the sponsorship of PETC (Contract No. AC22-83PC60419). The initial pulse combustor development program was conducted in three phases (MTCI, Development of a Pulsed Coal Combustor Fired with CWM, Phase III Final Report, DOE Contract No. AC22-83PC60419, November 1986). Phase I included a review of the prior art in the area of pulse combustion and the development of pulse combustor design concepts. It led to the conclusion that pulse combustors offer technical and base-of-operation advantages over conventional burners and also indicated favorable economics for replacement of oil- and gas-fired equipment.

  3. Oxy-fuel combustion systems for pollution free coal fired power generation

    SciTech Connect

    Ochs, Thomas L.; Oryshchyn, Danylo B.; Gross, Dietrich; Patrick, Brian; Gross, Alex; Dogan, Cindy; Summers, Cathy A.; Simmons, William; Schoenfeld, Mark

    2004-01-01

    Jupiter Oxygen's patented oxy-fuel combustion systems1 are capable of economically generating power from coal with ultra-low emissions and increased boiler efficiency. Jupiter's system uses pure oxygen as the combustion agent, excluding air and thus nitrogen, concentrating CO2 and pollutants for efficient capture with near zero NOx production, reducing exhaust mass flow, and increasing radiant heat transfer. Flue-gas recirculation rates can be varied to add flexibility to new boiler designs using this technology. Computer modeling and thermal analysis have identified important design considerations in retrofit applications.

  4. Bleederless ventilation systems as a spontaneous combustion control measure in US coal mines. Information circular/1994

    SciTech Connect

    Smith, A.C.; Diamond, W.P.; Mucho, T.P.; Organiscak, J.A.

    1994-01-01

    The U.S. Bureau of Mines conducted a worldwide literature review of bleederless ventilation practices to evaluate their use as a spontaneous combustion control measure in U.S. coal mines. Factors that must be taken into account in the design and use of these systems include seal construction, the use of ventilation control devices, the use of methane-drainage systems in gassy mines, and the ground control plan. Monitoring for the detection of spontaneous combustion and the control of methane when methane-drainage techniques are employed is critical to the successful use of a bleederless ventilation system. The report describes the types of ventilation systems used throughout the world and the spontaneous combustion risks associated with these systems.

  5. Fiber optic sensing system for monitoring of coal waste piles in combustion

    NASA Astrophysics Data System (ADS)

    Viveiros, D.; Ribeiro, J.; Carvalho, J. P.; Ferreira, J.; Pinto, A. M. R.; Perez-Herrera, R. A.; Diaz, S.; Lopez-Gil, A.; Dominguez-Lopez, A.; Esteban, O.; Martins, H. F.; Martin-Lopez, S.; Baierl, H.; Auguste, J.-L.; Jamier, R.; Rougier, S.; Santos, J. L.; Flores, D.; Roy, P.; González-Herráez, M.; López-Amo, M.; Baptista, J. M.

    2014-05-01

    The combustion of coal wastes resulting from mining is of particular environmental concern and therefore the importance of the proper management involving real-time assessment of their status and identification of probable evolution scenarios is recognized. Continuous monitoring of combustion temperature and emission levels of certain gases opens the possibility to plan corrective actions to minimize their negative impact in the surroundings. Optical fiber technology is well-suited to this purpose and in this work it is described the main attributes of a fiber optic sensing system projected to gather data on distributed temperature and gas emission in these harsh environments.

  6. Transformations of inorganic coal constituents in combustion systems

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. ); Kang, Shin-Gyoo; Sarofim, A.F.; Beer, J.M. ); Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L. ); Shah, N.; Huggins, F.E.; Huffman, G.P. )

    1991-09-01

    The technical objectives of this project are: (1) To define the partitioning of inorganic constituents associated with raw coal particles among products (including vapors, aerosols, and residual char/ash particles) formed under conditions representative of pulverized coal flames as a function of the specific (intrinsic and extrinsic) characteristics of the raw coal and the environment in which the transformations occur; and to characterize the resultant spectrum of products in detail. (2) To elucidate and quantify the fundamental processes (involving basic principles of physics, chemistry, thermodynamics) by which transformations of the inorganic constituents occur; and (3) to develop, based on the information required in (1) and (2), a tractable process'' model capable of predicting the significant features of the transformation process, most importantly, the nature and distribution of products. 26 refs., 151 figs., 51 tabs.

  7. Development and Testing of Industrial Scale Coal Fired Combustion System, Phase 3

    SciTech Connect

    Bert Zauderer

    1998-09-30

    Coal Tech Corp's mission is to develop, license & sell innovative, lowest cost, solid fuel fired power systems & total emission control processes using proprietary and patented technology for domestic and international markets. The present project 'DEVELOPMENT & TESTING OF INDUSTRIAL SCALE, COAL FIRED COMBUSTION SYSTEM, PHASE 3' on DOE Contract DE-AC22-91PC91162 was a key element in achieving this objective. The project consisted of five tasks that were divided into three phases. The first phase, 'Optimization of First Generation 20 MMBtu/hr Air-Cooled Slagging Coal Tech Combustor', consisted of three tasks, which are detailed in Appendix 'A' of this report. They were implemented in 1992 and 1993 at the first generation, 20 MMBtu/hour, combustor-boiler test site in Williamsport, PA. It consisted of substantial combustor modifications and coal-fired tests designed to improve the combustor's wall cooling, slag and ash management, automating of its operation, and correcting severe deficiencies in the coal feeding to the combustor. The need for these changes was indicated during the prior 900-hour test effort on this combustor that was conducted as part of the DOE Clean Coal Program. A combination of combustor changes, auxiliary equipment changes, sophisticated multi-dimensional combustion analysis, computer controlled automation, and series of single and double day shift tests totaling about 300 hours, either resolved these operational issues or indicated that further corrective changes were needed in the combustor design. The key result from both analyses and tests was that the combustor must be substantially lengthened to maximize combustion efficiency and sharply increase slag retention in the combustor. A measure of the success of these modifications was realized in the third phase of this project, consisting of task 5 entitled: 'Site Demonstration with the Second Generation 20 MMBtu/hr Air-Cooled Slagging Coal Tech Combustor'. The details of the task 5 effort are

  8. A coal-fired combustion system for industrial process heating applications

    SciTech Connect

    Not Available

    1992-09-03

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation's Phase III development contract DE-AC22-91PC91161 for a Coal-Fired Combustion System for Industrial Process Heating Applications'' is project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelling and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the current reporting period, approval of Vortec's Environmental Assessment (EA) required under the National Environmental Policy Act (NEPA) was approved. The EA approval cycle took approximately 9 months. The preliminary test program which was being held in abeyance pending approval of the EA was initiated. Six preliminary test runs were successfully competed during the period. Engineering and design activities in support of the Phase III proof of concept are continuing, and modifications to the existing test system configuration to allow performance of the preliminary tests were completed.

  9. TOXIC SUBSTANCES FROM COAL COMBUSTION

    SciTech Connect

    Kolker, A.; Sarofim, A.F.; Palmer, C.A.; Huggins, F.E.; Huffman, G.P.; Lighty, J.; Veranth, J.; Helble, J.J.; Wendt, J.O.L.; Ames, M.R.; Finkelman, R.; Mamani-Paco, M.; Sterling, R.; Mroczkowsky, S.J.; Panagiotou, T.; Seames, W.

    1999-05-10

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environ-mental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from 1 January 1999 to 31 March 1999. During this period, a full Program Review Meeting was held at the University of Arizona. At this meeting, the progress of each group was reviewed, plans for the following 9 month period were discussed, and action items (principally associated with the transfer of samples and reports among the various investigators) were identified.

  10. Development and testing of a commercial-scale coal-fired combustion system, Phase 3

    SciTech Connect

    Litka, A.F.; Breault, R.W.

    1992-05-01

    Within the commercial sector, oil and natural gas are the predominant fuels used to meet the space-heating needs of schools, office buildings, apartment complexes, and other similar structures. In general, these buildings require firing rates of 1 to 10 million Btu/hr. The objective of this program is to demonstrate the technical and economic viability of a coal-fired combustion system for this sector. The commercial-scale coal-water slurry (CWS)-fired space heating system will be a scale-up of a CWS-fired residential warm-air heating system developed by Tecogen under contract to the Department of Energy, Pittsburgh Energy Technology Center. This system included a patented nonslagging combustor known as IRIS, for Inertial Reactor with Internal Separation. This combustion technology, which has demonstrated high combustion efficiency using CWS fuels at input rates of 100,000 Btu/hr, will be scaled to operate at 2 to 5 millon Btu/hr. Along with the necessary fuel storage and delivery, heat recovery, and control equipment, the system will include pollution control devices to meet targeted values of NO{sub x}, S0{sub 2}, and particulate emissions. In general, the system will be designed to match the reliability, safety, turndown, and ignition performance of gas or oil-fired systems.

  11. Development and testing of a commercial-scale coal-fired combustion system, Phase 3

    SciTech Connect

    Litka, A.F.; Breault, R.W.

    1991-07-01

    Within the commercial sector, oil and natural gas are the predominant fuels used to meet the space-heating needs of schools, office buildings, apartment complexes, and other similar structures. In general, these buildings require firing rates of 1 to 10 million Btu/hr. The objective of this program is to demonstrate the technical and economic viability of a coal-fired combustion system for this sector. The commercial-scale coal-water slurry (CWS)-fired space heating system will be a scale-up of a CWS-fired residential warm-air heating system developed by Tecogen under contract to the Department of Energy, Pittsburgh Energy Technology Center. This system included a patented nonslagging combustor known as IRIS, for Inertial Reactor with Internal Separation. This combustion technology, which has demonstrated high combustion efficiency using CWS fuels at input rates of 100,000 Btu/hr, will be scaled to operate at 2 to 5 millon Btu/hr. Along with the necessary fuel storage and delivery, heat recovery, and control equipment, the system will include pollution control devices to meet targeted values of NO{sub x}, S0{sub 2}, and particulate emissions. In general, the system will be designed to match the reliability, safety, turndown, and ignition performance of gas or oil-fired systems.

  12. Development and testing of a commercial-scale coal-fired combustion system, Phase 3

    SciTech Connect

    Litka, A.F.; Breault, R.W.

    1991-10-01

    Within the commercial sector, oil and natural gas are the predominant fuels used to meet the space-heating needs of schools, office buildings, apartment complexes, and other similar structures. In general, these buildings require firing rates of 1 to 10 million Btu/hr. The objective of this program is to demonstrate the technical and economic viability of a coal-fired combustion system for this sector. The commercial-scale coal-water slurry (CWS)-fired space heating system will be a scale-up of a CWS-fired residential warm-air heating system developed by Tecogen under contract to the Department of Energy, Pittsburgh Energy Technology Center. This system included a patented nonslagging combustor known as IRIS, for Inertial Reactor with Internal Separation. This combustion technology, which has demonstrated high combustion efficiency using CWS fuels at input rates of 100,000 Btu/hr, will be scaled to operate at 2 to 5 millon Btu/hr. Along with the necessary fuel storage and delivery, heat recovery, and control equipment, the system will include pollution control devices to meet targeted values of NO{sub x}, S0{sub 2}, and particulate emissions. In general, the system will be designed to match the reliability, safety, turndown, and ignition performance of gas or oil-fired systems.

  13. Coal char fragmentation during pulverized coal combustion

    SciTech Connect

    Baxter, L.L.

    1995-07-01

    A series of investigations of coal and char fragmentation during pulverized coal combustion is reported for a suite of coals ranging in rank from lignite to low-volatile (lv) bituminous coal under combustion conditions similar to those found in commercial-scale boilers. Experimental measurements are described that utilize identical particle sizing characteristics to determine initial and final size distributions. Mechanistic interpretation of the data suggest that coal fragmentation is an insignificant event and that char fragmentation is controlled by char structure. Chars forming cenospheres fragment more extensively than solid chars. Among the chars that fragment, large particles produce more fine material than small particles. In all cases, coal and char fragmentation are seen to be sufficiently minor as to be relatively insignificant factors influencing fly ash size distribution, particle loading, and char burnout.

  14. The development of a coal-fired combustion system for industrial process heating applications

    SciTech Connect

    Not Available

    1992-07-16

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation's Coal-Fired Combustion System for Industrial Process Heating Applications has been selected for Phase III development under contract DE-AC22-91PC91161. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting, recycling, and refining processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase HI research effort is being focused on the development of a process heater system to be used for producing glass frits and wool fiber from boiler and incinerator ashes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. The economic evaluation of commercial scale CMS processes has begun. In order to accurately estimate the cost of the primary process vessels, preliminary designs for 25, 50, and 100 ton/day systems have been started under Task 1. This data will serve as input data for life cycle cost analysis performed as part of techno-economic evaluations. The economic evaluations of commercial CMS systems will be an integral part of the commercialization plan.

  15. Factors affecting the corrosion rates of ceramics in coal combustion systems

    SciTech Connect

    Hurley, J.P.

    1995-08-01

    The concentrations of approximately a dozen elements in the products of coal combustion affect the corrosion rates of ceramics used to construct the combustion system. The elements, including H, O, Na, Mg, Al, Si, P, S, Cl, K, Ca, and Fe, affect corrosion rates in three ways: as primary corrodants of the materials, as secondary corrodants that affect the activities of the primary corrodants, and by affecting the mass transport rate of the primary corrodants. A full factorial study of corrosion rates performed by varying the concentrations of these elements would involve X{sup n} tests, where X is the number of variations of each element and n is the number of different elements. For three variations (low, medium, and high concentrations) of each of 12 elements, the number of tests is 531,441 for a single temperature and pressure condition. The numbers can be reduced with the use of a fractional factorial test matrix, but the most effective way to perform corrosion tests is to base them on realistic system conditions. In this paper, the effects of the composition and physical state of the products of coal combustion on ceramic corrosion rates are given along with suggestions of appropriate test conditions for specific system components.

  16. Catalyzing the Combustion of Coal

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; Dokko, W.

    1982-01-01

    Reaction rate of coal in air can be increased by contacting or coating coal with compound such as calcium acetate. The enhanced reaction rate generates more heat, reducing furnace size. Increase in combustion rate is about 26 percent, and internal pollutants in powerplant are reduced.

  17. A coal-fired combustion system for industrial process heating applications

    SciTech Connect

    Not Available

    1992-10-30

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashesand industrial wastes. ne primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order toevaluate its potential marketability. During the current reporting period, three preliminary coal-fired tests were successfully completed. These tests used industrial boiler flyash, sewer sludge ash, and waste glass collet as feedstocks. The coal-fired ash vitrification tests are considered near term potential commercial applications of the CMS technology. The waste glass cullet provided necessary dam on the effect of coal firing with respect to vitrified product oxidation state. Engineering and design activities in support of the Phase III proof of concept are continuing, and modifications to the existing test system configuration to allow performance of the proof-of-concept tests are continuing. The economic evaluation of commercial scale CMS processes is continuing. Preliminary designs for 15, 25, 100 and 400 ton/day systems are in progress. This dam will serve as input data to the life cycle cost analysis which will be-an integral part of the CMS commercialization plan.

  18. A coal-fired combustion system for industrial processing heating applications. Quarterly technical progress report, January 1995--March 1995

    SciTech Connect

    1995-04-01

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation`s Phase III development contract DE-AC22-91PC91161 for a {open_quotes}Coal-Fired Combustion System for Industrial Process Heating Applications{close_quotes} is a project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. The test program consisted of one test run, with a duration of 100 hours at a nominal feed rate of 1000 lbs/hr. Throughout the test, the CMS was fired with coal and a coal by-product (i.e. coal-fired boiler fly ash) as the primary fuels. Natural gas was used as an auxiliary fuel as necessary to provide process trim. The feedstock consisted of a coal-fired utility boiler fly ash and dolomite and produced a stable, fully-reacted vitrified product. The fly ash, supplied by PENELEC, contained between 6 and 12% by weight of carbon because of the low NOx burners on the PENELEC boilers. Therefore, a substantial portion of the required thermal input came from the fly ash.

  19. Health impacts of domestic coal combustion

    SciTech Connect

    Finkelman, R.B.

    1999-07-01

    The US Environmental Protection Agency (EPA) has concluded that, with the possible exception of mercury, there is no compelling evidence to indicate that emissions from coal-burning electric utility generators cause human health problems. The absence of detectable health problems is in part due to the fact that the coals burned in the US generally contain low to modest concentrations of potentially toxic trace elements and that many coal-burning utilities employ sophisticated pollution control systems that efficiently reduce the emissions of hazardous elements. This is not so in many developing countries, especially in homes where coal is used for heating and cooking. Domestic use of coal can present serious human health problems because the coals are generally mined locally with little regard to their composition and the coals are commonly burned in poorly vented or unvented stoves directly exposing residents to the emissions. In China alone several hundred million people commonly burn raw coal in unvented stoves that permeate their homes with high levels of toxic metals and organic compounds. At least 3,000 people in Guizhou Province in southwest China are suffering from severe arsenic poisoning. The primary source of the arsenic appears to be consumption of chili peppers dried over fires fueled with high-arsenic coal. Coal's in the region contain up to 35,000 ppm arsenic. Chili peppers dried over these high-arsenic coal fires absorb 500 ppm arsenic on average. More than 10 million people in Guizhou Province and surrounding areas suffer from dental and skeletal fluorosis. The excess fluorine is due to eating corn dried over burning briquettes made from high-fluorine coals and high-fluoring clay binders. Polycyclic aromatic hydrocarbons formed during coal combustion are believed to cause or contribute to the high incidence of esophageal and lung cancers in parts of China. Domestic coal combustion has also caused selenium poisoning and possibly mercury poisoning

  20. Modeling the behavior of selenium in Pulverized-Coal Combustion systems

    SciTech Connect

    Senior, Constance; Otten, Brydger Van; Wendt, Jost O.L.; Sarofim, Adel

    2010-11-15

    The behavior of Se during coal combustion is different from other trace metals because of the high degree of vaporization and high vapor pressures of the oxide (SeO{sub 2}) in coal flue gas. In a coal-fired boiler, these gaseous oxides are absorbed on the fly ash surface in the convective section by a chemical reaction. The composition of the fly ash (and of the parent coal) as well as the time-temperature history in the boiler therefore influences the formation of selenium compounds on the surface of the fly ash. A model was created for interactions between selenium and fly ash post-combustion. The reaction mechanism assumed that iron reacts with selenium at temperatures above 1200 C and that calcium reacts with selenium at temperatures less than 800 C. The model also included competing reactions of SO{sub 2} with calcium and iron in the ash. Predicted selenium distributions in fly ash (concentration versus particle size) were compared against measurements from pilot-scale experiments for combustion of six coals, four bituminous and two low-rank coals. The model predicted the selenium distribution in the fly ash from the pilot-scale experiments reasonably well for six coals of different compositions. (author)

  1. Coal combustion science. Quarterly progress report, April 1993--June 1993

    SciTech Connect

    Hardesty, D.R.

    1994-05-01

    This document is a quarterly status report of the Coal Combustion Science Project that is being conducted at the Combustion Research Facility, Sandia National Laboratories. The information reported is for Apr-Jun 1993. The objective of this work is to support the Office of Fossil Energy in executing research on coal combustion science. This project consists of basic research on coal combustion that supports both the PETC Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. The objective of the kinetics and mechanisms of pulverized coal char combustion task is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. Work is being done in four areas: kinetics of heterogeneous fuel particle populations; char combustion kinetics at high carbon conversion; the role of particle structure and the char formation process in combustion and; unification of the Sandia char combustion data base. This data base on the high temperature reactivities of chars from strategic US coals will permit identification of important fuel-specific trends and development of predictive capabilities for advanced coal combustion systems. The objective of the fate of inorganic material during coal combustion task is the establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of inorganic material during coal combustion as a function of coal type, particle size and temperature, the initial forms and distribution of inorganic species in the unreacted coal, and the local gas temperature and composition. In addition, optical diagnostic capabilities are being developed for in situ, real-time detection of inorganic vapor species and surface species during ash deposition. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  2. Oxy-coal Combustion Studies

    SciTech Connect

    Wendt, J.; Eddings, E.; Lighty, J.; Ring, T.; Smith, P.; Thornock, J.; Y Jia, W. Morris; Pedel, J.; Rezeai, D.; Wang, L.; Zhang, J.; Kelly, K.

    2012-01-06

    The objective of this project is to move toward the development of a predictive capability with quantified uncertainty bounds for pilot-scale, single-burner, oxy-coal operation. This validation research brings together multi-scale experimental measurements and computer simulations. The combination of simulation development and validation experiments is designed to lead to predictive tools for the performance of existing air fired pulverized coal boilers that have been retrofitted to various oxy-firing configurations. In addition, this report also describes novel research results related to oxy-combustion in circulating fluidized beds. For pulverized coal combustion configurations, particular attention is focused on the effect of oxy-firing on ignition and coal-flame stability, and on the subsequent partitioning mechanisms of the ash aerosol.

  3. CO2 post-combustion capture in coal-fired power plants integrated with solar systems

    NASA Astrophysics Data System (ADS)

    Carapellucci, R.; Giordano, L.; Vaccarelli, M.

    2015-11-01

    The majority of the World's primary energy consumption is still based on fossil fuels, representing the largest source of global CO2 emissions. According to the Intergovernmental Panel on Climate Change (IPCC), such emissions must be significantly reduced in order to avoid the dramatic consequences of global warming. A potential way to achieve this ambitious goal is represented by the implementation of CCS (Carbon Capture and Storage) technologies. However, the significant amount of energy required by the CCS systems still represents one the major barriers for their deployment. Focusing on post-combustion capture based on amine absorption, several interesting options have been investigated to compensate the energy losses due to solvent regeneration, also using renewable energy sources. One of the most promising is based on the use of concentrating solar power (CSP), providing a part of the energy requirement of the capture island. In this study the integration of a CSP system into a coal-fired power plant with CO2 postcombustion capture is investigated. Basically, a CSP system is used to support the heat requirement for amine regeneration, by producing saturated steam at low temperature. This allows to reduce or even eliminate the conventional steam extraction from the main power plant, affecting positively net power production and efficiency. The energy analysis of the whole system is carried out using the GateCycle software to simulate the coal-fired power plant and ChemCad platform for the CO2 capture process based on amine absorption.

  4. Oxy Coal Combustion at the US EPA

    EPA Science Inventory

    Oxygen enriched coal (oxy-coal) combustion is a developing, and potentially a strategically key technology intended to accommodate direct CO2 recovery and sequestration. Oxy-coal combustion is also intended for retrofit application to existing power plants. During oxy-coal comb...

  5. Oxy Coal Combustion at the US EPA

    EPA Science Inventory

    Oxygen enriched coal (oxy-coal) combustion is a developing, and potentially a strategically key technology intended to accommodate direct CO2 recovery and sequestration. Oxy-coal combustion is also intended for retrofit application to existing power plants. During oxy-coal comb...

  6. Coal combustion by wet oxidation

    SciTech Connect

    Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.

    1980-11-15

    The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

  7. Nitrogen release during coal combustion

    SciTech Connect

    Baxter, L.L.; Mitchell, R.E.; Fletcher, T.H.; Hurt, R.H.

    1995-02-01

    Experiments in entrained flow reactors at combustion temperatures are performed to resolve the rank dependence of nitrogen release on an elemental basis for a suite of 15 U.S. coals ranging from lignite to low-volatile bituminous. Data were obtained as a function of particle conversion, with overall mass loss up to 99% on a dry, ash-free basis. Nitrogen release rates are presented relative to both carbon loss and overall mass loss. During devolatilization, fractional nitrogen release from low-rank coals is much slower than fractional mass release and noticeably slower than fractional carbon release. As coal rank increases, fractional nitrogen release rate relative to that of carbon and mass increases, with fractional nitrogen release rates exceeding fractional mass and fractional carbon release rates during devolatilization for high-rank (low-volatile bituminous) coals. At the onset of combustion, nitrogen release rates increase significantly. For all coals investigated, cumulative fractional nitrogen loss rates relative to those of mass and carbon passes through a maximum during the earliest stages of oxidation. The mechanism for generating this maximum is postulated to involve nascent thermal rupture of nitrogen-containing compounds and possible preferential oxidation of nitrogen sites. During later stages of oxidation, the cumulative fractional loss of nitrogen approaches that of carbon for all coals. Changes in the relative release rates of nitrogen compared to those of both overall mass and carbon during all stages of combustion are attributed to a combination of the chemical structure of coals, temperature histories during combustion, and char chemistry.

  8. Co-combustion of coal and biomass in pulverized fuel and fluidized bed systems -- Activities and research in Europe

    SciTech Connect

    Hein, K.R.G.; Spliethoff, H.

    1999-07-01

    Biomass or sewage sludge utilized as additional fuel in coal combustion systems has consequences on combustion behavior, emissions, corrosion, and residual matter. Therefore, at the beginning of 1993 the European Union within the frame of the APAS program launched a project called ``Combined Combustion of Biomass/Sewage Sludge and Coal''. Within this project, the effects of burning sewage sludge and agricultural residuals such as straw and manure as well as specially grown energy plants in combination with coals of various ranks and origin were studied for the most common large-scale systems in order to establish both the optimum and the technically achievable process modifications necessary for co-combustion. Based on the experience of the APAS program, the objective of a further EU-co-funded project titled ``Operational problems, trace emissions and by-product management for industrial biomass co-combustion'' was to concentrate the research effort on the problem areas like slagging, fouling, corrosion, ash utilization and trace emissions for different co-combustion systems and carefully investigate technical options to avoid these negative effects. The solution of these technical problems is essential for a technically and economically feasible and environmentally advantageous co-combustion and will promote a widespread utilization of existing biomass resources. The project provides a comparison of different biomass co-utilization concepts with regard to fouling, slagging, corrosion, ash utilization and trace emissions. In detail the project incorporated biofuels like wood, wood pulp, bark, straw, wood matter from pressed olive stones and sewage sludge. The major operational problems like slagging, fouling and corrosion were investigated in both PF and CFB units of various scales. Finally the effect of co-combustion on the by-product management - handling, utilization and disposal are evaluated and compared with a pure coal or pure biomass combustion system

  9. A coal-fired combustion system for industrial process heating applications

    SciTech Connect

    Not Available

    1993-01-29

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashesand industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the current reporting period, a majority of the effort was spent relining the separator/reservoir and the cyclone melter. The relinings were completed, the cyclonemelter was reinstalled, and the test system was returned to operational status. The wet ESP was delivered and placed on its foundation. The focus during the upcoming months will be completing the integration ofthe wet ESP and conducting the first industrial proof-of-concept test. The other system modifications are well underway with the designs of the recuperator installation and the batch/coal feed system progressing smoothly. The program is still slightly behind the original schedule but it is anticipated that it will be back on schedule by the end of the year. The commercialization planning is continuing with the identification of seven potential near-term commercial demonstration opportunities.

  10. Development and Testing of Industrial Scale, Coal-Fired Combustion System: Phase 3.

    SciTech Connect

    Zauderer, B.

    1997-04-21

    In the first quarter of calendar year 1997, 17 days of combustor- boiler tests were performed, including one day of tests on a parallel DOE sponsored project on sulfur retention in a slagging combustor. Between tests, modifications and improvements that were indicated by these tests were implemented. This brings the total number of test days required to meet the task 5 project plan. The key project objectives in the areas of combustor performance and environmental performance have been exceeded. With sorbent injection in the combustion gas train, NO{sub x} emissions as low as 0.07 lb/MMBtu and SO{sub 2} emissions as low as 0.2 lb/MMBtu have been measured in tests in this quarter. Tests in the present quarter have resulted in further optimizing the sorbent injection and NO{sub x} control processes. A very important milestone in this quarter was two successful combustor tests on a very high ash (37%) Indian coal. Work in the next quarter will focus on commercialization of the combustor- boiler system. In addition, further tests of the NO{sub x} and SO{sub 2} control process and on the Indian coal will be performed.

  11. Heavy metals and coal combustion

    SciTech Connect

    Danihelka, P.; Ochodek, T.; Noskievic, P.; Seidlerova, J.

    1998-07-01

    Combustion of coal may be an important source of heavy metals pollution. The distribution of heavy metals during combustion process has been studied in six power plants, where fuel, bottom ash, fly ash and emissions have been analyzed and the relative concentrations of heavy metals have been estimated. For the most volatile metals (arsenic, antimony, lead, and zinc), the redistribution process involving condensation on surface is probable. Some metals like manganese or chromium are concentrated rather in coarse particles. In such cases, no clear conclusion can be made and probably several mechanisms are involved, including mineral form of metal. Typical results of low chlorine coal (0.01--0.03% Cl) exhibit increasing concentration of volatile metals in the magnitude of around one order when going from bottom ash to emissions. Different results have been found in similar operation conditions in the case of high content of chlorine in coal (0.3% of Cl in coal). In this case, the concentration of metals in emissions is significantly higher and also nickel, copper and manganese concentrations increase. It seems to be probable that chlorine in the coal increases the redistribution of metals by volatile chlorides formation. At three operation condition (nominal output, 70% and 40% respectively) emission factors of heavy metals have been estimated for 35 MW stoker-fired boiler. Ba, Pb, Sb and Zn increased their emission factors and Cr and Mn decreased when output was decreased. Heavy metals pollution caused by emissions from combustion of coal may be decreased by fine particles removal, other possibilities (metals extraction from the coal, changes of condition in the flame) are rather limited.

  12. Advanced coal-fueled industrial cogeneration gas turbine system -- combustion development

    SciTech Connect

    LeCren, R.T.

    1994-06-01

    This topical report summarizes the combustor development work accomplished under the subject contract. The objective was to develop a combustion system for the Solar 4MW Type H Centaur gas turbine generator set which was to be used to demonstrate the economic, technical and environmental feasibility of a direct coal-fueled gas turbine in a 100 hour proof-of-concept test. This program started with a design configuration derived during the CSC program. The design went through the following evolution: CSC design which had some known shortcomings, redesigned CSC now designated as the Two Stage Slagging Combustor (TSSC), improved TSSC with the PRIS evaluated in the IBSTF, and full scale design. Supporting and complimentary activities included computer modelling, flow visualization, slag removal, SO{sub x} removal, fuel injector development and fuel properties evaluation. Three combustor rigs were utilized: the TSSC, the IBSTF and the full scale rig at Peoria. The TSSC rig, which was 1/10th scale of the proposed system, consisted of a primary and secondary zone and was used to develop the primary zone performance and to evaluate SO{sub x} and slag removal and fuel properties variations. The IBSTF rig which included all the components of the proposed system was also 1/10th scale except for the particulate removal system which was about 1/30th scale. This rig was used to verify combustor performance data obtained on the TSSC and to develop the PRIS and the particulate removal system. The full scale rig initially included the primary and secondary zones and was later modified to incorporate the PRIS. The purpose of the full scale testing was to verify the scale up calculations and to provide a combustion system for the proof-of-concept engine test that was initially planned in the program.

  13. Combustion properties of micronized coal for high intensity combustion applications

    SciTech Connect

    Freihaut, J.D.; Proscia, W.; Knight, B.; Vranos, A.; Hollick, H.; Wicks, K.

    1989-04-19

    Results are presented of an investigation of combustion related properties of micronized coal feeds (all particles less than 40 microns), mixing characteristics of centrifugally driven burner devices, and aerodynamic characteristics of micronized coal particles related to centrifugal mixing for high intensity combustion applications. Combustion related properties investigated are the evolution of fuel bound nitrogen and coal associated mineral matter during the initial stages of combustion. Parent and beneficiated micronized coal samples, as well as narrow size cut samples from a wide range of coal ranks, were investigated using a multireactor approach. The multireactor approach allowed the experimental separation of different aspects of the fuel nitrogen evolution process, enabling a comprehensive understanding of FBN to be formulated and empirical rate constants to be developed. A specially designed on-line gas analysis system allowed nitrogen balance to be achieved. A combined nitrogen and ash tracer technique allowed the quantitative determination of tar yields during rapid devolatilization. Empirical kinetic rates are developed for the evolution of FBN with tar at low temperatures and the appearance of HCN from tar and char species at high temperatures. A specially designed phase separation system, coupled to separate aerosol and char segregation trains, allowed the possible formation of ash aerosol by rapid devolatilization to be monitored. Compensated thermocouple, hot wire anemometry, and digital imaging techniques are employed to characterize the mixing properties of a centrifugally driven combustor. Analytical and experimental investigations of the fidelity of micronized coal particles to gas stream trajectories in the strong centrifugal fields are performed. Both spherical and nonspherical particle morphologies are considered analytically. 14 refs., 141 figs., 34 tabs.

  14. Transformations of inorganic coal constituents in combustion systems. Volume 1, sections 1--5: Final report

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A.; Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M.; Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L.; Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A.

    1992-11-01

    The inorganic constituents or ash contained in pulverized coal significantly increase the environmental and economic costs of coal utilization. For example, ash particles produced during combustion may deposit on heat transfer surfaces, decreasing heat transfer rates and increasing maintenance costs. The minimization of particulate emissions often requires the installation of cleanup devices such as electrostatic precipitators, also adding to the expense of coal utilization. Despite these costly problems, a comprehensive assessment of the ash formation and had never been attempted. At the start of this program, it was hypothesized that ash deposition and ash particle emissions both depended upon the size and chemical composition of individual ash particles. Questions such as: What determines the size of individual ash particles? What determines their composition? Whether or not particles deposit? How combustion conditions, including reactor size, affect these processes? remained to be answered. In this 6-year multidisciplinary study, these issues were addressed in detail. The ambitious overall goal was the development of a comprehensive model to predict the size and chemical composition distributions of ash produced during pulverized coal combustion. Results are described.

  15. Heavy metals and coal combustion

    SciTech Connect

    Danihelka, P.; Ochodek, T.; Noskievic, P.; Seidlerova, J.

    1998-04-01

    Combustion of coal may be an important source of heavy metals pollution. The distribution of heavy metals during combustion process has been studied in six power plants, where fuel, bottom ash, fly ash and emissions have been analysed and the relative concentrations of heavy metals have been estimated. For the most volatile metals (arsenic, antimony, lead, and zinc), the redistribution process involving condensation on surface is probable. Some metals like manganese or chromium are concentrated rather in coarse particles. In such cases, no clear conclusion can be made and probably several mechanisms are involved, including mineral form of metal. Typical results of low chlorine coal (0.01-0.03% Cl) exhibit increasing concentration of volatile metals in the magnitude of around one order when going from bottom ash to emissions. Different results have been found in similar operation conditions in the case of high content of chlorine in coal (0.3 % of Cl in coal). In this case, the concentration of metals in emissions is significantly higher and also nickel, copper and manganese concentrations increase. It seems to be probable that chlorine in the coal increases the redistribution of metals by volatile chlorides formation.

  16. Enhanced Combustion Low NOx Pulverized Coal Burner

    SciTech Connect

    David Towle; Richard Donais; Todd Hellewell; Robert Lewis; Robert Schrecengost

    2007-06-30

    For more than two decades, Alstom Power Inc. (Alstom) has developed a range of low cost, infurnace technologies for NOx emissions control for the domestic U.S. pulverized coal fired boiler market. This includes Alstom's internally developed TFS 2000{trademark} firing system, and various enhancements to it developed in concert with the U.S. Department of Energy. As of the date of this report, more than 270 units representing approximately 80,000 MWe of domestic coal fired capacity have been retrofit with Alstom low NOx technology. Best of class emissions range from 0.18 lb/MMBtu for bituminous coal to 0.10 lb/MMBtu for subbituminous coal, with typical levels at 0.24 lb/MMBtu and 0.13 lb/MMBtu, respectively. Despite these gains, NOx emissions limits in the U.S. continue to ratchet down for new and existing boiler equipment. On March 10, 2005, the Environmental Protection Agency (EPA) announced the Clean Air Interstate Rule (CAIR). CAIR requires 25 Eastern states to reduce NOx emissions from the power generation sector by 1.7 million tons in 2009 and 2.0 million tons by 2015. Low cost solutions to meet such regulations, and in particular those that can avoid the need for a costly selective catalytic reduction system (SCR), provide a strong incentive to continue to improve low NOx firing system technology to meet current and anticipated NOx control regulations. The overall objective of the work is to develop an enhanced combustion, low NOx pulverized coal burner, which, when integrated with Alstom's state-of-the-art, globally air staged low NOx firing systems will provide a means to achieve: Less than 0.15 lb/MMBtu NOx emissions when firing a high volatile Eastern or Western bituminous coal, Less than 0.10 lb/MMBtu NOx emissions when firing a subbituminous coal, NOx reduction costs at least 25% lower than the costs of an SCR, Validation of the NOx control technology developed through large (15 MWt) pilot scale demonstration, and Documentation required for economic

  17. Transformations of inorganic coal constituents in combustion systems. Volume 2, Sections 6 and 7: Final report

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A.; Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M.; Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L.; Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A.

    1992-11-01

    Results from an experimental investigation of the mechanisms governing the ash aerosol size segregated composition resulting from the combustion of pulverized coal in a laboratory scale down-flow combustor are described. The results of modeling activities used to interpret the results of the experiments conducted under his subtask are also described in this section. Although results from the entire program are included, Phase II studies which emphasized: (1) alkali behavior, including a study of the interrelationship between potassium vaporization and sodium vaporization; and (2) iron behavior, including an examination of the extent of iron-aluminosilicate interactions, are highlighted. Idealized combustion determination of ash particle formation and surface stickiness are also described.

  18. Coal combustion byproducts and environmental issues

    SciTech Connect

    Sajwan, K.S.; Twardowska, I.; Punshon, T.; Alva, A.K.

    2006-07-01

    The book addresses the major implications and critical issues surrounding coal combustion products and their impact upon the environment. It provides essential information for scientists conducting research on coal and coal combustion products, but also serves as a valuable reference for a wide variety of researchers and other professionals in the energy industry and in the fields of public health, engineering, and environmental sciences.

  19. Fluidized bed coal combustion reactor

    NASA Technical Reports Server (NTRS)

    Moynihan, P. I.; Young, D. L. (Inventor)

    1981-01-01

    A fluidized bed coal reactor includes a combination nozzle-injector ash-removal unit formed by a grid of closely spaced open channels, each containing a worm screw conveyor, which function as continuous ash removal troughs. A pressurized air-coal mixture is introduced below the unit and is injected through the elongated nozzles formed by the spaces between the channels. The ash build-up in the troughs protects the worm screw conveyors as does the cooling action of the injected mixture. The ash layer and the pressure from the injectors support a fluidized flame combustion zone above the grid which heats water in boiler tubes disposed within and/or above the combustion zone and/or within the walls of the reactor.

  20. DEVELOPMENT AND TESTING OF INDUSTRIAL SCALE, COAL FIRED COMBUSTION SYSTEM, PHASE 3

    SciTech Connect

    Dr. Bert Zauderer

    1999-03-11

    In the second half of calendar year 1998, no work was performed on the present project. The 20 MMBtu/hr combustor-boiler facility was operated for 11 tests, primarily with Coal Tech resources on biomass combustion and gasification. The total test days on the Philadelphia facility to the end of August 1998 was 119. Of these, 36 tests were part of another DOE project on sulfur retention is slag, and 8 were on an in-house biomass combustion effort. The test days on the other project are listed here because they demonstrate the durability of the combustor, which is one of the objectives of the present project. Also, the test work of 1998 revealed for the first time the major potential of this combustor for biomass combustion. These tests are double the 63 tests in the original plan for this project. All key project objectives have been exceeded including combustor durability, automated combustor operation, NO{sub x} emissions as low as 0.07 lb/MMBtu and SO{sub 2} emissions as low as 0.2 lb/MMBtu. In addition, a novel post-combustion NOx control process has been tested on a 37 MW and 100 MW utility boiler. The only effort remaining on this project is facility disassembly and Final Report. However, as part of the commercialization effort for this combustor technology, Coal Tech is planning to maintain the combustor facility in an operational mode at least through 2001. Coal Tech is focusing on utilizing the combustor with biomass fuels in very low cost, small (1 MW nominal) steam power plants. Worldwide application of this technology would have a major impact in reduction of greenhouse gas emissions because the energy content of agricultural biomass is equal to the energy content of the USA's annual coal production.

  1. Development and testing of industrial scale, coal fired combustion system, Phase 3

    SciTech Connect

    Zauderer, B.

    1993-02-15

    A major part of the work in this quarter was on the combustor tests in task 2. Three of the six planned tests in this task were completed. The first two were parametric tests of nominal one shift, (8 hour) duration on coal. Due to failure of the UV detector in the first test only several hours of coal fired operation were completed. In the second test, coal fired operation continued for the planned one shift until the 4 ton coal bin was empty. After reviewing this work with DOE, it was decided to focus the remaining test on longer duration operation with each test at one optimum condition. The third test was planned for two shift coal fired operation. Due to a problem with the pilot gas ignitor, combustion was delayed by 5 hours from 7 AM to Noon. As a result coal fired operation was limited to one shift between 3 PM and 11 PM. Throughout this period the combustor remained at one fixed condition with the use of computer control. Results for these three tests are presented in this report. Most of the work on the task 4 design and cost of a 20 MW combined gas-steam turbine power plant using the air cooled combustor was completed in the previous quarter. The results obtained by the A/E subcontractor on the installation desip and cost were evaluated in the present quarter and they are summarized in this report.

  2. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, October 1994--December 1994

    SciTech Connect

    1995-03-01

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation`s Phase III development contract DE-AC22-91PC91161 for a {open_quotes}Coal-Fired Combustion System for Industrial Process Heating Applications{close_quotes} is a project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the past quarter, the major effort was concentrated on conducting the 100 hour demonstration test. The test was successfully conducted from September 12th through the 16th. The test program consisted of one test run, with a duration of 100 hours at a nominal feed rate of 1000 lbs/hr. Throughout the test, the CMS was fired with coal and a coal by-product (i.e. coal-fired boiler flyash) as the primary fuels. Natural gas was used as an auxiliary fuel as necessary to provide process trim. The feedstock consisted of a coal-fired utility boiler flyash and dolomite and produced a stable, fully-reacted vitrified product. The fly ash, supplied by PENELEC, contained between 6 and 12% by weight of carbon because of the low NO{sub x} burners on the PENELEC boilers.

  3. DEVELOPMENT OF A VORTEX CONTAINMENT COMBUSTOR FOR COAL COMBUSTION SYTEMS

    EPA Science Inventory

    The report describes the development of a vortex containment combustor (VCC) for coal combustion systems, designed to solve major problems facing the conversion of oil- and gas-fired boilers to coal (e.g., derating, inorganic impurities in coal, and excessive formation of NOx and...

  4. DEVELOPMENT OF A VORTEX CONTAINMENT COMBUSTOR FOR COAL COMBUSTION SYTEMS

    EPA Science Inventory

    The report describes the development of a vortex containment combustor (VCC) for coal combustion systems, designed to solve major problems facing the conversion of oil- and gas-fired boilers to coal (e.g., derating, inorganic impurities in coal, and excessive formation of NOx and...

  5. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, April 1992--June 1992

    SciTech Connect

    Not Available

    1992-09-03

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation`s Phase III development contract DE-AC22-91PC91161 for a ``Coal-Fired Combustion System for Industrial Process Heating Applications`` is project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelling and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the current reporting period, approval of Vortec`s Environmental Assessment (EA) required under the National Environmental Policy Act (NEPA) was approved. The EA approval cycle took approximately 9 months. The preliminary test program which was being held in abeyance pending approval of the EA was initiated. Six preliminary test runs were successfully competed during the period. Engineering and design activities in support of the Phase III proof of concept are continuing, and modifications to the existing test system configuration to allow performance of the preliminary tests were completed.

  6. Intelligent Control via Wireless Sensor Networks for Advanced Coal Combustion Systems

    SciTech Connect

    Aman Behal; Sunil Kumar; Goodarz Ahmadi

    2007-08-05

    Numerical Modeling of Solid Gas Flow, System Identification for purposes of modeling and control, and Wireless Sensor and Actor Network design were pursued as part of this project. Time series input-output data was obtained from NETL's Morgantown CFB facility courtesy of Dr. Lawrence Shadle. It was run through a nonlinear kernel estimator and nonparametric models were obtained for the system. Linear and first-order nonlinear kernels were then utilized to obtain a state-space description of the system. Neural networks were trained that performed better at capturing the plant dynamics. It is possible to use these networks to find a plant model and the inversion of this model can be used to control the system. These models allow one to compare with physics based models whose parameters can then be determined by comparing them against the available data based model. On a parallel track, Dr. Kumar designed an energy-efficient and reliable transport protocol for wireless sensor and actor networks, where the sensors could be different types of wireless sensors used in CFB based coal combustion systems and actors are more powerful wireless nodes to set up a communication network while avoiding the data congestion. Dr. Ahmadi's group studied gas solid flow in a duct. It was seen that particle concentration clearly shows a preferential distribution. The particles strongly interact with the turbulence eddies and are concentrated in narrow bands that are evolving with time. It is believed that observed preferential concentration is due to the fact that these particles are flung out of eddies by centrifugal force.

  7. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, April 1993--June 1993

    SciTech Connect

    Not Available

    1993-07-30

    Vortec Corporation`s Phase III development contract DE-AC22-91PC91161 for a ``Coal-Fired Combustion System for Industrial Process Heating Applications`` is project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the past quarter, the designs of the remaining major components of the integrated system were completed and the equipment was ordered. DOE has elected to modify the scope of the existing R&D program being conducted under this contract to include testing of a simulated TSCA incinerator ash. The modification will be in the form of an additional Task (Task 8 -- TSCA Ash Testing) to the original Statement of Work.

  8. Development and Testing of Industrial Scale Coal-Fired Combustion System, Phase 3

    SciTech Connect

    Zauderer, Bert

    1997-02-27

    In the fourth quarter of calendar year 1996, 15 days of combust-boiler tests were performed, including 10 days of tests on a parallel DOE sponsored project on sulfur retention in a slagging combustor. Between tests, modifications and improvements that were indicated by these tests were implemented. This brings the total number of test days to the end of December in the task 5 effort to 57, increased to 65 as of the date of this Report, 1/27/97. This compares with a total of 63 test days needed to complete the task 5 test effort, and it completes the number of tests days required to meet the task 5 project plan. The key project objectives of the areas of combustor performance and environmental performance have been exceeded. With sorbent injection in the combustion gas train, NOX emissions as low as 0.07 lb/MMBtu and S02 emissions as low as 0.2 lb/MMBtu have been measured in tests in this quarter. Work in the next quarter will focus on even greater reductions in environmental emissions. Also tests are planned with coals other than the Eastern US bituminous coals tested in this project. For example, it is planned to tests Indian coals whose ash concentration is in the 40 {approx} 0 range.

  9. Transformations of inorganic coal constituents in combustion systems. Volume 3, Appendices: Final report

    SciTech Connect

    Helble, J.J.; Srinivasachar, S.; Wilemski, G.; Boni, A.A.; Kang, Shim-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M.; Peterson, T.W.; Wendt, O.L.; Gallagher, N.B.; Bool, L.; Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A.

    1992-11-01

    This report contains the computer codes developed for the coal combustion project. In Subsection B.1 the FORTRAN code developed for the percolative fragmentation model (or the discrete model, since a char is expressed as a collection of discrete elements in a discrete space) is presented. In Subsection B.2 the code for the continuum model (thus named because mineral inclusions are distributed in a continuum space) is presented. A stereological model code developed to obtain the pore size distribution from a two-dimensional data is presented in Subsection B.3.

  10. Disposal of coal combustion residues in terrestrial systems: contamination and risk management.

    PubMed

    Dellantonio, Alex; Fitz, Walter J; Repmann, Frank; Wenzel, Walter W

    2010-01-01

    The world's ever-growing energy demand will lead to the installation of new coal-fired power plants. At least part of the coal combustion residue (CCR) generated in the coming years will be disposed of, adding to the large number of CCR disposal sites generated in the past and reinforcing the need for sound assessment and management of associated risks. Physical and chemical composition of CCR varies considerably depending on the quality of the feed coal, the combustion technology, fraction considered, and the method of disposal. Related risk pathways include (i) aerial routes, i.e., dust resuspension (Cr(VI)), emanation of radioactivity (Rn associated with U and Th series), and Hg volatilization threatening animal and human health; (ii) phytoaccumulation (B, Se, Mo, As) and plant toxicity (B) with subsequent effects on animals (e.g., Mo-induced hypocuprosis, As and Se toxicity) and humans (e.g., selenosis; food chain); and (iii) effluent discharge and percolation to groundwater and rivers (suspended solids, unfavorable pH, high Se, B, Hg, and As(III) concentrations). Recent and projected changes of CCR composition due to emerging clean coal technologies require close monitoring as the concentration of volatile elements such as Hg and Se, solubility (Hg, Cd, Cu) and volatilization (Hg, NH(3)) of some pollutants are likely to increase because of higher retention in certain fractions of CCRs and concurrent changes in pH (e.g., by mineral carbonation) and NH(3) content. These changes require additional research efforts to explore the implications for CCR quality, use, and management of risk associated with disposal sites.

  11. Enhancement of pulverized coal combustion by plasma technology

    SciTech Connect

    Gorokhovski, M.A.; Jankoski, Z.; Lockwood, F.C.; Karpenko, E.I.; Messerle, V.E.; Ustimenko, A.B.

    2007-07-01

    Plasma-assisted pulverized coal combustion is a promising technology for thermal power plants (TPP). This article reports one- and three- dimensional numerical simulations, as well as laboratory and industrial measurements of coal combustion using a plasma-fuel system (PFS). The chemical kinetic and fluid mechanics involved in this technology are analysed. The results show that a PFS, can be used to promote early ignition and enhanced stabilization of a pulverized coal flame. It is shown that this technology, in addition to enhancing the combustion efficiency of the flame, reduces harmful emissions from power coals of all ranks (brown, bituminous, anthracite and their mixtures). Data summarising the experience of 27 pulverized coal boilers in 16 thermal power plants in several countries (Russia, Kazakhstan, Korea, Ukraine, Slovakia, Mongolia and China), embracing steam productivities from 75 to 670 tons per hour (TPH), are presented. Finally, the practical computation of the characteristics of the PFS, as function of coal properties, is discussed.

  12. Plasma-supported coal combustion in boiler furnace

    SciTech Connect

    Askarova, A.S.; Karpenko, E.I.; Lavrishcheva, Y.I.; Messerle, V.E.; Ustimenko, A.B.

    2007-12-15

    Plasma activation promotes more effective and environmentally friendly low-rank coal combustion. This paper presents Plasma Fuel Systems that increase the burning efficiency of coal. The systems were tested for fuel oil-free start-up of coal-fired boilers and stabilization of a pulverized-coal flame in power-generating boilers equipped with different types of burners, and burning all types of power-generating coal. Also, numerical modeling results of a plasma thermochemical preparation of pulverized coal for ignition and combustion in the furnace of a utility boiler are discussed in this paper. Two kinetic mathematical models were used in the investigation of the processes of air/fuel mixture plasma activation: ignition and combustion. A I-D kinetic code PLASMA-COAL calculates the concentrations of species, temperatures, and velocities of the treated coal/air mixture in a burner incorporating a plasma source. The I-D simulation results are initial data for the 3-D-modeling of power boiler furnaces by the code FLOREAN. A comprehensive image of plasma-activated coal combustion processes in a furnace of a pulverized-coal-fired boiler was obtained. The advantages of the plasma technology are clearly demonstrated.

  13. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, July 1993--September 1993

    SciTech Connect

    Not Available

    1994-01-30

    The Pittsburgh Energy Technology Center (PETC) of the US Department of Energy awarded Vortec Corporation this Phase III contract (No. DE-AC22-91PC91161) for the development of {open_quotes}A Coal-Fired Combustion System for Industrial Process Heating Applications{close_quotes}. The effective contrast start date was September 3, 1991. The contract period of performance is 36 months. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. Final detailed installation designs for the integrated test system configuration are being completed. The equipment is being fabricated and deliveries have begun. The industry funded testing consisted of vitrifying Spent Aluminum Potliner (SPL) which is a listed hazardous waste. This testing has verified that SPL can be vitrified into a safe recyclable glass product.

  14. Coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, April 1995--June 1995

    SciTech Connect

    1995-08-01

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. This includes new installations and those existing installations that were originally designed for oil or gas firing. The data generated by these projects must be sufficient for private-sector decisions on the feasibility of using coal as the fuel of choice. This work should also provide incentives for the private sector to continue and expand the development, demonstration, and application of these combustion systems. Vortec Corporation`s Coal-Fired Combustion System for Industrial Process Heating Applications is being developed under contract DE-AC22-91PC91161 as part of this DOE development program. The current contract represents the third phase of a three-phase development program. Phase I of the program addressed the technical and economic feasibility of the process, and was initiated in 1987 and completed 1989. Phase II was initiated in 1989 and completed in 1990. During Phase II of the development, design improvements were made to critical components and the test program addressed the performance of the process using several different feedstocks. Phase III of the program was initiated September 1991 and is scheduled for completion in 1994. The Phase III research effort is being focused on the development of a process heater system to be used for producing value-added vitrified glass products from boiler/incinerator ashes and selected industrial wastes.

  15. Coal Combustion Science quarterly progress report, April--June 1990

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Fletcher, T.H.; Mitchell, R.E.

    1990-11-01

    This document provides a quarterly status report of the Coal Combustion Science Program that is being conducted at the Combustion, Research Facility, Sandia National Laboratories, Livermore, California. Coal devolatilization, coal char combustion, and fate of mineral matter during coal combustion. 56 refs., 25 figs., 13 tabs.

  16. Study of instrumentation needs for process control and safety in coal fluidized-bed combustion systems

    SciTech Connect

    Herzenberg, C.L.; Griggs, K.E.; Henry, R.F.; Podolski, W.F.

    1981-02-01

    A study was conducted to evaluate the current state of the art of instrumentation for planned and operating fluidized-bed combustion systems. This study is intended to identify instrumentation needs and serve as a data base for projects to develop this instrumentation. A considerable number of needs for measurements for which presently available instrumentation is not suitable were reported by respondents. The identified deficiencies are presented with the associated physical parameter ranges for FBC processes. New techniques and instrumentation under development, as well as some available alternative instruments, are discussed briefly. Also, newly instituted mechanisms for technical information exchange on instrumentation for fossil energy applications are identified. Development of instruments to meet the identified measurement deficiencies is recommended in order to ensure the feasibility of automatic control of large-scale fluidized-bed combustion systems, and to advance the state of the art of fluidized-bed combustion technology.

  17. SPONTANEOUS COAL COMBUSTION; MECHANISMS AND PREDICTION.

    USGS Publications Warehouse

    Herring, James R.; Rich, Fredrick J.

    1983-01-01

    Spontaneous ignition and combustion of coal is a major problem to the coal mining, shipping, and use industries; unintentional combustion causes loss of the resource as well as jeopardy to life and property. The hazard to life is especially acute in the case of underground coal mine fires that start by spontaneous ignition. It is the intention of this research to examine previously suggested causes of spontaneous ignition, to consider new evidence, and to suggest an experimental approach to determine which of these suggested causes is relevant to western U. S. coal. This discussion focuses only on causes and mechanism of spontaneous ignition.

  18. Development and testing of industrial scale, coal-fire combustion system: phase 3

    SciTech Connect

    Zauderer, Dr. Bert

    1997-08-15

    In the second quarter of calendar year 1997, 9 days of combustor- boiler tests were performed, including 3 days of tests on a parallel DOE sponsored project on sulfur retention in a slagging combustor. Between tests, modifications and improvements that were indicated by these tests were implemented. This brings the total number of test days to the end of June 1997 in the task 5 effort to 83 days. This compares with a total of 63 test days needed to complete the task 5 test effort, and the number of tests days required to meet the task 5 project plan have been completed. The key project objectives in the areas of combustor performance and environmental performance have been exceeded. With sorbent injection in the combustion gas train, NO{sub x} emissions as low as 0.07 lb/MMBtu and SO{sub 2} emissions as low as 0.2 lb/MMBtu have been measured in tests in the previous quarter. The emphasis of tests in the present quarter have been on further optimizing post-combustion sorbent injection for SO{sub 2} and NO{sub x} control processes, with most of the test effort focused on the NO{sub x} control process. Many factors which control the NO{sub x} reduction were identified in tests on the 20 MMBtu/hr combustor-boiler. Another very important milestone in this quarter was the successful test of this Coal Tech post combustion NO{sub x} control process on a 100 MW utility boiler, where in a preliminary test 25% NO{sub x} reduction was measured.

  19. COSTS FOR ADVANCED COAL COMBUSTION TECHNOLOGIES

    EPA Science Inventory

    The report gives results of an evaluation of the development status of advanced coal combustion technologies and discusses the preparation of performance and economic models for their application to electric utility plants. he technologies addressed were atmospheric fluidized bed...

  20. COSTS FOR ADVANCED COAL COMBUSTION TECHNOLOGIES

    EPA Science Inventory

    The report gives results of an evaluation of the development status of advanced coal combustion technologies and discusses the preparation of performance and economic models for their application to electric utility plants. he technologies addressed were atmospheric fluidized bed...

  1. Combustion of Coal/Oil/Water Slurries

    NASA Technical Reports Server (NTRS)

    Kushida, R. O.

    1982-01-01

    Proposed test setup would measure combustion performance of new fuels by rapidly heating a droplet of coal/oil/water mixture and recording resulting explosion. Such mixtures are being considered as petroleum substitutes in oil-fired furnaces.

  2. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, July 1992--September 1992

    SciTech Connect

    Not Available

    1992-10-30

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashesand industrial wastes. ne primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order toevaluate its potential marketability. During the current reporting period, three preliminary coal-fired tests were successfully completed. These tests used industrial boiler flyash, sewer sludge ash, and waste glass collet as feedstocks. The coal-fired ash vitrification tests are considered near term potential commercial applications of the CMS technology. The waste glass cullet provided necessary dam on the effect of coal firing with respect to vitrified product oxidation state. Engineering and design activities in support of the Phase III proof of concept are continuing, and modifications to the existing test system configuration to allow performance of the proof-of-concept tests are continuing. The economic evaluation of commercial scale CMS processes is continuing. Preliminary designs for 15, 25, 100 and 400 ton/day systems are in progress. This dam will serve as input data to the life cycle cost analysis which will be-an integral part of the CMS commercialization plan.

  3. The coal slime slurry combustion technology

    SciTech Connect

    Li, Y.; Xu, Z.

    1997-12-31

    This paper presents the coal slime slurry combustion technology in circulating fluidized bed (CFB) boilers. The technique is that the slurry-based flow from the concentrator in the coal washery plant directly feeds into the fluidized bed by pump for combustion after a simple filtration and enrichment to an approximate concentration of 50% of coal. The coal slime slurry can burn in a CFB boiler alone or jointly with coal refuse. The technique has been used in a 35 t/h (6MWe) CFB for power generation. The result shows that the combustion efficiency is over 96% and boiler thermal efficiency is over 77%. As compared with burning coal refuse alone, the thermal efficiency was improved by 3--4 percent. This technology is simple, easy to operate and reliable. It is an effective way to utilize coal slime slurry. It has a practical significance for saving coal resources and reducing environmental pollution near coal mine areas. As a clean coal technology, it will result in great social, environmental and economic benefits.

  4. TRACE METAL TRANSFORMATION MECHANISMS DURING COAL COMBUSTION

    EPA Science Inventory

    The article reviews mechanisms governing the fate of trace metals during coal combustion and presents new theoretical results that interpret existing data. Emphasis is on predicting the size-segregated speciation of trace metals in pulverized-coal-fired power plant effluents. Thi...

  5. TRACE METAL TRANSFORMATION MECHANISMS DURING COAL COMBUSTION

    EPA Science Inventory

    The article reviews mechanisms governing the fate of trace metals during coal combustion and presents new theoretical results that interpret existing data. Emphasis is on predicting the size-segregated speciation of trace metals in pulverized-coal-fired power plant effluents. Thi...

  6. Coal slurry combustion and technology. Volume 2

    SciTech Connect

    Not Available

    1983-01-01

    Volume II contains papers presented at the following sessions of the Coal Slurry Combustion and Technology Symposium: (1) bench-scale testing; (2) pilot testing; (3) combustion; and (4) rheology and characterization. Thirty-three papers have been processed for inclusion in the Energy Data Base. (ATT)

  7. Coal Combustion Products Extension Program

    SciTech Connect

    Tarunjit S. Butalia; William E. Wolfe

    2006-01-11

    This final project report presents the activities and accomplishments of the ''Coal Combustion Products Extension Program'' conducted at The Ohio State University from August 1, 2000 to June 30, 2005 to advance the beneficial uses of coal combustion products (CCPs) in highway and construction, mine reclamation, agricultural, and manufacturing sectors. The objective of this technology transfer/research program at The Ohio State University was to promote the increased use of Ohio CCPs (fly ash, FGD material, bottom ash, and boiler slag) in applications that are technically sound, environmentally benign, and commercially competitive. The project objective was accomplished by housing the CCP Extension Program within The Ohio State University College of Engineering with support from the university Extension Service and The Ohio State University Research Foundation. Dr. Tarunjit S. Butalia, an internationally reputed CCP expert and registered professional engineer, was the program coordinator. The program coordinator acted as liaison among CCP stakeholders in the state, produced information sheets, provided expertise in the field to those who desired it, sponsored and co-sponsored seminars, meetings, and speaking at these events, and generally worked to promote knowledge about the productive and proper application of CCPs as useful raw materials. The major accomplishments of the program were: (1) Increase in FGD material utilization rate from 8% in 1997 to more than 20% in 2005, and an increase in overall CCP utilization rate of 21% in 1997 to just under 30% in 2005 for the State of Ohio. (2) Recognition as a ''voice of trust'' among Ohio and national CCP stakeholders (particularly regulatory agencies). (3) Establishment of a national and international reputation, especially for the use of FGD materials and fly ash in construction applications. It is recommended that to increase Ohio's CCP utilization rate from 30% in 2005 to 40% by 2010, the CCP Extension Program be

  8. Classification of Indian coals for combustion

    SciTech Connect

    Gopalakrishnan, V.; Vasudevan, R.

    1996-12-31

    In annual coal production India ranks fourth in the world, behind China, USA and Russia, with an estimated production of 225 million tons in 1995-96. The utilities burn nearly 60% of the mined coal while industries consume 25-30% of the coal for captive power generation and process heat. The remaining 10-15% goes for the production of coke and miscellaneous applications. Combustion is thus the most important use of coal in India or for that matter, anywhere in the world. Countries like USA have national coal sample banks and databases. The Pennsylvania state (PENN) coal sample bank and database are well known, which are also used by the US Department of Energy (DOE). The Argonne National Laboratory has used 200 samples from the PENN coal database and using cluster analysis, has identified 8 representative samples among American coals. Similar exercises have been carried out by Illinois Coal Development Board, US DOE`s Pittsburgh Energy Technology Center and several universities. The need for a similar coal data bank/database for India and the lack of it at present have been highlighted by Nandakumar and Gopalakrishnan. Especially, for the design of combustion equipment, it will be highly helpful if one can come up with a set of typical Indian coals.

  9. Combustion reactivity of low rank coal chars

    SciTech Connect

    Young, B.C.

    1983-08-01

    For many years the CSIRO has been involved in studies on the combustion kinetics of coal chars and related materials. Early work included studies on a char produced from a Victorian brown coal. More recently, the combustion kinetics of chars produced during the flash pyrolysis of sub-bituminous coals have been determined. Data are given for the combustion reactivities of four flash pyrolysis chars. Their reactivities are compared with the results for chars produced from low and high rank coals, and petroleum coke. Reactivity is expressed as the rate of combustion of carbon per unit external surface area of the particle, with due correction being made for the effect of the mass transfer of oxygen to the particle. It has been shown that the reactivities to oxygen of chars produced from Millmerran sub-bituminous coal decrease with increasing pyrolysis temperature but are similar in magnitude to the reactivities of chars derived from a brown and a bituminous coal and to the reactivities of anthracites and semi-anthracites. However, Wandoan char, also of sub-bituminous origin, exhibits about twice the reactivity of Millmerran char and about ten times the reactivity of petroleum coke. On the basis of observed activation energy values, particle size and particle density behaviour it is concluded that the combustion rates of Millmerran and Wandoan chars are controlled by the combined effects of pore diffusion and chemical reaction.

  10. DEVELOPMENT AND TESTING OF INDUSTRIAL SCALE, COAL FIRED COMBUSTION SYSTEM, PHASE 3

    SciTech Connect

    Dr. Bert Zauderer

    1998-07-08

    In the second quarter of calendar year 1998, no work was performed on the present project. The 20 MMBtu/hr combustor-boiler facility was not operated during this period. The total test days on the Philadelphia facility to the end of June 1998 remained at 108 as in the previous quarter. Of these, 34 tests were part of the other DOE project. The test days on the other project are listed here because they demonstrate the durability of the combustor, which is one of the objectives of the present project. As noted previously, this exceeds the planned 63 test days for this project. All key project objectives have been exceeded including combustor durability, automated combustor operation, NO{sub x} emissions as low as 0.07 lb/MMBtu and SO{sub 2} emissions as low as 0.2 lb/MMBtu. In addition, a novel post-combustion NO{sub x} control process has been tested on a 37 MW and 100 MW utility boiler. Any further tests will depend on the results of evaluations of current and prior tests. The only effort remaining on this project is facility disassembly and Final Report. Also, as part of the commercialization effort for this combustor technology, Coal Tech is developing alternative designs of the combustor that allow its fabrication as substantially reduced costs from the present unit.

  11. Combustion of dense streams of coal particles

    SciTech Connect

    Annamalai, K.

    1992-01-01

    Ignition of the high volatile isolated coal particles in vitiated environment seems to occur heterogeneously at the leading edge of the particle. Volatiles are observed to be ejected upward as jets in the direction of the convective flow but only after heterogeneous ignition. The volatiles burn in the gas phase homogeneously and form a wake flame; a black inner zone (unburned volatile) is formed (see Fig.A.3 for many common characteristics of isolated flames).Intermittent volatile ignition and combustion are observed to occur during the combustion process for a few of the isolated particle combustion experiments on high volatile non-swelling coal. The medium volatile coal particles ignite faster than the high volatile coal; but the intermittent ignition is not observed. The low volatile isolated coal particles combust in shorter time. The isolated char particles ignite at the surface of the particle heterogeneously with little volatile ejected, yet are not sufficient to form a volatile flame, resulting in a subsequent heterogeneous combustion. A group flame is formed for the two-particle arrays at closer interparticle spacing (Fig.A.4). Also, intermittent ignition does not occur for the high volatile particles when the two particles are at farther distances which suggests that radiation interaction between the particles might be occurring. However this conclusion is purely speculative. The char arrays experience heterogeneous ignition at the leading edge; combustion proceeds heterogeneously.

  12. Reducing NOx Emissions for a 600 MWe Down-Fired Pulverized-Coal Utility Boiler by Applying a Novel Combustion System.

    PubMed

    Ma, Lun; Fang, Qingyan; Lv, Dangzhen; Zhang, Cheng; Chen, Yiping; Chen, Gang; Duan, Xuenong; Wang, Xihuan

    2015-11-03

    A novel combustion system was applied to a 600 MWe Foster Wheeler (FW) down-fired pulverized-coal utility boiler to solve high NOx emissions, without causing an obvious increase in the carbon content of fly ash. The unit included moving fuel-lean nozzles from the arches to the front/rear walls and rearranging staged air as well as introducing separated overfire air (SOFA). Numerical simulations were carried out under the original and novel combustion systems to evaluate the performance of combustion and NOx emissions in the furnace. The simulated results were found to be in good agreement with the in situ measurements. The novel combustion system enlarged the recirculation zones below the arches, thereby strengthening the combustion stability considerably. The coal/air downward penetration depth was markedly extended, and the pulverized-coal travel path in the lower furnace significantly increased, which contributed to the burnout degree. The introduction of SOFA resulted in a low-oxygen and strong-reducing atmosphere in the lower furnace region to reduce NOx emissions evidently. The industrial measurements showed that NOx emissions at full load decreased significantly by 50%, from 1501 mg/m3 (O2 at 6%) to 751 mg/m3 (O2 at 6%). The carbon content in the fly ash increased only slightly, from 4.13 to 4.30%.

  13. Development and testing of a commercial scale coal-fired combustion system, Phase 3. Quarterly technical progress report No. 8, July 1, 1992--September 30, 1992

    SciTech Connect

    Litka, A.; Breault, R.

    1992-10-23

    This report summarizes the results of work performed in the development and proof-of-concept (POC) testing of a coal-fired space heating system for the commercial market sector. The objective of this program is to design, build and test a coal based heating system for this sector and determine the economic viability and market potential for the system. Coal water slurry (CWS) fuel has been chosen as the fuel form for this development effort. CWS eliminates the need to use dry pulverized coal with its attendant handling, metering and dusting problems as well as its explosive potential. Equally important in selecting a fuel form is the impact on emission levels and pollution control equipment requirements. CWS is amenable to coal washing since coal cleaning technologies are generally water-based processes requiring the fine grinding of the coal. In the first stage. an overall system heat balance was prepared, system components were designed and manufactured or purchased, the system was fully assembled and preliminary testing performed to validate component performance and identify key operating variables. In the second stage the system was operated for prolonged periods to simulate a commercial application, and combustion and thermal efficiencies; tendencies to slag, foul, erode and corrode; and gaseous and particulate emissions were evaluated. Also during the second stage, an assessment of the commercial viability of the system was made. This assessment included an evaluation of the economics and market potential, including the sensitivity to fluctuations in fuel prices.

  14. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, October 1992--December 1992

    SciTech Connect

    Not Available

    1993-01-29

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashesand industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the current reporting period, a majority of the effort was spent relining the separator/reservoir and the cyclone melter. The relinings were completed, the cyclonemelter was reinstalled, and the test system was returned to operational status. The wet ESP was delivered and placed on its foundation. The focus during the upcoming months will be completing the integration ofthe wet ESP and conducting the first industrial proof-of-concept test. The other system modifications are well underway with the designs of the recuperator installation and the batch/coal feed system progressing smoothly. The program is still slightly behind the original schedule but it is anticipated that it will be back on schedule by the end of the year. The commercialization planning is continuing with the identification of seven potential near-term commercial demonstration opportunities.

  15. Development and testing of commercial-scale, coal-fired combustion systems, Phase 3. Technical progress report, October 1990--December 1990

    SciTech Connect

    Not Available

    1990-12-31

    The US Department of Energy`s Pittsburgh Energy Technology Center (PETC) is actively pursuing the development and testing of coal-fired combustion systems for residential, commercial, and industrial market sectors. In response, MTCI initiated the development of a new combustor technology based on the principle of pulse combustion under the sponsorship of PETC (Contract No. AC22-83PC60419). The initial pulse combustor development program was conducted in three phases (MTCI, Development of a Pulsed Coal Combustor Fired with CWM, Phase III Final Report, DOE Contract No. AC22-83PC60419, November 1986). Phase I included a review of the prior art in the area of pulse combustion and the development of pulse combustor design concepts. It led to the conclusion that pulse combustors offer technical and base-of-operation advantages over conventional burners and also indicated favorable economics for replacement of oil- and gas-fired equipment.

  16. Mercury emissions control in coal combustion systems using potassium iodide: bench-scale and pilot-scale studies

    SciTech Connect

    Ying Li; Michael Daukoru; Achariya Suriyawong; Pratim Biswas

    2009-01-15

    Bench- and pilot-scale experiments were conducted using potassium iodide (KI) for capture and removal of Hg in air and coal combustion exhaust. Two bench-scale reactor systems were used: (1) a packed-bed reactor (PBR) packed with granular or powder KI and (2) an aerosol flow reactor (AFR) with injection of KI particles. It was found that a higher temperature, a higher concentration of KI, and a longer gas residence time resulted in a higher Hg removal efficiency. A 100% Hg removal was achieved in the PBR above 300{sup o}C using 0.5 g of powder KI and in the AFR above 500{sup o}C with a KI/Hg molar ratio of 600 at a 5.8 s residence time. The low KI injection ratio relative to Hg indicated that KI is highly effective for Hg removal in air. Formation of I{sub 2} vapor by the oxidation of KI by O{sub 2} at high temperatures, which then reacts with Hg to produce HgI{sub 2}, was identified as the pathway for removal. The pilot-scale experiments were conducted in a 160 kW pulverized coal combustor. KI was introduced in two ways: as a powder mixed with coal and by spraying KI solution droplets into the flue gas. In both cases the Hg removal efficiency increased with an increase in the feed rate of KI. Mixing KI powder with coal was found to be more effective than spraying KI into the flue gas. The Hg removal by KI was less efficient in the pilot-scale tests than in the bench-scale tests probably due to certain flue gas components reacting with KI or I{sub 2}. Hg speciation measurements in both bench- and pilot-scale experiments indicated no oxidized mercury in the gas phase upon introduction of KI, indicating that the oxidation product HgI2 was captured in the particulate phase. This is very beneficial in coal-fired power plants equipped with electrostatic precipitators where particulate-bound Hg can be efficiently removed. 27 refs., 8 figs., 4 tabs.

  17. Coal combustion aerothermochemistry research. Final report

    SciTech Connect

    Witte, A.B.; Gat, N.; Denison, M.R.; Cohen, L.M.

    1980-12-15

    On the basis of extensive aerothermochemistry analyses, laboratory investigations, and combustor tests, significant headway has been made toward improving the understanding of combustion phenomena and scaling of high swirl pulverized coal combustors. A special attempt has been made to address the gap between scientific data available on combustion and hardware design and scaling needs. Both experimental and theoretical investigations were conducted to improve the predictive capability of combustor scaling laws. The scaling laws derived apply to volume and wall burning of pulverized coal in a slagging high-swirl combustor. They incorporate the findings of this investigation as follows: laser pyrolysis of coal at 10/sup 6/ K/sec and 2500K; effect of coal particle shape on aerodynamic drag and combustion; effect of swirl on heat transfer; coal burnout and slag capture for 20 MW/sub T/ combustor tests for fine and coarse coals; burning particle trajectories and slag capture; particle size and aerodynamic size; volatilization extent and burnout fraction; and preheat level. As a result of this work, the following has been gained: an increased understanding of basic burning mechanisms in high-swirl combustors and an improved model for predicting combustor performance which is intended to impact hardware design and scaling in the near term.

  18. Corrosion performance of materials in coal-combustion environments

    SciTech Connect

    Natesan, K.

    1993-04-01

    Reliability of components and long-term trouble-free performance of structural materials are essential for the acceptance of power-generating process that utilize coal as a feedstock- The combustion environments encompass a wide range of oxygen partial pressures, from excess-air conditions in conventional systems to air-deficient conditions in low-NO[sub x] systems. Apart from the environmental aspects of the effluent from coal combustion, one of the concerns from the systems standpoint is the aggressiveness of the combustion environment toward the boiler structural components such as waterwall tubes and steam superheaters. The corrosion tests in this program address the combined effect of sulfur and chlorine on the corrosion response of several ASME-coded and noncoded boiler materials exposed to air-deficient and excess-air combustion conditions. Thermodynamic calculations were made to evaluate the gas chemistries that will arise from combustion of coals. The results of such calculations, coupled with oxygen-sulfur-chlorine thermochemical diagrams, were used to select gas environments for the laboratory test program. Tests were conducted at 400 and 650[degrees]C to stimulate the waterwall and superheater environments, respectively, in pulverized-coal-fired boilers. Experimental results obtained thus far indicate that both sulfur and chlorine can accelerate corrosion of ferritic and austenitic alloys; in addition, the protective capacity of the oxide scale in resisting further corrosion seems to degrade in the presence of both sulfur and chlorine.

  19. Corrosion performance of materials in coal-combustion environments

    SciTech Connect

    Natesan, K.

    1993-04-01

    Reliability of components and long-term trouble-free performance of structural materials are essential for the acceptance of power-generating process that utilize coal as a feedstock- The combustion environments encompass a wide range of oxygen partial pressures, from excess-air conditions in conventional systems to air-deficient conditions in low-NO{sub x} systems. Apart from the environmental aspects of the effluent from coal combustion, one of the concerns from the systems standpoint is the aggressiveness of the combustion environment toward the boiler structural components such as waterwall tubes and steam superheaters. The corrosion tests in this program address the combined effect of sulfur and chlorine on the corrosion response of several ASME-coded and noncoded boiler materials exposed to air-deficient and excess-air combustion conditions. Thermodynamic calculations were made to evaluate the gas chemistries that will arise from combustion of coals. The results of such calculations, coupled with oxygen-sulfur-chlorine thermochemical diagrams, were used to select gas environments for the laboratory test program. Tests were conducted at 400 and 650{degrees}C to stimulate the waterwall and superheater environments, respectively, in pulverized-coal-fired boilers. Experimental results obtained thus far indicate that both sulfur and chlorine can accelerate corrosion of ferritic and austenitic alloys; in addition, the protective capacity of the oxide scale in resisting further corrosion seems to degrade in the presence of both sulfur and chlorine.

  20. Optical diagnostic measurements of coal-slag parameters in combustion MHD systems

    SciTech Connect

    Ariessohn, P.C.

    1980-08-01

    Hydrodynamic models have been developed to predict the behavior of slag layers on MHD generator walls and these have indicated a strong dependence of slag layer thickness on a number of system parameters. The first objective of this thesis was the development of a diagnostic technique capable of making continuous, in-situ measurements of the slag layer thickness, and the application of this technique in an MHD system for comparison with the predictions of one of the existing hydrodynamic models. The second objective of this thesis was the development of a diagnostic technique capable of making in-situ measurements of ash droplet size and concentration at the exit of an MHD combustor, and the study of the sensitivity of these quantities to various combustion parameters. A slag layer surface position monitor employing a laser triangulation method has been developed and used to measure variations in slag layer thickness as a function of substrate temperature for a variety of ash loadings and total reactant flowrates. Slag layer thickness is seen to decrease with increasing substrate temperature and plasma velocity. The measurement of mean size and concentration of suspended ash droplets in the plasma exiting the M-8 combustor has been accomplished utilizing a two-wavelength transmissometer developed for this purpose. This instrument incorporates several unique features which were required to overcome the difficulties imposed by the MHD environment. Measurements obtained with this device show that mean ash droplet diameter is relatively independent of ash loading, combustor residence time and combustion stoichiometry, but is a decreasing function of plasma temperature.

  1. Toxic Substances From Coal Combustion - Phase I Coal Selection and Chaacterization

    SciTech Connect

    A. Kolker; A. Sarofim; C.A. Palmer; C.L. Senior; F.E. Huggins; G.P. Huffman; I. Olmez; N. Shah; R. Finkelman; S. Crowley; T. Zeng

    1998-07-16

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. Over the past decade, a large database identifying the partitioning and emitted concentrations of several toxic metals on the list of HAPs has been developed. Laboratory data have also been generated to help define the general behavior of several elements in combustion systems. These data have been used to develop empirical and probabalistic models to predict emissions of trace metals from coal-fired power plants. While useful for providing average emissions of toxic species, these empirically based models fail when extrapolated beyond their supporting database. This represents a critical gap; over the coming decades, new fuels and combustion systems will play an increasing role in our nation's power generation system. For example, new fuels, such as coal blends or beneficiated fuels, new operating conditions, such as low-NO burners or staged combustion, or new power x systems, for example, those being developed under the DoE sponsored Combustion 2000 programs and integrated gasification combined cycle (IGCC) systems, are all expected to play a role in power generation in the next century. The need for new predictive tools is not limited to new combustion systems, however. Existing combustion systems may have to employ controls for HAPs, should regulations be imposed. Testing of new control methods, at pilot and full scale, is expensive. A sound under-standing of the chemical transformations of both organic and inorganic HAPs will promote the development of new control methods in a cost-effective manner. To ensure that coal-fired power generation proceeds in an environmentally benign fashion, methods for the prediction and

  2. Thermally induced structural changes in coal combustion

    SciTech Connect

    Flagan, R.C.; Gavalas, G.R.

    1992-01-01

    The effects of the temperature-time history during coal devolitization and oxidation on the physical properties and the reactivity of resulting char were studied experimentally for temperatures and residence times typical of pulverized combustion. Experiments were also carried out at somewhat lower temperatures and correspondingly longer residence times. An electrically heated laminar flow reactor was used to generate char and measure the rates of oxidation at gas temperatures about 1600K. Partially oxidized chars were extracted and characterized by gas adsorption and mercury porosimetry, optical and scanning electron microscopy, and oxidation in a thermogravimetric analysis system (TGA). A different series of experiments was conducted using a quadrople electrodynamic balance. Single particles were suspended electrodynamically and heated by an infrared laser in an inert or oxygen-containing atmosphere. During the laser heating, measurements were taken of particle mass, size/shape, and temperature.

  3. A systems approach to risk assessment: Application to methylmercury from coal combustion

    SciTech Connect

    Saroff, L.; Lipfert, F.W.; Moskowitz, P.D.

    1995-01-01

    The Department of Energy (DOE) asked Brookhaven National Laboratory (BNL) to perform a probabilistic assessment of the health risks associated with Hg from coal-fired power plants. The objective of the assessment is to estimate the incremental health risks that might ensue from a typical coal-fired power plant, together with their uncertainties, taking into account existing background levels and the actual adverse health effects that have previously been associated with exposure to various Hg species. Mercury has a long history of association with adverse neurological effects at high exposure levels. The most important current exposure pathway has been found to be ingestion of fish containing methylmercury (MeHg), which is the end product of bioconcentration moving up the aquatic food chain. Mercury can enter natural waters from either industrial discharges or from atmospheric deposition of various inorganic Ho. compounds. Because of the worldwide background and the existence of local emissions sources, Hg deposition must be considered on local, regional and global scales. The regulatory technical challenge presented by methy1mercury is to protect public health without foreclosing an appreciable a portion of the food supply or impacting on the lifestyles of North American native populations. This paper presents an abbreviated account of the DOE/BNL risk assessment, as viewed from a systems perspective. We review the structure of the model, the sources of data used, the assumptions that were made, and the interpretation of the findings. Since publication of the first risk assessment report, we have refined our estimates of local atmospheric dispersion and deposition and {open_quotes}calibrated{close_quotes} the pharmacokinetic portion of the model against observations.

  4. Biomedically relevant chemical and physical properties of coal combustion products.

    PubMed Central

    Fisher, G L

    1983-01-01

    The evaluation of the potential public and occupational health hazards of developing and existing combustion processes requires a detailed understanding of the physical and chemical properties of effluents available for human and environmental exposures. These processes produce complex mixtures of gases and aerosols which may interact synergistically or antagonistically with biological systems. Because of the physicochemical complexity of the effluents, the biomedically relevant properties of these materials must be carefully assessed. Subsequent to release from combustion sources, environmental interactions further complicate assessment of the toxicity of combustion products. This report provides an overview of the biomedically relevant physical and chemical properties of coal fly ash. Coal fly ash is presented as a model complex mixture for health and safety evaluation of combustion processes. PMID:6337824

  5. Temporal measurements and kinetics of selenium release during coal combustion and gasification in a fluidized bed.

    PubMed

    Shen, Fenghua; Liu, Jing; Zhang, Zhen; Yang, Yingju

    2016-06-05

    The temporal release of selenium from coal during combustion and gasification in a fluidized bed was measured in situ by an on-line analysis system of trace elements in flue gas. The on-line analysis system is based on an inductively coupled plasma optical emission spectroscopy (ICP-OES), and can measure concentrations of trace elements in flue gas quantitatively and continuously. The results of on-line analysis suggest that the concentration of selenium in flue gas during coal gasification is higher than that during coal combustion. Based on the results of on-line analysis, a second-order kinetic law r(x)=0.94e(-26.58/RT)(-0.56 x(2) -0.51 x+1.05) was determined for selenium release during coal combustion, and r(x)=11.96e(-45.03/RT)(-0.53 x(2) -0.56 x+1.09) for selenium release during coal gasification. These two kinetic laws can predict respectively the temporal release of selenium during coal combustion and gasification with an acceptable accuracy. Thermodynamic calculations were conducted to predict selenium species during coal combustion and gasification. The speciation of selenium in flue gas during coal combustion differs from that during coal gasification, indicating that selenium volatilization is different. The gaseous selenium species can react with CaO during coal combustion, but it is not likely to interact with mineral during coal gasification.

  6. [Distribution of fluoride in the combustion products of coal].

    PubMed

    Liu, Jianzhong; Qi, Qingjie; Zhou, Junhu; Cao, Xinyu; Cen, Kefa

    2003-07-01

    The static distribution characteristic of fluoride in the combustion products of coal was studied by ashing procedure of coal, and the dynamic distribution characteristics of fluorine in the combustion products of coal in pulverized-coal-fired boiler and layer-burning boiler were investigated. Experimental results identified that fluorine in coal belong to volatile elements, fluorine in fly ash and bottom ash were non-rich. About 94.5% of the fluorine in coal emitted as gaseous-fluorine during coal combustion in pulverized-coal-fired boiler, and about 80% of the fluorine in coal emitted as gaseous-fluorine during coal combustion in layer-burning boiler. 55%-60% of the fluorine in fly ash of pulverized-coal-fired boiler were distributed in fly ash particles with a diameter of 74 microns-104 microns.

  7. Electricity from Coal Combustion: Improving the hydrophobicity of oxidized coals

    NASA Astrophysics Data System (ADS)

    Seehra, Mohindar; Singh, Vivek

    2011-03-01

    To reduce pollution and improve efficiency, undesirable mineral impurities in coals are usually removed in coal preparation plants prior to combustion first by crushing and grinding coals followed by gravity separation using surfactant aided water flotation. However certain coals in the US are not amendable to this process because of their poor flotation characteristics resulting in a major loss of an energy resource. This problem has been linked to surface oxidation of mined coals which make these coals hydrophilic. In this project, we are investigating the surface and water flotation properties of the eight Argonne Premium (AP) coals using x-ray diffraction, IR spectroscopy and zeta potential measurements. The role of the surface functional groups, (phenolic -OH and carboxylic -COOH), produced as a result of chemisorptions of O2 on coals in determining their flotation behavior is being explored. The isoelectric point (IEP) in zeta potential measurements of good vs. poor floaters is being examined in order to improved the hydrophobicity of poor floating coals (e.g. Illinois #6). Results from XRD and IR will be presented along with recent findings from zeta potential measurements, and use of additives to improve hydrophobicity. Supported by USDOE/CAST, Contract #DE-FC26-05NT42457.

  8. REDUCTION OF NOx VIA COAL COMBUSTION CATALYSIS

    SciTech Connect

    George Ford; Stan Harding; Jeff Hare

    2003-04-28

    The primary objective of this investigation is to determine the effect of different iron catalysts on the production of NO{sub x} during fuel-rich and fuel-lean combustion of coal. Iron in various forms and quantities will be introduced with the pulverized coal and tested in a laboratory-scale combustion furnace. The testing protocol is based on simulation of the near burner region in a full-scale boiler. This semi-annual report describes the selection of the iron catalysts used in the program as well as catalyst preparation. A detailed description of the combustion reactor and ancillary equipment is provided combined with a discussion of the test procedures. The first preliminary data have been collected and are presented followed by the plans to complete the project over the next six months.

  9. Thermodynamic assessment of the possibility of emission of submicron particles in the process of coal combustion

    NASA Astrophysics Data System (ADS)

    Lebedeva, L. N.; Kortsenshtein, N. M.; Samuilov, E. V.

    2014-12-01

    Methods of chemical thermodynamics of multicomponent reactive systems are used to study the distribution of the most volatile components (potassium and sodium) in the products of combustion of 15 types of coal. The effect of the mineral part of coals and various potassium and sodium compounds on the temperature of their transition into the gas phase is investigated. It is shown that the distribution of potassium and sodium in the products of coal combustion depends on the speciation of these elements in the initial coal; the mineral part composition; the ash content of coals; and the sulfur, potassium, and sodium content of the initial coals.

  10. Development and testing of industrial scale, coal fired combustion system, Phase 3. Fifth quarterly technical progress report, January 1, 1993--March 31, 1993

    SciTech Connect

    Zauderer, B.

    1993-05-17

    In the present reporting period, the first quarter of calendar year 1993, the effort was divided between Task 2. ``Pre Systems Tests`` and Task 4 ``Economics and Commercialization Plan.`` A major part of the task 2 effort was devoted converting the nozzle from adiabatic to air cooted operation. This conversion will allow immediate implementation of the longer duration task 3.2 tests after the completion of the task 2 tests. Therefore, a significant pan of the exit nozzle conversion effort is also part of task 3.1, ``Combustor Refurbishment.`` In task 1 the only activity remaining is to receive the results of the BYU combustion modeling. The results are anticipated this Spring. One of the three remaining tests in task 2 was implemented in late January under freezing weather and snow conditions. Ice plugged the coal feed lines and stack scrubber water outlet and ice jammed and damaged the coal metering auger. While these lines were thawed, the combustor was fired with oil. The coal used in this test contained fine fibrous tramp material which passed through the two tramp material retaining screens and eventually plugged several of the coal feed lines to the combustor. This cut the planned coal feed rate in half. As a result it was decided for the next test to increase the number of coal injection ports by 50% in order to provide excess capacity in the pneumatic feed feed. This will allow continued operation even in the presence of fine tramp material in the coal.

  11. On-Line Analysis and Kinetic Behavior of Arsenic Release during Coal Combustion and Pyrolysis.

    PubMed

    Shen, Fenghua; Liu, Jing; Zhang, Zhen; Dai, Jinxin

    2015-11-17

    The kinetic behavior of arsenic (As) release during coal combustion and pyrolysis in a fluidized bed was investigated by applying an on-line analysis system of trace elements in flue gas. This system, based on inductively coupled plasma optical emission spectroscopy (ICP-OES), was developed to measure trace elements concentrations in flue gas quantitatively and continuously. Obvious variations of arsenic concentration in flue gas were observed during coal combustion and pyrolysis, indicating strong influences of atmosphere and temperature on arsenic release behavior. Kinetic laws governing the arsenic release during coal combustion and pyrolysis were determined based on the results of instantaneous arsenic concentration in flue gas. A second-order kinetic law was determined for arsenic release during coal combustion, and the arsenic release during coal pyrolysis followed a fourth-order kinetic law. The results showed that the arsenic release rate during coal pyrolysis was faster than that during coal combustion. Thermodynamic calculations were carried out to identify the forms of arsenic in vapor and solid phases during coal combustion and pyrolysis, respectively. Ca3(AsO4)2 and Ca(AsO2)2 are the possible species resulting from As-Ca interaction during coal combustion. Ca(AsO2)2 is the most probable species during coal pyrolysis.

  12. The effect of biomass on pollutant emission and burnout in co-combustion with coal

    SciTech Connect

    Kruczek, H.; Raczka, P.; Tatarek, A.

    2006-08-15

    This paper presents experimental and numerical results on the co-combustion of different types of biomass with hard and brown coal. The main aim of this work was to assess the impact of the cocombustion of biomass in brown and hard coal-fired systems on the combustion process itself and on the level of pollutant formation and its dependence on combustion temperature stoichiometry. The experimental results obtained have shown that in general biomass addition leads to decreased NO and SO{sub 2} emissions, except with the hard coal Bogdanka. In addition, the biomass has a beneficial effect on the burnout of the coal/biomass mixture. To help to account for this effect, the behaviour of coal and biomass, the coal/biomass mixture and of fuel-N was studied by thermal analysis, in nitrogen and in air. The results obtained have shown that gas phase interactions are dominant in the combustion of biomass/coal mixtures.

  13. Coal combustion and heavy metals pollution

    SciTech Connect

    Danihelka, P.; Ochodek, T.; Borovec, K.

    1996-12-31

    Combustion of coal may be an important source of heavy metals pollution. The major environmental risks of heavy metals are connected to their toxicity and mobility in the environment. In the flame, heavy metals are re-distributed with respect to their volatility. Enrichment of fine particles by volatile metals is the most important mechanism for most of the metals. Nevertheless, Hg is emitted mainly in gaseous form and some metals like Mn are concentrated rather in coarse particles. Heavy metals pollution caused by emissions from combustion of coal may be decreased by fine particles removal; other possibilities (metals extraction from the coal, changes of condition in the flame) are limited. Fly ashes from the most important Czech power plants were examined with respect to the heavy metals content. The easily leachable elements with high volatility in the flame (arsenic, zinc, lead) were recognized as the most important fly ash pollutants. The average concentrations of these metals in fly ash were: bituminous coal 46{+-}18 ppm As, 196{+-}93 ppm Zn, 126{+-}46 ppm Pb; brown coal 283{+-}260 ppm As, 60{+-}28 ppm Pb and 212{+-}116 ppm Zn. When ESP and cyclones are used in series, fly ashes from ESP have higher concentration of volatile heavy metals, mainly Pb, Zn and As. Presence of chlorine in fuel increases the volatility of metals.

  14. Radiation properties of coal combustion products

    SciTech Connect

    Im, K.H.; Ahluwalia, R.K.

    1990-11-01

    An assessment is made of the experimental data and the theoretical bases for determining the absorption and scattering coefficients of the coal products of combustion. Particular attention is devoted to the complex refractive indices for char and ash. A dispersion relation is developed from sparse extinction data that can be used to estimate the optical constants of char. Considerable uncertainty and scatter is found in the literature data on ash optical constants and is attributed to variability in ash composition, lack of experimental rigor and limitations in the data reduction procedures. A correlation is presented for estimating the complex refractive indices of ash as a function of its mineral composition. A parametric study is conducted to elucidate the role of char, soot and ash particulates in determining the radiation properties of coal flames. The effects of combustion particulates are discussed in terms of the modification of the band structure of gas radiation to a luminous spectrum, introduction of scattering in radiation transport, particle size distribution, particle loading and particle composition. The results are interpreted as possible effects of coal beneficiation, coal micronization and flyash composition on heat transfer to the water walls of a coal furnace. 19 refs., 13 figs., 10 tabs.

  15. A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, July 1993--September 1993

    SciTech Connect

    Not Available

    1993-10-30

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase 3 research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase 3 project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the past quarter, the major effort was completing some of the system modification installation designs, completing industry funded testing, developing a surrogate TSCA ash composition, and completing the TSCA ash Test Plan. The installation designs will be used for the equipment modifications planned for the end of CY 93. The industry funded testing consisted of vitrifying Spent Aluminum Potliner (SPL) which is a listed hazardous waste. This testing has verified that SPL can be vitrified into a safe, recyclable glass product. Some results from this testing are provided in Section 2.2.1. The surrogate TSCA ash composition was developed with input from various DOE laboratories and subcontractors. The surrogate ash consists of a mixture of MSW fly ash and bottom ash spiked with heavy metal contaminants. The levels of metal additives are sufficient to ascertain the partitioning of the contaminants between the glass and effluent flow streams. Details of the surrogate composition and the planned testing is provided in Section 4.2.2.

  16. System Study of Rich Catalytic/Lean burn (RCL) Catalytic Combustion for Natural Gas and Coal-Derived Syngas Combustion Turbines

    SciTech Connect

    Shahrokh Etemad; Lance Smith; Kevin Burns

    2004-12-01

    Rich Catalytic/Lean burn (RCL{reg_sign}) technology has been successfully developed to provide improvement in Dry Low Emission gas turbine technology for coal derived syngas and natural gas delivering near zero NOx emissions, improved efficiency, extending component lifetime and the ability to have fuel flexibility. The present report shows substantial net cost saving using RCL{reg_sign} technology as compared to other technologies both for new and retrofit applications, thus eliminating the need for Selective Catalytic Reduction (SCR) in combined or simple cycle for Integrated Gasification Combined Cycle (IGCC) and natural gas fired combustion turbines.

  17. Assessment of Solid Sorbent Systems for Post-Combustion Carbon Dioxide Capture at Coal-Fired Power Plants

    NASA Astrophysics Data System (ADS)

    Glier, Justin C.

    In an effort to lower future CO2 emissions, a wide range of technologies are being developed to scrub CO2 from the flue gases of fossil fuel-based electric power and industrial plants. This thesis models one of several early-stage post-combustion CO2 capture technologies, solid sorbent-based CO2 capture process, and presents performance and cost estimates of this system on pulverized coal power plants. The spreadsheet-based software package Microsoft Excel was used in conjunction with AspenPlus modelling results and the Integrated Environmental Control Model to develop performance and cost estimates for the solid sorbent-based CO2 capture technology. A reduced order model also was created to facilitate comparisons among multiple design scenarios. Assumptions about plant financing and utilization, as well as uncertainties in heat transfer and material design that affect heat exchanger and reactor design were found to produce a wide range of cost estimates for solid sorbent-based systems. With uncertainties included, costs for a supercritical power plant with solid sorbent-based CO2 capture ranged from 167 to 533 per megawatt hour for a first-of-a-kind installation (with all costs in constant 2011 US dollars) based on a 90% confidence interval. The median cost was 209/MWh. Post-combustion solid sorbent-based CO2 capture technology is then evaluated in terms of the potential cost for a mature system based on historic experience as technologies are improved with sequential iterations of the currently available system. The range costs for a supercritical power plant with solid sorbent-based CO2 capture was found to be 118 to 189 per megawatt hour with a nominal value of 163 per megawatt hour given the expected range of technological improvement in the capital and operating costs and efficiency of the power plant after 100 GW of cumulative worldwide experience. These results suggest that the solid sorbent-based system will not be competitive with currently available

  18. An investigation on polycyclic aromatic hydrocarbon emissions from pulverized coal combustion systems

    PubMed

    Pisupati; Wasco; Scaroni

    2000-05-29

    Results from a series of tests conducted to study the emission of polynuclear or polycyclic aromatic hydrocarbons (PAHs) from bench-scale and small industrial, water-tube boiler are discussed. A Middle Kittanning, and Upper Freeport seam coals were used in the study. Samples were extracted from the reactor outlet and from the inlet and outlet sides of the research boiler's (RB) baghouse using EPA promulgated methods.Only acenaphthene and fluoranthene were detected in down-fired combustor (DFC) samples. In addition to these two, naphthalene was detected in the RB samples. Emission factors ranged from 80 to 320 &mgr;g/kg of fuel fired. Although there were minor trends in the emissions' data, given the reproducibility limits for PAH compounds, no significant differences were found in the emissions with respect to the fuel type or form (pulverized coal (PC) vs. coal-water slurry fuel (CWSF), and raw vs. cleaned coal) and firing conditions (high and low excess air). The PAH emissions showed a decrease with increase in the firing rate.A bench-scale drop-tube reactor (DTR) was used to study the effects of temperature and residence time on PAH formation. The results revealed near constant PAH concentrations in the solid-phase samples, while the PAH concentrations in the vapor-phase samples increased as a function of temperature. At a temperature of around 1300 degrees C, the rate of PAH formation was exceeded by the rate of PAH oxidation, and PAH concentrations in the vapor phase began to decrease.

  19. Development and testing of a commercial-scale coal-fired combustion system, Phase 3. Quarterly technical progress report No. 5, October 1, 1991--December 31, 1991

    SciTech Connect

    Litka, A.F.; Breault, R.W.

    1992-05-01

    Within the commercial sector, oil and natural gas are the predominant fuels used to meet the space-heating needs of schools, office buildings, apartment complexes, and other similar structures. In general, these buildings require firing rates of 1 to 10 million Btu/hr. The objective of this program is to demonstrate the technical and economic viability of a coal-fired combustion system for this sector. The commercial-scale coal-water slurry (CWS)-fired space heating system will be a scale-up of a CWS-fired residential warm-air heating system developed by Tecogen under contract to the Department of Energy, Pittsburgh Energy Technology Center. This system included a patented nonslagging combustor known as IRIS, for Inertial Reactor with Internal Separation. This combustion technology, which has demonstrated high combustion efficiency using CWS fuels at input rates of 100,000 Btu/hr, will be scaled to operate at 2 to 5 millon Btu/hr. Along with the necessary fuel storage and delivery, heat recovery, and control equipment, the system will include pollution control devices to meet targeted values of NO{sub x}, S0{sub 2}, and particulate emissions. In general, the system will be designed to match the reliability, safety, turndown, and ignition performance of gas or oil-fired systems.

  20. Development and testing of a commercial-scale coal-fired combustion system, Phase 3. Quarterly technical progress report No. 2, January 1, 1991--March 31, 1991

    SciTech Connect

    Litka, A.F.; Breault, R.W.

    1991-07-01

    Within the commercial sector, oil and natural gas are the predominant fuels used to meet the space-heating needs of schools, office buildings, apartment complexes, and other similar structures. In general, these buildings require firing rates of 1 to 10 million Btu/hr. The objective of this program is to demonstrate the technical and economic viability of a coal-fired combustion system for this sector. The commercial-scale coal-water slurry (CWS)-fired space heating system will be a scale-up of a CWS-fired residential warm-air heating system developed by Tecogen under contract to the Department of Energy, Pittsburgh Energy Technology Center. This system included a patented nonslagging combustor known as IRIS, for Inertial Reactor with Internal Separation. This combustion technology, which has demonstrated high combustion efficiency using CWS fuels at input rates of 100,000 Btu/hr, will be scaled to operate at 2 to 5 millon Btu/hr. Along with the necessary fuel storage and delivery, heat recovery, and control equipment, the system will include pollution control devices to meet targeted values of NO{sub x}, S0{sub 2}, and particulate emissions. In general, the system will be designed to match the reliability, safety, turndown, and ignition performance of gas or oil-fired systems.

  1. Development and testing of a commercial-scale coal-fired combustion system, Phase 3. Quarterly technical progress report No. 3, April 1, 1991--June 30, 1991

    SciTech Connect

    Litka, A.F.; Breault, R.W.

    1991-10-01

    Within the commercial sector, oil and natural gas are the predominant fuels used to meet the space-heating needs of schools, office buildings, apartment complexes, and other similar structures. In general, these buildings require firing rates of 1 to 10 million Btu/hr. The objective of this program is to demonstrate the technical and economic viability of a coal-fired combustion system for this sector. The commercial-scale coal-water slurry (CWS)-fired space heating system will be a scale-up of a CWS-fired residential warm-air heating system developed by Tecogen under contract to the Department of Energy, Pittsburgh Energy Technology Center. This system included a patented nonslagging combustor known as IRIS, for Inertial Reactor with Internal Separation. This combustion technology, which has demonstrated high combustion efficiency using CWS fuels at input rates of 100,000 Btu/hr, will be scaled to operate at 2 to 5 millon Btu/hr. Along with the necessary fuel storage and delivery, heat recovery, and control equipment, the system will include pollution control devices to meet targeted values of NO{sub x}, S0{sub 2}, and particulate emissions. In general, the system will be designed to match the reliability, safety, turndown, and ignition performance of gas or oil-fired systems.

  2. Coal Combustion Products Extension Program

    SciTech Connect

    Tarunjit S. Butalia; William E. Wolfe

    2003-12-31

    The primary objective of the CCP Extension Program is to promote the responsible uses of Ohio CCPs that are technically sound, environmentally safe, and commercially competitive. A secondary objective is to assist other CCP generating states (particularly neighboring states) in establishing CCP use programs within their states. The goal of the CCP extension program at OSU is to work with CCP stakeholders to increase the overall CCP state utilization rate to more than 30% by the year 2005. The program aims to increase FGD utilization for Ohio to more than 20% by the year 2005. The increased utilization rates are expected to be achieved through increased use of CCPs for highway, mine reclamation, agricultural, manufacturing, and other civil engineering uses. In order to accomplish these objectives and goals, the highly successful CCP pilot extension program previously in place at the university has been expanded and adopted by the university as a part of its outreach and engagement mission. The extension program is an innovative technology transfer program with multiple sponsors. The program is a collaborative effort between The Ohio State University (College of Engineering and University Extension Service), United States Department of Energy's National Energy Technology Laboratory, Ohio Department of Development's Coal Development Office, and trade associations such as the American Coal Ash Association as well as the Midwest Coal Ash Association. Industry co-sponsors include American Electric Power, Dravo Lime Company, and ISG Resources. Implementation of the proposed project results in both direct and indirect as well as societal benefits. These benefits include (1) increased utilization of CCPs instead of landfilling, (2) development of proper construction and installation procedures, (3) education of regulators, specification-writers, designers, construction contractors, and the public, (4) emphasis on recycling and decrease in the need for landfill space, (5

  3. Catalytic combustion of coal-derived liquids

    NASA Technical Reports Server (NTRS)

    Bulzan, D. L.; Tacina, R. R.

    1981-01-01

    A noble metal catalytic reactor was tested with three grades of SRC 2 coal derived liquids, naphtha, middle distillate, and a blend of three parts middle distillate to one part heavy distillate. A petroleum derived number 2 diesel fuel was also tested to provide a direct comparison. The catalytic reactor was tested at inlet temperatures from 600 to 800 K, reference velocities from 10 to 20 m/s, lean fuel air ratios, and a pressure of 3 x 10 to the 5th power Pa. Compared to the diesel, the naphtha gave slightly better combustion efficiency, the middle distillate was almost identical, and the middle heavy blend was slightly poorer. The coal derived liquid fuels contained from 0.58 to 0.95 percent nitrogen by weight. Conversion of fuel nitrogen to NOx was approximately 75 percent for all three grades of the coal derived liquids.

  4. Catalytic combustion of coal-derived liquids

    NASA Astrophysics Data System (ADS)

    Bulzan, D. L.; Tacina, R. R.

    A noble metal catalytic reactor was tested with three grades of SRC 2 coal derived liquids, naphtha, middle distillate, and a blend of three parts middle distillate to one part heavy distillate. A petroleum derived number 2 diesel fuel was also tested to provide a direct comparison. The catalytic reactor was tested at inlet temperatures from 600 to 800 K, reference velocities from 10 to 20 m/s, lean fuel air ratios, and a pressure of 3 x 10 to the 5th power Pa. Compared to the diesel, the naphtha gave slightly better combustion efficiency, the middle distillate was almost identical, and the middle heavy blend was slightly poorer. The coal derived liquid fuels contained from 0.58 to 0.95 percent nitrogen by weight. Conversion of fuel nitrogen to NOx was approximately 75 percent for all three grades of the coal derived liquids.

  5. Managing coal combustion residues in mines

    SciTech Connect

    2006-07-01

    Burning coal in electric utility plants produces, in addition to power, residues that contain constituents which may be harmful to the environment. The management of large volumes of coal combustion residues (CCRs) is a challenge for utilities, because they must either place the CCRs in landfills, surface impoundments, or mines, or find alternative uses for the material. This study focuses on the placement of CCRs in active and abandoned coal mines. The Committee on Mine Placement of Coal Combustion Wastes of the National Research Council believes that placement of CCRs in mines as part of the reclamation process may be a viable option for the disposal of this material as long as the placement is properly planned and carried out in a manner that avoids significant adverse environmental and health impacts. This report discusses a variety of steps that are involved in planning and managing the use of CCRs as minefills, including an integrated process of CCR characterization and site characterization, management and engineering design of placement activities, and design and implementation of monitoring to reduce the risk of contamination moving from the mine site to the ambient environment. Enforceable federal standards are needed for the disposal of CCRs in minefills to ensure that states have adequate, explicit authority and that they implement minimum safeguards. 267 refs., 6 apps.

  6. Performance of PAHs emission from bituminous coal combustion.

    PubMed

    Yan, Jian-Hua; You, Xiao-Fang; Li, Xiao-Dong; Ni, Ming-Jiang; Yin, Xue-Feng; Cen, Ke-Fa

    2004-12-01

    Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion.

  7. Plasma Torch for Plasma Ignition and Combustion of Coal

    NASA Astrophysics Data System (ADS)

    Ustimenko, Alexandr; Messerle, Vladimir

    2015-09-01

    Plasma-fuel systems (PFS) have been developed to improve coal combustion efficiency. PFS is a pulverized coal burner equipped with arc plasma torch producing high temperature air stream of 4000 - 6000 K. Plasma activation of coal at the PFS increases the coal reactivity and provides more effective ignition and ecologically friendly incineration of low-rank coal. The main and crucial element of PFS is plasma torch. Simplicity and reliability of the industrial arc plasma torches using cylindrical copper cathode and air as plasma forming gas predestined their application at heat and power engineering for plasma aided coal combustion. Life time of these plasma torches electrodes is critical and usually limited to 200 hours. Considered in this report direct current arc plasma torch has the cathode life significantly exceeded 1000 hours. To ensure the electrodes long life the process of hydrocarbon gas dissociation in the electric arc discharge is used. In accordance to this method atoms and ions of carbon from near-electrode plasma deposit on the active surface of the electrodes and form electrode carbon condensate which operates as ``actual'' electrode. Complex physicochemical investigation showed that deposit consists of nanocarbon material.

  8. Development and testing of a commercial-scale coal-fired combustion system: Phase 2, Quarterly technical progress report No. 7, April 1, 1992--June 20, 1992

    SciTech Connect

    Litka, A.F.; Breault, R.W.

    1992-08-01

    The objective of this program is to demonstrate the technical and economic viability of a coal-fired combustion system for the commercial sector. The commercial-scale coal-water slurry (CWS) fired space heating system will be a scale-up of a CWS-fired residential warm-air heating system developed by Tecogen Inc. under contract to the Department of Energy (DOE), Pittsburgh Energy Technology Center. This system included a patented nonslagging combustor known as IRIS, for Inertial Reactor with Internal Separation. This combustion technology, which has demonstrated high combustion efficiency using CWS fuels at input rates of 100,000 Btu/hr. will be scaled to operate at 2 to 5 million Btu/hr. Along with the necessary fuel storage and delivery, heat recovery, and control equipment, the system will include pollution control devices to meet targeted values of NO{sub x}, SO{sub 2}, and particulate emissions. In general, the system will be designed to match the reliability, safety, turndown, and ignition performance of gas or oil-fired systems. This report documents the work carried out in the seventh quarter of the program. During this period, proof-of-concept tests aimed at eliminating ash accumulation in the combustor and boiler were conducted. A compressed air soot blower system was installed on the boiler and combustor design changes implemented to reduced direct impingement of slurry on the upper chamber partition. As part of this testing, emission performance goals using Kentucky Hazard Prince Mine coal water slurry were met. Also, during this period the automatic control system for the system was installed and operation with this system was implemented.

  9. A Sensor System Based on Semi-Conductor Metal Oxide Technology for In Situ Detection of Coal Fired Combustion Gases

    SciTech Connect

    Brent Marquis

    2007-05-31

    Sensor Research and Development Corporation (SRD) proposed a two-phase program to develop a robust, autonomous prototype analyzer for in situ, real-time detection, identification, and measurement of coal-fired combustion gases and perform field-testing at an approved power generation facility. SRD developed and selected sensor materials showing selective responses to carbon monoxide, carbon dioxide, nitric oxide, nitrogen dioxide, ammonia, sulfur dioxide and hydrogen chloride. Sensor support electronics were also developed to enable prototype to function in elevated temperatures without any issues. Field-testing at DOE approved facility showed the ability of the prototype to detect and estimate the concentration of combustion by-products accurately with relatively low false-alarm rates at very fast sampling intervals.

  10. Coal combustion: Science and technology of industrial and utility applications

    SciTech Connect

    Junkai, F.

    1988-01-01

    This reference source offers material on theoretical research (including mathematical modeling, low NO/sub x/ combustion, and studies of sulfur), applications of the newest technologies, and actual experience of low-grade coal combustion.

  11. Quantifying of the Thermal Dynamic Characteristics of the Combustion System for Underground Coal Fire and its Impact on Environment in Xinjiang region, China

    NASA Astrophysics Data System (ADS)

    ZENG, Qiang; Tiyip, Tashpolat; Wuttke, Manfred; NIE, Jing; PU, Yan

    2015-04-01

    Underground Coal fire (UCF) is one disaster associated with coal mining activities around the world. The UCF not only burns up the coal reservoir, but also causes serious environmental problems, such as the pollution to air, the damage to soils, and the contamination to surface and underground water and consequently the health problem to human beings. In the present paper, the authors attempts to quantify the thermal dynamic characteristics of the combustion system for UCF and its impact on environment by modeling, including delineating the physical boundary of UCF zone, modeling of the capacity of the oxygen supply to UCF, modeling the intensity of heat generation from UCF and modeling the process of heat transfer within UCF and its surrounding environment. From this research, results were obtained as follows: First of all, based on the rock control theory, a model was proposed to depict the physical boundary of UCF zone which is important for coal fire research. Secondly, with analyzing the characteristics of air and smoke flow within UCF zone, an air/smoke flow model was proposed and consequently a method was put forward to calculate the capacity of oxygen supply to the UCF. Thirdly, with analyzing the characteristics of coal combustion within UCF zone, a method of calculating the intensity of heat generation from UCF, i.e., the heat source models, was established. Heat transfer with UCF zone includes the heat conductivity within UCF zone, the heat dissipation by radiation from the surface of fire zone, and the heat dissipation by convection as well as the heat loss taken away by mass transport. The authors also made an effort to depict the process of heat transfer by quantitative methods. Finally, an example of Shuixigou coal fire was given to illustrate parts of above models. Further more, UCF's impact on environment, such as the heavy metals contamination to surface soil of fire zone and the characteristics of gaseous pollutants emission from the UCF also was

  12. The development of a coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, January 1992--March 1992

    SciTech Connect

    Not Available

    1992-07-16

    PETC has implemented a number of advanced combustion research projects that will lead to the establishment of a broad, commercially acceptable engineering data base for the advancement of coal as the fuel of choice for boilers, furnaces, and process heaters. Vortec Corporation`s Coal-Fired Combustion System for Industrial Process Heating Applications has been selected for Phase III development under contract DE-AC22-91PC91161. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting, recycling, and refining processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase HI research effort is being focused on the development of a process heater system to be used for producing glass frits and wool fiber from boiler and incinerator ashes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. The economic evaluation of commercial scale CMS processes has begun. In order to accurately estimate the cost of the primary process vessels, preliminary designs for 25, 50, and 100 ton/day systems have been started under Task 1. This data will serve as input data for life cycle cost analysis performed as part of techno-economic evaluations. The economic evaluations of commercial CMS systems will be an integral part of the commercialization plan.

  13. Mercury emissions from coal combustion in China

    SciTech Connect

    David G. Streets; Jiming Hao; Shuxiao Wang; Ye Wu

    2009-07-01

    This chapter reviews the magnitude and spatial distribution of mercury emissions from coal combustion in China. Due to the large quantities of coal burned and the relatively low level of technology, particularly in industry, emissions are high. Emissions were stable at about 200-210 Mg during the period 1995-2000, but because of rapid economic growth starting in 2001, mercury emissions grew quickly to a value of 334 Mg in 2005. The annual average growth rate for the period 1995-2005 was 5.1%. The uncertainty in emission estimates is about {+-}35% (95% confidence intervals). Emissions are concentrated in those provinces with high concentrations of mercury in coal (like Guizhou Province) and provinces in which a lot of coal is burned (like Shanxi Province). Because significant amounts of coal are burned in homes and small industrial facilities, without any kind of emission control at all, emissions of particulate mercury are higher in China than in the developed world; the speciation profile nationwide is: 64% Hg{sup II}, 19% Hg{sup p}, and 17% Hg{sup 0}. In the future, growth in mercury emissions is expected to be limited by the application of FGD for SO{sub 2} control and other advanced technologies. Estimates of emissions are hampered by the lack of comprehensive and reliable emissions testing programs in China.

  14. [Emission factors of polycyclic aromatic hydrocarbons (PAHs) in residential coal combustion and its influence factors].

    PubMed

    Hai, Ting-Ting; Chen, Ying-Jun; Wang, Yan; Tian, Chong-Guo; Lin, Tian

    2013-07-01

    As the emission source of polycyclic aromatic hydrocarbons (PAHs), domestic coal combustion has attracted increasing attention in China. According to the coal maturity, combustion form and stove type associated with domestic coal combustion, a large-size, full-flow dilution tunnel and fractional sampling system was employed to collect the emissions from five coals with various maturities, which were burned in the form of raw-coal-chunk (RCC)/honeycomb-coal-briquettes (HCB) in different residential stoves, and then the emission factors of PAHs (EF(PAHs)) were achieved. The results indicate that the EF(PAHs) of bituminous coal ranged from 1.1 mg x kg(-1) to 3.9 mg x kg(-1) for RCC and 2.5 mg x kg(-1) to 21. 1 mg x kg(-1) for HCB, and the anthracite EF(PAH8) were 0.2 mg x kg(-1) for RCC and 0.6 mg x kg(-1) for HCB, respectively. Among all the influence factors of emission factors of PAHs from domestic coal combustion, the maturity of coal played a major role, the range of variance reaching 1 to 2 orders of magnitude in coals with different maturity. Followed by the form of combustion (RCC/HCB), the EF(PAHs) of HCB was 2-6 times higher than that of RCC for the same geological maturity of the coal. The type of stove had little influence on EF(PAHs).

  15. Simultaneous combustion of waste plastics with coal for pulverized coal injection application

    SciTech Connect

    Sushil Gupta; Veena Sahajwalla; Jacob Wood

    2006-12-15

    A bench-scale study was conducted to investigate the effect of simultaneous cofiring of waste plastic with coal on the combustion behavior of coals for PCI (pulverized coal injection) application in a blast furnace. Two Australian coals, premixed with low- and high-density polyethylene, were combusted in a drop tube furnace at 1473 K under a range of combustion conditions. In all the tested conditions, most of the coal blends including up to 30% plastic indicated similar or marginally higher combustion efficiency compared to those of the constituent coals even though plastics were not completely combusted. In a size range up to 600 {mu}m, the combustion efficiency of coal and polyethylene blends was found be independent of the particle size of plastic used. Both linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE) are shown to display similar influence on the combustion efficiency of coal blends. The effect of plastic appeared to display greater improvement on the combustion efficiency of low volatile coal compared to that of a high volatile coal blend. The study further suggested that the effect of oxygen levels of the injected air in improving the combustion efficiency of a coal-plastic blend could be more effective under fuel rich conditions. The study demonstrates that waste plastic can be successfully coinjected with PCI without having any adverse effect on the combustion efficiency particularly under the tested conditions. 22 refs., 12 figs., 2 tabs.

  16. Influence of sulfur in coals on char morphology and combustion

    SciTech Connect

    Marsh, H.

    1991-01-01

    During coal carbonization (pyrolysis), as during the combustion process of pulverized coal in a combustor, not all of the sulfur is released. Significant proportions become pat of the structure of the resultant coke and char. The combustion process of the char within the flames of the combustor in influenced dominantly by char morphology. This, in turn, controls the accessibility of oxidizing gases to the surfaces of the carbonaceous substance of the char. Mineral matter content, its extent and state of distribution, also exerts an influence on char morphology created during pyrolysis/carbonization. This complexity of coal renders it a very difficult material to study, systematically, to distinguish and separate out the contributing factors which influence combustion characteristics. Therefore, in such circumstances, it is necessary to simplify the systems by making use of model chars/cokes/carbons which can be made progressively more complex, but in a controlled way. In this way complicating influence in chars from coals can be eliminated, so enabling specific influences to be studied independently. It is important to note that preliminary work by Marsh and Gryglewicz (1990) indicated that levels of sulfur of about 3 to 5 wt % can reduce reactivities by 10 to 25%. The overall purpose of the study is to provide meaningful kinetic data to establish, quantitatively, the influence of organically-bound sulfur on the reactivity of carbons, and to ascertain if gasification catalysts are effective in the preferential removal of sulfur from the chars.

  17. Development & Testing of Industrial Scale, Coal Fired Combustion System, Phase 3

    SciTech Connect

    Bert Lauderer

    1998-01-17

    In the fourth quarter of calendar year 1997, 11 days of tests on the 20 MMBtu/hr combustor-boiler facility were performed as part of a parallel project on sulfur capture in slag. No work was performed on the present project in this quarter. The total test days on the Philadelphia facility to the end of December 1997 was 103, of which 30 tests were part of the other DOE project. This exceeds the planned 63 test days for this project. All key project objectives have been exceeded including combustor durability, automated combustor operation, NO emissions as x low as 0.07 lb/MMBtu and SO emissions as low as 0.2 lb/MMBtu. In addition, a novel post- 2 combustion NOx control process has been tested on a 37 MW and 100 MW utility boiler. Any further tests will depend on the results of evaluations of current and prior tests. The only effort remaining on this project is facility disassembly and Final Report. This report also contains clarification of project results reported in the 22 Quarterly Technical Report in response to nd comments by DOE.

  18. Development & Testing of Industrial Scale, Coal Fired Combustion System, Phase 3

    SciTech Connect

    Bert Lauderer

    1998-04-01

    In the first quarter of calendar year 1998, 4 days of tests on the 20 MMBtu/hr combustor-boiler facility were performed as part of a parallel project on sulfur capture in slag. No work was performed on the present project in this quarter. The total test days on the Philadelphia facility to the end of March 1998 was 108, of which 34 tests were part of the other DOE project. This exceeds the planned 63 test days for this project. All key project objectives have been exceeded including combustor durability, automated combustor operation, NOx emissions as low as 0.07 lb/MMBtu and SO2 emissions as low as 0.2 lb/MMBtu. In addition, a novel post-combustion NOx control process has been tested on a 37 MW and 100 MW utility boiler. Any further tests will depend on the results of evaluations of current and prior tests. The only effort remaining on this project is facility disassembly and Final Report. Almost all of the effort in the present quarter focussed on applying the results of this project and the parallel sulfur capture in slag project on new applications of this technology. Several very promising areas were identified and a number of proposals to implement them were prepared.

  19. Coal combustion products: trash or treasure?

    SciTech Connect

    Hansen, T.

    2006-07-15

    Coal combustion by-products can be a valuable resource to various industries. The American Coal Ash Association (ACAA) collects data on production and uses of coal combustion products (CCPs). 122.5 million tons of CCPs were produced in 2004. The article discusses the results of the ACCA's 2004 survey. Fly ash is predominantly used as a substitute for Portland cement; bottom ash for structural fill, embankments and paved road cases. Synthetic gypsum from the FGD process is commonly used in wallboard. Plant owners are only likely to have a buyer for a portion of their CCPs. Although sale of hot water (from Antelope Valley Station) from condensers for use in a fish farm to raise tilapia proved unviable, the Great Plains Synfuels Plant which manufactures natural gas from lignite produces a wide range of products including anhydrous ammonia, phenol, krypton, carbon dioxide (for enhanced oil recovery), tar oils and liquid nitrogen. ACCA's goal is to educate people about CCPs and how to make them into useful products, and market them, in order to reduce waste disposal and enhance revenue. The article lists members of the ACCA. 2 photos., 1 tab.

  20. Toxic substances from coal combustion -- A comprehensive assessment

    SciTech Connect

    Senior, C.L.; Panagiotou, T.; Huggins, F.E.; Huffman, G.P.; Yap, N.; Wendt, J.O.L.; Seames, W.; Ames, M.R.; Sarofim, A.F.; Lighty, J.; Kolker, A.; Finkelman, R.; Palmer, C.A.; Mroczkowsky, S.J.; Helble, J.J.; Mamani-Paco, R.

    1999-07-30

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the period from 1 April 1999 to 30 June 1999. During this quarter low temperature ashing and elemental analysis of the three Phase II coals were completed. Results from MIT and USGS are comparable. Plans were made for measurements of loss of trace elements during devolatilization and for single particle combustion studies at the University of Utah. The iodated charcoal trap was tested on coal combustion flue gas and was shown to collect both Hg and Se in from the vapor phase with 100% efficiency. Data from the University of Arizona self-sustained combustor were analyzed from the combustion of three coals: Ohio, Wyodak and Illinois No. 6. Ash size distributions and enrichment factors for selected trace elements were calculated. The correlation between the concentration of the more volatile trace elements in the ash and the

  1. TOXIC SUBSTANCES FROM COAL COMBUSTION: A COMPREHENSIVE ASSESSMENT

    SciTech Connect

    C.L. Senior; T. Panagiotou; J.O.L. Wendt; W. Seames; F.E. Huggins; G.P Huffman; N. Yap; M.R. Ames; I.Olmez; T. Zeng; A.F. Sarofim; A. Kolker; R. Finkelman; J.J. Helble

    1998-07-16

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, the Massachusetts Institute of Technology (MIT), the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (W) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NO{sub x} combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from the submission of the draft Phase 1 Final Report through the end of June, 1998. During this period two of the three Phase 2 coals were procured and pulverized samples were distributed to team members. Analysis of Phase 1 X-Ray Absorption Fine Structure (XAFS) data, particularly of mercury in sorbent samples, continued. An improved method for identifying mercury compounds on sorbents was developed, leading to a clearer understanding of forms of mercury in char and sorbents exposed to flue gas. Additional analysis of Phase 1 large scale combustion data was performed to investigate mechanistic information related to the fate of the radionuclides Cs, Th, and Co. Modeling work for this period was focused on building and testing a sub-model for vaporization

  2. Development and testing of a commercial-scale coal-fired combustion system: Phase 3, Quarterly progress report No. 9, October 1, 1992--December 31, 1992

    SciTech Connect

    Litka, A.F.; Breault, R.W.

    1993-05-01

    In the commercial sector, oil and natural gas are the predominant fuels used to meet space-heating needs of schools, office buildings, apartment complexes, etc. These buildings generally require firing rates of 1 to 10 million Btu/hr. Objective of this program is to demonstrate the technical and economic viability of a coal-fired combustion system for this sector. The commercial-scale coal-water slurry (CWS)-fired space heating system is a scale-up of a CWS-fired residential warm-air heating system developed by Tecogen Inc. This system included a patented nonslagging combustor known as IRIS (Inertial Reactor with Internal Separation). The combustor concept employs centrifugal forces combined with a staged combustion process to achieve high carbon conversion efficiencies and low N oxides generation. Along with the necessary fuel storage and delivery, heat recovery, and control equipment, the system includes pollution control devices to meet targeted values of SO{sub 2} and particulate emissions. In general, the system is designed to match the reliability, safety, turndown, and ignition performance of gas or oil-fired systems. During the 8th quarter of this program, a demonstration plan was developed for installation and operation of the space heating system at an actual installation. Also, equipment upgrades were implemented and laboratory testing performed to evaluate the performance of the system with these changes.

  3. Economics of coal combustion residue transportation

    SciTech Connect

    Sevim, H.; Gwamaka, S.

    1995-12-31

    A group of researchers at the Southern Illinois University is engaged in a research project whereby technical, environmental, and economic feasibility of coal combustion residue disposal into old underground coal mines is being investigated. Safe and economic transportation of residues from power plants to mine sites is an important segment of this project. A number of transportation alternatives have been examined, and among these, pneumatic trucks, pressure differential rail cars, and collapsible intermodal containers have been found to be promising. In this paper, all three alternatives are applied to hypothetical cases pertaining to central and southern Illinois. The operating scenarios are described and a comparative economic analysis is conducted using After-Tax Cost method. Each alternative is evaluated for varying distances and tonnages to reveal its favorable operating range.

  4. TOXIC SUBSTANCES FROM COAL COMBUSTION A COMPREHENSIVE ASSESSMENT

    SciTech Connect

    A KOLKER; AF SAROFIM; CA PALMER; FE HUGGINS; GP HUFFMAN; J LIGHTY; JJ HELBLE; JOL WENDT; MR AMES; N YAP; R FINKELMAN; R. MAMANI-PACO; SJ MROCZKOWSKY; T PANAGIOTOU; W SEAMES

    1999-01-28

    The technical objectives of this project are: (a) To identify the effect of the mode-of-occurrence of toxic elements in coal on the partitioning of these elements among vapor, submicron fume, and fly ash during the combustion of pulverized coal, (b) To identify the mechanisms governing the post-vaporization interaction of toxic elements and major minerals or unburnt char, (c) To determine the effect of combustion environment (i.e., fuel rich or fuel lean) on the partitioning of trace elements among vapor, submicron fume, and fly ash during the combustion of pulverized coal, (d) To model the partitioning of toxic elements among various chemical species in the vapor phase and between the vapor phase and complex aluminosilicate melts, (e) To develop the new Toxics Partitioning Engineering Model (ToPEM), applicable to all combustion conditions including new fuels and coal blends, low-NO{sub x} combustion systems, and new power generation plants. A description of the work plan for accomplishing these objectives is presented in Section 2.1 of this report. The work discussed in this report covers the reporting period from 1 October 1998 to 31 December 1998. During this quarter, basic coal testing at USGS was completed. Total sulfur contents range from 0.43 wt-% in the Wyodak to 2.68 wt-% in the Ohio sample. In the North Dakota and Ohio samples, about half of the total sulfur is pyritic and half is organic. The North Dakota sample also contains a minor amount of sulfate, consistent with the presence of barite in this sample. In the Wyodak sample, the majority of the sulfur is organic. Preliminary mineralogy of the three Phase II coals was determined by SEM/EDX. The Ohio coal contains all of the five most common major phases: quartz, illitic clay, kaolinitic clay, pyrite and calcite. Based on this preliminary work, the North Dakota sample appears to lack both kaolinite and calcite, and the Wyodak sample appears to lack calcite. Subsequent SEM work will attempt to reconfirm

  5. Development of coal combustion sensitivity test for smoke detectors

    SciTech Connect

    Edwards, J.C.; Morrow, G.S.

    1995-09-01

    Standard smoldering and flaming combustion tests using small coal samples have been developed by the US Bureau of Mines as a method to evaluate the response of a smoke detector. The tests are conducted using a standard smoke box designed and constructed according to Underwriters Laboratories. The tests provide a standard, easily reproducible smoke characteristic for smoldering and flaming coal combustion, based upon a comparison of the smoke optical density and the response of a standard ionization chamber to the smoke. With these standard tests, the range of threshold limits for the response of a smoke detector and the detector`s reliability can be evaluated for nearly identical smoke visibility and smoke physical characteristics. The detector`s threshold response limits and reliability need to be well defined prior to the instrument`s use as part of a mine fire warning system for improved mine safety.

  6. MERCURY CAPTURE ON COAL COMBUSTION FLY ASH. (R827649)

    EPA Science Inventory

    A study was performed at the Energy and Environmental Research Center (EERC) to test the hypotheses that (1) different carbon types contained in coal combustion fly ash have variable sorption capabilities relative to mercury and (2) the inorganic fraction of coal combustion fl...

  7. MERCURY CAPTURE ON COAL COMBUSTION FLY ASH. (R827649)

    EPA Science Inventory

    A study was performed at the Energy and Environmental Research Center (EERC) to test the hypotheses that (1) different carbon types contained in coal combustion fly ash have variable sorption capabilities relative to mercury and (2) the inorganic fraction of coal combustion fl...

  8. Coal Combustion Science. Quarterly progress report, October--December 1994

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Davis, K.A.; Hurt, R.H.; Yang, N.Y.C.

    1996-02-01

    The objective of this work is to support the Office of Fossil Energy in executing research on coal combustion science. This project consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: Task 1--Kinetics and mechanisms of pulverized coal char combustion; and Task 2--deposit growth and property development in coal-fired furnaces. The objective of task 1 is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. Work is being done in four areas: (a) kinetics of heterogeneous fuel particle populations; (b) char combustion kinetics at high carbon conversion; (c) the role of particle structure and the char formation process in combustion and; (d) unification of the Sandia char combustion data base. The objectives of Task 2 are to provide a self-consistent database of simultaneously measured, time-resolved, ash deposit properties in well-controlled and well-defined environments and to provide analytical expressions that relate deposit composition and structure to deposit properties of immediate relevance to PETC`s Combustion 2000 program. The task include the development and use of diagnostics to monitor, in situ and in real time, deposit properties, including information on both the structure and composition of the deposits.

  9. Computer-assisted analyses of the thermodynamic properties of slags in coal-combustion systems

    SciTech Connect

    Blander, M.; Pelton, A.D.

    1983-09-01

    Equations were developed for the analysis of the thermodynamic properties of molten silicate solutions; the equations take into account the unusual concentration and temperature dependence of the solution properties of ordered systems. For binary systems, these equations were coupled with an optimization computer program to analyze all reliable thermodynamic data, including phase diagrams, free energies and enthalpies of formation of compounds, activities of components, enthalpies of mixing, entropies of fusion, miscibility gaps, etc. In this manner, we analyzed data for five binary systems: CaO-SiO/sub 2/, Na/sub 2/O-SiO/sub 2/, CaO-Al/sub 2/O/sub 3/, Na/sub 2/O-Al/sub 2/O/sub 3/, and Al/sub 2/O/sub 3/-SiO/sub 2/. The results of the binary systems were combined, and an analysis done of three ternary systems: CaO-Al/sub 2/O/sub 3/-SiO/sub 2/, Na/sub 2/O-CaO-SiO/sub 2/, and Na/sub 2/O-Al/sub 2/O/sup 3/-SiO/sub 2/. A tentative analysis of the quaternary system, Na/sub 2/O-CaO-Al/sub 2/O/sub 3/-SiO/sub 2/, was also undertaken. 53 references, 51 figures, 3 tables.

  10. Combustion characteristics of dry coal-powder-fueled adiabatic diesel engine: Final report

    SciTech Connect

    Kakwani, R.M.; Kamo, R.

    1989-01-01

    This report describes the progress and findings of a research program aimed at investigating the combustion characteristics of dry coal powder fueled diesel engine. During this program, significant achievements were made in overcoming many problems facing the coal-powder-fueled engine. The Thermal Ignition Combustion System (TICS) concept was used to enhance the combustion of coal powder fuel. The major coal-fueled engine test results and accomplishments are as follows: design, fabrication and engine testing of improved coal feed system for fumigation of coal powder to the intake air; design, fabrication and engine testing of the TICS chamber made from a superalloy material (Hastelloy X); design, fabrication and engine testing of wear resistant chrome oxide ceramic coated piston rings and cylinder liner; lubrication system was improved to separate coal particles from the contaminated lubricating oil; control of the ignition timing of fumigated coal powder by utilizing exhaust gas recirculation (EGR) and variable TICS chamber temperature; coal-fueled engine testing was conducted in two configurations: dual fuel (with diesel pilot) and 100% coal-fueled engine without diesel pilot or heated intake air; cold starting of the 100% coal-powder-fueled engine with a glow plug; and coal-fueled-engine was operated from 800 to 1800 rpm speed and idle to full load engine conditions.

  11. Combustion engineering issues for solid fuel systems

    SciTech Connect

    Bruce Miller; David Tillman

    2008-05-15

    The book combines modeling, policy/regulation and fuel properties with cutting edge breakthroughs in solid fuel combustion for electricity generation and industrial applications. This book provides real-life experiences and tips for addressing the various technical, operational and regulatory issues that are associated with the use of fuels. Contents are: Introduction; Coal Characteristics; Characteristics of Alternative Fuels; Characteristics and Behavior of Inorganic Constituents; Fuel Blending for Combustion Management; Fuel Preparation; Conventional Firing Systems; Fluidized-Bed Firing Systems; Post-Combustion Emissions Control; Some Computer Applications for Combustion Engineering with Solid Fuels; Gasification; Policy Considerations for Combustion Engineering.

  12. Investigation of the liquid/vapor composition of compressed liquid CO2 with N2 and O2 in integrated pollutant removal systems for coal combustion

    SciTech Connect

    Oryshchyn, Danylo B.; Ochs, Thomas L.; Summers, Cathy A.; Penner, Larry R.; Gerdemann, Stephen J.

    2005-01-01

    Accurate prediction of the processes in Integrated Pollutant Removal (IPR) using compression and condensation of coal combustion products requires an understanding of the liquid/vapor ternary CO2/O2/N2 system. At conditions close to the critical point of CO2 the existing equations of state deviate from the sparse measured results available in the literature. Building on existing data and procedures, the USDOE/Albany Research Center has designed an apparatus for examining compositions in this region. The design of the apparatus and planned initial experiments are presented.

  13. TOXIC SUBSTANCES FROM COAL COMBUSTION-A COMPREHENSIVE ASSESSMENT

    SciTech Connect

    C.L. Senior; F. Huggins; G.P. Huffman; N. Shah; N. Yap; J.O.L. Wendt; W. Seames; M.R. Ames; A.F. Sarofim; S. Swenson; J.S. Lighty; A. Kolker; R. Finkelman; C.A. Palmer; S.J. Mroczkowski; J.J. Helble; R. Mamani-Paco; R. Sterling; G. Dunham; S. Miller

    2001-06-30

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the National Energy Technology Laboratory (NETL), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). The work discussed in this report covers the Phase II program. Five coals were studied (three in Phase I and two new ones in Phase II). In this work UK has used XAFS and Moessbauer spectroscopies to characterize elements in project coals. For coals, the principal use was to supply direct information about certain hazardous and other key elements (iron) to complement the more complete indirect investigation of elemental modes of occurrence being carried out by colleagues at USGS. Iterative selective leaching using ammonium acetate, HCl, HF, and HNO3, used in conjunction with mineral identification/quantification, and microanalysis of individual mineral grains, has allowed USGS to delineate modes of occurrence for 44 elements. The Phase II coals show rank-dependent systematic differences in trace-element modes of occurrence. The work at UU

  14. Theoretical principles of use of coal fractions with different densities for combustion

    SciTech Connect

    S.G. Gagarin; A.M. Gyul'maliev

    2009-02-15

    It is reasonable to complement the conventional preparation of steam coal involving the removal of ash components and pyritic sulfur by the isolation of the lightest organic fractions, which possess enhanced performance characteristics. These fractions are smoothly saleable both on the domestic and world markets for effective pulverized-coal combustion via new combustion technologies. Heavier (inertinite) fractions of the coal preparation concentrate marketed at lower prices can be considered appropriate fuel for burning in circulating fluidized-bed combustion systems. 13 refs., 5 figs., 4 tabs.

  15. Ignition and combustion of coal particles

    SciTech Connect

    Gomez, C.O.; Vastola, F.J.

    1983-09-01

    A subbituminous coal was used in this study. Particles from the 850 to 1000 ..mu.. sieve fraction were injected into a reaction furnace swept with air at temperature levels of 928/sup 0/, 980/sup 0/, 1076/sup 0/, 1118/sup 0/ and 1273/sup 0/K. The experimental technique, based upon the simultaneous measurement of the carbon monoxide, carbon dioxide, and the intensity of the light generated during the combustion, provides quantitative information about the ignition and the subsequent burn-off of the residual particle. Homogeneous ignition is detected at temperatures of 1076/sup 0/K and higher. The apparatus designed provides the special characteristics required in this study, and the transition between the ignition mechanisms is achieved within the range of operation conditions for this particular coal. The ignition mechanism is determined not only from the measurement of light intensity during the combustion, but also from the gas evolution curves. The results show the convenience of using these complementary techniques for the measurement of the ignition mechanism. 4 figures, 2 tables.

  16. Combustion characterization of coals for industrial applications. Final technical report, January 1, 1981-May 29, 1985

    SciTech Connect

    Nsakala, N.; Patel, R.L.; Lao, T.C.

    1985-03-01

    In-depth fundamental information was obtained from a two-inch inner diameter laminar flow reactor referred to as the Drop Tube Furnace System (DTFS). This information consists of the following: (1) pyrolysis kinetic characteristics of four coals of various rank (Texas lignite, Montana subbituminous, Alabama high volatile bituminous, and Pennsylvania anthracite); and (2) combustion kinetic studies of chars produced from the foregoing parent coals. A number of standard ASTM and special in-house bench scale tests were also performed on the coals and chars prepared therefrom to characterize their physicochemical properties. The pilot scale (500,000 Btu/hr) Controlled Mixing History Furnace (CMHF) was used to determine the effect of staged combustion on NO/sub x/ emissions control from an overall combustion performance of the Alabama high volatile bituminous coal. The quantitative fundamental data developed from this study indicate significant differences in coal/char chemical, physical, and reactivity characteristics, which should be useful to those interested in modeling coal combustion and pyrolysis processes. These results underscore the fact that coal selection is one of the keys governing a successful coal conversion/utilization process. The combustion kinetic information obtained on the high volatile bituminous coal has been used in conjunction with combustion engineering's proprietary mathematical models to predict the combustion performance of this coal in the Controlled Mixing History Furnace. Comparison of the predicted data with the experimental results shows a virtually one-to-one scale-up from the DTFS to the CMHF. These data should provide vital information to designers in the area of carbon burnout and NO/sub x/ reduction for large scale coal utilization applications. 31 refs., 28 figs., 17 tabs.

  17. A relevant study on characteristic parameters of coal combustion and boiler structure

    SciTech Connect

    Zhang, Z.; Zhao, L.; Wun, Y.; Lu, F.

    1997-12-31

    This paper analyzes over 40 power plant coal-fired utility boilers with capacities of more than 200MW and 300MW for its coal particle combustion characteristics, boiler structural parameters and actual condition of boiler performance. Two kinds of parameters of coal particle combustion characteristic and boiler structure are given. They are pulverized coal air jets ignition stability index (Mw), coal-ash slagging index (Mz), coal burn-out index (Mj) as well as boiler structural stability index (Lw), boiler structural slagging index (Lz), boiler structural burn-out index (Lj). The relevant relations between them of Mw-Lw, Mz-Lz and Mj-Lj are set up by interpolation function. This paper also describes a boiler design predicting expert system, with which the design parameters of power plant coal-fired utility boilers with large capacity may be calculated based on coal characteristics parameters and the boiler`s performance be predicted to guarantee power plant coal-fired utility boilers` stable combustion, less slagging and higher combustion efficiency. According to its application to an actual power plant coal-fired utility boiler, the result of prediction is accurate and reliable.

  18. Development of a coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, January--March 1994

    SciTech Connect

    Not Available

    1994-04-30

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system, controls, and then test the complete system in order to evaluate its potential marketability. The past quarter began with a two-day test performed in January to determine the cause of pulsations in the batch feed system observed during pilot-scale testing of surrogate TSCA incinerator ash performed in December of 1993. Two different batch feedstocks were used during this test: flyash and cullet. The cause of the pulsations was traced to a worn part in the feeder located at the bottom of the batch feed tank. The problem was corrected by replacing the wom part with the corresponding part on the existing coal feed tank. A new feeder for the existing coal tank, which had previously been ordered as part of the new coal handling system, was procured and installed. The data from the pilot-scale tests performed on surrogate TSCA incinerator ash during December of 1993 was collected and analyzed. All of the glass produced during the test passed both the Toxicity characteristics Leach Procedure (TCLP) and the Product Consistency Test (PCT) by approximately two orders of magnitude.

  19. Plane flame furnace combustion tests on JPL desulfurized coal

    NASA Technical Reports Server (NTRS)

    Reuther, J. J.; Kim, H. T.; Lima, J. G. H.

    1982-01-01

    The combustion characteristics of three raw bituminous (PSOC-282 and 276) and subbituminous (PSOC-230) coals, the raw coals partially desulfurized (ca -60%) by JPL chlorinolysis, and the chlorinated coals more completely desulfurized (ca -75%) by JPL hydrodesulfurization were determined. The extent to which the combustion characteristics of the untreated coals were altered upon JPL sulfur removal was examined. Combustion conditions typical of utility boilers were simulated in the plane flame furnace. Upon decreasing the parent coal voltaile matter generically by 80% and the sulfur by 75% via the JPL desulfurization process, ignition time was delayed 70 fold, burning velocity was retarded 1.5 fold, and burnout time was prolonged 1.4 fold. Total flame residence time increased 2.3 fold. The JPL desulfurization process appears to show significant promise for producing technologically combustible and clean burning (low SO3) fuels.

  20. Coal devolatilization and char combustion study using FTIR spectroscopy

    SciTech Connect

    Raines, T.S.; Brown, R.C.

    1995-12-31

    The goal of this research is to characterize coals during the normal operation of an industrial-scale circulating fluidized bed (CFB) boiler. The method determines coal properties based on the analysis of transient CO and CO{sub 2} emissions from the boiler. Fourier Transform Infrared (FTIR) spectroscopy is used to qualitatively and quantitatively analyze the gaseous products of combustion. The method is non-intrusive and is performed under realistic combustion conditions. Preliminary data suggest that coal devolatilization is complete before char combustion commences in a circulating fluidized bed boiler.

  1. The simulation of influence of different coals on the circulating fluidized bed Boiler's combustion performance

    NASA Astrophysics Data System (ADS)

    Yong, Yumei; Lu, Qinggang

    2003-05-01

    The combustion performance of the boiler largely depends on the coal type. Lots of experimental research shows that different fuels have different combustion characteristics. It is obvious that fuel will change the whole operating performance of Circulating Fluidized Bed Combustion (CFBC). We know even in a pilot-scale running boiler, the measurement of some parameters is difficult and costly. Therefore, we developed the way of simulation to evaluate the combustion performance of Chinese coals in CFB. The simulation results show that, different coals will result in different coal particle diameter and comminution depending on their mineral component and the change will affect the distribution of ash in CFBC system. In a word, the computational results are in accordance with experimental results qualitatively but there are some differences quantitatively.

  2. Influence of combustion conditions and coal properties on physical properties of fly ash generated from pulverized coal combustion

    SciTech Connect

    Hiromi Shirai; Hirofumi Tsuji; Michitaka Ikeda; Toshinobu Kotsuji

    2009-07-15

    To develop combustion technology for upgrading the quality of fly ash, the influences of the coal properties, such as the size of pulverized coal particles and the two-stage combustion ratio during the combustion, on the fly ash properties were investigated using our test furnace. The particle size, density, specific surface area (obtained by the Blaine method), and shape of fly ash particles of seven types of coal were measured. It was confirmed that the size of pulverized coal particles affects the size of the ash particles. Regarding the coal properties, the fuel ratio affected the ash particle size distribution. The density and shape of the ash particles strongly depended on their ash size. Our results indicated that the shape of the ash particles and the concentration of unburned carbon affected the specific surface area. The influence of the two-stage combustion ratio was limited. 8 refs., 13 figs., 3 tabs.

  3. Metallic species derived from fluidized bed coal combustion. [59 references

    SciTech Connect

    Natusch, D.F.S.; Taylor, D.R.

    1980-01-01

    Samples of fly ash generated by the combustion of Montana Rosebud coal in an experimental 18 inch fluidized bed combustor were collected. The use of a heated cascade impactor permitted collection of size fractionated material that avoided condensation of volatile gases on the particles. Elemental concentration trends were determined as a function of size and temperature and the results compared to published reports for conventional power plants. The behavior of trace metals appears to be substantially different in the two systems due to lower operating temperatures and the addition of limestone to the fluidized bed. Corrosion of the impactor plates was observed at the highest temperature and lowest limestone feed rate sampled during the study. Data from the elemental concentration and leaching studies suggest that corrosion is most likely due to reactions involving sodium sulfate. However, it is concluded that corrosion is less of a potential problem in fluidized-bed systems than in conventional coal-fired systems.

  4. Carbon dioxide from coal combustion: Variation with rank of US coal

    USGS Publications Warehouse

    Quick, J.C.; Glick, D.C.

    2000-01-01

    Carbon dioxide from combustion of US coal systematically varies with ASTM rank indices, allowing the amount of CO2 produced per net unit of energy to be predicted for individual coals. No single predictive equation is applicable to all coals. Accordingly, we provide one equation for coals above high volatile bituminous rank and another for lower rank coals. When applied to public data for commercial coals from western US mines these equations show a 15% variation of kg CO2 (net GJ)-1. This range of variation suggests reduction of US CO2 emissions is possible by prudent selection of coal for combustion. Maceral and mineral content are shown to slightly affect CO2 emissions from US coal. We also suggest that CO2 emissions increased between 6 and 8% in instances where Midwestern US power plants stopped burning local, high-sulfur bituminous coal and started burning low-sulfur, subbituminous C rank coal from the western US.

  5. Hardened, environmentally disposable composite granules of coal cleaning refuse, coal combustion waste, and other wastes, and method preparing the same

    SciTech Connect

    Burnet, G.; Gokhale, A.J.

    1990-07-10

    A hardened, environmentally inert and disposable composite granule of coal cleaning refuse and coal combustion waste and method for producing the same are disclosed, wherein the coal combustion waste is first granulated. The coal cleaning refuse is pulverized into fine particles and is then bound, as an outer layer, to the granulated coal combustion waste granules. This combination is then combusted and sintered. After cooling, the combination results in hardened, environmentally inert and disposable composite granules having cores of coal combustion waste, and outer shells of coal cleaning refuse. The composite particles are durable and extremely resistant to environmental and chemical forces. 3 figs.

  6. Hardened, environmentally disposable composite granules of coal cleaning refuse, coal combustion waste, and other wastes, and method preparing the same

    DOEpatents

    Burnet, G.; Gokhale, A.J.

    1990-07-10

    A hardened, environmentally inert and disposable composite granule of coal cleaning refuse and coal combustion waste and method for producing the same are disclosed, wherein the coal combustion waste is first granulated. The coal cleaning refuse is pulverized into fine particles and is then bound, as an outer layer, to the granulated coal combustion waste granules. This combination is then combusted and sintered. After cooling, the combination results in hardened, environmentally inert and disposable composite granules having cores of coal combustion waste, and outer shells of coal cleaning refuse. The composite particles are durable and extremely resistant to environmental and chemical forces. 3 figs.

  7. Hardened, environmentally disposable composite granules of coal cleaning refuse, coal combustion waste, and other wastes, and method preparing the same

    DOEpatents

    Burnet, George; Gokhale, Ashok J.

    1990-07-10

    A hardened, environmentally inert and disposable composite granule of coal cleaning refuse and coal combustion waste, and method for producing the same, wherein the coal combustion waste is first granulated. The coal cleaning refuse is pulverized into fine particles and is then bound, as an outer layer, to the granulated coal combustion waste granules. This combination is then combusted and sintered. After cooling, the combination results in hardened, environmentally inert and disposable composite granules having cores of coal combustion waste, and outer shells of coal cleaning refuse. The composite particles are durable and extremely resistant to environmental and chemical forces.

  8. Investigation of the behavior of mercury compounds in coal combustion products

    SciTech Connect

    G.Ya. Gerasimov

    2005-07-15

    The main mechanisms of transformation of mercury compounds in coal combustion products in the region of high temperatures have been analyzed. A kinetic model of the process of gas-phase oxidation of metal mercury vapors is proposed. The features of the behavior of the investigated compounds in systems of cleaning combustion products from harmful impurities have been considered.

  9. MECHANISMS AND OPTIMIZATION OF COAL COMBUSTION

    SciTech Connect

    Kyriacos Zygourakis

    2000-10-31

    The completed research project has made some significant contributions that will help us meet the challenges outlined in the previous section. One of the major novelties of our experimental approach involves the application of video microscopy and digital image analysis to study important transient phenomena (like particle swelling and ignitions) occurring during coal pyrolysis and combustion. Image analysis was also used to analyze the macropore structure of chars, a dominant factor in determining char reactivity and ignition behavior at high temperatures where all the commercial processes operate. By combining advanced experimental techniques with mathematical modeling, we were able to achieve the main objectives of our project. More specifically: (1) We accurately quantified the effect of several important process conditions (like pyrolysis heating rate, particle size, heat treatment temperature and soak time) on the combustion behavior of chars. These measurements shed new light into the fundamental mechanisms of important transient processes like particle swelling and ignitions. (2) We developed and tested theoretical models that can predict the ignition behavior of char particles and their burn-off times at high temperatures where intraparticle diffusional limitations are very important.

  10. Combustion and gasification characteristics of pulverized coal using high-temperature air

    SciTech Connect

    Hanaoka, R.; Nakamura, M.; Kiga, T.; Kosaka, H.; Iwahashi, T.; Yoshikawa, K.; Sakai, M.; Muramatsu, K.; Mochida, S.

    1998-07-01

    In order to confirm performance of high-temperature-air combusting of pulverized coal, laboratory-scale combustion and gasification tests of coal were conducted changing air temperature and oxygen concentration in the air. Theses were conducted in a drop tube furnace of 200mm in inside diameter and 2,000mm in length. The furnace was heated by ceramic heater up to 1,300 C. A high-temperature air preheater utilizing the HRS (High Cycle Regenerative Combustion System) was used to obtain high-temperature combustion air. As the results, NOx emission was reduced when pulverized coal was fired with high-temperature-air. On the other hand, by lower oxygen concentration in combustion air diluted by nitrogen, NOx emission slightly decreased while became higher under staging condition.

  11. Combustion characterization of beneficiated coal-based fuels

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1990-11-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a three-year project on Combustion Characterization of Beneficiated Coal-Based Fuels.'' The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are being run at the cleaning facility in Homer City, Pennsylvania, to produce 20-ton batches of fuels for shipment to CE's laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CVVT) or a dry microfine pulverized coal (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors to CE to perform parts of the test work are the Massachusetts Institute of Technology (MIT), Physical Science, Inc. Technology Company (PSIT) and the University of North Dakota Energy and Environmental Research Center (UNDEERC). Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFS, and two conventionally cleaned coals for full-scale tests. Approximately, nine BCFs will be in dry microfine coal (DMPC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements.

  12. Simulation of coal ash deposition under pulverized coal combustion conditions

    SciTech Connect

    Yilmaz, S.; Cliffe, K.R.

    1994-12-31

    The deposition of coal ash onto the superheater tubes of a pulverized fuel fired boiler is simulated by injecting soda lime silica glass, SLSG, particles into hot combustion gases produced from the combustion of natural gas and by measuring the amount of deposit formed on a probe in a horizontally fired furnace. The effect of various parameters, including gas and probe surface temperatures, gas velocity, particle size and composition on deposit formation were investigated. The results showed that operating parameters, namely the gas temperature and probe surface temperature are of primary importance since deposition rates doubled over the range investigated. The deposition rate of 6 and 8 {mu}m particles was constant and considered to be controlled by their transport to the probe surface while that of larger particles showed an asymptotic behavior which suggested the deposition rate was controlled by the stickiness of the deposit surface on the probe. The addition of NaCl to SLSG particles increased deposition rates by approximately 100%, while addition of CACO{sub 3} showed no influence on the deposition rate of the SLSG particles. The addition of NaCl to CACO{sub 3} formed less deposit than CaCO{sub 3} particles on their own. Similarly, the deposition rate of SLSG and CaCO{sub 3} was lowered by addition of NaCl into it. This was probably caused by formation of some high melting point compounds between NaCl and CACO{sub 3}.

  13. Environmentally sound thermal energy extraction from coal and wastes using high temperature air combustion technology

    SciTech Connect

    Yoshikawa, Kunio

    1999-07-01

    High temperature air combustion is one of promising ways of burning relatively low BTU gas obtained from gasification of low grade coal or wastes. In this report, the author proposes a new power generation system coupled with high temperature air gasification of coal/wastes and high temperature air combustion of the syngas from coal/wastes. This system is realized by employing Multi-staged Enthalpy Extraction Technology (MEET). The basic idea of the MEET system is that coal or wastes are gasified with high temperature air of about 1,000 C, then the generated syngas is cooled in a heat recovery boiler to be cleaned-up in a gas cleanup system (desulfurization, desalinization and dust removal). Part of thermal energy contained in this cleaned-up syngas is used for high temperature air preheating, and the complete combustion of the fuel gas is done using also high temperature air for driving gas turbines or steam generation in a boiler.

  14. Methodology for Evaluating Encapsulated Beneficial Uses of Coal Combustion Residuals

    EPA Pesticide Factsheets

    The primary purpose of this document is to present an evaluation methodology developed by the EPA for making determinations about environmental releases from encapsulated products containing coal combustion residuals.

  15. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 18, July--September 1993

    SciTech Connect

    Chow, O.K.; Hargrove, M.J.

    1993-11-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coal (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the third quarter of 1993, the following technical progress was made: Continued with data and sample analysis from the pilot-scale tests of Upper Freeport feed coal, air-dried and mulled microagglomerate products; air-dried Pittsburgh No. 8 as-is and mulled products for upcoming Task 3 combustion testing; and prepared two abstracts for presentation for the March 1 994 Coal Utilization and Fuel Systems Conference.

  16. Development of a coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, January 1993--March 1993

    SciTech Connect

    Not Available

    1993-04-30

    This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater concepts to be developed are based on advanced glass melting and ore smelting furnaces developed and patented by Vortec Corporation. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the current reporting period, a majority of the effort was spent performing the initial industrial proof-of-concept test and installing and integrating the Wet Electrostatic Precipitator (WESP). The other system modifications are well underway with the designs of the modifications to the batch/coal feed system being completed. A Purchase Order has been issued to a material conveying equipment vendor for the purchase of the batch/coal feeding equipment. The delivery and installation of the material conveying equipment is expected to occur in July and early August. The commercialization planning is continuing with the completion of a draft Business Plan. This plan is currently undergoing internal review, and will be submitted to Dawnbreaker, a DOE contracted small business consulting firm, for review.

  17. Characteristics of particulate carbon emissions from real-world Chinese coal combustion

    SciTech Connect

    Yuanxun Zhang; James Jay Schauer; Yuanhang Zhang; Limin Zeng; Yongjie Wei; Yuan Liu; Min Shao

    2008-07-15

    Particulate matter emissions from a series of different Chinese coal combustion systems were collected and analyzed for elemental and organic carbon (EC, OC), and molecular markers. Emissions from both industrial boilers and residential stoves were investigated. The coal used in this study included anthracite, bituminite, and brown coal, as well as commonly used coal briquettes produced in China for residential coal combustion. Results show significant differences in the contribution of carbonaceous species to particulate mass emissions. Industrial boilers had much higher burn out of carbon yielding particulate matter emissions with much lower levels of OC, EC, and speciated organic compounds, while residential stoves had significantly higher emissions of carbonaceous particulate matter with emission rates of approximately 100 times higher than that of industrial boilers. Quantified organic compounds emitted from industrial boilers were dominated by oxygenated compounds, of which 46-68% were organic acids, whereas the dominate species quantified in the emissions from residential stoves were PAHs (38%) and n-alkanes (20%). An important observation was the fact that emission factors of PAHs and the distribution of hopanoids were different among the emissions from industrial and residential coal combustion even using the same coal for combustion. Although particulate matter emissions from industrial and residential combustion were different in many regards, picene was detected in all samples with detectable OC mass concentrations, which supports the use of this organic tracer for OC from all types of coal combustion. 17{alpha}(H),21{beta}(H)-29-norhopane was the predominant hopanoid in coal combustion emissions, which is different from mobile source emissions and may be used to distinguish emissions from these different fossil fuel sources. 32 refs., 4 figs., 1 tab.

  18. Characteristics of particulate carbon emissions from real-world Chinese coal combustion.

    PubMed

    Zhang, Yuanxun; Schauer, James Jay; Zhang, Yuanhang; Zeng, Limin; Wei, Yongjie; Liu, Yuan; Shao, Min

    2008-07-15

    Particulate matter emissions from a series of different Chinese coal combustion systems were collected and analyzed for elemental and organic carbon (EC, OC), and molecular markers. Emissions from both industrial boilers and residential stoves were investigated. The coal used in this study included anthracite, bituminite, and brown coal, as well as commonly used coal briquettes produced in China for residential coal combustion. Results show significant differences in the contribution of carbonaceous species to particulate mass emissions. Industrial boilers had much higher burn out of carbon yielding particulate matter emissions with much lower levels of OC, EC, and speciated organic compounds, while residential stoves had significantly higher emissions of carbonaceous particulate matter with emission rates of approximately 100 times higher than that of industrial boilers. Quantified organic compounds emitted from industrial boilers were dominated by oxygenated compounds, of which 46-68% were organic acids, whereas the dominate species quantified in the emissions from residential stoves were PAHs (38%) and n-alkanes (20%). An important observation was the fact that emission factors of PAHs and the distribution of hopanoids were different among the emissions from industrial and residential coal combustion even using the same coal for combustion. Although particulate matter emissions from industrial and residential combustion were different in many regards, picene was detected in all samples with detectable OC mass concentrations, which supports the use of this organic tracer for OC from all types of coal combustion. 17alpha(H),21beta(H)-29-norhopane was the predominant hopanoid in coal combustion emissions, which is different from mobile source emissions and may be used to distinguish emissions from these different fossil fuel sources.

  19. Combustion characterization of beneficiated coal-based fuels

    SciTech Connect

    Chow, O.K.; Levasseur, A.A.

    1995-11-01

    The Pittsburgh Energy Technology Center (PETC) of the U.S. Department of Energy is sponsoring the development of advanced coal-cleaning technologies aimed at expanding the use of the nation`s vast coal reserves in an environmentally and economically acceptable manner. Because of the lack of practical experience with deeply beneficiated coal-based fuels, PETC has contracted Combustion Engineering, Inc. to perform a multi-year project on `Combustion Characterization of Beneficiated Coal-Based Fuels.` The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of Beneficiated Coal-Based Fuels (BCs) influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs.

  20. Proceedings of the conference on Coal Feeding Systems

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Development of coal feed systems for coal gasification, fluidized bed combustion, and magnetohydrodynamic applications is discussed. Process operations experience, energy conversion efficiency, and environment effects are among the factors considered.

  1. Combustion and gasification characteristics of chars from four commercially significant coals of different rank. Final report

    SciTech Connect

    Nsakala, N.Y.; Patel, R.L.; Lao, T.C.

    1982-09-01

    The combustion and gasification kinetics of four size graded coal chars were investigated experimentally in Combustion Engineering's Drop Tube Furnace System (DTFS). The chars were prepared in the DTFS from commercially significant coals representing a wide range of rank; these included a Pittsburgh No. 8 Seam hvAb coal, an Illinois No. 6 Seam hvCb coal, a Wyoming Sub C, and a Texas Lignite A. Additionally, a number of standard ASTM and special bench scale tests were performed on the coals and chars to characterize their physicochemical properties. Results showed that the lower rank coal chars were more reactive than the higher rank coal chars and that combustion reactions of chars were much faster than the corresponding gasification reactions. Fuel properties, temperature, and reactant gas partial pressure had a significant influence on both combustion and gasification, and particle size had a mild but discernible influence on gasification. Fuel reactivities were closely related to pore structure. Computer simulation of the combustion and gasification performances of the subject samples in the DTFS supported the experimental findings.

  2. Partitioning of mercury, arsenic, selenium, boron, and chloride in a full-scale coal combustion process equipped with selective catalytic reduction, electrostatic precipitation, and flue gas desulfurization systems

    SciTech Connect

    Chin-Min Cheng; Pauline Hack; Paul Chu; Yung-Nan Chang; Ting-Yu Lin; Chih-Sheng Ko; Po-Han Chiang; Cheng-Chun He; Yuan-Min Lai; Wei-Ping Pan

    2009-09-15

    A full-scale field study was carried out at a 795 MWe coal-fired power plant equipped with selective catalytic reduction (SCR), an electrostatic precipitator (ESP), and wet flue gas desulfurization (FGD) systems to investigate the distribution of selected trace elements (i.e., mercury, arsenic, selenium, boron, and chloride) from coal, FGD reagent slurry, makeup water to flue gas, solid byproduct, and wastewater streams. Flue gases were collected from the SCR outlet, ESP inlet, FGD inlet, and stack. Concurrent with flue gas sampling, coal, bottom ash, economizer ash, and samples from the FGD process were also collected for elemental analysis. By combining plant operation parameters, the overall material balances of selected elements were established. The removal efficiencies of As, Se, Hg, and B by the ESP unit were 88, 56, 17, and 8%, respectively. Only about 2.5% of Cl was condensed and removed from flue gas by fly ash. The FGD process removed over 90% of Cl, 77% of B, 76% of Hg, 30% of Se, and 5% of As. About 90% and 99% of the FGD-removed Hg and Se were associated with gypsum. For B and Cl, over 99% were discharged from the coal combustion process with the wastewater. Mineral trona (trisodium hydrogendicarbonate dehydrate, Na{sub 3}H(CO{sub 3}){sub 2}.2H{sub 2}O) was injected before the ESP unit to control the emission of sulfur trioxide (SO{sub 3}). By comparing the trace elements compositions in the fly ash samples collected from the locations before and after the trona injection, the injection of trona did not show an observable effect on the partitioning behaviors of selenium and arsenic, but it significantly increased the adsorption of mercury onto fly ash. The stack emissions of mercury, boron, selenium, and chloride were for the most part in the gas phase. 47 refs., 3 figs., 11 tabs.

  3. Coal systems analysis

    SciTech Connect

    Warwick, P.D.

    2005-07-01

    This collection of papers provides an introduction to the concept of coal systems analysis and contains examples of how coal systems analysis can be used to understand, characterize, and evaluate coal and coal gas resources. Chapter are: Coal systems analysis: A new approach to the understanding of coal formation, coal quality and environmental considerations, and coal as a source rock for hydrocarbons by Peter D. Warwick. Appalachian coal assessment: Defining the coal systems of the Appalachian Basin by Robert C. Milici. Subtle structural influences on coal thickness and distribution: Examples from the Lower Broas-Stockton coal (Middle Pennsylvanian), Eastern Kentucky Coal Field, USA by Stephen F. Greb, Cortland F. Eble, and J.C. Hower. Palynology in coal systems analysis The key to floras, climate, and stratigraphy of coal-forming environments by Douglas J. Nichols. A comparison of late Paleocene and late Eocene lignite depositional systems using palynology, upper Wilcox and upper Jackson Groups, east-central Texas by Jennifer M.K. O'Keefe, Recep H. Sancay, Anne L. Raymond, and Thomas E. Yancey. New insights on the hydrocarbon system of the Fruitland Formation coal beds, northern San Juan Basin, Colorado and New Mexico, USA by W.C. Riese, William L. Pelzmann, and Glen T. Snyder.

  4. Atmospheric emission of mercury due to combustion of steam coal and domestic coal in China

    NASA Astrophysics Data System (ADS)

    Wang, Shaobin; Luo, Kunli

    2017-08-01

    To study the mercury emission due to the combustion of steam coal and domestic coal in China, we analyzed the mercury contents of coal, fly ash, bottom ash and sluicing water in thermal power plants, steam boilers as well as domestic coal-stoves, in Shaanxi, Shanxi, Shandong and Yunnan Provinces. This study conduct an estimate of the Hg emission rates from steam coal and domestic coal combustion based on the method of mass distribution ratio of fly ash and bottom ash. The results show that the Hg emission rate of coal combustion in thermal power plants is about 50.21% (electrostatic precipitators + wet flue gas desulfurization), and that in heating boilers is about 67.23%, and 92.28% in industrial boilers without flue gas desulphurisation equipment. Furthermore, Hg emission rate is 83.61% due to domestic coal combustion in coal-stoves. The Hg emission amount into the atmosphere from power and heat generation, industrial boilers, domestic coal-stoves and spontaneous combustion of coal gangue is roughly estimated to be 133 ± 4, 100 ± 17, 11 ± 0.1 and 47 ± 26 tons in China in 2014, respectively, and the total Hg emission amount from this paper is estimated at 292 tons. The trends of Hg emission in China from 1991 to 2014 show an accelerating growth after 2002. The proportion of mercury emission due to thermal power, heating generation and industrial energy utilization continuously increased. The atmospheric emission of mercury due to combustion of steam coal, domestic coal and coal gangue accounts nearly 50% in total anthropogenic Hg emissions in China, indicating one of the largest sources of Hg emission in China which should draw more public and scientific attention in the future.

  5. Recent coal-oil mixture combustion tests at PETC

    SciTech Connect

    Pan, Y. S.; Bellas, G. T.; Mathur, M. P.; Joubert, J. I.; Bienstock, D.

    1980-06-01

    Coal-oil mixture combustion tests with coal concentrations of up to 50 percent were successfully conducted in a 700 horsepower watertube boiler designed originally for oil firing. A 500-h duration test with coal-oil mixture containing 40 percent coal has also been completed. No derating of the boiler occurred, carbon-conversion efficiencies were above 98 percent, and boiler efficiencies were the same as when firing No. 6 fuel oil. All combustion tests were conducted with No. 6 fuel oil mixed with Pittsburgh Seam coal pulverized to a coal particle size of 90 percent minus 200 mesh. Test results relating to boiler performance, pollutant emissions, ash deposition, and corrosion, erosion, and fouling behavior are presented.

  6. Transformation of substances containing trace elements in coal combustion

    NASA Astrophysics Data System (ADS)

    Samuilov, E. V.; Lebedeva, L. N.; Faminskaya, M. V.; Pokrovskaya, L. S.

    2010-12-01

    A new complex approach to simulation of phase and chemical transformation of substances containing trace elements in coal burning units is proposed; this approach unites capabilities of geochemistry, chemical thermodynamics, and physical-chemical kinetics. Processes of transformation of these substances in the flow of combustion products of Moscow basin coals along the flow path of the P-59 boiler are studied.

  7. Mathematical modeling of MILD combustion of pulverized coal

    SciTech Connect

    Schaffel, N.; Mancini, M.; Weber, R.; Szlek, A.

    2009-09-15

    MILD (flameless) combustion is a new rapidly developing technology. The IFRF trials have demonstrated high potential of this technology also for N-containing fuels. In this work the IFRF experiments are analyzed using the CFD-based mathematical model. Both the Chemical Percolation Devolatilization (CPD) model and the char combustion intrinsic reactivity model have been adapted to Guasare coal combusted. The flow-field as well as the temperature and the oxygen fields have been accurately predicted by the CFD-based model. The predicted temperature and gas composition fields have been uniform demonstrating that slow combustion occurs in the entire furnace volume. The CFD-based predictions have highlighted the NO{sub x} reduction potential of MILD combustion through the following mechanism. Before the coal devolatilization proceeds, the coal jet entrains a substantial amount of flue gas so that its oxygen content is typically not higher than 3-5%. The volatiles are given off in a highly sub-stoichiometric environment and their N-containing species are preferentially converted to molecular nitrogen rather than to NO. Furthermore, there exists a strong NO-reburning mechanism within the fuel jet and in the air jet downstream of the position where these two jets merge. In other words, less NO is formed from combustion of volatiles and stronger NO-reburning mechanisms exist in the MILD combustion if compared to conventional coal combustion technology. (author)

  8. STUDIES OF THE SPONTANEOUS COMBUSTION OF LOW RANK COALS AND LIGNITES

    SciTech Connect

    Joseph M. Okoh; Joseph N.D. Dodoo

    2005-07-26

    Spontaneous combustion has always been a problem in coal utilization especially in the storage and transportation of coal. In the United States, approximately 11% of underground coal mine fires are attributed to spontaneous coal combustion. The incidence of such fires is expected to increase with increased consumption of lower rank coals. The cause is usually suspected to be the reabsorption of moisture and oxidation. To understand the mechanisms of spontaneous combustion this study was conducted to (1) define the initial and final products during the low temperature (10 to 60 C) oxidation of coal at different partial pressures of O{sub 2}, (2) determine the rate of oxidation, and (3) measure the reaction enthalpy. The reaction rate (R) and propensity towards spontaneous combustion were evaluated in terms of the initial rate method for the mass gained due to adsorbed O{sub 2}. Equipment that was used consisted of a FT-IR (Fourier Transform-Infrared Spectrometer, Perkin Elmer), an accelerated surface area porosimeter (ASAP, Micromeritics model 2010), thermogravimetric analyzer (TGA, Cahn Microbalance TG 121) and a differential scanning calorimeter (DSC, Q1000, thermal analysis instruments). Their combination yielded data that established a relation between adsorption of oxygen and reaction enthalpy. The head space/ gas chromatograph/ mass spectrometer system (HS/GC/MS) was used to identify volatiles evolved during oxidation. The coal samples used were Beulah lignite and Wyodak (sub-bituminous). Oxygen (O{sub 2}) absorption rates ranged from 0.202 mg O{sub 2}/mg coal hr for coal sample No.20 (Beulah pyrolyzed at 300 C) to 6.05 mg O{sub 2}/mg coal hr for coal sample No.8 (wyodak aged and pyrolyzed at 300 C). Aging of coal followed by pyrolysis was observed to contribute to higher reaction rates. Reaction enthalpies ranged from 0.42 to 1580 kcal/gm/mol O{sub 2}.

  9. Mercury transformation behavior on a bench scale coal combustion furnace

    NASA Astrophysics Data System (ADS)

    Fujiwara, N.; Fujita, Y.; Tomura, K.; Moritomi, H.; Murakami, E.; Akimoto, A.; Ikeda, S.; Tadakuma, Y.

    2003-05-01

    The mercury release behavior in bituminous coals, and the partitioning rate of mercury in solids and gaseous in flue gases have measured to develop technologies for evaluating the partitioning of mercury in coal combustion process and develop in-situ adsorption and removal technologies using three kinds of experiment equipments - a thermo-balance, a drop-tube furnace (DTF), a bench-scale pulverized coal combustion fumace. The results showed that about 20 to 60% of the mercury in coal was released between 573K and 673K, which was the range of temperature in which the release of the volatile matter of coal began. And more than 90% of the mercury was released at 773K, the temperature at which the release of the volatile matter was completed. The rate of mercury partitioned into bottom ash in a bench-scale pulverized coal combustion furnace was the smallest irrespective of the type of coal. The rate of mercury partitioned into cyclone ash was also low for all types of coal with values generally below 10%. The rest of the mercury was partitioned into mercury in gaseous form, but the rate partitioned into dust, oxidized mercury and elemental mercury varied slightly depending on the flue gas temperature and the type of coal.

  10. Catalytic Unmixed Combustion of Coal with Zero Pollution

    SciTech Connect

    George Rizeq; Parag Kulkarni; Raul Subia; Wei Wei

    2005-12-01

    GE Global Research is developing an innovative energy-based technology for coal combustion with high efficiency and near-zero pollution. This Unmixed Combustion of coal (UMC-Coal) technology simultaneously converts coal, steam and air into two separate streams of high pressure CO{sub 2}-rich gas for sequestration, and high-temperature, high-pressure vitiated air for producing electricity in gas turbine expanders. The UMC process utilizes an oxygen transfer material (OTM) and eliminates the need for an air separation unit (ASU) and a CO{sub 2} separation unit as compared to conventional gasification based processes. This is the final report for the two-year DOE-funded program (DE-FC26-03NT41842) on this technology that ended in September 30, 2005. The UMC technology development program encompassed lab- and pilot-scale studies to demonstrate the UMC concept. The chemical feasibility of the individual UMC steps was established via lab-scale testing. A pilot plant, designed in a related DOE funded program (DE-FC26-00FT40974), was reconstructed and operated to demonstrate the chemistry of UMC process in a pilot-scale system. The risks associated with this promising technology including cost, lifetime and durability OTM and the impact of contaminants on turbine performance are currently being addressed in detail in a related ongoing DOE funded program (DE-FC26-00FT40974, Phase II). Results obtained to date suggest that this technology has the potential to economically meet future efficiency and environmental performance goals.

  11. Development and testing of industrial scale, coal fired combustion system, Phase 3. Sixteenth quarterly technical progress report, October 1--December 31, 1995

    SciTech Connect

    Zauderer, B.

    1996-01-03

    In the fourth quarter of calendar year 1995 the installation and checkout of the 20 MMBtu/hr combustor and auxiliary equipment in Philadelphia was completed. The task 5, Site Demonstration Testing, combustor-boiler tests on gas, oil, and coal were initiated. The task 5 effort involves testing the combustor over extended periods under conditions that fully simulate commercial operation and that meet the combustion and environmental specifications for this project. To meet this project objective within the current work scope requires up to 500 hours of testing. The focus of this testing will be on the component and environmental performance of combustor, boiler, coal preparation and feeding, and the stack gas equipment. The facility can be converted to a 500 kW power plant by the addition of a steam turbine, condenser, and cooling tower. However, this added effort is beyond the current work scope and its implementation will depend on recovering the added costs by placing the steam production from the boiler to beneficial use. During the present quarterly reporting period, all the components needed to implement the initial 100 hours of testing under task 5 were installed at the test site, and checkout of this equipment was performed. Since the present installation contained substantial improvements and simplifications to all sub-systems that had been used in the Williamsport facility, each component and sub-system had to be tested individually.

  12. Compilation of Sandia coal char combustion data and kinetic analyses

    SciTech Connect

    Mitchell, R.E.; Hurt, R.H.; Baxter, L.L.; Hardesty, D.R.

    1992-06-01

    An experimental project was undertaken to characterize the physical and chemical processes that govern the combustion of pulverized coal chars. The experimental endeavor establishes a database on the reactivities of coal chars as a function of coal type, particle size, particle temperature, gas temperature, and gas and composition. The project also provides a better understanding of the mechanism of char oxidation, and yields quantitative information on the release rates of nitrogen- and sulfur-containing species during char combustion. An accurate predictive engineering model of the overall char combustion process under technologically relevant conditions in a primary product of this experimental effort. This document summarizes the experimental effort, the approach used to analyze the data, and individual compilations of data and kinetic analyses for each of the parent coals investigates.

  13. A clean coal combustion technology-slagging combustors

    SciTech Connect

    Chang, S. L.; Berry, G. F.

    1989-03-01

    Slagging combustion is an advanced clean coal technology technique characterized by low NOx and SOx emission, high combustion efficiency, high ash removal, simple design and compact size. The design of slagging combustors has operational flexibility for a wide range of applications, including retrofitting boilers, magnetohydrodynamic combustors, coal-fired gas turbines, gasifiers and hazardous waste incinerators. In recent years, developers of slagging combustors have achieved encouraging progress toward the commercialization of this technology. Although there is a diversity of technical approaches among the developers, they all aim for a compact design of pulverized coal combustion with high heat release and sub-stoichiometric combustion regimes of operation to suppress NOx formation, and most aim to capture sulfur by using sorbent injection in the combustor. If the present pace toward commercialization continues, retrofitting boilers of sizes ranging from 20 to 250 MMBtu/hr (5.9 to 73 MWt) may be available for commercial use in the 1990's. 18 refs., 2 figs.

  14. EFFECTS OF COMBUSTION PARAMETERS ON POLYCHLORINATED DIBENZODIOXIN AND DIBENZOFURAN HOMOLOGUE PROFILES FROM MUNICIPAL WASTE AND COAL CO-COMBUSTION

    EPA Science Inventory

    Variation in polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD and PCDF) homologue profiles from a pilot scale (0.6 MWt, 2x106 Btu/hr), co-fired-fuel [densified refuse derived fuel (dRDF) and high-sulfur Illinois coal] combustion system was used to provide i...

  15. The effecting factors of sulfur evolution during coal combustion

    SciTech Connect

    Liu Zechang; Yu Hongguan; Wang Li

    1997-12-31

    Three kinds of bituminous coal and one kind of anthracite have been used to investigate the factors affecting sulfur evolution during coal combustion by means of improved automatic sulfur analyzer. In this paper the sulfur evolution index, that is, the relative quantity of sulfur evolution (Vs), the final quantity of sulfur evolution (Va), the rate of sulfur evolution and delay time, are selected to describe the sulfur evolution. The results show that the rate and quantity of sulfur evolution is affected by the temperature, retention time, type of coal, sulfur forms, calcium-based content in coal, oxygen concentration and flow velocity of air. The study can provide some knowledge for selecting sorbent for coal combustion.

  16. Toxic substances from coal combustion -- A comprehensive assessment. Quarterly report, October 1, 1996--December 31, 1996

    SciTech Connect

    Bool, L.E. III; Senior, C.L.; Huggins, F.; Huffman, G.P.; Shah, N.

    1997-01-31

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UKy), the University of Connecticut, and Princeton University to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI`s existing Engineering Model for Ash Formation (EMAF). During the past quarter the final program coal, from the Wyodak seam in the Powder River Basin, was acquired and distributed. Extensive coal characterization and laboratory work is underway to develop and test new sub-models. Coal characterization in the past quarter included direct identification of the modes of occurrence of various trace inorganic species in coal and ash using unique analytical techniques such as XAFS analysis and selective leaching. Combustion testing of the bituminous coals continued and additional data were obtained on trace element vaporization in the combustion zone. Studies of post-combustion trace element transformations, such as mercury speciation in the flue gas, were also begun in the last quarter.

  17. STRUCTURE-BASED PREDICTIVE MODEL FOR COAL CHAR COMBUSTION

    SciTech Connect

    CHRISTOPHER M. HADAD; JOSEPH M. CALO; ROBERT H. ESSENHIGH; ROBERT H. HURT

    1998-06-04

    During the past quarter of this project, significant progress continued was made on both major technical tasks. Progress was made at OSU on advancing the application of computational chemistry to oxidative attack on model polyaromatic hydrocarbons (PAHs) and graphitic structures. This work is directed at the application of quantitative ab initio molecular orbital theory to address the decomposition products and mechanisms of coal char reactivity. Previously, it was shown that the �hybrid� B3LYP method can be used to provide quantitative information concerning the stability of the corresponding radicals that arise by hydrogen atom abstraction from monocyclic aromatic rings. In the most recent quarter, these approaches have been extended to larger carbocyclic ring systems, such as coronene, in order to compare the properties of a large carbonaceous PAH to that of the smaller, monocyclic aromatic systems. It was concluded that, at least for bond dissociation energy considerations, the properties of the large PAHs can be modeled reasonably well by smaller systems. In addition to the preceding work, investigations were initiated on the interaction of selected radicals in the �radical pool� with the different types of aromatic structures. In particular, the different pathways for addition vs. abstraction to benzene and furan by H and OH radicals were examined. Thus far, the addition channel appears to be significantly favored over abstraction on both kinetic and thermochemical grounds. Experimental work at Brown University in support of the development of predictive structural models of coal char combustion was focused on elucidating the role of coal mineral matter impurities on reactivity. An �inverse� approach was used where a carbon material was doped with coal mineral matter. The carbon material was derived from a high carbon content fly ash (Fly Ash 23 from the Salem Basin Power Plant. The ash was obtained from Pittsburgh #8 coal (PSOC 1451). Doped

  18. Chemical analyses of coal, coal-associated rocks and coal combustion products collected for the National Coal Quality Inventory

    USGS Publications Warehouse

    Hatch, Joseph R.; Bullock, John H.; Finkelman, Robert B.

    2006-01-01

    In 1999, the USGS initiated the National Coal Quality Inventory (NaCQI) project to address a need for quality information on coals that will be mined during the next 20-30 years. At the time this project was initiated, the publicly available USGS coal quality data was based on samples primarily collected and analyzed between 1973 and 1985. The primary objective of NaCQI was to create a database containing comprehensive, accurate and accessible chemical information on the quality of mined and prepared United States coals and their combustion byproducts. This objective was to be accomplished through maintaining the existing publicly available coal quality database, expanding the database through the acquisition of new samples from priority areas, and analysis of the samples using updated coal analytical chemistry procedures. Priorities for sampling include those areas where future sources of compliance coal are federally owned. This project was a cooperative effort between the U.S. Geological Survey (USGS), State geological surveys, universities, coal burning utilities, and the coal mining industry. Funding support came from the Electric Power Research Institute (EPRI) and the U.S. Department of Energy (DOE).

  19. The release of iron during coal combustion. Milestone report

    SciTech Connect

    Baxter, L.L.

    1995-06-01

    Iron plays an important role in the formation of both fly ash and deposits in many pulverized-coal-fired boilers. Several authors indicate that iron content is a significant indicator of the slagging propensity of a majority of US bituminous coals, in particular eastern bituminous coals. The pyritic iron content of these coals is shown to be a particularly relevant consideration. A series of investigations of iron release during combustion is reported for a suite of coals ranging in rank from lignite to low-volatile bituminous coal under combustion conditions ranging from oxidizing to inert. Experimental measurements are described in which, under selected conditions, major fractions of the iron in the coal are released within a 25 ms period immediately following coal devolatilization. Mechanistic interpretation of the data suggest that the iron is released as a consequence of oxygen attack on porous pyrrhotite particles. Experimental testing of the proposed mechanism reveals that the release is dependent on the presence of both pyrite in the raw coal and oxygen in the gas phase, that slow preoxidation (weathering) of the pyrite significantly inhibits the iron release, and that iron loss increases as oxygen penetration of the particle increases. Each observation is consistent with the postulated mechanism.

  20. Combustion characteristics of coal and refuse from passenger trains.

    PubMed

    Fu-min, Ren; Feng, Yue; Ming, Gao; Min, Yu

    2010-07-01

    Refuse from passenger trains is becoming a significant issue with the development of the Chinese railway. Co-firing is regarded as a promising thermal technology, both environmentally and economically, in reducing the quantity of refuse. The co-firing property of passenger train refuse with coal, however, may differ due to the differences in the composition of the refuse. In the present study, combustion properties of refuse from passenger train samples and the mixture of refuse with coal were studied in a tube furnace. Thermo analysis methods, such as thermogravimetry (TG), differential scanning calorimetry (DSC), differential thermal analysis (DTA) and derivative thermogravimetry (DTG) analyses were employed to evaluate combustion performance. We found that the mixture of passenger train refuse and coal at a ratio of 1:1 has a lower ignition and burnout temperature than the coal-only sample. Moreover, refuse from railway passenger trains has more reactive combustion properties than the coal-only sample, and the addition of railway passenger train refuse to coal can promote the reactivity of coal.

  1. Isotopic signature of atmospheric phosphate emitted from coal combustion

    NASA Astrophysics Data System (ADS)

    Weinberger, Roi; Weiner, Tal; Angert, Alon

    2016-07-01

    Atmospheric deposition of phosphorus (P) serves as an important nutrient input for many terrestrial, marine and freshwater ecosystems, influencing their biogeochemistry and primary production. Fossil fuel combustion, principally coal, is estimated to be a major source of atmospheric-P in industrialized regions. In this research, we aim to find a distinct isotopic signature for fly coal ash, the by-product of coal combustion that is emitted to the atmosphere. This signature could be used to identify coal's contribution to atmospheric-P. For this aim, ten fly coal ash samples from different coal sources, collected by power station filters, were analyzed for P concentrations and stable oxygen isotopic composition (δ18OP). Two inorganic phosphate fractions were analyzed: HCl-extractable and resin-extractable (bioavailable P). High HCl-P concentrations of up to 3500 μg P/g ash were found with a distinct δ18OP range of 17.1-20.5‰. The resin-P concentrations were substantially lower (<8 μg/g) with a wider and significantly lower δ18OP range of 10.6-16.5‰. The ash samples were found to have HCl-P δ18OP higher in ∼0-∼9‰ relative to the source coal. Similar isotopic values were found for ash with the same coal source country, regardless of the power station. Despite the low bioavailable P concentrations, fly ash could still be an important atmospheric P source to the biosphere since these combustion products likely acidify in the atmosphere to become bioavailable. This is also supported by our finding that smaller particles, which are more indicative of the particles actually emitted to the atmosphere, are significantly P-richer. Natural dust sources' δ18OP overlap fly ash's range, complicating the assessment of coal's contribution. Nonetheless, our results provide a new tool for identification of fossil fuel combustion sources in local and global atmospheric P deposition.

  2. Burning of suspended coal-water slurry droplet with oil as combustion additive

    SciTech Connect

    Yao, S.C.; Manwani, P.

    1986-10-01

    Coal-water slurries have been regarded as a potential substitute for heavy fuel oil. Various demonstrations of coal-water slurry combustion have been performed; however, a fundamental understanding of how the combustion process of a slurry fuel is enhanced is still not adequate. The combustion of coal-water mixture droplets suspended on microthermocouples has been investigated. It was found that droplets of lignite coal (which is a noncaking coal) burn effectively; however, droplets of bituminous coal (which is a caking coal) are relatively difficult to burn. During the heat-up of bituminous coal-water slurry droplets may turn to ''popcorn'' and show significant agglomeration. The incomplete combustion of coal-water slurry droplets in furnaces has been reported, and this is a drawback of this process. The objective of the present study is to explore the possibility of enhancing the combustion of coal-water slurry droplets with the use of a combustible emulsified oil.

  3. Coal desulfurization by chlorinolysis production and combustion test evaluation of product coals

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Daly, D.

    1982-01-01

    Laboratory-scale screening tests were carried out on coal from Harrison County, Ohio to establish chlorination and hydrodesulfurization conditions for the batch reactor production of chlorinolysis and chlorinolysis-hydrodesulfurized coals. In addition, three bituminous coals, were treated on the lab scale by the chlorinolysis process to provide 39 to 62% desulfurization. Two bituminous coals and one subbituminous coal were then produced in 11 to 15 pound lots as chlorinolysis and hydrodesulfurized coals. The chlorinolysis coals had a desulfurization of 29-69%, reductions in voltatiles and hydrogen. Hydrodesulfurization provided a much greater desulfurization (56-86%), reductions in volatiles and hydrogen. The three coals were combustion tested in the Penn State ""plane flame furnace'' to determine ignition and burning characteristics. All three coals burned well to completion as: raw coals, chlorinolysis processed coals, and hydrodesulfurized coals. The hydrodesulfurized coals experienced greater ignition delays and reduced burning rates than the other coals because of the reduced volatile content. It is thought that the increased open pore volume in the desulfurized-devolatilized coals compensates in part for the decreased volatiles effect on ignition and burning.

  4. Toxic substances from coal combustion -- A comprehensive assessment

    SciTech Connect

    C.L. Senior; T. Panagiotou; F.E. Huggins; G.P. Huffman; N. Yap; J.O.L. Wendt; W. Seames; M.R. Ames; A.F Sarofim; J. Lighty; A. Kolker; R. Finkelman; C.A. Palmer; S.J. Mroczkowsky; J.J. Helble; R. Mamani-Paco

    1999-11-01

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from 1 July 1999 to 30 September 1999. During this period the MIT INAA procedures were revised to improve the quality of the analytical results. Two steps have been taken to reduce the analytical errors. A new nitric acid leaching procedure, modified from ASTM procedure D2492, section 7.3.1 for determination of pyritic sulfur, was developed by USGS and validated. To date, analytical results have been returned for all but the last complete round of the four-step leaching procedure. USGS analysts in Denver have halted development of the cold vapor atomic fluorescence technique for mercury analysis procedure in favor of a new direct analyzer for Hg that the USGS is in the process of acquiring. Since early June, emphasis at USGS has been placed on microanalysis of clay minerals in project coals in preparation

  5. Combustion of coal gas fuels in a staged combustor

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.; Mcvey, J. B.; Sederquist, R. A.; Schultz, D. F.

    1982-01-01

    Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.

  6. Combustion and fuel characterization of coal-water fuels

    SciTech Connect

    Chow, O.K.; Durant, J.F.; Griffith, B.F.; Miemiec, L.S.; Levasseur, A.A.; Teigen, B.C.

    1987-07-01

    The ash deposition and performance behavior of a cross-section of coal-water fuels (CWFs) were investigated during comprehensive pilot-scale testing under Task 5 of the Department of Energy's Combustion and Fuel Characterization of Coal-Water Fuels project. The key results from this effort including combustion, furnace slagging, convective pass fouling, fly ash erosion and electrostatic precipitator collection characteristics of the test fuels, are summarized in this report. Data were obtained on twelve different CWFs as well as three baseline pulverized coals. Three coal types were fired at different levels of coal beneficiation to assess the effects of coal cleaning on performance. Five CWFs prepared from the same feed coal by different manufactures were tested to assess the effects of slurry processing. CWFs prepared from both standard grind and microfine grind coals were evaluated. In addition a microfine CWF was fired at fuel temperatures up to 220{degree}F to evaluate the effect of thermal atomization on performance. 8 refs., 16 figs., 12 tabs.

  7. To improve the stability of combustion of low rank coal

    SciTech Connect

    Jing Bin Wei

    1995-03-01

    A new aerothermodynamic method, Bi-Flat Inlet Flow Precombustor with Control Jets, developed for flame stabilization of pulverized-coal and the improvement of the ignition condition of low grade coal is described in this paper. The BI-flat flow precombustor consists of a rectangular combustion chamber which can be installed in the location of the burner in the utility and industrial boilers to be used to advance ignition of fuel and primary air mixture and to increase combustion stability of the furnace flames. This type of precombustor simply constructs with two flattened primary air flow and control jets at the head end of the combustor. The velocity of control jets is higher than that of primary flow. A very large recirculation zone with high temperature burnt gases and high turbulent intensity as an ignition source is created in the center of combustion chamber based upon the principles of the actions of jets entraining and Coanda effect. Meanwhile, the higher velocity air layers with lower concentration of coal characteristics on preventing walls from slagging accumulation. Another very important feature is that coal particles could enter directly into the recirculation zone as their inertia and diffusion forces so that it shows a good compatibility of the flow paths of coal particles and high temperature gases. Finally, it is full of promise to be a low pollution emissions combustor since its staged flow and combustion structures.

  8. Low-rank coal research: Volume 3, Combustion research: Final report. [Great Plains

    SciTech Connect

    Mann, M. D.; Hajicek, D. R.; Zobeck, B. J.; Kalmanovitch, D. P.; Potas, T. A.; Maas, D. J.; Malterer, T. J.; DeWall, R. A.; Miller, B. G.; Johnson, M. D.

    1987-04-01

    Volume III, Combustion Research, contains articles on fluidized bed combustion, advanced processes for low-rank coal slurry production, low-rank coal slurry combustion, heat engine utilization of low-rank coals, and Great Plains Gasification Plant. These articles have been entered individually into EDB and ERA. (LTN)

  9. Coal combustion products 2007 production and use report

    SciTech Connect

    2009-07-01

    The American Coal Ash Association's 2007 Annual Coal Combustion Products (CCP) are derived from data from more than 170 power plants. The amount of CCPs used was 40.55%, a decrease of 2.88% from 2006, attributed to reduced fuel burn and a decrease in demand in the building industry. Figures are given for the production of fly ash, flue gas desulfurization gypsum, bottom ash, FBC ash and boiler slag. The article summarises results of the survey. 1 ref., 1 tab.

  10. CO2 emission of coal spontaneous combustion and its relation with coal microstructure, China.

    PubMed

    Wang, Haiyan; Chen Chen; Huang, Tao; Gao, Wei

    2015-07-01

    Coal spontaneous combustion is widely distributed all over the world. CO2 is the main greenhouse gas emitted by coal spontaneous combustion. In the present study characters of CO2 emitted by 10 typical Chinese coal spontaneous combustion and the influence of raw coal functional group on CO2 was studied. CO2 already exists under normal temperature as coal exposed in atmosphere. Under low temperature, the quality of CO2 released by coal spontaneous combustion is relatively small, but tends to increase. And corresponding with it, the oxygen consumption amount is also small. At medium temperature, the oxygen consumption increases rapidly and CO2 mass release rate begins to increase rapidly. Then, CO2 release rate increase rapidly under relatively high temperature (higher than 673 K). Over 873K, concentration of O2 is 6% and release rate of CO2 tends to be steady. It also concluded that mass ratio of CO to CO2 (CO/CO2) during coal spontaneous combustion was lowerthan 0.10 at low temperature. And then, it increased rapidly at medium temperature and reached to top at about 673 K. At 673-873 K, the ratio decreased again, and did not decrease evidently at about 873K. At temperature higher than 873K, the ratio was about 0.13. During the whole testing temperature range, CO/CO2 was not be higher than 0.26, lower than 0.2. This means that release rate of CO2 was much higher than CO during the whole process of coal spontaneous combustion. Moreover, the gas release quantity of CO2 is positively related with carbony content in raw coal. Carbonyl and carboxyl were both material basis of CO2.

  11. Combustion of Illinois coals and chars with natural gas

    SciTech Connect

    Buckius, R.O.

    1991-01-01

    There are applications where the combined combustion of coal and natural gas offers potential advantages over the use of either coal or natural gas alone. For example, low volatile coals or low volatile chars derived from treatment or gasification processes can be of limited use during to their poor flammability characteristics. However, the use of natural gas in conjunction with the solid fuel can provide the necessary volatiles'' to enhance the combustion. In addition, natural gas provides a clean fuel source of fuel which, in cofiring situations, can extend the usefulness of coals with high sulfur content. The addition of natural gas may reduce SO{sub x} emission through increased sulfur retention in the ash and reduce NO{sub x} emissions by varying local stoichiometry and temperature levels. In this research program, studies of combined coal and natural gas combustion will provide particle ignition, burnout rates and ash characterization, that will help clarify the effect of coal and natural gas and identify the controlling parameters and mechanisms.

  12. The mechanism controlling sticking ash separation and reentrainment in pulverized coal combustion products

    SciTech Connect

    Goldman, Y.; Greenberg, J.B.; Timnat, Y.M.

    1993-12-31

    One of the main areas of development and research in intensification of coal combustion involves burning of pulverized fuel. In this process the overall interaction surface between the reactants (oxygen and coal particles) is about two orders of magnitude bigger than in other methods (stokers, grates, fluidized beds, etc.); such systems of firing are suitable for a wide range of applications from power generation boilers to gas turbines. The ash formed during the combustion process has a strong influence on the combustion intensity and is particularly important for future applications to gas turbines, in a first stage for power generation and later for vehicle powerplants (trucks, ships, eventually airplanes). Improvement of combustion intensity in PF combustors can be attained by two basic techniques. The cyclone furnace is based on the use of tangential injection of air containing pulverized coal, so swirling motion of the combustion products is created in the combustion chamber, with intensive chemical reaction occurring in the boundary layers adjacent to the walls. Attempts were made to reduce NO{sub x} formation and to model mathematically the detailed flow and mixing processes in tangentially fired furnaces. The three-dimensional calculations supply valuable predictions concerning these processes but do not include combustion and heat transfer effects. However such effects can also be calculated. Recently Gillis and Smith evaluated a three-dimensional industrial furnace using a comprehensive code developed at Brigham Young University.

  13. Thermodynamic analysis of the behavior of microimpurities of toxic metals in coal combustion products

    SciTech Connect

    G.Ya. Gerasimov

    2004-01-15

    The thermodynamic approach to the description of the fuel-oxidizer system is used to elucidate the basic laws of behavior of compounds of the most toxic elements/microimpurities in combustion products of coal (Hg, Pb, Cr, Mn, Ni, Co, and As). It has been shown that the distribution of elements over components of the gas and condensed phases strongly depends on the process temperature and the composition of the mineral part of the coal.

  14. JV Task 108 - Circulating Fluidized-Bed Combustion and Combustion Testing of Turkish Tufanbeyli Coal

    SciTech Connect

    Douglas Hajicek; Jay Gunderson; Ann Henderson; Stephen Sollom; Joshua Stanislowski

    2007-08-15

    Two combustion tests were performed at the Energy & Environmental Research Center (EERC) using Tufanbeyli coal from Turkey. The tests were performed in a circulating fluidized-bed combustor (CFBC) and a pulverized coal-fired furnace, referred to as the combustion test facility (CTF). One of the goals of the project was to determine the type of furnace best suited to this coal. The coal is high in moisture, ash, and sulfur and has a low heating value. Both the moisture and the sulfur proved problematic for the CTF tests. The fuel had to be dried to less than 37% moisture before it could be pulverized and further dried to about 25% moisture to allow more uniform feeding into the combustor. During some tests, water was injected into the furnace to simulate the level of flue gas moisture had the fuel been fed without drying. A spray dryer was used downstream of the baghouse to remove sufficient sulfur to meet the EERC emission standards permitted by the North Dakota Department of Health. In addition to a test matrix varying excess air, burner swirl, and load, two longer-term tests were performed to evaluate the fouling potential of the coal at two different temperatures. At the lower temperature (1051 C), very little ash was deposited on the probes, but deposition did occur on the walls upstream of the probe bank, forcing an early end to the test after 2 hours and 40 minutes of testing. At the higher temperature (1116 C), ash deposition on the probes was significant, resulting in termination of the test after only 40 minutes. The same coal was burned in the CFBC, but because the CFBC uses a larger size of material, it was able to feed this coal at a higher moisture content (average of 40.1%) compared to the CTF (ranging from 24.2% to 26.9%). Sulfur control was achieved with the addition of limestone to the bed, although the high calcium-to-sulfur rate required to reduce SO{sub 2} emissions resulted in heat loss (through limestone calcination) and additional ash

  15. Numerical simulation of the coal combustion process initiated by a plasma source

    NASA Astrophysics Data System (ADS)

    Askarova, A. S.; Messerle, V. E.; Ustimenko, A. B.; Bolegenova, S. A.; Maksimov, V. Yu.

    2014-12-01

    Numerical experiments on the torch combustion of the coal dust prepared by a plasma-thermochemical treatment for combustion have been done using the method of three-dimensional simulation. It is shown that the plasma preparation of coal for combustion enables one to optimize the process, improve the conditions for inflammation and combustion and minimize the emissions of harmful substances.

  16. Development and testing of industrial scale, coal fired combustion system, Phase 3. Fourth quarterly technical progress report, October 1, 1992--December 31, 1992

    SciTech Connect

    Zauderer, B.

    1993-02-15

    A major part of the work in this quarter was on the combustor tests in task 2. Three of the six planned tests in this task were completed. The first two were parametric tests of nominal one shift, (8 hour) duration on coal. Due to failure of the UV detector in the first test only several hours of coal fired operation were completed. In the second test, coal fired operation continued for the planned one shift until the 4 ton coal bin was empty. After reviewing this work with DOE, it was decided to focus the remaining test on longer duration operation with each test at one optimum condition. The third test was planned for two shift coal fired operation. Due to a problem with the pilot gas ignitor, combustion was delayed by 5 hours from 7 AM to Noon. As a result coal fired operation was limited to one shift between 3 PM and 11 PM. Throughout this period the combustor remained at one fixed condition with the use of computer control. Results for these three tests are presented in this report. Most of the work on the task 4 design and cost of a 20 MW combined gas-steam turbine power plant using the air cooled combustor was completed in the previous quarter. The results obtained by the A/E subcontractor on the installation desip and cost were evaluated in the present quarter and they are summarized in this report.

  17. NITRIC OXIDE FORMATION DURING PULVERIZED COAL COMBUSTION

    EPA Science Inventory

    Data on the overall conversion of coal-nitrogen to NOx were obtained at 1250 K and 1750 K for a residence time of one second. The conversion of coal-nitrogen to NOx decreased monotonically with increasing fuel/oxygen equivalence ratio and decreased slightly with increasing temper...

  18. NITRIC OXIDE FORMATION DURING PULVERIZED COAL COMBUSTION

    EPA Science Inventory

    Data on the overall conversion of coal-nitrogen to NOx were obtained at 1250 K and 1750 K for a residence time of one second. The conversion of coal-nitrogen to NOx decreased monotonically with increasing fuel/oxygen equivalence ratio and decreased slightly with increasing temper...

  19. Zinc isotopic composition of particulate matter generated during the combustion of coal and coal + tire-derived fuels

    USGS Publications Warehouse

    Borrok, D.M.; Gieré, R.; Ren, M.; Landa, E.R.

    2010-01-01

    Atmospheric Zn emissions from the burning of coal and tire-derived fuel (TDF) for power generation can be considerable. In an effort to lay the foundation for tracking these contributions, we evaluated the Zn isotopes of coal, a mixture of 95 wt % coal + 5 wt % TDF, and the particulate matter (PM) derived from their combustion in a power-generating plant. The average Zn concentrations and δ(66)Zn were 36 mg/kg and 183 mg/kg and +0.24‰ and +0.13‰ for the coal and coal + TDF, respectively. The δ(66)Zn of the PM sequestered in the cyclone-type mechanical separator was the lightest measured, -0.48‰ for coal and -0.81‰ for coal+TDF. The δ(66)Zn of the PM from the electrostatic precipitator showed a slight enrichment in the heavier Zn isotopes relative to the starting material. PM collected from the stack had the heaviest δ(66)Zn in the system, +0.63‰ and +0.50‰ for the coal and coal + TDF, respectively. Initial fractionation during the generation of a Zn-rich vapor is followed by temperature-dependent fractionation as Zn condenses onto the PM. The isotopic changes of the two fuel types are similar, suggesting that their inherent chemical differences have only a secondary impact on the isotopic fractionation process.

  20. Zinc isotopic composition of particulate matter generated during the combustion of coal and coal + tire-derived fuels.

    PubMed

    Borrok, David M; Gieré, Reto; Ren, Minghua; Landa, Edward R

    2010-12-01

    Atmospheric Zn emissions from the burning of coal and tire-derived fuel (TDF) for power generation can be considerable. In an effort to lay the foundation for tracking these contributions, we evaluated the Zn isotopes of coal, a mixture of 95 wt % coal + 5 wt % TDF, and the particulate matter (PM) derived from their combustion in a power-generating plant. The average Zn concentrations and δ(66)Zn were 36 mg/kg and 183 mg/kg and +0.24‰ and +0.13‰ for the coal and coal + TDF, respectively. The δ(66)Zn of the PM sequestered in the cyclone-type mechanical separator was the lightest measured, -0.48‰ for coal and -0.81‰ for coal+TDF. The δ(66)Zn of the PM from the electrostatic precipitator showed a slight enrichment in the heavier Zn isotopes relative to the starting material. PM collected from the stack had the heaviest δ(66)Zn in the system, +0.63‰ and +0.50‰ for the coal and coal + TDF, respectively. Initial fractionation during the generation of a Zn-rich vapor is followed by temperature-dependent fractionation as Zn condenses onto the PM. The isotopic changes of the two fuel types are similar, suggesting that their inherent chemical differences have only a secondary impact on the isotopic fractionation process.

  1. Thermally induced structural changes in coal combustion. Final report

    SciTech Connect

    Flagan, R.C.; Gavalas, G.R.

    1992-01-01

    The effects of the temperature-time history during coal devolitization and oxidation on the physical properties and the reactivity of resulting char were studied experimentally for temperatures and residence times typical of pulverized combustion. Experiments were also carried out at somewhat lower temperatures and correspondingly longer residence times. An electrically heated laminar flow reactor was used to generate char and measure the rates of oxidation at gas temperatures about 1600K. Partially oxidized chars were extracted and characterized by gas adsorption and mercury porosimetry, optical and scanning electron microscopy, and oxidation in a thermogravimetric analysis system (TGA). A different series of experiments was conducted using a quadrople electrodynamic balance. Single particles were suspended electrodynamically and heated by an infrared laser in an inert or oxygen-containing atmosphere. During the laser heating, measurements were taken of particle mass, size/shape, and temperature.

  2. Coal Combustion Wastes Reuse in Low Energy Artificial Aggregates Manufacturing

    PubMed Central

    Ferone, Claudio; Colangelo, Francesco; Messina, Francesco; Iucolano, Fabio; Liguori, Barbara; Cioffi, Raffaele

    2013-01-01

    Sustainable building material design relies mostly on energy saving processes, decrease of raw materials consumption, and increase of waste and by-products recycling. Natural and lightweight artificial aggregates production implies relevant environmental impact. This paper addresses both the issues of residues recycling and energy optimization. Particularly, three coal combustion wastes (Weathered Fly Ash, WFA; Wastewater Treatment Sludge, WTS; Desulfurization Device Sludge, DDS) supplied by the Italian electric utility company (ENEL) have been employed in the manufacture of cold bonded artificial aggregates. Previously, the residues have been characterized in terms of chemical and mineralogical compositions, water content, particle size distribution, and heavy metal release behavior. These wastes have been used in the mix design of binding systems with the only addition of lime. Finally, the artificial aggregates have been submitted to physical, mechanical, and leaching testing, revealing that they are potentially suitable for many civil engineering applications. PMID:28788372

  3. Coal Combustion Wastes Reuse in Low Energy Artificial Aggregates Manufacturing.

    PubMed

    Ferone, Claudio; Colangelo, Francesco; Messina, Francesco; Iucolano, Fabio; Liguori, Barbara; Cioffi, Raffaele

    2013-10-31

    Sustainable building material design relies mostly on energy saving processes, decrease of raw materials consumption, and increase of waste and by-products recycling. Natural and lightweight artificial aggregates production implies relevant environmental impact. This paper addresses both the issues of residues recycling and energy optimization. Particularly, three coal combustion wastes (Weathered Fly Ash, WFA; Wastewater Treatment Sludge, WTS; Desulfurization Device Sludge, DDS) supplied by the Italian electric utility company (ENEL) have been employed in the manufacture of cold bonded artificial aggregates. Previously, the residues have been characterized in terms of chemical and mineralogical compositions, water content, particle size distribution, and heavy metal release behavior. These wastes have been used in the mix design of binding systems with the only addition of lime. Finally, the artificial aggregates have been submitted to physical, mechanical, and leaching testing, revealing that they are potentially suitable for many civil engineering applications.

  4. Coal-feeding mechanism for a fluidized bed combustion chamber

    DOEpatents

    Gall, Robert L.

    1981-01-01

    The present invention is directed to a fuel-feeding mechanism for a fluidized bed combustor. In accordance with the present invention a perforated conveyor belt is utilized in place of the fixed grid normally disposed at the lower end of the fluidized bed combustion zone. The conveyor belt is fed with fuel, e.g. coal, at one end thereof so that the air passing through the perforations dislodges the coal from the belt and feeds the coal into the fluidized zone in a substantially uniform manner.

  5. Coal-feeding mechanism for a fluidized bed combustion chamber

    SciTech Connect

    Gall, R. L.

    1981-06-02

    The present invention is directed to a fuel-feeding mechanism for a fluidized bed combustor. In accordance with the present invention a perforated conveyor belt is utilized in place of the fixed grid normally disposed at the lower end of the fluidized bed combustion zone. The conveyor belt is fed with fuel, E.G. Coal, at one end thereof so that the air passing through the perforations dislodges the coal from the belt and feeds the coal into the fluidized zone in a substantially uniform manner.

  6. Toxic substances form coal combustion--a co prehemsice assessment

    SciTech Connect

    Huggins, F.; Huffman, G.P.; Shah, N.

    1997-04-01

    The Clean Coal Act Amendments of 1990 identify a number of hazardous air pollutants as candidates for regulation. Should regulations be imposed on emission of these pollutants from coal-fired power plants, a sound understanding of the fundamental principles controlling their formation and partition will be needed. A new Toxics Partitioning Engineering Model (ToPEM) has been developed by a broad consortium to be useful to regulators and utility planners. During the last quarter coal analysis was completed on the final program coal, from the Wyodak Seam of the Powder River Basin, Combustion testing continued, including data collected on the self-sustained combustor. Efforts were directed to identify the governing mechanisms for trace element vaporization from the program coals. Mercury speciation and measurements were continued. Review of the existing trace element and organics emission literature was completed. And, model development was begun.

  7. Method for increasing the calorific value of gas produced by the in situ combustion of coal

    DOEpatents

    Shuck, Lowell Z.

    1978-01-01

    The present invention relates to the production of relatively high Btu gas by the in situ combustion of subterranean coal. The coal bed is penetrated with a horizontally-extending borehole and combustion is initiated in the coal bed contiguous to the borehole. The absolute pressure within the resulting combustion zone is then regulated at a desired value near the pore pressure within the coal bed so that selected quantities of water naturally present in the coal will flow into the combustion zone to effect a hydrogen and carbon monoxide-producing steam-carbon reaction with the hot carbon in the combustion zone for increasing the calorific value of the product gas.

  8. PULVERIZED COAL COMBUSTION: POLLUTANT FORMATION AND CONTROL, 1970-1980

    EPA Science Inventory

    The report documents the support role of EPA's Air and Energy Engineering Research Laboratory in the major research effort directed by EPA in the l970s to understand pollutant formation during pulverized coal combustion (PCC). Understanding the conversion of fuel nitrogen to nit...

  9. PULVERIZED COAL COMBUSTION: POLLUTANT FORMATION AND CONTROL, 1970-1980

    EPA Science Inventory

    The report documents the support role of EPA's Air and Energy Engineering Research Laboratory in the major research effort directed by EPA in the l970s to understand pollutant formation during pulverized coal combustion (PCC). Understanding the conversion of fuel nitrogen to nit...

  10. Photostabilization of a landfill containing coal combustion waste

    Treesearch

    Christopher Barton; Donald Marx; Domy Adriano; Bon Jun Koo; Lee Newman; Stephen Czapka; John Blake

    2005-01-01

    The establishment of a vegetative cover to enhance evapotranspiration and control runoff and drainage was examined as a method for stabilizing a landfill containing coal combustion waste. Suitable plant species and pretreatment techniques in the form of amendments, tilling, and chemical stabilization were evaluated. A randomized plot design consisting of three...

  11. Phytostabilization of a landfill containing coal combustion waste

    Treesearch

    Christopher Barton; Donald Marx; Domy Adriano; Bon Jun Koo; Lee Newman; Stephen Czapka; John Blake

    2005-01-01

    The establishment of a vegetative cover to enhance evapotranspiration and control runoff and drainage was examined as a method for stabilizing a landfill containing coal combustion waste. Suitable plant species and pretreatment techniques in the form of amendments, tilling, and chemical stabilization were evaluated. A randomized plot design consisting of three...

  12. Combustion of dense streams of coal particles

    SciTech Connect

    Annamalai, K.

    1991-01-01

    The main objective of our work is to obtain a specific velocity of the resulting flame and to maintain this flame consistent throughout the experiment. To optimize our work, theoretical study has been conducted relating the flow rate of the premixed gas (gas + air), stoichiometric coal mass flow rate, interparticle distance of the coal particles, number of particles and the max. coal mass flow rate needed to maintain a specific velocity. Runs were made for velocities of 1.5, 2.0, 2.5, and 3.0 m/s.

  13. Combustion characteristics and arsenic retention during co-combustion of agricultural biomass and bituminous coal.

    PubMed

    Zhou, Chuncai; Liu, Guijian; Wang, Xudong; Qi, Cuicui; Hu, Yunhu

    2016-08-01

    A combination of thermogravimetric analysis (TG) and laboratory-scale circulated fluidized bed combustion experiment was conducted to investigate the thermochemical, kinetic and arsenic retention behavior during co-combustion bituminous coal with typical agricultural biomass. Results shown that ignition performance and thermal reactivity of coal could be enhanced by adding biomass in suitable proportion. Arsenic was enriched in fly ash and associated with fine particles during combustion of coal/biomass blends. The emission of arsenic decreased with increasing proportion of biomass in blends. The retention of arsenic may be attributed to the interaction between arsenic and fly ash components. The positive correlation between calcium content and arsenic concentration in ash suggesting that the arsenic-calcium interaction may be regarded as the primary mechanism for arsenic retention. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Transition nozzle combustion system

    DOEpatents

    Kim, Won-Wook; McMahan, Kevin Weston; Maldonado, Jaime Javier

    2016-11-29

    The present application provides a combustion system for use with a cooling flow. The combustion system may include a head end, an aft end, a transition nozzle extending from the head end to the aft end, and an impingement sleeve surrounding the transition nozzle. The impingement sleeve may define a first cavity in communication with the head end for a first portion of the cooling flow and a second cavity in communication with the aft end for a second portion of the cooling flow. The transition nozzle may include a number of cooling holes thereon in communication with the second portion of the cooling flow.

  15. Mercury emissions and species during combustion of coal and waste

    SciTech Connect

    Hong Yao; Guangqian Luo; Minghou Xu; Tamotsu Kameshima; Ichiro Naruse

    2006-10-15

    The behaviors of mercury evolution for three types of coal and three types of dried sewage sludge are studied using a thermogravimetric (TG) analyzer. The mercury speciations in the flue gas from coal and sludge combustion are also analyzed by implementing a horizontal electrically heated tube furnace. Furthermore, the kinetic calculations of mercury oxidizing processes are carried out using the software package CHEMKIN in order to interpret the homogeneous mechanism of mercury oxidization. The results obtained show that the sulfur content in the sludge inhibits the evolution of mercury at low temperature if the Cl concentration is high enough. Chlorine enhances mercury evolution in the coal combustion, whereas there is no relationship when the Cl concentration is high. Fixed carbon content plays a role in depression of the mercury evolution. Formation of oxidized mercury (HgCl{sub 2}) does not relate to the chlorine concentration in the raw coal and sludge. Whereas the ash and sulfur content in the sludge affects the Hg oxidization, kinetic calculations show that HgCl, Cl{sub 2}, and HOCl formation is important in producing the oxidized mercury during combustion of coal and sludge at 873 K. A suitable temperature for Hg oxidization when Cl{sub 2} is the oxidization resource is 700-1200 K. 32 refs., 10 figs., 5 tabs.

  16. Control of Trace Metal Emissions During Coal Combustion

    SciTech Connect

    Thomas C. Ho

    1997-10-01

    Emissions of toxic trace metals in the form of metal fumes or submicron particulates from a coal-fired combustion source have received greater environmental and regulatory concern over the past years. Current practice of controlling these emissions is to collect them at the cold-end of the process by air-pollution control devices (APCDs) such as electrostatic precipitators and baghouses. However, trace metal fumes may not always be effectively collected by these devices because the formed fumes are extremely small. The proposed research is to explore the opportunities for improved control of toxic trace metal emissions, alternatively, at the hot-end of the coal combustion process, i.e., in the combustion chamber. The technology proposed is to prevent the metal fumes from forming during the process, which would effectively eliminate the metal emission problems. Specifically, the technology is to employ suitable sorbents to (1) reduce the amount of metal volatilization during combustion and (2) capture volatilized metal vapors. The objectives of the project are to demonstrate the technology and to characterize the metal capture process during coal combustion in a fluidized bed combustor. The project was started on July 1, 1994 and this is the thirteenth quarterly technical progress report. Specifically, the following progress has been made during this performance period from July 1, 1997 through September 30, 1997.

  17. [Lead emission amount from coal combustion and its environment effect in Xi'an City].

    PubMed

    Luo, Kunli; Wang, Douhu; Tan, Jianan; Wang, Lizheng; Feng, Fujian; Li, Ribang

    2002-01-30

    For study the lead emission amount from coal combustion and its environment effect, the lead content of coal, ash and cinder of power station and coal-fired boiler, the lead content of dusts in the period of heating time and the non-heating time in Xi'an City were studied in this paper. The results show that amount of lead emission from 1 ton coal combustion, which lead content in coal was 30 g, was 20 g in atmosphere. The rate of lead emission of coal combustion was about 66%. About 10 million tons of coal was straight burning every year in Xi'an City and suburb, those coal mainly come from Permo-Carboniferous coal in Weibei coal mine, Shaanxi, their average lead content was 30 mg/kg. So the total lead emission from coal combustion to atmosphere was about 200 t annually in Xi'an City.

  18. Temperature Trends in Coal Char Combustion under Oxy-fuel Conditions for the Determination of Kinetics

    SciTech Connect

    Iqbal, Samira; Hecht, Ethan

    2014-08-01

    Oxy-fuel combustion technology with carbon capture and storage could significantly reduce global CO2 emissions, a greenhouse gas. Implementation can be aided by computational fluid dynamics (CFD) simulations, which require an accurate understanding of coal particle kinetics as they go through combustion in a range of environments. To understand the kinetics of pulverized coal char combustion, a heated flow reactor was operated under a wide range of experimental conditions. We varied the environment for combustion by modifying the diluent gas, oxygen concentration, gas flow rate, and temperature of the reactor/reacting gases. Measurements of reacting particle temperatures were made for a sub-bituminous and bituminous coal char, in environments with CO2 or N2 as the diluent gas, with 12, 24, and 36 vol-% oxygen concentration, at 50, 80, 100, and 200 standard liters per minute flowing through the reactor, reactor temperatures of 1200, 1400 K, at pressures slightly above atmospheric. The data shows consistent increasing particle temperature with increased oxygen concentration, reactor temperature and higher particle temperatures for N2 diluent than CO2. We also see the effects of CO2 gasification when different ranks of coal are used, and how the reduction in the temperature due to the CO2 diluent is greater for the coal char that has higher reactivity. Quantitative measurements for temperature are not yet complete due to ongoing calibration of detection systems.

  19. Experiment and computation studies of high concentration pulverized coal combustion

    SciTech Connect

    Zhang, Z.; Qiu, J.; Chen, G.; Chen, C.; Li, F.; Sun, X.; Liu, S.

    1994-12-31

    This article gives out the studies of high concentration pulverized coal combustion. A series experiment and computation were done during research process. According to the result of the studies, if the authors increase the concentration of pulverized coal in primary air, some other method must be used to improve the mixture between primary and secondary air. Cross-flow of the two air jets is a way to get this effect. The importance of this technique is to determine the cross-angle and distance of two air jets. Through cold state two-phase and combustion experiment for a special coal they had chosen the cross-angle and distance between up and down secondary air as 30 and d/r as 8 (r is the relative diameter). In addition the mathematical computation was done to compare with experiment result. The comparison between experiment and computation shows agreement.

  20. Application of polymer membrane technology in coal combustion processes

    SciTech Connect

    Kaldis, S.P.; Skodras, G.; Grammelis, P.; Sakellaropoulos, G.P.

    2007-03-15

    The energy efficiency and the environmental consequences of typical coal upgrading processes, such as combustion, depend to a large extent on the degree of gas separation, recovery, and recycle. Among the available methods used in chemical industry for a variety of gas separation tasks, the technology of polymer membranes offers several advantages such as low size, simplicity of operation and maintenance, compatibility, and use with a diversity of fuel sources. To examine the impact of membrane separation on coal upgrading processes, the Aspen Plus simulation software was used, in combination with developed membrane mathematical models. Energy analysis in coal combustion processes, where the main scope is CO{sub 2} removal, showed that very promising results can be attained. It is estimated that 95% of the emitted CO{sub 2} can be captured with a moderately low energy penalty (10%). This penalty can be further decreased if higher selectivity and/or permeability polymers can be developed.

  1. Electricity from coal and utilization of coal combustion by-products

    SciTech Connect

    Demirbas, A.

    2008-07-01

    Most electricity in the world is conventionally generated using coal, oil, natural gas, nuclear energy, or hydropower. Due to environmental concerns, there is a growing interest in alternative energy sources for heat and electricity production. The major by-products obtained from coal combustion are fly ash, bottom ash, boiler slag, and flue gas desulfurization (FGD) materials. The solid wastes produced in coal-fired power plants create problems for both power-generating industries and environmentalists. The coal fly ash and bottom ash samples may be used as cementitious materials.

  2. Mercury emissions from coal combustion in Silesia, analysis using geostatistics

    NASA Astrophysics Data System (ADS)

    Zasina, Damian; Zawadzki, Jaroslaw

    2015-04-01

    Data provided by the UNEP's report on mercury [1] shows that solid fuel combustion in significant source of mercury emission to air. Silesia, located in southwestern Poland, is notably affected by mercury emission due to being one of the most industrialized Polish regions: the place of coal mining, production of metals, stone mining, mineral quarrying and chemical industry. Moreover, Silesia is the region with high population density. People are exposed to severe risk of mercury emitted from both: industrial and domestic sources (i.e. small household furnaces). Small sources have significant contribution to total emission of mercury. Official and statistical analysis, including prepared for international purposes [2] did not provide data about spatial distribution of the mercury emitted to air, however number of analysis on Polish public power and energy sector had been prepared so far [3; 4]. The distribution of locations exposed for mercury emission from small domestic sources is interesting matter merging information from various sources: statistical, economical and environmental. This paper presents geostatistical approach to distibution of mercury emission from coal combustion. Analysed data organized in 2 independent levels: individual, bottom-up approach derived from national emission reporting system [5; 6] and top down - regional data calculated basing on official statistics [7]. Analysis, that will be presented, will include comparison of spatial distributions of mercury emission using data derived from sources mentioned above. Investigation will include three voivodeships of Poland: Lower Silesian, Opole (voivodeship) and Silesian using selected geostatistical methodologies including ordinary kriging [8]. References [1] UNEP. Global Mercury Assessment 2013: Sources, Emissions, Releases and Environmental Transport. UNEP Chemicals Branch, Geneva, Switzerland, 2013. [2] NCEM. Poland's Informative Inventory Report 2014. NCEM at the IEP-NRI, 2014. http

  3. Alkali injection system with controlled CO.sub.2 /O.sub.2 ratios for combustion of coal

    DOEpatents

    Berry, Gregory F.

    1988-01-01

    A high temperature combustion process for an organic fuel containing sulfur n which the nitrogen of air is replaced by carbon dioxide for combination with oxygen with the ratio of CO.sub.2 /O.sub.2 being controlled to generate combustion temperatures above 2000 K. for a gas-gas reaction with SO.sub.2 and an alkali metal compound to produce a sulfate and in which a portion of the carbon-dioxide rich gas is recycled for mixing with oxygen and/or for injection as a cooling gas upstream from heating exchangers to limit fouling of the exchangers, with the remaining carbon-dioxide rich gas being available as a source of CO.sub.2 for oil recovery and other purposes.

  4. Fuel and ash characterization of Indian coal for their suitability in fluidized bed combustions

    SciTech Connect

    Palit, A.; Mandal, P.K.

    1995-12-31

    The fluidized bed combustion (FBC) technology is now fully recognized and units with high capacity are in operation the world over. In the Indian context, now is the time to exploit the fluidized bed technology for electric power generation, which may nurture the poor grade Indian coal in a better way as compared to that of pulverized fuel fired system. The present paper deals with Indian coals and ash characterization and the effect of various coal properties on combustion in a fluidized bed like moisture, mineral/ash content, volatile matter, maceral structure (petrographic properties), swelling/caking index, ash properties including ash fusion temperature, etc. and their critical discussion based on experimental investigations with Indian coals and also their suitability in FBC. In addition, the experience with a 10 MW FBC unit in India with problems and parameters, some experimental investigations on suitability of Lalmatia coal (Rajmahal coal field) in fluidized bed combustion and pollutant formations vis-a-vis control (NOx, SOx, etc.) have also been discussed.

  5. Measurement of alkali-vapor emission from pressurized fluidized-bed combustion of Illinois coals

    SciTech Connect

    Lee, S.H.D.; Teats, F.G.; Swift, W.M.; Banerjee, D.D.

    1993-04-01

    Two Illinois Herrin No. 6 coals and one Illinois Springfield No. 5 coal were separately combusted in a laboratory-scale (15-cm dia) pressurized fluidized-bed combustor (PFBC) combined with an alkali sorber. These coals were combusted in a fluidized bed of Tymochtee dolomite at temperatures ranging from 910 to 950{degree}C and a system pressure of 9.2 atm absolute. Alkali-vapor emission (Na and K) in the PFBC flue gas was determined by the analytical activated-bauxite sorber bed technique developed at Argonne National Laboratory. The test results showed that sodium is the major alkali-vapor species present in the PFBC flue gas, and that the level of sodium-vapor emission increases linearly with both Na and Cl contents in the coals. This suggests that the sodium-vapor emission results from direct vaporization of NaCl present in the coals. The measured alkali-vapor concentration (Na + K), 67 to 190 ppbW, is more than 2.5 times greater than the allowable alkali limit of 24 ppb for an industrial gas turbine. Combusting these coals in a PFBC for power generation may require developing a method to control alkali vapors.

  6. Measurement of alkali-vapor emission from pressurized fluidized-bed combustion of Illinois coals

    SciTech Connect

    Lee, S.H.D.; Teats, F.G.; Swift, W.M. ); Banerjee, D.D. )

    1993-01-01

    Two Illinois Herrin No. 6 coals and one Illinois Springfield No. 5 coal were separately combusted in a laboratory-scale (15-cm dia) pressurized fluidized-bed combustor (PFBC) combined with an alkali sorber. These coals were combusted in a fluidized bed of Tymochtee dolomite at temperatures ranging from 910 to 950[degree]C and a system pressure of 9.2 atm absolute. Alkali-vapor emission (Na and K) in the PFBC flue gas was determined by the analytical activated-bauxite sorber bed technique developed at Argonne National Laboratory. The test results showed that sodium is the major alkali-vapor species present in the PFBC flue gas, and that the level of sodium-vapor emission increases linearly with both Na and Cl contents in the coals. This suggests that the sodium-vapor emission results from direct vaporization of NaCl present in the coals. The measured alkali-vapor concentration (Na + K), 67 to 190 ppbW, is more than 2.5 times greater than the allowable alkali limit of 24 ppb for an industrial gas turbine. Combusting these coals in a PFBC for power generation may require developing a method to control alkali vapors.

  7. Formation and use of coal combustion residues from three types of power plants burning Illinois coals

    USGS Publications Warehouse

    Demir, I.; Hughes, R.E.; DeMaris, P.J.

    2001-01-01

    Coal, ash, and limestone samples from a fluidized bed combustion (FBC) plant, a pulverized coal combustion (PC) plant, and a cyclone (CYC) plant in Illinois were analyzed to determine the combustion behavior of mineral matter, and to propose beneficial uses for the power plant ashes. Pyrite and marcasite in coal were converted during combustion to glass, hematite and magnetite. Calcite was converted to lime and anhydrite. The clay minerals were altered to mullite and glass. Quartz was partially altered to glass. Trace elements in coal were partially mobilized during combustion and, as a result, emitted into the atmosphere or adsorbed on fly ash or on hardware on the cool side of the power plants. Overall, the mobilities of 15 trace elements investigated were lower at the FBC plant than at the other plants. Only F and Mn at the FBC plant, F, Hg, and Se at the PC plant and Be, F, Hg, and Se at the CYC plant had over 50% of their concentrations mobilized. Se and Ge could be commercially recovered from some of the combustion ashes. The FBC ashes could be used as acid neutralizing agents in agriculture and waste treatment, and to produce sulfate fertilizers, gypsum wall boards, concrete, and cement. The PC and CYC fly ashes can potentially be used in the production of cement, concrete, ceramics, and zeolites. The PC and CYC bottom ashes could be used in stabilized road bases, as frits in roof shingles, and perhaps in manufacturing amber glass. ?? 2001 Elsevier Science Ltd. All rights reserved.

  8. Thermal ignition combustion system

    DOEpatents

    Kamo, Roy; Kakwani, Ramesh M.; Valdmanis, Edgars; Woods, Melvins E.

    1988-01-01

    The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m.degree. C. and a specific heat greater than 480 J/kg.degree. C. with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber.

  9. Thermal ignition combustion system

    DOEpatents

    Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

    1988-04-19

    The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m C and a specific heat greater than 480 J/kg C with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber. 8 figs.

  10. WASTE COMBUSTION SYSTEM ANALYSIS

    EPA Science Inventory

    The report gives results of a study of biomass combustion alternatives. The objective was to evaluate the thermal performance and costs of available and developing biomass systems. The characteristics of available biomass fuels were reviewed, and the performance parameters of alt...

  11. WASTE COMBUSTION SYSTEM ANALYSIS

    EPA Science Inventory

    The report gives results of a study of biomass combustion alternatives. The objective was to evaluate the thermal performance and costs of available and developing biomass systems. The characteristics of available biomass fuels were reviewed, and the performance parameters of alt...

  12. The partitioning of trace elements during pulverized coal combustion

    NASA Astrophysics Data System (ADS)

    Seames, Wayne Stewart

    The environmental impact resulting from the release of trace elements during coal combustion is an important issue for the coal-fired electric utility industry. Trace elements exit the combustor by partitioning between the flue gas and the fly ash particles. A comprehensive study has been conducted to investigate the mechanisms governing the partitioning of trace elements during pulverized coal combustion. The behavior of seven trace elements (arsenic, selenium, antimony, cobalt, cesium, thorium, and cerium) in six pulverized coals were studied under commercially relevant conditions in a well-described laboratory combustion environment. The partitioning of trace elements is governed by the extent of volatilization during combustion, the form of occurrence in the flue gas, and the mechanisms controlling vapor-to-solid phase transformation to fly ash particle surfaces. The most common vapor-to-solid phase partitioning mechanism for semi-volatile trace elements is reaction with active fly ash surfaces. Trace elements that form oxy-anions upon volatilization (e.g. arsenic, selenium, antimony) will react with active calcium and iron cation fly ash surface sites. Trace elements that form simple oxides upon volatilization (e.g. cobalt, cesium) will react with active aluminum oxy-anion fly ash surface sites. The maximum combustion temperature affects the availability of active calcium and iron surface sites but not aluminum sites. Sulfur inhibits the reactivity of oxy-anions with iron surface sites. For coals with high sulfur contents (>1 wt % as SO 2), volatilized trace elements that form oxy-anions will partition by reaction with calcium surface sites if sufficient sites are available. For coals with low sulfur contents, volatilized trace elements that form oxy-anions, will partition by reaction with iron surface sites. Volatilized trace elements that form oxy-anions will not partition by reaction if the coal sulfur content is high and the calcium content is low (<3 wt

  13. Development and Testing of Industrial Scale, Coal Fired Combustion System, Phase 3: Twentieth quarterly technical progress report, October 1-December 31, 1996

    SciTech Connect

    Zauderer, Bert

    1997-02-27

    In the fourth quarter of calendar year 1996, 15 days of combust boiler tests were performed, including 10 days of tests on a parallel DOE sponsored project on sulfur retention in a slagging combustor. Between tests, modifications and improvements that were indicated by these tests were implemented. This brings the total number of test days to the end of December in the task 5 effort to 57, increased to 65 as of the date of this Report, 1/27/97. This compares with a total of 63 test days needed to complete the task 5 test effort, and it completes the number of tests days required to meet the task 5 project plan. The key project objectives of the areas of combustor performance and environmental performance have been exceeded. With sorbent injection in the combustion gas train, NO{sub x} emissions as low as 0.07 lb/MMBtu and SO{sub 2} emissions as low as 0.2 lb/MMBtu have been measured in tests in this quarter. Work in the next quarter will focus on even greater reductions in environmental emissions. Also tests are planned with coals other than the Eastern U.S. bituminous coals tested in this project. For example, it is planned to tests Indian coals whose ash concentration is in the 40% range.

  14. Fate of selenium in coal combustion: volatilization and speciation in the flue gas.

    PubMed

    Yan, R; Gauthier, D; Flamant, G; Peraudeau, G; Lu, J; Zheng, C

    2001-04-01

    In light of Title I of the Clean Air Act Amendments of 1990, selenium will most probably be considered for regulation in the electric power industry. This has generated interest for removing this element from fossil-fired flue gas. This study deals with coal combustion: selenium volatilization and its speciation in the cooled flue gas were investigated to better understand its chemical behavior to validate the thermodynamic approach to such complex systems and to begin developing emission control strategies. Se volatility is influenced by several factors such as temperature, residence time, fuel type, particle size, and Se speciation of the fuels, as well as the forms of the Se inthe spiked coal/coke. Spiked coke and coal samples were burned in a thermobalance, and atomic Se and its dioxide were identified in the cooled combustion flue gas by X-ray photoelectron spectroscopy (XPS). A thermodynamic calculation was applied to a complex system including 54 elements and 3,200 species that describes the coal combustion. Several theoretical predictions concerning Se behavior, such as its speciation in flue gas, agreed well with experiments, which supports using thermodynamics for predicting trace element chemistry in combustion systems.

  15. Structure Based Predictive Model for Coal Char Combustion

    SciTech Connect

    Robert Hurt; Joseph Calo; Robert Essenhigh; Christopher Hadad

    2000-12-30

    This unique collaborative project has taken a very fundamental look at the origin of structure, and combustion reactivity of coal chars. It was a combined experimental and theoretical effort involving three universities and collaborators from universities outside the U.S. and from U.S. National Laboratories and contract research companies. The project goal was to improve our understanding of char structure and behavior by examining the fundamental chemistry of its polyaromatic building blocks. The project team investigated the elementary oxidative attack on polyaromatic systems, and coupled with a study of the assembly processes that convert these polyaromatic clusters to mature carbon materials (or chars). We believe that the work done in this project has defined a powerful new science-based approach to the understanding of char behavior. The work on aromatic oxidation pathways made extensive use of computational chemistry, and was led by Professor Christopher Hadad in the Department of Chemistry at Ohio State University. Laboratory experiments on char structure, properties, and combustion reactivity were carried out at both OSU and Brown, led by Principle Investigators Joseph Calo, Robert Essenhigh, and Robert Hurt. Modeling activities were divided into two parts: first unique models of crystal structure development were formulated by the team at Brown (PI'S Hurt and Calo) with input from Boston University and significant collaboration with Dr. Alan Kerstein at Sandia and with Dr. Zhong-Ying chen at SAIC. Secondly, new combustion models were developed and tested, led by Professor Essenhigh at OSU, Dieter Foertsch (a collaborator at the University of Stuttgart), and Professor Hurt at Brown. One product of this work is the CBK8 model of carbon burnout, which has already found practical use in CFD codes and in other numerical models of pulverized fuel combustion processes, such as EPRI's NOxLOI Predictor. The remainder of the report consists of detailed technical

  16. Coal-water slurry fuel internal combustion engine and method for operating same

    DOEpatents

    McMillian, Michael H.

    1992-01-01

    An internal combustion engine fueled with a coal-water slurry is described. About 90 percent of the coal-water slurry charge utilized in the power cycle of the engine is directly injected into the main combustion chamber where it is ignited by a hot stream of combustion gases discharged from a pilot combustion chamber of a size less than about 10 percent of the total clearance volume of main combustion chamber with the piston at top dead center. The stream of hot combustion gases is provided by injecting less than about 10 percent of the total coal-water slurry charge into the pilot combustion chamber and using a portion of the air from the main combustion chamber that has been heated by the walls defining the pilot combustion chamber as the ignition source for the coal-water slurry injected into the pilot combustion chamber.

  17. Optical fiber system for combustion quality analysis in power boilers

    NASA Astrophysics Data System (ADS)

    Wojcik, Waldemar; Surtel, Wojciech; Smolarz, Andrzej; Kotyra, Andrzej; Komada, Pawel

    2001-06-01

    The introduction of low emission techniques of combustion caused side-effects like oxygen lean corrosion. It also enforced more precise management of technological air, better coal milling and application of devices for combustion process monitoring. In the article authors presented their own solution of optical fiber system for combustion quality evaluation, already operating on power boiler type OP-650. Its functionality was described together with selected results of measurements. Directions of further development of the system were also indicated.

  18. Combustion characterization of beneficiated coal-based fuels

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1990-08-01

    The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, conbustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors to CE to perform parts of the test work are the Massachusetts Institute of Technology (MIT), Physical Sciences, Inc. Technology Company (PSIT) and the University of North Dakota Energy and Environmental Research Center (UNDEERC). Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFs, and two conventionally cleaned coals for the full-scale tests. Approximately nine BCFs will be in dry ultra-fine coal (DUC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements.

  19. Sulfur emission from Victorian brown coal under pyrolysis, oxy-fuel combustion and gasification conditions.

    PubMed

    Chen, Luguang; Bhattacharya, Sankar

    2013-02-05

    Sulfur emission from a Victorian brown coal was quantitatively determined through controlled experiments in a continuously fed drop-tube furnace under three different atmospheres: pyrolysis, oxy-fuel combustion, and carbon dioxide gasification conditions. The species measured were H(2)S, SO(2), COS, CS(2), and more importantly SO(3). The temperature (873-1273 K) and gas environment effects on the sulfur species emission were investigated. The effect of residence time on the emission of those species was also assessed under oxy-fuel condition. The emission of the sulfur species depended on the reaction environment. H(2)S, SO(2), and CS(2) are the major species during pyrolysis, oxy-fuel, and gasification. Up to 10% of coal sulfur was found to be converted to SO(3) under oxy-fuel combustion, whereas SO(3) was undetectable during pyrolysis and gasification. The trend of the experimental results was qualitatively matched by thermodynamic predictions. The residence time had little effect on the release of those species. The release of sulfur oxides, in particular both SO(2) and SO(3), is considerably high during oxy-fuel combustion even though the sulfur content in Morwell coal is only 0.80%. Therefore, for Morwell coal utilization during oxy-fuel combustion, additional sulfur removal, or polishing systems will be required in order to avoid corrosion in the boiler and in the CO(2) separation units of the CO(2) capture systems.

  20. Combustion engine system

    NASA Technical Reports Server (NTRS)

    Houseman, John (Inventor); Voecks, Gerald E. (Inventor)

    1986-01-01

    A flow through catalytic reactor which selectively catalytically decomposes methanol into a soot free hydrogen rich product gas utilizing engine exhaust at temperatures of 200 to 650 C to provide the heat for vaporizing and decomposing the methanol is described. The reactor is combined with either a spark ignited or compression ignited internal combustion engine or a gas turbine to provide a combustion engine system. The system may be fueled entirely by the hydrogen rich gas produced in the methanol decomposition reactor or the system may be operated on mixed fuels for transient power gain and for cold start of the engine system. The reactor includes a decomposition zone formed by a plurality of elongated cylinders which contain a body of vapor permeable, methanol decomposition catalyst preferably a shift catalyst such as copper-zinc.

  1. Emission factors of polycyclic aromatic hydrocarbons from domestic coal combustion in China.

    PubMed

    Geng, Chunmei; Chen, Jianhua; Yang, Xiaoyang; Ren, Lihong; Yin, Baohui; Liu, Xiaoyu; Bai, Zhipeng

    2014-01-01

    Domestic coal stove is widely used in China, especially for countryside during heating period of winter, and polycyclic aromatic hydrocarbons (PAHs) are important in flue gas of the stove. By using dilution tunnel system, samples of both gaseous and particulate phases from domestic coal combustion were collected and 18 PAH species were analyzed by GC-MS. The average emission factors of total 18 PAH species was 171.73 mg/kg, ranging from 140.75 to 229.11 mg/kg for bituminous coals, while was 93.98 mg/kg, ranging from 58.48 to 129.47 mg/kg for anthracite coals. PAHs in gaseous phases occupied 95% of the total of PAHs emission of coal combustion. In particulate phase, 3-ring and 4-ring PAHs were the main components, accounting for 80% of the total particulate PAHs. The total toxicity potency evaluated by benzo[a]pyrene-equivalent carcinogenic power, sum of 7 carcinogenic PAH components and 2,3,7,8-tetrachlorodibenzodioxin had a similar tendency. And as a result, the toxic potential of bituminous coal was higher than that of anthracite coal. Efficient emission control should be conducted to reduce PAH emissions in order to protect ecosystem and human health.

  2. Kinetics of Coal Char Combustion in Oxygen-Enriched Environment

    NASA Astrophysics Data System (ADS)

    Czakiert, T.; Nowak, W.

    The influence of oxygen-enriched gaseous atmosphere on coal char combustion was studied. Two different coals, i.e. lignite and bituminous coal, were used as a basic fuel and the reacting gases of oxygen & CO2 were used to simulate flue gas recirculation. Moreover, a broad range of in-furnace conditions, i.e. five temperatures of 873, 973, 1073, 1173, 1273K and five oxygen concentrations of 20, 40, 60, 80, 100%vol., was investigated. Thermogravimetric method of measurement was employed to obtain the processing data on fuel conversion rate under foregoing investigated conditions. For further calculations, simplified Shrinking-Core Model was introduced. Finally, fundamental kinetic parameters, i.e. pre-exponential factor, activation energy and reaction order, were established and then on the basis of their values reaction-controlling regime for coal char combustion in oxygen-enriched environment was predicted. The investigations, financially supported by Polish Government, are a part of Framework Project "Supercritical Coal-fired Power Units".

  3. Impact of nongray multiphase radiation in pulverized coal combustion

    NASA Astrophysics Data System (ADS)

    Roy, Somesh; Wu, Bifen; Modest, Michael; Zhao, Xinyu

    2016-11-01

    Detailed modeling of radiation is important for accurate modeling of pulverized coal combustion. Because of high temperature and optical properties, radiative heat transfer from coal particles is often more dominant than convective heat transfer. In this work a multiphase photon Monte Carlo radiation solver is used to investigate and to quantify the effect of nongray radiation in a laboratory-scale pulverized coal flame. The nongray radiative properties of carrier phase (gas) is modeled using HITEMP database. Three major species - CO, CO2, and H2O - are treated as participating gases. Two optical models are used to evaluate radiative properties of coal particles: a formulation based on the large particle limit and a size-dependent correlation. Effect of scattering due to coal particle is also investigated using both isotropic scattering and anisotropic scattering using a Henyey-Greenstein function. Lastly, since the optical properties of ash is very different from that of coal, the effect of ash content on the radiative properties of coal particle is examined. This work used Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant Number ACI-1053575.

  4. Ultrafine ash aerosols from coal combustion: Characterization and health effects

    SciTech Connect

    William P. Linak; Jong-Ik Yoo; Shirley J. Wasson; Weiyan Zhu; Jost O.L. Wendt; Frank E. Huggins; Yuanzhi Chen; Naresh Shah; Gerald P. Huffman; M. Ian Gilmour

    2007-07-01

    Ultrafine coal fly-ash particles withdiameters less than 0.5 {mu}m typically comprise less than 1% of the total fly-ash mass. This paper reports research focused on both characterization and health effects of primary ultrafine coal ash aerosols alone. Ultrafine, fine, and coarse ash particles were segregated and collected from a coal burned in a 20 kW laboratory combustor and two additional coals burned in an externally heated drop tube furnace. Extracted samples from both combustors were characterized by transmission electron microscopy (TEM), wavelength dispersive X-ray fluorescence(WD-XRF) spectroscopy, Moessbauer spectroscopy, and X-ray absorption fine structure (XAFS) spectroscopy. Pulmonary inflammation was characterized by albumin concentrations in mouse lung lavage fluid after instillation of collected particles in saline solutions and a single direct inhalation exposure. Results indicate that coal ultrafine ash sometimes contains significant amounts of carbon, probably soot originating from coal tar volatiles, depending on coal type and combustion device. Surprisingly, XAFS results revealed the presence of chromium and thiophenic sulfur in the ultrafine ash particles. The instillation results suggested potential lung injury, the severity of which could be correlated with the carbon (soot) content of the ultrafines. This increased toxicity is consistent with theories in which the presence of carbon mediates transition metal (i.e., Fe) complexes, as revealed in this work by TEM and XAFS spectroscopy, promoting reactive oxygenspecies, oxidation-reduction cycling, and oxidative stress. 24 refs., 7 figs.

  5. Grindability and combustion behavior of coal and torrefied biomass blends.

    PubMed

    Gil, M V; García, R; Pevida, C; Rubiera, F

    2015-09-01

    Biomass samples (pine, black poplar and chestnut woodchips) were torrefied to improve their grindability before being combusted in blends with coal. Torrefaction temperatures between 240 and 300 °C and residence times between 11 and 43 min were studied. The grindability of the torrefied biomass, evaluated from the particle size distribution of the ground sample, significantly improved compared to raw biomass. Higher temperatures increased the proportion of smaller-sized particles after grinding. Torrefied chestnut woodchips (280 °C, 22 min) showed the best grinding properties. This sample was blended with coal (5-55 wt.% biomass). The addition of torrefied biomass to coal up to 15 wt.% did not significantly increase the proportion of large-sized particles after grinding. No relevant differences in the burnout value were detected between the coal and coal/torrefied biomass blends due to the high reactivity of the coal. NO and SO2 emissions decreased as the percentage of torrefied biomass in the blend with coal increased.

  6. Residual carbon from pulverized coal fired boilers 1: Size distribution and combustion reactivity

    SciTech Connect

    Hurt, R.H.; Gibbins, J.R.

    1994-08-01

    The amount of residual, or unburned, carbon in fly ash is an important concern in the design and operation of pulverized coal-fired boilers. Char oxidation is the slowest step in the coal combustion process, and the rate at which this heterogeneous reaction-proceeds has an important effect on the degree of carbon burnout. There is an extensive literature on char combustion kinetics based on data in the early and intermediate stages of carbon conversion. A critical fundamental question is whether the small fraction of the fuel carbon that passes unreacted through a boiler is representative of the char during the main portion of the combustion process. This article addresses that question through a detailed characterization of eight carbon-containing fly ash samples acquired from commercial-scale combustion systems. The fly ash characterization included measurement-of joint carbon/size distribution and determination.of the combustion reactivity of the residual carbon. To minimize mineral matter interactions in the reactivity tests, the technique of incipient fluidization was developed for separation of carbon-rich extracts from the inorganic portion of the fly ash. Reactivity measurements were made at 1400--1800 K to represent conditions in pulverized coal fired boilers. Measurements were also made at 700--1100 K to. minimize transport effects and isolate the influence of char chemistry and microstructure. In both temperature regimes, the residual carbon extracts. were significantly less reactive than chars extracted from a laboratory-scale laminar flow reactor in the early-to-intermediate stages of combustion. It is concluded that the boiler environment deactivates chars, making high carbon burnout more difficult to achieve than is predicted by existing char combustion kinetic models that were developed from data on the laboratory chars. Finally, the results are used to discuss potential char deactivation mechanisms, both thermal and oxidative, in coal-fired boilers.

  7. Beneficial use of coal combustion products continues to grow

    SciTech Connect

    MacDonald, M.

    2008-07-01

    In August 2007 the American Coal Ash Association (ACAA) released results of the Coal Combustion Products Production (CCP) and use survey. Production was 124,795,000 tons while beneficial use was 54,203,000 tons, a utilization rate of over 43%, 3% higher than in 2005. The article includes graphs of 40 years of CCP production and use and projected trade of CCP utilization until 2011. It also gives 2006 figures for Production and use of fly ash, bottom ash, boiler slag, FGD gypsum and other FGD products, and FBC ash. 3 refs., 3 figs.

  8. STRUCTURE BASED PREDICTIVE MODEL FOR COAL CHAR COMBUSTION

    SciTech Connect

    Robert Hurt; Joseph Calo; Robert Essenhigh; Christopher Hadad

    2001-06-15

    This report is part on the ongoing effort at Brown University and Ohio State University to develop structure based models of coal combustion. A very fundamental approach is taken to the description of coal chars and their reaction processes, and the results are therefore expected to have broad applicability to the spectrum of carbon materials of interest in energy technologies. This quarter, the project was in a period no-cost extension and discussions were held about the end phase of the project and possible continuations. The technical tasks were essentially dormant this period, but presentations of results were made, and plans were formulated for renewed activity in the fiscal year 2001.

  9. Balancing act creating the right regulation for coal combustion waste

    SciTech Connect

    Manuel, J.

    2009-11-15

    The December 2008 collapse of a coal ash pond in Tennessee threw safe management of coal combustion waste (CCW) into the spotlight. Millions of tons of CCW are produced in the United States each year, and a large percentage of that is recycled. The US Environmental Protection Agency is pursuing a host of initiatives that could directly or indirectly affect the disposition of CCW. States, too, are taking a look at how they regulate CCW. Among the options is the possibility of regulating CCW under the Resource Conservation and Recovery Act, a move that could have far-reaching implications for both the recycling and the disposal of this waste.

  10. Evaluation of catalytic combustion of actual coal-derived gas

    NASA Technical Reports Server (NTRS)

    Blanton, J. C.; Shisler, R. A.

    1982-01-01

    The combustion characteristics of a Pt-Pl catalytic reactor burning coal-derived, low-Btu gas were investigated. A large matrix of test conditions was explored involving variations in fuel/air inlet temperature and velocity, reactor pressure, and combustor exit temperature. Other data recorded included fuel gas composition, reactor temperatures, and exhaust emissions. Operating experience with the reactor was satisfactory. Combustion efficiencies were quite high (over 95 percent) over most of the operating range. Emissions of NOx were quite high (up to 500 ppm V and greater), owing to the high ammonia content of the fuel gas.

  11. Development and testing of a commercial scale coal-fired combustion system -- Phase 3. Final technical progress report, September 26, 1990--August 31, 1994

    SciTech Connect

    Litka, A.; Breault, R.

    1994-10-01

    This report summarizes the results of work performed in the development and testing of a coal-fired space heating system for the commercial market sector. Although coal is the most plentiful energy resource in the US, its use since World War II has been largely restricted to utility power generation for environmental and economic reasons. Within the commercial sector, oil and natural gas are the predominant heating fuels for office buildings, apartment complexes, and similar structures. Generally, these buildings require firing rates of 1 to 10 million Btu/hr. The objective of this program was to design, build, and test a coal-based heating system for this sector, and determine the economic viability and market potential for the system. Coal water slurry (CWS) fuel was chosen as the fuel form for this development effort. CWS eliminates the need to use dry pulverized coal with its attendant handling, metering, and dusting problems, as well as its explosive potential. A brief description of the overall system design is given in this report, as well as a discussion of the unique features of the system configuration and key components. This is followed by a summary of the testing performed, including a comparison between system performance and program goals. Finally, the results of the economic evaluation are presented, along with a commercialization plan for the technology. A key issue in the eventual commercialization of the technology is the availability of a competitively priced coal water slurry fuel. Predicted prices and availability of CWS are discussed.

  12. EFFECTS OF IRON CONTENT IN COAL COMBUSTION FLY ASHES ON SPECIATION OF MERCURY

    EPA Science Inventory

    The paper discusses the effects of iron content in coal combustion fly ashes on speciation of mercury. (NOTE: The chemical form of mercury species in combustion flue gases is an important influence on the control of mercury emissions from coal combustion). The study focused on th...

  13. EFFECTS OF IRON CONTENT IN COAL COMBUSTION FLY ASHES ON SPECIATION OF MERCURY

    EPA Science Inventory

    The paper discusses the effects of iron content in coal combustion fly ashes on speciation of mercury. (NOTE: The chemical form of mercury species in combustion flue gases is an important influence on the control of mercury emissions from coal combustion). The study focused on th...

  14. Behavior of fluorine in the combustion of Chinese coal in small furnaces

    SciTech Connect

    Dan Liu; Yuji Sakai; Mitsuo Yamamoto; Masayoshi Sadakata

    2006-08-15

    Research into fluoride emissions from coal-combustion systems is becoming increasingly important as the issue of fluoride pollution in China becomes more serious. In some rural areas in China, indoor fluoride pollution has particularly been caused by the use of high fluorine content coal in stoves. As a result, many residents suffer from dental fluorosis and bone fluorosis. In this study, X-ray diffraction (XRD) analysis was carried out to confirm the mode by which inorganic fluorides exist in such coals. Analytical results showed that inorganic fluorides in Chinese coals exist mainly as muscovite and apatite. The fluorine concentration in gases emitted from a boat in a quartz tube furnace was measured during combustion of volatile matter and char. The times for volatile matter and char combustions were determined through continuous monitoring of SO{sub 2}. Experimental results under different combustion conditions showed that fluoride in the emitted gas increased with an increase in oxygen concentration and temperature, while fluoride in the residue decreased with the increase in oxygen concentration and temperature. 23 refs., 8 figs., 2 tabs.

  15. Study of boron behaviour in two Spanish coal combustion power plants.

    PubMed

    Ochoa-González, Raquel; Cuesta, Aida Fuente; Córdoba, Patricia; Díaz-Somoano, Mercedes; Font, Oriol; López-Antón, M Antonia; Querol, Xavier; Martínez-Tarazona, M Rosa; Giménez, Antonio

    2011-10-01

    A full-scale field study was carried out at two Spanish coal-fired power plants equipped with electrostatic precipitator (ESP) and wet flue gas desulfurisation (FGD) systems to investigate the distribution of boron in coals, solid by-products, wastewater streams and flue gases. The results were obtained from the simultaneous sampling of solid, liquid and gaseous streams and their subsequent analysis in two different laboratories for purposes of comparison. Although the final aim of this study was to evaluate the partitioning of boron in a (co-)combustion power plant, special attention was paid to the analytical procedure for boron determination. A sample preparation procedure was optimised for coal and combustion by-products to overcome some specific shortcomings of the currently used acid digestion methods. In addition boron mass balances and removal efficiencies in ESP and FGD devices were calculated. Mass balance closures between 83 and 149% were obtained. During coal combustion, 95% of the incoming boron was collected in the fly ashes. The use of petroleum coke as co-combustible produced a decrease in the removal efficiency of the ESP (87%). Nevertheless, more than 90% of the remaining gaseous boron was eliminated via the FGD in the wastewater discharged from the scrubber, thereby causing environmental problems. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Detection of smoldering combustion of coal with an odor meter

    SciTech Connect

    Edwards, J.C.

    1995-05-01

    A commercially available odor meter was evaluated as a detector of smoldering coal combustion, and compared with incipient carbon monoxide (CO) and hydrogen sulfide (H{sub 2}S) detection and a commercially available ionization-type smoke detector. Ten smoldering coal combustion experiments were conducted. For eight of the experiments, Pittsburgh seam coal with an average particle diameter of approximately 5 cm was heated by embedded electrical strip heaters. For two of the experiments mine size Pittsburgh seam coal was heated. Heating rates of 0.5, 0.8, and 1.1. kw were selected to provide experimental conditions characteristic of very slow and moderately fast heating for coal sample mass between 3 and 10 kg. It was found that the odor meter and smoke detector alarm had a good correlation, with the odor meter alarm occurring prior to the smoke alarm in four of the ten experiments. The odor meter gave an increase in its output signal above ambient equivalent to detecting 1 ppm of H{sub 2}S (ten times the odor threshold of H{sub 2}S) as an alarm value. This observed odor meter response occurred prior to the electrochemical detection of H{sub 2}S for five of the six experiments for which it was evaluated. In all six experiments for which the smoke optical density was evaluated, it was less than 0.023 m{sup -1} prior to the odor meter reaching alarm. In each of the eight experiments with 5 cm diameter coal particles the CO exceeded 5 ppm at odor meter alarm, while for the two experiments with mine size coal the CO was less than 3 ppm at odor meter alarm. The odor meter, as tested, is not a significant improvement over smoke and CO detectors. Because the odor meter responds to a variety of chemical compounds, with suitable modification and increased sensitivity it may be useful for detection of mine fires and thereby enhance mine safety.

  17. Investigation of mechanisms of ash deposit formation from low-rank coal combustion: Final report

    SciTech Connect

    Greene, F.T.; O'Donnell, J.E.

    1987-08-01

    This project was undertaken to determine the chemical behavior of alkali metal and other species implicated in the ash fouling which can occur during the combustion of low rank coals. The coal combustion was studied in unaugmented premixed pulverized coal flames. Vapor species were measured by molecular beam mass spectrometry. Temperatures were also measured, and time-resolved coal/ash particulate samples were collected and analyzed. A major part of the research on this project was devoted to: (1) the development and refinement of techniques for the MBMS analysis of trace quantities of unstable and reactive high temperature vapor species from the pulverized coal flames; and (2) the time-resolved sampling and collection of particulates. The equipment is now operating very satisfactorily. Inorganic species, some of which were present at parts-per-million levels, were quantitatively sampled and measured in the pulverized coal flames. Time-resolved particulate samples which were free of vapor deposited contaminants were collected without the use of an interfering substrate. Profiles of the alkali metal species in Beulah lignite and Decker subbituminous coal flames were obtained. It was found in both flames that sodium is volatilized as the atomic species early (milliseconds) in the combustion process. The gaseous Na reacts, also in milliseconds, to form an unknown species which is probably an oxide fume, but which is not NaOH or Na/sub 2/SO/sub 4/. This is probably the mechanism for the formation of the alkali ''fumes'' observed in other systems. Measurements were also made of a number of other gaseous species, and time-resolved coal/ash samples were obtained and analyzed. 27 refs., 23 figs., 8 tabs.

  18. Capture of toxic metals by vaious sorbents during fluidized bed coal combustion

    SciTech Connect

    Ho, T.C.; Ghebremeskel, A.; Hopper, J.R.

    1995-12-31

    This study investigated the potential of employing suitable sorbents to capture trace metallic substances during fluidized bed coal combustion. The objectives of the study were to demonstrate the capture process, identify effective sorbents, and characterize the capture efficiency. Experiments were carried out in a 25.4 mm (1 ``) quartz fluidized bed coal combustor enclosed in an electric furnace. In an experiment, a coal sample from the DOE Coal Sample Bank or the Illinois Basin Coal Sample Bank was burned in the bed with a sorbent under various combustion conditions and the amount of metal capture by the sorbent was determined. The metals involved in the study were arsenic, cadmium, lead, mercury and selenium, and the sorbents tested included bauxite, zeolite and lime. The combustion conditions examined included bed temperature, particle size, fluidization velocity (percent excess air), and sorbent bed height. In addition to the experimental investigations, potential metal-sorbent reactions were also identified through performing chemical equilibrium analyses based on the minimization of system free energy.

  19. [Fluorine removal efficiency of organic-calcium during coal combustion].

    PubMed

    Liu, Jing; Liu, Jian-Zhong; Zhou, Jun-Hu; Xiao, Hai-Ping; Cen, Ke-Fa

    2006-08-01

    Effectiveness of calcium magnesium acetate (CMA) and calcium acetate(CA) as feasible HF capture were studied by means of fixed bed tube furnaces. The effects of temperature, particle diameter and Ca/S molar ratio on the fluorine removal efficiency were studied. By contract with CaCO3 at the same condition, we find that the HF capture effectiveness of those sorbents is superior to CaCO3, especially at high temperature. At 1 000 - 1 100 degrees C, the efficiency of fluorine removal during coal combustion of CMA is 1.68 - 1.74 times as that of CaCO3; the efficiency of fluorine removal during coal combustion of CA is 1.28 - 1.37 times as that of CaCO3.

  20. Combustion studies of coal derived solid fuels by thermogravimetric analysis. III. Correlation between burnout temperature and carbon combustion efficiency

    USGS Publications Warehouse

    Rostam-Abadi, M.; DeBarr, J.A.; Chen, W.T.

    1990-01-01

    Burning profiles of 35-53 ??m size fractions of an Illinois coal and three partially devolatilized coals prepared from the original coal were obtained using a thermogravimetric analyzer. The burning profile burnout temperatures were higher for lower volatile fuels and correlated well with carbon combustion efficiencies of the fuels when burned in a laboratory-scale laminar flow reactor. Fuels with higher burnout temperatures had lower carbon combustion efficiencies under various time-temperature conditions in the laboratory-scale reactor. ?? 1990.

  1. Combustion of coal/water mixtures with thermal preconditioning. Final report

    SciTech Connect

    Novack, M.; Roffe, G.; Miller, G.

    1985-12-01

    Thermal preconditioning is a process in which coal/water mixtures are vaporized to produce coal/steam suspensions, and then superheated to allow the coal to devolatilize producing suspensions of char particles in hydrocarbon gases and steam. This final product of the process can be injected without atomization, and burned directly in a gas turbine combustor. This paper reports on the results of an experimental program in which thermally preconditioned coal/water mixture was successfully burned with a stable flame in a gas turbine combustor test rig. Tests were performed at a mixture flowrate of 300 lb/hr and combustor pressure of 8 atmospheres. The coal/water mixture was thermally preconditioned and injected into the combustor over a temperature range from 350 to 600/sup 0/F, and combustion air was supplied at between 600 to 725/sup 0/F. Test durations generally varied between 10 to 20 minutes. Major results of the combustion testing were that: a stable flame was maintained over a wide equivalence ratio range, between phi = 2.4 (rich) to 0.2 (lean); and, combustion efficiency of over 99% was achieved when the mixture was preconditioned to 600/sup 0/F and the combustion air preheated to 725/sup 0/F. Measurements of ash particulates captured in the exhaust sampling probe located 20 inches from the injector face, show typical sizes collected to be about 1 micron, with agglomerates of these particulates to be not more than 8 microns. The original mean coal particle size for these tests, prior to preconditioning was 25 microns. System studies indicate that preconditioning can be incorporated into either stationary or mobile power plant designs without system derating. On the basis of these results, thermal pretreatment offers a practical alternative to fuel atomization in gas turbine applications. 20 figs., 4 tabs.

  2. Acoustically enhanced combustion of micronized coal water slurry fuel

    SciTech Connect

    Koopmann, G. M.; Scaroni, A. W.; Yavuzkurt, S.; Reethof, G.; Ramachandran, P.; Ha, M. Y.

    1989-05-01

    A multi-faceted investigation has been carried out to demonstrate analytically and experimentally, that a high intensity acoustic field can be substantially enhance the convective transfer processes occurring during MCWSF (micronized coal water slurry fuel) combustion. The initial stage of the investigation dealt with elucidating the transient as well as time-averaged efforts of high intensity acoustic fields on the heat and mass transfer between a single spherical particle and its environment. A two-dimensional unsteady computer code was developed, which employs the unsteady conservation of mass, momentum, and energy equations for laminar flow in spherical coordinates. One objective of the present project was the modeling of MCWSF combustion in a laboratory scale combustor with and without the application of a sonic field. The influence of various operating parameters (sound frequency and level, etc.) on sonic enhancement could thus be studied. The combustion of pulverized coal (PC) was also modeled for the sake of comparison. The first of the two coal combustion experiments was performed using a flat flame methane-air burner. Micronized coal was injected in the same direction as, and burned together with the methane. The final investigation was carried out in a 300,000 Btu/h sonic combustor. For the runs conducted, SPLs of 156 dB and 145 dB, respectively, were measured below the fuel injection point and before the exit to the combustor. Frequency was held at 1400 Hz. Finally, an attempt was made to model the runs performed in the down-fired unit, using the PCGC-2 code. 61 refs., 60 figs., 8 tabs.

  3. Combustion of dense streams of coal particles. Final report, August 29, 1990--February 28, 1994

    SciTech Connect

    Annamalai, K.; Gopalakrishnan, C.; Du, X.

    1994-05-01

    The USA consumes almost 94 quads of energy (1 quad = 10{sup 15} BTU or 1.05 {times} 10{sup 15} KJ). The utilities account for about 30 quads of fossil energy where coal is predominantly used as energy source. The coal is ground to finer size and fired into the boiler as dense suspension. Under dense conditions, the particles burn at slower rate due to deficient oxygen within the interparticle spacing. Thus interactions exist amongst the particles for dense clouds. While the earlier literature dealt with combustion processes of isolated particles, the recent research focusses upon the interactive combustion. The interactive combustion studies include arrays consisting of a finite number of particles, and streams and clouds of a large number of particles. Particularly stream combustion models assume cylindrical geometry and predict the ignition and combustion characteristics. The models show that the ignition starts homogeneously for dense streams of coal particles and the ignition time show a minimum as the stream denseness is increased, and during combustion, there appears to be an inner flame within the stream and an outer flame outside the stream for a short period of time. The present experimental investigation is an attempt to verify the model predictions. The set-up consists of a flat flame burner for producing hot vitiated gases, a locally fluidizing feeder system for feeding coal particles, a particle collection probe for collecting particles and an image processing system for analyzing the flame structure. The particles are introduced as a stream into the hot gases and subsequently they ignite and burn. The ash % of fired and collected particles are determined and used to estimate the gasification efficiency or burnt fraction. The parametric studies include gas temperature, oxygen % in gases, residence time, and A:F ratio of the stream.

  4. Near-extinction and final burnout in coal combustion

    SciTech Connect

    Hurt, R.H.; Davis, K.A.

    1994-02-01

    The late stages of char combustion have a special technological significance, as carbon conversions of 99% or greater are typically required for the economic operation of pulverized coal fired boilers. In the present article, two independent optical techniques are used to investigate near-extinction and final burnout phenomenas. Captive particle image sequences, combined with in situ optical measurements on entrained particles, provide dramatic illustration of the asymptotic nature of the char burnout process. Single particle combustion to complete burnout is seen to comprise two distinct stages: (1) a rapid high-temperature combustion stage, consuming about 70% of the char carbon and ending with near-extinction of the heterogeneous reactions due to a loss of global particle reactivity, and (2) a final burnout stage occurring slowly at lower temperatures. For particles containing mineral matter, the second stage can be further subdivided into: (2a) late char combustion, which begins after the near-extinction event, and converts carbon-rich particles to mixed particle types at a lower temperature and a slower rate; and (2b) decarburization of ash -- the removal of residual carbon inclusions from inorganic (ash) frameworks in the very late stages of combustion. This latter process can be extremely slow, requiring over an order of magnitude more time than the primary rapid combustion stage. For particles with very little ash, the loss of global reactivity leading to early near-extinction is clearly related to changes in the carbonaceous char matrix, which evolves over the course of combustion. Current global kinetic models used for the prediction of char combustion rates and carbon burnout in boilers do not predict the asymptotic nature of char combustion. More realistic models accounting for the evolution of char structure are needed to make accurate predictions in the range of industrial interest.

  5. Toxic Substances from Coal Combustion: A Comprehensive Assessment: Quarterly report, 1 July 1996-30 September 1996

    SciTech Connect

    Bool, L.E.; Senior, C.L.; Huggins, F.; Huffman, G.P.; Shah, N.; Wendt, J.O.L.; Peterson, T.W.; Sarofim, A.F.; Olmez, I.; Zeng, T.; Crowley, S.; Finkelman, R.

    1996-10-01

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPS) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Pittsburgh Energy Technology Center (PETC), the Electric Power Research Institute (EPRI), and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UKy), the University of Connecticut, and Princeton University to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NO{sub x}, combustion systems, and new power generation plants. Development of ToPEM will be based on PSI`s existing Engineering Model for Ash Formation (EMAF). Extensive coal characterization and laboratory work has begun in order to develop and test new sub-models. Trace element concentrations in the Pittsburgh, Elkhorn/Hazard, and Illinois No. 6 coals, and in size/density fractions of these coals, were completed. Coal characterization in the past quarter also included direct identification of the modes of occurrence of various trace inorganic species in coal and ash using unique analytical techniques such as XAFS analysis and selective leaching. Combustion testing of these two coals was begun and preliminary data obtained on trace element 0301 vaporization in the combustion zone. Modeling efforts in the past quarter include the development on a preliminary model to assess mercury speciation in combustion systems.

  6. Slag processing system for direct coal-fired gas turbines

    DOEpatents

    Pillsbury, Paul W.

    1990-01-01

    Direct coal-fired gas turbine systems and methods for their operation are provided by this invention. The gas turbine system includes a primary zone for burning coal in the presence of compressed air to produce hot combustion gases and debris, such as molten slag. The turbine system further includes a secondary combustion zone for the lean combustion of the hot combustion gases. The operation of the system is improved by the addition of a cyclone separator for removing debris from the hot combustion gases. The cyclone separator is disposed between the primary and secondary combustion zones and is in pressurized communication with these zones. In a novel aspect of the invention, the cyclone separator includes an integrally disposed impact separator for at least separating a portion of the molten slag from the hot combustion gases.

  7. Combustion and fuel characterization of coal-water fuels

    SciTech Connect

    Lachowicz, Y.V.; LaFlesh, R.C.

    1987-07-01

    This five-year research project was established to provide sufficient data on coal-water fuel (CWF) chemical, physical, and combustion properties to assess the potential for commercial firing in furnaces designed for gas or oil firing. Extensive laboratory testing was performed at bench-scale, pilot-scale (4 {times} 10{sup 6}Btu/hr) and commercial-scale (25 {times} 10{sup 6} to 50 {times} 10{sup 6}Btu/hr) on a cross-section of CWFs. Fuel performance characteristics were assessed with respect to coal properties, level of coal beneficiation, and slurry formulation. The performance of four generic burner designs was also assessed. Boiler performance design models were applied to analyze the impacts associated with conversion of seven different generic unit designs to CWF firing. Equipment modifications, operating limitations, and retrofit costs were determined for each design when utilizing several CWFs. This report summarizes studies conducted under Task 4. The objective was to quantify CWF atomization and combustion properties utilizing industrial/utility scale equipment. Burners were evaluated and combustion performance differences identified for various CWF formulations. 12 refs., 23 figs., 6 tabs.

  8. Advanced coal-fueled gas turbine systems

    SciTech Connect

    Wenglarz, R.A.

    1994-08-01

    Several technology advances since the early coal-fueled turbine programs that address technical issues of coal as a turbine fuel have been developed in the early 1980s: Coal-water suspensions as fuel form, improved methods for removing ash and contaminants from coal, staged combustion for reducing NO{sub x} emissions from fuel-bound nitrogen, and greater understanding of deposition/erosion/corrosion and their control. Several Advanced Coal-Fueled Gas Turbine Systems programs were awarded to gas turbine manufacturers for for components development and proof of concept tests; one of these was Allison. Tests were conducted in a subscale coal combustion facility and a full-scale facility operating a coal combustor sized to the Allison Model 501-K industrial turbine. A rich-quench-lean (RQL), low nitrogen oxide combustor design incorporating hot gas cleanup was developed for coal fuels; this should also be applicable to biomass, etc. The combustor tests showed NO{sub x} and CO emissions {le} levels for turbines operating with natural gas. Water washing of vanes from the turbine removed the deposits. Systems and economic evaluations identified two possible applications for RQL turbines: Cogeneration plants based on Allison 501-K turbine (output 3.7 MW(e), 23,000 lbs/hr steam) and combined cycle power plants based on 50 MW or larger gas turbines. Coal-fueled cogeneration plant configurations were defined and evaluated for site specific factors. A coal-fueled turbine combined cycle plant design was identified which is simple, compact, and results in lower capital cost, with comparable efficiency and low emissions relative to other coal technologies (gasification, advanced PFBC).

  9. HIGH PRESSURE COAL COMBUSTION KINETICS PROJECT

    SciTech Connect

    Chris Guenther, Ph.D.

    2003-01-28

    SRI has completed the NBFZ test program, made modification to the experimental furnace for the HPBO test. The NBFZ datasets provide the information NEA needs to simulate the combustion and fuel-N conversion with detailed chemical reaction mechanisms. BU has determined a linear swell of 1.55 corresponding to a volumetric increase of a factor of 3.7 and a decrease in char density by the same factor. These results are highly significant, and indicate significantly faster burnout at elevated pressure due to the low char density and large diameter.

  10. Influence of carbon structure and mineral association of coals on their combustion characteristics for pulverized coal injection (PCI) application

    SciTech Connect

    Gupta, S.; Al-Omari, Y.; Sahajwalla, V.; French, D.

    2006-06-15

    The influence of carbon structure and mineral matter of three pulverized coals on their char characteristics including reactivity was studied under a range of combustion conditions in a drop tube furnace (DTF) and thermogravimetric (TGA) furnace for PCI application. Physical and chemical properties of coals and their combustion derivatives were characterized by automated reflectogram. X-ray diffraction, scanning electron microscope, and BET N{sub 2} adsorption. The QEMSCAN{asterisk} technique was used to characterize the heterogeneous nature of minerals of discrete coal particles. The TGA char reactivity was related to the proportion of coal particles displaying strong association of calcium/sulfur phases with carbon matrix to highlight the catalytic influence of minerals on char reactivity at low temperatures. The study suggested that during DTF combustion tests at 1200{sup o}C, char reaction rates might have been catalyzed by coal minerals, particularly due to illite and its association with carbon. Under the same combustion conditions, most of the coal minerals did not transform significantly to slag phases. Coal burnout was found to improve significantly in a combustion temperature range of 1200 to 1500{sup o}C. The improvement of coal burnout with temperature appeared to be influenced by coal properties, particularly as a function of the chemical nature of minerals, as well as the degree of associations with other minerals. The study implies that coals with similar mineral compositions might not necessarily reflect similar combustion behavior due to the differences in their associations with other phases.

  11. Combustion and fuel characterization of coal-water fuels

    SciTech Connect

    Not Available

    1989-07-01

    Pittsburgh Energy Technology Center (PETC) of the Department of Energy initiated a comprehensive effort in 1982 to develop the necessary performance and cost data and to assess the commercial viability of coal water fuels (CWFs) as applied to representative utility and industrial units. The effort comprised six tasks beginning with coal resource evaluation and culminating in the assessment of the technical and economic consequences of switching representative commercial units from oil to state-of-the-art CWF firing. Extensive bench, pilot and commercial-scale tests were performed to develop necessary CWF combustion and fireside performance data for the subsequent boiler performance analyses and retrofit cost estimates. This report (Volume 2) provides a review of the fuel selection and procurement activities. Included is a discussion on coal washability, transport of the slurry, and characterization. 20 figs., 26 tabs.

  12. Progression in sulfur isotopic compositions from coal to fly ash: Examples from single-source combustion in Indiana

    USGS Publications Warehouse

    Yaofa, Jiang; Elswick, E.R.; Mastalerz, Maria

    2008-01-01

    Sulfur occurs in multiple mineral forms in coals, and its fate in coal combustion is still not well understood. The sulfur isotopic composition of coal from two coal mines in Indiana and fly ash from two power plants that use these coals were studied using geological and geochemical methods. The two coal beds are Middle Pennsylvanian in age; one seam is the low-sulfur ( 5%) Springfield Coal Member of the Petersburg Formation. Both seams have ash contents of approximately 11%. Fly-ash samples were collected at various points in the ash-collection system in the two plants. The results show notable difference in ??34S for sulfur species within and between the low-sulfur and high-sulfur coal. The ??34S values for all sulfur species are exclusively positive in the low-sulfur Danville coal, whereas the ??34S values for sulfate, pyritic, and organic sulfur are both positive and negative in the high-sulfur Springfield coal. Each coal exhibits a distinct pattern of stratigraphic variation in sulfur isotopic composition. Overall, the ??34S for sulfur species values increase up the section in the low-sulfur Danville coal, whereas they show a decrease up the vertical section in the high-sulfur Springfield coal. Based on the evolution of ??34S for sulfur species, it is suggested that there was influence of seawater on peat swamp, with two marine incursions occurring during peat accumulation of the high-sulfur Springfield coal. Therefore, bacterial sulfate reduction played a key role in converting sulfate into hydrogen sulfide, sulfide minerals, and elemental sulfur. The differences in ??34S between sulfate sulfur and pyritic sulfur is very small between individual benches of both coals, implying that some oxidation occurred during deposition or postdeposition. The ??34S values for fly ash from the high-sulfur Springfield coal (averaging 9.7???) are greatly enriched in 34S relative to those in the parent coal (averaging 2.2???). This indicates a fractionation of sulfur isotopes

  13. Combustion characterization of beneficiated coal-based fuels

    SciTech Connect

    Not Available

    1990-03-01

    This three-year research project at Combustion Engineering, Inc. (CE), will assess the potential economic and environmental benefits derived from coal beneficiation by various advanced cleaning processes. The objectives of this program include the development of a detailed generic engineering data base, comprised of fuel combustion and ash performance data on beneficiated coal-based fuels (BCFs), which is needed to permit broad application. This technical data base will provide detailed information on fundamental fuel properties influencing combustion and mineral matter behavior as well as quantitative performance data on combustion, ash deposition, ash erosion, particulate collection, and gaseous and particulate emissions. Program objectives also address the application of this technical data base to predict performance impacts associated with firing BCFs in various commercial boiler designs as well as assessment of the economic implications of BCF utilization. Additionally, demonstration of this technology, with respect to large-scale fuel preparation, firing equipment operation, fuel performance, environmental impacts, and verification of prediction methodology, will be provided during field testing.

  14. Validation of Coal Combustion Model by Using Experimental Data of Utility Boilers

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kenji; Taniguchi, Masayuki; Kobayashi, Hironobu; Sakata, Taro; Kudo, Kazuhiko

    Applicability of a coal combustion model was validated by comparing its predictions with experimental data of utility boilers. The coal combustion model had gasification and NOx reaction submodels and it was developed by using a small drop-tube-furnace (coal feed rate 0.6kg/h). A turbulence combustion simulation program was developed by introducing the coal combustion model. The program was validated by comparing its predictions with 23 sets of experimental results which contained different plant, load and coal data. The temperature difference between simulated and experimental results was within 30°C at the furnace exit. The decreasing characteristic of coal burnout with increasing load was well predicted. The NOx emission difference between simulated and experimental results was less than 15%. The coal combustion model was judged applicable to utility boilers.

  15. Thermogravimetric investigation on co-combustion characteristics of tobacco residue and high-ash anthracite coal.

    PubMed

    Li, X G; Lv, Y; Ma, B G; Jian, S W; Tan, H B

    2011-10-01

    The thermal behavior of high-ash anthracite coal, tobacco residue and their blends during combustion processes was investigated by means of thermogravimetric analysis (20 K min(-1), ranging from ambient temperature to 1273 K). Effects of the mixed proportion between coal and tobacco residue on the combustion process, ignition and burnout characteristics were also studied. The results indicated that the combustion of tobacco residue was controlled by the emission of volatile matter; the regions were more complex for tobacco residue (four peaks) than for coal (two peaks). Also, the blends had integrative thermal profiles that reflected both tobacco residue and coal. The incorporation of tobacco residue could improve the combustion characteristics of high-ash anthracite coal, especially the ignition and burnout characteristics comparing with the separate burning of tobacco residue and coal. It was feasible to use the co-combustion of tobacco residue and high-ash anthracite coal as fuel. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Co-combustion of agricultural residues with coal in a fluidized bed combustor.

    PubMed

    Ghani, W A W A K; Alias, A B; Savory, R M; Cliffe, K R

    2009-02-01

    Power generation from biomass is an attractive technology that utilizes agricultural residual waste. In order to explain the behavior of biomass-fired fluidized bed incinerator, biomass sources from agricultural residues (rice husk and palm kernel) were co-fired with coal in a 0.15m diameter and 2.3m high fluidized bed combustor. The combustion efficiency and carbon monoxide emissions were studied and compared with those for pure coal combustion. Co-combustion of a mixture of biomass with coal in a fluidized bed combustor designed for coal combustion increased combustion efficiency up to 20% depending upon excess air levels. Observed carbon monoxide levels fluctuated between 200 and 900 ppm with the addition of coal. It is evident from this research that efficient co-firing of biomass with coal can be achieved with minimal modifications to existing coal-fired boilers.

  17. HIGH PRESSURE COAL COMBUSTION KINETICS PROJECT

    SciTech Connect

    Chris Guenther

    2002-10-28

    The modifications to the SRT-RCFR facility described in the June report were completed. As a result of these changes, the furnace hot zone was increased in length from 7 cm to 15.5 cm. The injector region of the furnace, providing entrainment and sheath flows, was unchanged, while the flow path from the exit of the furnace to the sample collection section was shortened by approximately 10 cm. The modified facility was used to resume testing of Pittsburgh No. 8 coal at 10 atm. The first goal was to confirm that the facility now provides true secondary pyrolysis test conditions. That is, the tar product should be completely converted to soot even in the absence of oxygen in the gas stream. We have now performed four tests with pure argon carrier gas, and have consistently observed voluminous soot product with little or no evidence of tar. Thus, this objective was met. The clogging problems for Pittsburgh No. 8 coal under secondary pyrolysis test conditions may preclude achieving this data point. In that case, we will make measurements under oxidizing conditions, which are expected to eliminate the clogging, and to gradually reduce the oxygen content to the point where product yields can reliably be extrapolated to the zero oxygen case.

  18. Volatile metal species in coal combustion flue gas.

    PubMed

    Pavageau, Marie-Pierre; Pécheyran, Christophe; Krupp, Eva M; Morin, Anne; Donard, Olivier F X

    2002-04-01

    Metals are released in effluents of most of combustion processes and are under intensive regulations. To improve our knowledge of combustion process and their resulting emission of metal to the atmosphere, we have developed an approach allowing usto distinguish between gaseous and particulate state of the elements emitted. This study was conducted on the emission of volatile metallic species emitted from a coal combustion plant where low/medium volatile coal (high-grade ash) was burnt. The occurrence of volatile metal species emission was investigated by cryofocusing sampling procedure and detection using low-temperature packed-column gas chromatography coupled with inductively coupled plasma-mass spectrometry as multielement detector (LT-GC/ICP-MS). Samples were collected in the stack through the routine heated sampling line of the plant downstream from the electrostatic precipitator. The gaseous samples were trapped with a cryogenic device and analyzed by LT-GC/ICP-MS. During the combustion process, seven volatile metal species were detected: three for Se, one for Sn, two for Hg, and one for Cu. Thermodynamic calculations and experimental metal species spiking experiments suggest that the following volatile metal species are present in the flue gas during the combustion process: COSe, CSSe, CSe2, SeCl2, Hg0, HgCl2, CuO-CuSO4 or CuSO4 x H2O, and SnO2 or SnCl2. The quantification of volatile species was compared to results traditionally obtained by standardized impinger-based sampling and analysis techniques recommended for flue gas combustion characterization. Results showed that concentrations obtained with the standard impinger approach are at least 10 times higher than obtained with cryogenic sampling, suggesting the trapping microaerosols in the traditional methods. Total metal concentrations in particles are also reported and discussed.

  19. Toxic Substances from Coal Combustion - Forms of Occurrence Analyses

    SciTech Connect

    Allan Kolker; Curtis A. Palmer; Harvey E. Belkin; Jason Willet; Kathleen C. Kolb; Robert B. Finkelman; Sharon S. Crowley; Stanley J. Mroczkowski

    1998-12-14

    In a cooperative agreement with DOE (Contract No. DE- AC22- 95101), the USGS has participated with Physical Sciences, Inc. (PSI) in a project entitled "Toxic Substances From Coal Combustion -A Comprehensive Assessment". Samples from the Pittsburgh, Elkhorn/ Hazard, Illinois No. 6, and Wyodak program coals were examined to determine the mode of occurrence of selected trace elements (As, Se, Cr, Hg, and Ni) using selective leaching, scanning electron microscopy, electron microprobe analysis, and X- ray diffraction techniques. Among other findings, our results indicate that the bulk of the arsenic in the Pittsburgh and Illinois No. 6 coals is in pyrite. High percentages (60- 80%) of arsenic were leached by nitric acid, and microprobe data confirm the presence of arsenic in pyrite in each of these coals (concentrations ranging from <0.01 to 0.09 wt.% of the pyrite grains). In the Elkhorn/ Hazard coal, arsenic may have several modes of occurrences. About 30 percent of the arsenic in the Elkhorn/ Hazard coal was leached by hydrochloric acid, possibly indicating the presence of arsenates that were formed by the oxidation of pyrite. About 25 percent of the arsenic in the Elkhorn/ Hazard coal was leached by nitric acid, suggesting an association with pyrite. Only sixty percent of the total arsenic in the Elkhorn/ Hazard coal was leached. The low percentage of leachable arsenic may be accounted for by unleached pyrite grains, which were detected in solid residues from the nitric acid leach. In the Wyodak coal, arsenic probably occurs in iron oxides or carbonates (35 % arsenic leached by HCl) and clays (15% arsenic leached by HF). Arsenic in the Wyodak coal may also have an organic association, as indicated by low totals for leaching (50% unleached arsenic). In the four program coals 20 to 45 percent of the chromium was leached by hydrofluoric acid, suggesting an association with silicates (probably illite). Microprobe analysis of the Pittsburgh, Elkhorn/ Hazard, and Illinois

  20. ON TRIMODAL PARTICLE SIZE DISTRIBUTIONS IN FLY ASH FROM PULVERIZED COAL COMBUSTION

    EPA Science Inventory

    Combustion generated fine particles, defined as those with aerodynamic diameters less than 2.5 micrometers, have come under increased regulatory scrutiny because of suspected links to adverse human health effects. Whereas classical theories regarding coal combustion suggest that ...

  1. ON TRIMODAL PARTICLE SIZE DISTRIBUTIONS IN FLY ASH FROM PULVERIZED COAL COMBUSTION

    EPA Science Inventory

    Combustion generated fine particles, defined as those with aerodynamic diameters less than 2.5 micrometers, have come under increased regulatory scrutiny because of suspected links to adverse human health effects. Whereas classical theories regarding coal combustion suggest that ...

  2. Modelling of the process of coal dust combustion in a cyclone furnace

    NASA Astrophysics Data System (ADS)

    Zarzycki, Robert; Bis, Zbigniew

    2017-04-01

    This study presents the concept of a cyclone furnace for coal dust oxy-fuel combustion and gasification. The results of numerical calculations for the combustion and gasification processes were also presented.

  3. Nitrogen oxides, sulfur trioxide, and mercury emissions during oxy-fuel fluidized bed combustion of Victorian brown coal.

    PubMed

    Roy, Bithi; Chen, Luguang; Bhattacharya, Sankar

    2014-12-16

    This study investigates, for the first time, the NOx, N2O, SO3, and Hg emissions from combustion of a Victorian brown coal in a 10 kWth fluidized bed unit under oxy-fuel combustion conditions. Compared to air combustion, lower NOx emissions and higher N2O formation were observed in the oxy-fuel atmosphere. These NOx reduction and N2O formations were further enhanced with steam in the combustion environment. The NOx concentration level in the flue gas was within the permissible limit in coal-fired power plants in Victoria. Therefore, an additional NOx removal system will not be required using this coal. In contrast, both SO3 and gaseous mercury concentrations were considerably higher under oxy-fuel combustion compared to that in the air combustion. Around 83% of total gaseous mercury released was Hg(0), with the rest emitted as Hg(2+). Therefore, to control harmful Hg(0), a mercury removal system may need to be considered to avoid corrosion in the boiler and CO2 separation units during the oxy-fuel fluidized-bed combustion using this coal.

  4. Thermally induced structural changes in coal combustion

    SciTech Connect

    Gavalas, G.R.; Flagan, R.C.

    1990-01-17

    The effect of particle shape on char burnout is investigated in the limit of shrinking core combustion. As a first step, the particle temperature is assumed to proceed in the shrinking core regime and under conditions of negligible Stefan flow. The problem then reduces to calculating the oxygen concentration field around a non-spherical particle with the oxidation reaction taking place on the external surface. This problem has been addressed by an analytical technique and a numerical technique. An analytical technique known as domain perturbation'' was used to examine the change due to reaction in the shape of a slightly nonspherical, but axisymmetric, particle. It was found that the aspect ratio always increases with conversion, i.e., the particle becomes less spherical. A numerical technique, based on the boundary integral'' method was developed to handle the case of an axisymmetric particle with otherwise arbitrary shape. Numerical results are presented which again show the aspect ratio to increase with conversion. 8 refs.

  5. Advanced coal-fueled gas turbine systems reference system definition update

    SciTech Connect

    Not Available

    1991-09-01

    The objective of the the Direct Coal-Fueled 80 MW Combustion Turbine Program is to establish the technology required for private sector use of an advanced coal-fueled combustion turbine power system. Under this program the technology for a direct coal-fueled 80 MW combustion turbine is to be developed. This unit would be an element in a 207 MW direct coal-fueled combustion turbine combined cycle which includes two combustion turbines, two heat recovery steam generators and a steam turbine. Key to meeting the program objectives is the development of a successful high pressure slagging combustor that burns coal, while removing sulfur, particulates, and corrosive alkali matter from the combustion products. Westinghouse and Textron (formerly AVCO Research Laboratory/Textron) have designed and fabricated a subscale slagging combustor. This slagging combustor, under test since September 1988, has been yielding important experimental data, while having undergone several design iterations.

  6. Thermal behaviour and kinetics of coal/biomass blends during co-combustion.

    PubMed

    Gil, M V; Casal, D; Pevida, C; Pis, J J; Rubiera, F

    2010-07-01

    The thermal characteristics and kinetics of coal, biomass (pine sawdust) and their blends were evaluated under combustion conditions using a non-isothermal thermogravimetric method (TGA). Biomass was blended with coal in the range of 5-80 wt.% to evaluate their co-combustion behaviour. No significant interactions were detected between the coal and biomass, since no deviations from their expected behaviour were observed in these experiments. Biomass combustion takes place in two steps: between 200 and 360 degrees C the volatiles are released and burned, and at 360-490 degrees C char combustion takes place. In contrast, coal is characterized by only one combustion stage at 315-615 degrees C. The coal/biomass blends presented three combustion steps, corresponding to the sum of the biomass and coal individual stages. Several solid-state mechanisms were tested by the Coats-Redfern method in order to find out the mechanisms responsible for the oxidation of the samples. The kinetic parameters were determined assuming single separate reactions for each stage of thermal conversion. The combustion process of coal consists of one reaction, whereas, in the case of the biomass and coal/biomass blends, this process consists of two or three independent reactions, respectively. The results showed that the chemical first order reaction is the most effective mechanism for the first step of biomass oxidation and for coal combustion. However, diffusion mechanisms were found to be responsible for the second step of biomass combustion. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  7. CONCEPTUAL STUDIES OF A FUEL-FLEXIBLE LOW-SWIRL COMBUSTION SYSTEM FOR THE GAS TURBINE IN CLEAN COAL POWER PLANTS

    SciTech Connect

    Smith, K.O.; Littlejohn, David; Therkelsen, Peter; Cheng, Robert K.; Ali, S.

    2009-11-30

    This paper reports the results of preliminary analyses that show the feasibility of developing a fuel flexible (natural gas, syngas and high-hydrogen fuel) combustion system for IGCC gas turbines. Of particular interest is the use of Lawrence Berkeley National Laboratory's DLN low swirl combustion technology as the basis for the IGCC turbine combustor. Conceptual designs of the combustion system and the requirements for the fuel handling and delivery circuits are discussed. The analyses show the feasibility of a multi-fuel, utility-sized, LSI-based, gas turbine engine. A conceptual design of the fuel injection system shows that dual parallel fuel circuits can provide range of gas turbine operation in a configuration consistent with low pollutant emissions. Additionally, several issues and challenges associated with the development of such a system, such as flashback and auto-ignition of the high-hydrogen fuels, are outlined.

  8. Mercury stable isotope signatures of world coal deposits and historical coal combustion emissions.

    PubMed

    Sun, Ruoyu; Sonke, Jeroen E; Heimbürger, Lars-Eric; Belkin, Harvey E; Liu, Guijian; Shome, Debasish; Cukrowska, Ewa; Liousse, Catherine; Pokrovsky, Oleg S; Streets, David G

    2014-07-01

    Mercury (Hg) emissions from coal combustion contribute approximately half of anthropogenic Hg emissions to the atmosphere. With the implementation of the first legally binding UNEP treaty aimed at reducing anthropogenic Hg emissions, the identification and traceability of Hg emissions from different countries/regions are critically important. Here, we present a comprehensive world coal Hg stable isotope database including 108 new coal samples from major coal-producing deposits in South Africa, China, Europe, India, Indonesia, Mongolia, former USSR, and the U.S. A 4.7‰ range in δ(202)Hg (-3.9 to 0.8‰) and a 1‰ range in Δ(199)Hg (-0.6 to 0.4‰) are observed. Fourteen (p < 0.05) to 17 (p < 0.1) of the 28 pairwise comparisons between eight global regions are statistically distinguishable on the basis of δ(202)Hg, Δ(199)Hg or both, highlighting the potential application of Hg isotope signatures to coal Hg emissions tracing. A revised coal combustion Hg isotope fractionation model is presented, and suggests that gaseous elemental coal Hg emissions are enriched in the heavier Hg isotopes relative to oxidized forms of emitted Hg. The model explains to first order the published δ(202)Hg observations on near-field Hg deposition from a power plant and global scale atmospheric gaseous Hg. Yet, model uncertainties appear too large at present to permit straightforward Hg isotope source identification of atmospheric forms of Hg. Finally, global historical (1850-2008) coal Hg isotope emission curves were modeled and indicate modern-day mean δ(202)Hg and Δ(199)Hg values for bulk coal emissions of -1.2 ± 0.5‰ (1SD) and 0.05 ± 0.06‰ (1SD).

  9. Phytostabilization of a landfill containing coal combustion waste.

    SciTech Connect

    Barton, Christopher; Marx, Donald; Adriano, Domy; Koo, Bon Jun; Newman, Lee; Czapka, Stephen; Blake, John

    2005-12-01

    The establishment of a vegetative cover to enhance evapotranspiration and control runoff and drainage was examined as a method for stabilizing a landfill containing coal combustion waste. Suitable plant species and pretreatment techniques in the form of amendments, tilling, and chemical stabilization were evaluated. A randomized plot design consisting of three subsurface treatments (blocks) and five surface amendments (treatments) was implemented. The three blocks included (1) ripping and compost amended, (2) ripping only, and (3) control. Surface treatments included (1) topsoil, (2) fly ash, (3) compost, (4) apatite, and (5) control. Inoculated loblolly (Pinus taeda) and Virginia (Pinus virginiana) pine trees were planted on each plot. After three growing seasons, certain treatments were shown to be favorable for the establishment of vegetation on the basin. Seedlings located on block A developed a rooting system that penetrated into the basin media without significant adverse effects to the plant. However, seedlings on blocks B and C displayed poor rooting conditions and high mortality, regardless of surface treatment. Pore-water samples from lysimeters in block C were characterized by high acidity, Fe, Mn, Al, sulfate, and traceelement concentrations. Water-quality characteristics of the topsoil plots in block A, however, conformed to regulatory protocols. A decrease in soil-moisture content was observed in the rooting zone of plots that were successfully revegetated, which suggests that the trees, in combination with the surface treatments, influenced the water balance by facilitating water loss through transpiration and thereby reducing the likelihood of unwanted surface runoff and/or drainage effluent.

  10. Structure-Based Predictive model for Coal Char Combustion.

    SciTech Connect

    Hurt, R.; Calo, J.; Essenhigh, R.; Hadad, C.; Stanley, E.

    1997-06-25

    During the second quarter of this project, progress was made on both major technical tasks. Three parallel efforts were initiated on the modeling of carbon structural evolution. Structural ordering during carbonization was studied by a numerical simulation scheme proposed by Alan Kerstein involving molecular weight growth and rotational mobility. Work was also initiated to adapt a model of carbonaceous mesophase formation, originally developed under parallel NSF funding, to the prediction of coke texture. This latter work makes use of the FG-DVC model of coal pyrolysis developed by Advanced Fuel Research to specify the pool of aromatic clusters that participate in the order/disorder transition. Boston University has initiated molecular dynamics simulations of carbonization processes and Ohio State has begun theoretical treatment of surface reactions. Experimental work has also begun on model compound studies at Brown and on pilot-scale combustion systems with widely varying flame types at OSE. The work on mobility / growth models shows great promise and is discussed in detail in the body of the report.

  11. Effect of multiphase radiation on coal combustion in a pulverized coal jet flame

    NASA Astrophysics Data System (ADS)

    Wu, Bifen; Roy, Somesh P.; Zhao, Xinyu; Modest, Michael F.

    2017-08-01

    The accurate modeling of coal combustion requires detailed radiative heat transfer models for both gaseous combustion products and solid coal particles. A multiphase Monte Carlo ray tracing (MCRT) radiation solver is developed in this work to simulate a laboratory-scale pulverized coal flame. The MCRT solver considers radiative interactions between coal particles and three major combustion products (CO2, H2O, and CO). A line-by-line spectral database for the gas phase and a size-dependent nongray correlation for the solid phase are employed to account for the nongray effects. The flame structure is significantly altered by considering nongray radiation and the lift-off height of the flame increases by approximately 35%, compared to the simulation without radiation. Radiation is also found to affect the evolution of coal particles considerably as it takes over as the dominant mode of heat transfer for medium-to-large coal particles downstream of the flame. To investigate the respective effects of spectral models for the gas and solid phases, a Planck-mean-based gray gas model and a size-independent gray particle model are applied in a frozen-field analysis of a steady-state snapshot of the flame. The gray gas approximation considerably underestimates the radiative source terms for both the gas phase and the solid phase. The gray coal approximation also leads to under-prediction of the particle emission and absorption. However, the level of under-prediction is not as significant as that resulting from the employment of the gray gas model. Finally, the effect of the spectral property of ash on radiation is also investigated and found to be insignificant for the present target flame.

  12. Preparation and combustion of high ash coal tailing slurry

    SciTech Connect

    Zhang Ziping; Zhang Wenfu; Fu Xiaoheng; Wang Zuna; Li Hui

    1998-12-31

    Flotation tailings from a coal preparation plant are known for their high ash, low heating value, high moisture content even after thickening and filtration, and difficult handability. However, they can be easily converted into a slurry fuel for boilers. Two flotation tailings, containing ash of 31.89% and 41.87% respectively, have been converted into slurry fuel with the following properties: solid content being 70.4% and 74.4% respectively; low heating value, 13,694kj/kg and 10,970kj/kg; and viscosity, 379 mPa.s and 180 mPa.s at a shear rate of 100s{sup {minus}1}. An eccentric slant jet coal slurry burner was installed at the boiler. Slurry atomizing nozzle operated at low pressure. Both slurries gave stable combustion without supporting fuel under the condition of cool air supply. A new way of flotation tailing utilization was demonstrated. China has more than 200 coal preparation plants washing more than 300 million tons of coal annually. These preparation plants generate more than 10 million tons of tailing annually, most of which is not currently being used, causing great environmental pollution and waste management difficulties for the enterprises. Comprehensive utilization of coal washer tailings is one of the key issues of environmental protection and energy saving in China.

  13. Method for reducing NOx during combustion of coal in a burner

    DOEpatents

    Zhou, Bing; Parasher, Sukesh; Hare, Jeffrey J.; Harding, N. Stanley; Black, Stephanie E.; Johnson, Kenneth R.

    2008-04-15

    An organically complexed nanocatalyst composition is applied to or mixed with coal prior to or upon introducing the coal into a coal burner in order to catalyze the removal of coal nitrogen from the coal and its conversion into nitrogen gas prior to combustion of the coal. This process leads to reduced NOx production during coal combustion. The nanocatalyst compositions include a nanoparticle catalyst that is made using a dispersing agent that can bond with the catalyst atoms. The dispersing agent forms stable, dispersed, nano-sized catalyst particles. The catalyst composition can be formed as a stable suspension to facilitate storage, transportation and application of the catalyst nanoparticles to a coal material. The catalyst composition can be applied before or after pulverizing the coal material or it may be injected directly into the coal burner together with pulverized coal.

  14. Revised users manual, Pulverized Coal Gasification or Combustion: 2-dimensional (87-PCGC-2): Final report, Volume 2. [87-PCGC-2

    SciTech Connect

    Smith, P.J.; Smoot, L.D.; Brewster, B.S.

    1987-12-01

    A two-dimensional, steady-state model for describing a variety of reactive and non-reactive flows, including pulverized coal combustion and gasification, is presented. Recent code revisions and additions are described. The model, referred to as 87-PCGC-2, is applicable to cylindrical axi-symmetric systems. Turbulence is accounted for in both the fluid mechanics equations and the combustion scheme. Radiation from gases, walls, and particles is taken into account using either a flux method or discrete ordinates method. The particle phase is modeled in a Lagrangian framework, such that mean paths of particle groups are followed. Several multi-step coal devolatilization schemes are included along with a heterogeneous reaction scheme that allows for both diffusion and chemical reaction. Major gas-phase reactions are modeled assuming local instantaneous equilibrium, and thus the reaction rates are limited by the turbulent rate mixing. A NO/sub x/ finite rate chemistry submodel is included which integrates chemical kinetics and the statistics of the turbulence. The gas phase is described by elliptic partial differential equations that are solved by an iterative line-by-line technique. Under-relaxation is used to achieve numerical stability. The generalized nature of the model allows for calculation of isothermal fluid mechanicsgaseous combustion, droplet combustion, particulate combustion and various mixtures of the above, including combustion of coal-water and coal-oil slurries. Both combustion and gasification environments are permissible. User information and theory are presented, along with sample problems. 106 refs.

  15. Char crystalline transformations during coal combustion and their implications for carbon burnout

    SciTech Connect

    Hurt, R.H.

    1999-03-11

    Residual, or unburned carbon in fly ash affects many aspects of power plant performance and economy including boiler efficiency, electrostatic precipitator operation, and ash as a salable byproduct. There is a large concern in industry on the unburned carbon problem due to a variety of factors, including low-NOx combustion system and internationalization of the coal market. In recent work, it has been found that residual carbon extracted from fly ash is much less reactive than the laboratory chars on which the current kinetics are based. It has been suggested that thermal deactivation at the peak temperature in combustion is a likely phenomenon and that the structural ordering is one key mechanism. The general phenomenon of carbon thermal annealing is well known, but there is a critical need for more data on the temperature and time scale of interest to combustion. In addition, high resolution transmission electron microscopy (HRTEM) fringe imaging, which provides a wealth of information on the nature and degree of crystallinity in carbon materials such as coal chars, has become available. Motivated by these new developments, this University Coal Research project has been initiated with the following goals: to determine transient, high-temperature, thermal deactivation kinetics as a function of parent coal and temperature history; and to characterize the effect of this thermal treatment on carbon crystalline structure through high-resolution transmission electron microscopy and specialized, quantitative image analysis.

  16. EFFECTS OF COFIRING LIGNIN AND BIOSOLIDS WITH COAL ON FIRESIDE PERFORMANCE AND COMBUSTION PRODUCTS

    SciTech Connect

    Kevin C. Galbreath

    2002-08-01

    Lignin, derived from municipal solid waste and biosolid feedstocks using Masada Resource Group's patented CES OxyNol{trademark} process, and acidified biosolids were evaluated as supplemental fuels with coal for producing steam and electricity. Tests were conducted in a pilot-scale (550,000-Btu/hr [580-MJ/hr]) combustion system to evaluate the effects of coal characteristics, blend mixture (on a dry wt% basis) and furnace exit gas temperature (FEGT) on boiler heat-exchange surface slagging and fouling, NO{sub x} and SO{sub x} production, fly ash characteristics, and combustion efficiency. The effects of blending lignin and acidified biosolids with coal on fuel handling and pulverization characteristics were also addressed. An 80 wt% Colorado--20 wt% subbituminous Powder River Basin coal blend from the Tennessee Valley Authority Colbert Steam Plant, hereafter referred to as the Colbert coal, and a bituminous Pittsburgh No. 8 coal were tested. The lignin and acidified biosolids were characterized by possessing higher moisture content and lower carbon, hydrogen, and heating values relative to the coals. Ash contents of the fuels were similar. The lignin also possessed higher concentrations of TiO{sub 2}, CaO, and SO{sub 3} and lower concentrations of SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}, K{sub 2}O, and N relative to the coals. The sulfur content of lignin could be reduced through a more thorough washing and drying of the lignin in an efficient commercial-scale dewatering device. Acidified biosolids were distinguished by higher concentrations of P{sub 2}O{sub 5} and MgO and lower SiO{sub 2} and Al{sub 2}O{sub 3} relative to the other fuels. Trace element concentrations, especially for Cr, Pb, Hg, and Ni, were generally greater in the lignin and acidified biosolid fuels relative to the Colbert coal. Maximum trace element emission factors were calculated for 95:5 Colbert coal--lignin and 90:5:5 Colbert coal--lignin--acidified biosolid blends and compared to U

  17. Characterization of feed coal and coal combustion products from power plants in Indiana and Kentucky

    SciTech Connect

    Brownfield, M.E.; Affolter, R.H.; Cathcart, J.D.; O'Connor, J.T.; Brownfield, I.K.

    1999-07-01

    The US Geological Survey, Kentucky Geological Survey, and the University of Kentucky Center for Applied Energy Research are collaborating with Indiana and Kentucky utilities to determine the physical and chemical properties of feed coal and coal combustion products (CCP) from three coal-fired power plants. These three plants are designated as Units K1, K2, and I1 and burn high-, moderate-, and low-sulfur coals, respectively. Over 200 samples of feed coal and CCP were analyzed by various chemical and mineralogical methods to determine mode of occurrence and distribution of trace elements in the CCP. Generally, feed coals from all 3 Units contain mostly well-crystallized kaolinite and quartz. Comparatively, Unit K1 feed coals have higher amounts of carbonates, pyrite and sphalerite. Unit K2 feed coals contain higher kaolinite and illite/muscovite when compared to Unit K1 coals. Unit I1 feed coals contain beta-form quartz and alumino-phosphates with minor amounts of calcite, micas, anatase, and zircon when compared to K1 and K2 feed coals. Mineralogy of feed coals indicate that the coal sources for Units K1 and K2 are highly variable, with Unit K1 displaying the greatest mineralogic variability; Unit I1 feed coal however, displayed little mineralogic variation supporting a single source. Similarly, element contents of Units K1 and K2 feed coals show more variability than those of Unit I1. Fly ash samples from Units K1 and K2 consist mostly of glass, mullite, quartz, and spines group minerals. Minor amounts of illite/muscovite, sulfates, hematite, and corundum are also present. Spinel group minerals identified include magnetite, franklinite, magnesioferrite, trevorite, jacobisite, and zincochromite. Scanning Electron Microscope analysis reveals that most of the spinel minerals are dendritic intergrowths within aluminum silicate glass. Unit I1 fly ash samples contain glass, quartz, perovskite, lime, gehlenite, and apatite with minor amounts of periclase, anhydrite

  18. Dry low combustion system with means for eliminating combustion noise

    DOEpatents

    Verdouw, Albert J.; Smith, Duane; McCormick, Keith; Razdan, Mohan K.

    2004-02-17

    A combustion system including a plurality of axially staged tubular premixers to control emissions and minimize combustion noise. The combustion system includes a radial inflow premixer that delivers the combustion mixture across a contoured dome into the combustion chamber. The axially staged premixers having a twist mixing apparatus to rotate the fluid flow and cause improved mixing without causing flow recirculation that could lead to pre-ignition or flashback.

  19. Development and testing of industrial scale coal fired combustion systems, Phase 3. Sixth quarterly technical progress report, April 1, 1993--June 30, 1993

    SciTech Connect

    Zauderer, B.

    1993-09-22

    The most significant effort in the quarter was the completion of the conversion of the exit nozzle from adiabatic operation to air cooled operation. This conversion was implemented midway in the task 2 test effort, and the final two tests in task 2 were with the cooled nozzle. It performed as per design. The second significant result was the successful implementation of a computer controlled combustor wall cooling procedure. The hot side combustor liner temperature can now be maintained within a narrow range of less than 5OF at the nominal wall temperature of 2000F. This is an essential requirement for long term durability of the combustor wall. The first tests with the computer control system were implemented in June 1993. A third development in this period was the decision to replace the coal feeder that had been in use since coal fired operation began in late 1987. Since that time, this commercial device has been modified numerous times in order to achieve uniform coal feed. Uniform feed was achieved in 1991. However, the feeder operation was not sufficiently reliable for commercial use. The new feeder has the same design as the sorbent feeders that have been successfully used since 1987. This design has much better speed control and it can be rapidly restarted when the feed auger becomes jammed with tramp material. The last task 2 test was a long duration coal fired test with almost 12 hours of coal fired operation until the 4 ton coal bin was empty. It was the longest coal firing period of the task 2 tests. The exit nozzle cooling maintained the wall temperature in the desired operating range.

  20. Characterization of organic aerosol produced during pulverized coal combustion in a drop tube furnace

    NASA Astrophysics Data System (ADS)

    Wang, X.; Williams, B. J.; Wang, X.; Tang, Y.; Huang, Y.; Kong, L.; Yang, X.; Biswas, P.

    2013-11-01

    Controlled bench scale pulverized coal combustion studies were performed, demonstrating that inorganic particles play a critical role as carriers of organic species. Two commonly-used aerosol mass spectrometry techniques were applied to characterize fine particle formation during coal combustion. It was found that the organic species in coal combustion aerosols have mass spectra similar to those generated by biomass combustion. Ambient measurements in Shanghai, China confirm the presence of these species in approximately 29-38% of the sampled particles. With the absence of major biomass sources in the Shanghai area, it is suggested that coal combustion may be the main source of these particles. This work indicates there is a significant potential for incorrect apportionment of coal combustion particles to biomass burning sources using widely adopted mass spectrometry techniques.

  1. Characterization of organic aerosol produced during pulverized coal combustion in a drop tube furnace

    NASA Astrophysics Data System (ADS)

    Wang, X.; Williams, B. J.; Wang, X.; Tang, Y.; Huang, Y.; Kong, L.; Yang, X.; Biswas, P.

    2013-02-01

    Controlled bench scale pulverized coal combustion studies were performed that demonstrate that inorganic particles play a critical role as carrier of organic species. Two commonly-used aerosol mass spectrometry techniques have been applied to characterize fine particle formation during coal combustion. It was found that the organic species in coal combustion aerosols have similar mass spectra as those from biomass combustion. Ambient measurements in Shanghai, China confirm the presence of these species in approximately 36~42% of the sampled particles. With the absence of major biomass sources in the Shanghai area, it is suggested that coal combustion may be the main source of these particles. This work indicates there is a significant potential for incorrect apportionment of coal combustion particles to biomass burning sources using widely adopted mass spectrometry techniques.

  2. Behavior of sulfur and chlorine in coal during combustion and boiler corrosion. Technical report, December 1, 1991--February 29, 1992

    SciTech Connect

    Chou, C.L.; Hackley, K.C.; Donnals, G.L.; Cao, J.; Ruch, R.R.; Pan, W.P.; Shao, D.

    1992-08-01

    The goal of this project is to study the evolution of gaseous sulfur and chlorine species during temperature-controlled pyrolysis and combustion and their effect on boiler corrosion. We have been developing two techniques for determining the gas evolution profiles of sulfur and chlorine during coal pyrolysis and combustion. First, using a pyrolysis-combustion system in combination with a quadrupole gas analyzer, the evolution of sulfur dioxide (SO{sub 2}) in combustion gas during temperature-programmed coal pyrolysis-combustion was monitored. When the atmosphere of the combustion chamber was changed to a reducing condition, gaseous COS and H{sub 2}S were also detected in the combustion gas. Detection of hydrogen chloride by QGA has been improved by using a larger-diameter (75 {mu}m) capillary tubing. The HC1 evolution profile during the pyrolysis of coal IBC-109 was determined by QGA and by a chloride ion selective electrode for quantitative purposes. Second, the technique of thermogravimetry (TG) in conjunction with Fourier transform infrared (FTIR) spectroscopy was used to characterize gaseous species during coal pyrolysis. Gas evolution profiles of sulfur (SO{sub 2} and COS), chlorine (HC1), and nitrogen (NH{sub 3} and HCN) species were determined for coal IBC-109. Similar release profiles of HCI and NH{sub 3} supported an interpretation that chlorine gnd nitrogen are closely associated in coal. COS may be formed by reaction of CO with H{sub 2}S in the gas phase. A mass balance study of chlorine evolution from coal IBC-109 in a TG-FTIR experiment was completed; the chloride dissolved in solutions was determined by an ion chromatographic technique.

  3. Boron as a tracer of aerosol from combustion of coal

    NASA Astrophysics Data System (ADS)

    Fogg, Thomas R.; Rahn, Kenneth A.

    1984-09-01

    Atmospheric boron was found to be predominantly gaseous in ambient samples and in stacks of coal-fired power plants. Typical gas/particulate ratios ranged from 20 to more than 100, with stack ratios above 100 and ambient ratios generally below 100. In the stacks, B/SO2 ratios were lower than expected from bulk U.S. coals, consistent with volatilization of 20-80 percent of the boron during combustion. Midwestern ambient B/SO2 ratios were at or above stack values, with the lowest ratios associated with highest concentrations. SO2 was always more variable than gaseous boron. These observations are consistent with coal combustion as the major source of atmospheric boron (and SO2) in the Midwest. In northern Vermont, concentrations of gaseous boron and SO2 were several times lower than in the Midwest, but the B/SO2 ratio was several times higher. Both species passed through quasiweekly in-phase cycles of concentration with the relative amplitudes being greater for SO2 than for gaseous boron. All major pulses of boron and SO2 came from the direction of the Midwest, on the backsides of high-pressure areas. Since the ocean is also a source of gaseous boron, its anthropogenic tracer potential for acid deposition studies will be most useful in the interior of continents.

  4. CONTROL OF TRACE METAL EMISSIONS DURING COAL COMBUSTION

    SciTech Connect

    THOMAS C. HO

    1998-02-18

    Emissions of toxic trace metals in the form of metal fumes or submicron particulates from a coal-fired combustion source have received greater environmental and regulatory concern over the past years. Current practice of controlling these emissions is to collect them at the cold-end of the process by air-pollution control devices (APCDs) such as electrostatic precipitators and baghouses. However, trace metal fumes may not always be effectively collected by these devices because the formed fumes are extremely small. The proposed research is to explore the opportunities for improved control of toxic trace metal emissions, alternatively, at the hot-end of the coal combustion process, i.e., in the combustion chamber. The technology proposed is to prevent the metal fumes from forming during the process, which would effectively eliminate the metal emission problems. Specifically, the technology is to employ suitable sorbents to (1) reduce the amount of metal volatilization during combustion and (2) capture volatilized metal vapors. The objectives of the project are to demonstrate the technology and to characterize the metal capture process during coal combustion in a fluidized bed combustor. This final technical report details the work performed, the conclusions obtained, and the accomplishments achieved over the project performance period from July 1, 1994 through December 31, 1997. Specifically, this report consists of the following five chapters: Chapter 1. Executive Summary; Chapter 2. Metal Capture by Various Sorbents; Chapter 3. Simultaneous Metal and Sulfur Capture; Chapter 4. Sorption and Desorption of Mercury on Sorbents; and Chapter 5. Project Conclusions. In summary, the metals involved in the project were arsenic, cadmium, chromium, lead, mercury and selenium and the sorbents tested included bauxite, zeolite and calcined limestone. The three sorbents have been found to have various degree of metal capture capability on arsenic, cadmium, chromium and lead

  5. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    SciTech Connect

    Harold H. Schobert; M. Mercedes Maroto-Valer; Zhe Lu

    2003-09-30

    The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, the principal objective of this work was to characterize and utilize the unburned carbon in fly ash for the production of activated carbons. The unburned carbon samples were collected from different combustion systems, including pulverized utility boilers, a utility cyclone, a stoker, and a fluidized bed combustor. LOI (loss-on-ignition), proximate, ultimate, and petrographic analyses were conducted, and the surface areas of the samples were characterized by N2 adsorption isotherms at 77K. The LOIs of the unburned carbon samples varied between 21.79-84.52%. The proximate analyses showed that all the samples had very low moisture contents (0.17 to 3.39 wt %), while the volatile matter contents varied between 0.45 to 24.82 wt%. The elemental analyses show that all the unburned carbon samples consist mainly of carbon with very little hydrogen, nitrogen, sulfur and oxygen In addition, the potential use of unburned carbon as precursor for activated carbon (AC) was investigated. Activated carbons with specific surface area up to 1075m{sup 2}/g were produced from the unburned carbon. The porosity of the resultant activated carbons was related to the properties of the unburned carbon feedstock and the activation conditions used. It was found that not all the unburned carbon samples are equally suited for activation, and furthermore, their potential as activated carbons precursors could be

  6. Combustion pinhole camera system

    DOEpatents

    Witte, Arvel B.

    1984-02-21

    A pinhole camera system utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor.

  7. Combustion pinhole camera system

    DOEpatents

    Witte, A.B.

    1984-02-21

    A pinhole camera system is described utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor. 2 figs.

  8. Historical releases of mercury to air, land, and water from coal combustion.

    PubMed

    Streets, David G; Lu, Zifeng; Levin, Leonard; Ter Schure, Arnout F H; Sunderland, Elsie M

    2017-09-28

    Coal combustion is one of the largest contemporary sources of anthropogenic mercury (Hg). It releases geologically sequestered Hg to the atmosphere, and fly ash can contaminate terrestrial and aquatic systems. We estimate that coal combustion has released a cumulative total of 38.0 (14.8-98.9, 80% C.I.) Gg (gigagrams, 10(9)g or thousand tonnes) of Hg to air, land, and water up to the year 2010, most of which (97%) has occurred since 1850. The rate of release has grown by two orders of magnitude from 0.01Ggyr(-1) in 1850 to 1Ggyr(-1) in 2010. Geographically, Asia and Europe each account for 32% of cumulative releases and an additional 18% is from North America. About 26.3 (10.2-68.3) Gg, 71% of the total, were directly emitted to the atmosphere, mostly from the industrial (45%) and power generation (36%) sectors, while the remainder was disposed of to land and water bodies. While Europe and North America were the major contributing regions until 1950, Asia has surpassed both in recent decades. By 2010, Asia was responsible for 69% of the total releases of Hg from coal combustion to the environment. Control technologies installed on major emitting sources capture mainly particulate and divalent Hg, and therefore the fraction of elemental Hg in emissions from coal combustion has increased over time from 0.46 in 1850 to 0.61 in 2010. About 11.8 (4.6-30.6) Gg of Hg, 31% of the total, have been transferred to land and water bodies through the disposal or utilization of Hg-containing combustion waste and collected fly ash/FGD waste; approximately 8.8Gg of this Hg have simply been discarded to waste piles or ash ponds or rivers. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

    SciTech Connect

    Adams, Bradley; Davis, Kevin; Senior, Constance; Shim, Hong Shim; Otten, Brydger Van; Fry, Andrew; Wendt, Jost; Eddings, Eric; Paschedag, Alan; Shaddix, Christopher; Cox, William; Tree, Dale

    2013-09-30

    Reaction Engineering International (REI) managed a team of experts from University of Utah, Siemens Energy, Praxair, Vattenfall AB, Sandia National Laboratories, Brigham Young University (BYU) and Corrosion Management Ltd. to perform multi-scale experiments, coupled with mechanism development, process modeling and CFD modeling, for both applied and fundamental investigations. The primary objective of this program was to acquire data and develop tools to characterize and predict impacts of CO{sub 2} flue gas recycle and burner feed design on flame characteristics (burnout, NO{sub x}, SO{sub x}, mercury and fine particle emissions, heat transfer) and operational concerns (fouling, slagging and corrosion) inherent in the retrofit of existing coal-fired boilers for oxy-coal combustion. Experimental work was conducted at Sandia National Laboratories’ Entrained Flow Reactor, the University of Utah Industrial Combustion Research Facility, and Brigham Young University. Process modeling and computational fluid dynamics (CFD) modeling was performed at REI. Successful completion of the project objectives resulted in the following key deliverables: 1) Multi-scale test data from 0.1 kW bench-scale, 100 kW and 200 kW laboratory-scale, and 1 MW semi-industrial scale combustors that describe differences in flame characteristics, fouling, slagging and corrosion for coal combustion under air-firing and oxygen-firing conditions, including sensitivity to oxy-burner design and flue gas recycle composition. 2) Validated mechanisms developed from test data that describe fouling, slagging, waterwall corrosion, heat transfer, char burnout and sooting under coal oxy-combustion conditions. The mechanisms were presented in a form suitable for inclusion in CFD models or process models. 3) Principles to guide design of pilot-scale and full-scale coal oxy-firing systems and flue gas recycle configurations, such that boiler operational impacts from oxy-combustion retrofits are minimized. 4

  10. Catalysts for cleaner combustion of coal, wood and briquettes sulfur dioxide reduction options for low emission sources

    SciTech Connect

    Smith, P.V.

    1995-12-31

    Coal fired, low emission sources are a major factor in the air quality problems facing eastern European cities. These sources include: stoker-fired boilers which feed district heating systems and also meet local industrial steam demand, hand-fired boilers which provide heat for one building or a small group of buildings, and masonary tile stoves which heat individual rooms. Global Environmental Systems is marketing through Global Environmental Systems of Polane, Inc. catalysts to improve the combustion of coal, wood or fuel oils in these combustion systems. PCCL-II Combustion Catalysts promotes more complete combustion, reduces or eliminates slag formations, soot, corrosion and some air pollution emissions and is especially effective on high sulfur-high vanadium residual oils. Glo-Klen is a semi-dry powder continuous acting catalyst that is injected directly into the furnace of boilers by operating personnel. It is a multi-purpose catalyst that is a furnace combustion catalyst that saves fuel by increasing combustion efficiency, a cleaner of heat transfer surfaces that saves additional fuel by increasing the absorption of heat, a corrosion-inhibiting catalyst that reduces costly corrosion damage and an air pollution reducing catalyst that reduces air pollution type stack emissions. The reduction of sulfur dioxides from coal or oil-fired boilers of the hand fired stoker design and larger, can be controlled by the induction of the Glo-Klen combustion catalyst and either hydrated lime or pulverized limestone.

  11. Co-firing a pressurized fluidized-bed combustion system with coal and refuse derived fuels and/or sludges. Task 16

    SciTech Connect

    DeLallo, M.; Zaharchuk, R.

    1994-01-01

    The co-firing of waste materials with coal in utility scale power plants has emerged as an effective approach to produce energy and manage municipal waste. Leading this approach, the atmospheric fluidized-bed combustor (AFBC) has demonstrated its commercial acceptance in the utility market as a reliable source of power burning a variety of waste and alternative fuels. The fluidized bed, with its stability of combustion, reduces the amount of thermochemical transients and provides for easier process control. The application of pressurized fluidized-bed combustor (PFBC) technology, although relatively new, can provide significant enhancements to the efficient production of electricity while maintaining the waste management benefits of AFBC. A study was undertaken to investigate the technical and economic feasibility of co-firing a PFBC with coal and municipal and industrial wastes. Focus was placed on the production of electricity and the efficient disposal of wastes for application in central power station and distributed locations. Wastes considered for co-firing include municipal solid waste (MSW), tire-derived fuel (TDF), sewage sludge, and industrial de-inking sludge. Issues concerning waste material preparation and feed, PFBC operation, plant emissions, and regulations are addressed. This paper describes the results of this investigation, presents conclusions on the key issues, and provides recommendations for further evaluation.

  12. AOI 1— COMPUTATIONAL ENERGY SCIENCES:MULTIPHASE FLOW RESEARCH High-fidelity multi-phase radiation module for modern coal combustion systems

    SciTech Connect

    Modest, Michael

    2013-11-15

    The effects of radiation in particle-laden flows were the object of the present research. The presence of particles increases optical thickness substantially, making the use of the “optically thin” approximation in most cases a very poor assumption. However, since radiation fluxes peak at intermediate optical thicknesses, overall radiative effects may not necessarily be stronger than in gas combustion. Also, the spectral behavior of particle radiation properties is much more benign, making spectral models simpler (and making the assumption of a gray radiator halfway acceptable, at least for fluidized beds when gas radiation is not large). On the other hand, particles scatter radiation, making the radiative transfer equation (RTE) much more di fficult to solve. The research carried out in this project encompassed three general areas: (i) assessment of relevant radiation properties of particle clouds encountered in fluidized bed and pulverized coal combustors, (ii) development of proper spectral models for gas–particulate mixtures for various types of two-phase combustion flows, and (iii) development of a Radiative Transfer Equation (RTE) solution module for such applications. The resulting models were validated against artificial cases since open literature experimental data were not available. The final models are in modular form tailored toward maximum portability, and were incorporated into two research codes: (i) the open-source CFD code OpenFOAM, which we have extensively used in our previous work, and (ii) the open-source multi-phase flow code MFIX, which is maintained by NETL.

  13. Development and testing of industrial scale, coal-fired combustion system, Phase 3. Seventeenth quarterly technical progress report, January 1, 1996--March 31, 1996

    SciTech Connect

    Zauderer, B.

    1996-04-07

    In the first quarter of calendar year 1996, 9 days of combust-boiler tests were performed. Between these tests, modifications and improvements that were indicated by these tests were implemented. In January and early February, the modifications and installations indicated by the 6 days of testing in December 1995 were implemented. This was followed by 6 additional consecutive test days in mid- February. This was in turn followed by additional modifications, followed by a series of 3 one day, coal fired tests at end of March. These latter tests were the first ones in which slagging conditions were achieved in the combustor. The maximum thermal input was 13 MMBtu/hr, which equals two-thirds of the rated boiler heat input. The measured thermal, combustion, and slagging performance achieved in the combustor was superior to that achieved in the final series of tests conducted in Williamsport in 1993. The combustor-boiler facility is now ready for implementation of the task 5 site demonstration.

  14. Kinetics of coal combustion: Part 3, Mechanisms and kinetics of char combustion

    SciTech Connect

    Gavalas, G. R.; Flagan, R. C.

    1988-09-01

    This report summarizes a three-year research program aimed at developing this level of understanding of char combustion through a combination of detailed analysis of chars as produced during devolatilization and as they evolve during oxidation, and theoretical studies of the porous microstructures and of pore diffusion and reaction within the coal particles. A small number of coals have been studied in detail, namely a HVA bituminous (PSOC 1451), a sub-bituminous (PSOC 1488), and a lignite (PSOC 1443). Chars have been generated from size-classified samples of these coals by pyrolysis in an inert atmosphere in a drop tube furnace. The chars were then characterized both chemically and physically. Subsequent oxidation studies were performed on these chars. 42 refs., 54 figs., 4 tabs.

  15. Combustion of volatile matter during the initial stages of coal combustion

    SciTech Connect

    Marlow, D.; Niksa, S.; Kruger, C.H.

    1990-08-01

    Both the secondary pyrolysis and combustion of the volatiles from a bituminous coal will be studied. Devolatilization and secondary pyrolysis experiments will be conducted in a novel flow reactor in which secondary pyrolysis of the volatiles occurs after devolatilization is complete. This allows unambiguous measurements of the yields from both processes. Measurements will be made for reactor temperatures from 1500 to 1700 K, and a nominal residence time of 200 msec. These conditions are typical of coal combustion. Yields of tar, soot, H{sub 2}, CO, CH{sub 4}, and C{sub 2} and C{sub 3} hydrocarbons will be determined as a function of reactor temperature. The yields will be reported as a function of the temperature of the reactor. The instrumentation for temperature measurements will be developed during future studies. Combustion studies will be conducted in a constant volume bomb, which will be designed and constructed for this study. Tar and soot will be removed before introducing the volatiles to the bomb, so that only the combustion of the light gas volatiles will be considered. The burning velocities of light gas volatiles will be determined both as functions of mixture stoichiometry and the temperature at which the volatiles are pyrolysed. 90 refs., 70 figs., 13 tabs.

  16. Examination of bleederless ventilation practices for spontaneous combustion control in US coal mines

    SciTech Connect

    Organiscak, J.A.; Smith, A.C.; Diamond, W.P.; Mucho, T.P.

    1995-12-31

    The U.S. Bureau of Mines examined bleederless ventilation practices to evaluate their use as a spontaneous combustion control measure in U.S. coal mines. Results indicate that restricting airflow into mined-out areas (bleederless ventilation) is recognized worldwide as a spontaneous combustion control measure. However, ventilation practices commonly used to limit airflow to mined-out areas are not easily applicable to United States mining conditions, systems, experience and regulations. The types of bleederless ventilation systems used throughout the world and the spontaneous combustion risks associated with these systems are discussed. Primary design considerations for bleederless ventilation consist of the interaction of ventilation practices, methane drainage, ground control, seal construction and mine monitoring. Technological improvements needed for U.S. application of bleederless ventilation are also discussed.

  17. Coal combustion science: Task 1, Coal char combustion: Task 2, Fate of mineral matter. Quarterly progress report, July--September 1993

    SciTech Connect

    Hardesty, D.R.; Hurt, R.H.; Davis, K.A.; Baxter, L.L.

    1994-07-01

    Progress reports are presented for the following tasks: (1) kinetics and mechanisms of pulverized coal char combustion and (2) fate of inorganic material during coal combustion. The objective of Task 1 is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. In Sandia`s Coal Combustion Laboratory (CCL), optical techniques are used to obtain high-resolution images of individual burning coal char particles and to measure, in situ, their temperatures, sizes, and velocities. Detailed models of combustion transport processes are then used to determine kinetic parameters describing the combustion behavior as a function of coal type and combustion environment. Partially reacted char particles are also sampled and characterized with advanced materials diagnostics to understand the critical physical and chemical transformations that influence reaction rates and burnout times. The ultimate goal of the task is the establishment of a data base of the high temperature reactivities of chars from strategic US coals, from which important trends may be identified and predictive capabilities developed. The overall objectives for task 2 are: (1) to complete experimental and theoretical investigation of ash release mechanisms; (2) to complete experimental work on char fragmentation; (3) to establish the extent of coal (as opposed to char) fragmentation as a function of coal type and particle size; (4) to develop diagnostic capabilities for in situ, real-time, qualitative indications of surface species composition during ash deposition, with work continuing into FY94; (5) to develop diagnostic capabilities for in situ, real-time qualitative detection of inorganic vapor concentrations; and (6) to conduct a literature survey on the current state of understanding of ash deposition, with work continuing into FY94.

  18. Modeling of pulverized coal combustion in cement rotary kiln

    SciTech Connect

    Shijie Wang; Jidong Lu; Weijie Li; Jie Li; Zhijuan Hu

    2006-12-15

    In this paper, based on analysis of the chemical and physical processes of clinker formation, a heat flux function was introduced to take account of the thermal effect of clinker formation. Combining the models of gas-solid flow, heat and mass transfer, and pulverized coal combustion, a set of mathematical models for a full-scale cement rotary kiln were established. In terms of commercial CFD code (FLUENT), the distributions of gas velocity, gas temperature, and gas components in a cement rotary kiln were obtained by numerical simulation of a 3000 t/d rotary kiln with a four-channel burner. The predicted results indicated that the improved model accounts for the thermal enthalpy of the clinker formation process and can give more insight (such as fluid flow, temperature, etc,) from within the cement rotary kiln, which is a benefit to better understanding of combustion behavior and an improvement of burner and rotary kiln technology. 25 refs., 12 figs., 5 tabs.

  19. Navajo Coal Combustion and Respiratory Health Near Shiprock, New Mexico

    DOE PAGES

    Bunnell, Joseph E.; Garcia, Linda V.; Furst, Jill M.; ...

    2010-01-01

    Indoormore » air pollution has been identified as a major risk factor for acute and chronic respiratory diseases throughout the world. In the sovereign Navajo Nation, an American Indian reservation located in the Four Corners area of the USA, people burn coal in their homes for heat. To explore whether/how indoor coal combustion might contribute to poor respiratory health of residents, this study examined respiratory health data, identified household risk factors such as fuel and stove type and use, analyzed samples of locally used coal, and measured and characterized fine particulate airborne matter inside selected homes. In twenty-five percent of homes surveyed coal was burned in stoves not designed for that fuel, and indoor air quality was frequently found to be of a level to raise concerns. The average winter 24-hour PM 2.5 concentration in 20 homes was 36.0  μ g/ m 3 . This is the first time that PM 2.5 has been quantified and characterized inside Navajo reservation residents' homes.« less

  20. Navajo Coal Combustion and Respiratory Health Near Shiprock, New Mexico

    PubMed Central

    Bunnell, Joseph E.; Garcia, Linda V.; Furst, Jill M.; Lerch, Harry; Olea, Ricardo A.; Suitt, Stephen E.; Kolker, Allan

    2010-01-01

    Indoor air pollution has been identified as a major risk factor for acute and chronic respiratory diseases throughout the world. In the sovereign Navajo Nation, an American Indian reservation located in the Four Corners area of the USA, people burn coal in their homes for heat. To explore whether/how indoor coal combustion might contribute to poor respiratory health of residents, this study examined respiratory health data, identified household risk factors such as fuel and stove type and use, analyzed samples of locally used coal, and measured and characterized fine particulate airborne matter inside selected homes. In twenty-five percent of homes surveyed coal was burned in stoves not designed for that fuel, and indoor air quality was frequently found to be of a level to raise concerns. The average winter 24-hour PM2.5 concentration in 20 homes was 36.0 μg/m3. This is the first time that PM2.5 has been quantified and characterized inside Navajo reservation residents' homes. PMID:20671946

  1. Combustion and fuel characterization of coal-water fuels

    SciTech Connect

    Chow, O.K.; Gralton, G.W.; Lachowicz, Y.V.; Laflesh, R.C.; Levasseur, A.A.; Liljedahl, G.N.

    1989-02-01

    This five-year research project was established to provide sufficient data on coal-water fuel (CWF) chemical, physical, and combustion properties to assess the potential for commercial firing in furnaces designed for gas or oil firing. Extensive laboratory testing was performed at bench-scale, pilot-scale (4 {times} 10{sup 6}Btu/hr) and commercial-scale (25 {times} 10{sup 6} to 50 {times} 10{sup 6}Btu/hr) on a cross-section of CWFs. Fuel performance characteristics were assessed with respect to coal properties, level of coal beneficiation, and slurry formulation. The performance of four generic burner designs was also assessed. Boiler performance design models were applied to analyze the impacts associated with conversion of seven different generic unit designs to CWF firing. Equipment modifications, operating limitations, and retrofit costs were determined for each design when utilizing several CWFs. Unit performance analyses showed significantly better load capacity for utility and industrial boilers as the CWF feed coal ash content is reduced to 5% or 2.6%. In general, utility units had more attractive capacity limits and retrofit costs than the industrial boilers and process heaters studied. Economic analyses indicated that conversion to CWF firing generally becomes feasible when differential fuel costs are above $1.00/10{sup 6}Btu. 60 figs., 24 tabs.

  2. Global environmental security implications of advanced coal combustion options

    SciTech Connect

    Moskowitz, P.D.; Lipfert, F.W.; Saroff, L.

    1996-12-31

    Global environmental security is of growing national and international concern. Demand and supply of energy is a contributor to many problems threatening global environmental security deforestation, decertification, climate change, stratospheric ozone depletion, water pollution, land contamination, and solid waste management. In this paper, costs and benefits of conventional and advanced energy supply options are characterized in terms of these security concerns. Special attention is focused on changes in fuel demands and operating characteristics of energy supply options. The specific circumstances under which advanced coal combustion options enhance environmental security will be qualitatively and quantitatively characterized.

  3. Pulverized coal combustion. Semi-annual report, October 1, 1981-March 31, 1982

    SciTech Connect

    Leslie, I.; Jost, M.; Kruger, C.H.

    1982-05-01

    A flow tube reactor for the study of the reactivity of pulverized coal under controlled conditions has been developed. The reactor system incorporates optical diagnostics as well as probe sampling techniques to measure the reactivity of coals with differing physical and chemical properties. The aim of the research is to provide fundamental data that can be used in the design and development of coal combustion systems. Two size ranges of pulverized Montana Rosebud and one size of Illinois No. 6 coal were burned in a 7.3% oxygen-containing Ar/N/sub 2/ atmosphere. Gas temperatures were between 1140 K and 1750 K. In addition several measurements were made of micropore volume using CO/sub 2/ adsorption at room temperature. Qualitative behavior of both coals at high gas temperatures is consistent with a two stage combustion mechanism: devolatilization followed by char burnout. Results for the low temperature cases are less easy to interpret. Despite the fact that both diffusion and heterogeneous chemical rates decrease with decreasing temperature, the reactivity rates in the low gas temperature environment are comparable to those in the high gas temperature. It is quite likely that devolatilization occurring over periods much longer than 20 msec contributes to this high reactivity. Physical and chemical measurements have been made on the raw and partially burned coal. Specific mircopore volume, specific internal surface area, particle size distribution, and chemical composition have been determined. No single measurement as yet explains the unexpectedly high reactivity rates for coals in the lower gas temperature environment.

  4. Combustion characteristics of fine-ground coal. Project 61052 quarterly technical report, June 1-August 31, 1981

    SciTech Connect

    1982-03-01

    This program consists of a research study to investigate the effect of coal particle size on the flame characteristics of pulverized coal. The purpose is to determine if fine grinding will allow replacement of oil by coal in some industrial applications. The Plant Engineering Development Department of General Motors Corporation (GM) and the Research and Development Staff of York-Shipley, Inc. (Y-S), a major boiler manufacturer, are assisting IGT in this effort. These companies have offered to donate time to the program as industrial consultants. Pulverized coal will be fired at about 2 million Btu/h (approximately 160 lb/h) in a special experimental furnace designed to collect data on the combustion and heat-transfer characteristics of flames. Combustion trials with No. 6 oil are also planned to allow for direct correlation with the coal combustion data. Some of the information to be obtained from this study will be a determination of how the flame heat release density, mass burning rate, flame temperatures, and heat-transfer characteristics change with fuel particle size (fineness of coal grinding). It will also be possible to directly compare these parameters from the various coal flames with comparable oil flames to determine the feasibility of substituting fine-ground pulverized coal flames for heavy-oil flames. Data will also be collected to allow for the correlation of the flue-gas pollutant emissions with the fuel characteristics. Progress included purchasing the major equipment for the coal milling system, coal selection, and preparation of the combustion facility.

  5. Corrosion performance of materials for advanced combustion systems

    SciTech Connect

    Natesan, K.; Yanez-Herrero, M.; Fornasieri, C.

    1993-12-01

    Conceptual designs of advanced combustion systems that utilize coal as a feedstock require high-temperature furnaces and heat transfer surfaces capable of operating at more elevated temperatures than those prevalent in current coal-fired power plants. The combination of elevated temperatures and hostile combustion environments necessitates development/application of advanced ceramic materials in these designs. This report characterizes the chemistry of coal-fired combustion environments over the wide temperature range that is of interest in these systems and discusses preliminary experimental results on several materials (alumina, Hexoloy, SiC/SiC, SiC/Si{sub 3}N{sub 4}/Si{sub 3}N{sub 4}, ZIRCONIA, INCONEL 677 and 617) with potential for application in these systems.

  6. Materials performance in advanced combustion systems

    SciTech Connect

    Natesan, K.

    1992-12-01

    A number of advanced technologies are being developed to convert coal into clean fuels for use as feedstock in chemical plants and for power generation. From the standpoint of component materials, the environments created by coal conversion and combustion in these technologies and their interactions with materials are of interest. The trend in the new or advanced systems is to improve thermal efficiency and reduce the environmental impact of the process effluents. This paper discusses several systems that are under development and identifies requirements for materials application in those systems. Available data on the performance of materials in several of the environments are used to examine the performance envelopes for materials for several of the systems and to identify needs for additional work in different areas.

  7. Soot, organics, and ultrafine ash from air- and oxy-fired coal combustion

    EPA Science Inventory

    This paper/presentation is concerned with determining the effects of oxy-combustion of coal on the composition of the ultrafine fly ash. To this end, a 10 W externally heated entrained flow furnace was modified to allow the combustion of pulverized coal in flames under practicall...

  8. Soot, organics and ultrafine ash from air- and oxy-fired coal combustion

    EPA Science Inventory

    This paper is concerned with determining the effects of oxy-combustion of coal on the composition of the ultrafine fly ash. To this end, a 10 W externally heated entrained flow furnace was modified to allow the combustion of pulverized coal in flames under practically relevant s...

  9. Pyrolysis of Compositions of Mixtures of Combustible Shales and Brown Coals Deposited in Belarus

    NASA Astrophysics Data System (ADS)

    Lishtvan, I. I.; Dudarchik, V. M.; Kraiko, V. M.; Belova, Yu. V.

    2013-11-01

    This paper presents the results of investigating the pyrolysis of compositions of mixtures of brown coals and combustible shales in a close-packed and a moving layer and the yield dynamics of the pyrolysis gas and resin. A comparative analysis of the quality of pyrolysis products obtained from combustible shales and brown coal and from their mixtures has been performed.

  10. Soot, organics, and ultrafine ash from air- and oxy-fired coal combustion

    EPA Science Inventory

    This paper/presentation is concerned with determining the effects of oxy-combustion of coal on the composition of the ultrafine fly ash. To this end, a 10 W externally heated entrained flow furnace was modified to allow the combustion of pulverized coal in flames under practicall...

  11. Study of spontaneous combustion coals by GC and GC-MS.

    PubMed

    Shu, X; Xu, J; Xu, J; Ge, L; Chen, D

    1996-06-01

    Organic geochemical characteristics of 3 Chinese spontaneous combustion coals have been carried out by means of GC and GC-MS analysis. It has been observed that more compounds with low to medium carbon number, such as terpenoids and others can be found in spontaneous combustion coals than in normal samples.

  12. 75 FR 64974 - Notice of Data Availability on Coal Combustion Residual Surface Impoundments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-21

    ... Coal Combustion Residual Surface Impoundments AGENCY: Environmental Protection Agency (EPA). ACTION... of Coal Combustion Residuals from Electric Utilities. The Agency is seeking public comment on how, if... consists of responses to Information Collection Requests that EPA sent to electric utilities on their...

  13. Volatilization behavior of Cd and Zn based on continuous emission measurement of flue gas from laboratory-scale coal combustion.

    PubMed

    Liu, J; Falcoz, Q; Gauthier, D; Flamant, G; Zheng, C Z

    2010-06-01

    The accumulation of toxic metals generated by coal-fired power stations presents a serious threat to the environment. The volatilization behavior of two representative metals (Cd and Zn), and the influence of temperature were investigated during coal combustion. An inductively coupled plasma atomic emission spectrometric (ICP-AES) method was developed to continuously measure the heavy metal concentrations quantitatively in flue gas under combustion conditions in order to track the metal release process. This continuous heavy metal analysis system was implemented by coupling it to two types of high temperature reactors: a bubbling fluidized bed reactor and a fixed bed reactor with diameter of 0.1 m and 0.08 m respectively. For the two metals considered in this study (Cd and Zn), the experimental setup was successfully used to continuously monitor the metal vaporization process during coal combustion independent of reactor design, and at different temperatures. Cd is more easily vaporized than Zn during coal combustion. Temperature significantly influences the metal vaporization process. In general, the higher the temperature, the higher the metal vaporization, although the vaporization is not proportional to temperature. In addition to the experimental study, a thermodynamic calculation was carried out to simulate the heavy metal speciation during coal combustion process. The theoretical volatilization tendency is consistent with the experiment. The thermodynamic calculation identified the formation of binary oxides retarding heavy metal vaporization.

  14. Emission control of sodium compounds and their formation mechanisms during coal combustion

    SciTech Connect

    Tsuyoshi Takuwa; Ichiro Naruse

    2007-07-01

    In order to control emissions of sodium compounds during coal combustion, the sorbent injection technology is tested during coal combustion. Kaolin is selected as the sorbent to absorb vapors of sodium compounds evolved from the coals. In the combustion experiments, the kaolin is physically mixed with coal. Two types of coal, which have the similar coal properties, are burned. Combustion tests are conducted, using an electrically heated drop tube furnace, to study effect of kaolin addition on the capture characteristics of sodium compounds. In order to elucidate fundamentals on transformation behaviors of sodium compounds during hydrogen-air combustion, chemical kinetic simulation by elementary reactions relating to sodium compounds is also performed, varying the reaction atmosphere. As a result, the kaolin can effectively capture the vapor of sodium compounds even during coal combustion. The capture efficiency depends on the coal type. The sodium compounds for the coals, which produce many fine particles with size of less than 1 {mu}m, tend to be effectively captured by the kaolin. According to the kinetic simulation of sodium species, difference of the reaction atmosphere affects occurrence species of sodium vapor. In the combustion region, the sodium compounds become metallic sodium vapor in any reaction atmospheres due to occurrence of the reducing radical species. HCl gas rather than SO{sub 2} gas plays an important role to transform gaseous sodium compounds. 44 refs., 8 figs., 3 tabs.

  15. Environmental indicators of the combustion of prospective coal water slurry containing petrochemicals.

    PubMed

    Dmitrienko, Margarita A; Nyashina, Galina S; Strizhak, Pavel A

    2017-09-15

    Negative environmental impact of coal combustion has been known to humankind for a fairly long time. Sulfur and nitrogen oxides are considered the most dangerous anthropogenic emissions. A possible solution to this problem is replacing coal dust combustion with that of coal water slurry containing petrochemicals (CWSP). Coal processing wastes and used combustible liquids (oils, sludge, resins) are promising in terms of their economic and energy yield characteristics. However, no research has yet been conducted on the environmental indicators of fuels based on CWSP. The present work contains the findings of the research of CO, CO2, NOx, SOx emissions from the combustion of coals and CWSPs produced from coal processing waste (filter cakes). It is demonstrated for the first time that the concentrations of dangerous emissions from the combustion of CWSPs (carbon oxide and dioxide), even when combustible heavy liquid fractions are added, are not worse than those of coal. As for the concentration of sulfur and nitrogen oxides, it is significantly lower for CWSPs combustion as compared to coals. The presented research findings illustrate the prospects of the wide use of CWSPs as a fuel that is cheap and beneficial, in terms of both energy output and ecology, as compared to coal. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Pressurized chemical-looping combustion of coal with an iron ore-based oxygen carrier

    SciTech Connect

    Xiao, Rui; Song, Min; Zhang, Shuai; Shen, Laihong; Song, Qilei; Lu, Zuoji

    2010-06-15

    Chemical-looping combustion (CLC) is a new combustion technology with inherent separation of CO{sub 2}. Most of the previous investigations on CLC of solid fuels were conducted under atmospheric pressure. A pressurized CLC combined cycle (PCLC-CC) system is proposed as a promising coal combustion technology with potential higher system efficiency, higher fuel conversion, and lower cost for CO{sub 2} sequestration. In this study pressurized CLC of coal with Companhia Valedo Rio Doce (CVRD) iron ore was investigated in a laboratory fixed bed reactor. CVRD iron ore particles were exposed alternately to reduction by 0.4 g of Chinese Xuzhou bituminous coal gasified with 87.2% steam/N{sub 2} mixture and oxidation with 5% O{sub 2} in N{sub 2} at 970 C. The operating pressure was varied between 0.1 MPa and 0.6 MPa. First, control experiments of steam coal gasification over quartz sand were performed. H{sub 2} and CO{sub 2} are the major components of the gasification products, and the operating pressure influences the gas composition. Higher concentrations of CO{sub 2} and lower fractions of CO, CH{sub 4}, and H{sub 2} during the reduction process with CVRD iron ore was achieved under higher pressures. The effects of pressure on the coal gasification rate in the presence of the oxygen carrier were different for pyrolysis and char gasification. The pressurized condition suppresses the initial coal pyrolysis process while it also enhances coal char gasification and reduction with iron ore in steam, and thus improves the overall reaction rate of CLC. The oxidation rates and variation of oxygen carrier conversion are higher at elevated pressures reflecting higher reduction level in the previous reduction period. Scanning electron microscope and energy-dispersive X-ray spectroscopy (SEM-EDX) analyses show that particles become porous after experiments but maintain structure and size after several cycles. Agglomeration was not observed in this study. An EDX analysis demonstrates

  17. STRUCTURE-BASED PREDICTIVE MODEL FOR COAL CHAR COMBUSTION

    SciTech Connect

    CHRISTOPHER M. HADAD; JOSEPH M. CALO; ROBERT H. ESSENHIGH; ROBERT H. HURT

    1999-01-13

    Significant progress continued to be made during the past reporting quarter on both major technical tasks. During the reporting period at OSU, computational investigations were conducted of addition vs. abstraction reactions of H, O(3 P), and OH with monocyclic aromatic hydrocarbons. The potential energy surface for more than 80 unique reactions of H, O ( 3 P), and OH with aromatic hydrocarbons were determined at the B3LYP/6-31G(d) level of theory. The calculated transition state barriers and reaction free energies indicate that the addition channel is preferred at 298K, but that the abstraction channel becomes dominant at high temperatures. The thermodynamic preference for reactivity with aromatic hydrocarbons increases in the order O(3 P) < H < OH. Abstraction from six-membered aromatic rings is more facile than abstraction from five-membered aromatic rings. However, addition to five-membered rings is thermodynamically more favorable than addition to six-membered rings. The free energies for the abstraction and addition reactions of H, O, and OH with aromatic hydrocarbons and the characteristics of the respective transition states can be used to calculate the reaction rate constants for these important combustion reactions. Experimental work at Brown University on the effect of reaction on the structural evolution of different chars (i.e., phenolic resin char and chars produced from three different coals) have been investigated in a TGA/TPD-MS system. It has been found that samples of different age of these chars appeared to lose their "memory" concerning their initial structures at high burn-offs. During the reporting period, thermal desorption experiments of selected samples were conducted. These spectra show that the population of low temperature oxygen surface complexes, which are primarily responsible for reactivity, are more similar for the high burn-off than for the low burn-off samples of different ages; i.e., the population of active sites are more

  18. Burning of suspended coal-water slurry droplet with oil as combustion additive. Final report

    SciTech Connect

    Yao, S.C.

    1984-10-01

    The combustion of single coal-water slurry droplet with oil as combustion additive (CWOM) has been studied. In this study, the droplet is suspended on a fine quartz fiber and is exposed to the hot combustion product of propane (C/sub 3/H/sub 8/) and air. The results are documented in a movie series. The combustion of CWOM with various combinations of concentrations are compared with that of coal-water slurry and water-oil mixture droplets. The combustion of coal-water slurry is enhanced significantly due to the presence of emulsified kerosene. The enhancement is also dependent upon the mixing procedure during preparation of CWOM. The presence of emulsified kerosene induces local boil-off and combustion that coal particles are splashed as fire works during the early evaporation stage of droplet heat-up. After particle splashing, blow-holes appear on the droplet surface. The popcorn and swelling phenomena usually occurred in coal-water-slurry combustion is greatly reduced. Significant combustion enhancement occurs with the use of kerosene in an amount of about 15 percent of the overall CWOM. This process of using kerosene as combustion additive may provide obvious advantage for the combustion of bituminous coal-water slurry. 4 references, 6 figures.

  19. NO reduction in decoupling combustion of biomass and biomass-coal blend

    SciTech Connect

    Li Dong; Shiqiu Gao; Wenli Song; Jinghai Li; Guangwen Xu

    2009-01-15

    Biomass is a form of energy that is CO{sub 2}-neutral. However, NOx emissions in biomass combustion are often more than that of coal on equal heating-value basis. In this study, a technology called decoupling combustion was investigated to demonstrate how it reduces NO emissions in biomass and biomass-coal blend combustion. The decoupling combustion refers to a two-step combustion method, in which fuel pyrolysis and the burning of char and pyrolysis gas are separated and the gas burns out during its passage through the burning-char bed. Tests in a quartz dual-bed reactor demonstrated that, in decoupling combustion, NO emissions from biomass and biomass-coal blends were both less than those in traditional combustion and that NO emission from combustion of blends of biomass and coal decreased with increasing biomass percentage in the blend. Co-firing rice husk and coal in a 10 kW stove manufactured according to the decoupling combustion technology further confirmed that the decoupling combustion technology allows for truly low NO emission as well as high efficiency for burning biomass and biomass-coal blends, even in small-scale stoves and boilers. 22 refs., 6 figs., 1 tab.

  20. Pressurized pulverized coal combustion combined cycle with high temperature heat exchanger

    SciTech Connect

    Ehlers, C.; Leithner, R.

    2000-07-01

    Among power plants based on coal combustion, a Pressurized Pulverized Coal Combustion Combined Cycle (PPCCCC) can achieve highest electrical efficiencies. This cycle is not yet state of the art as a reliable and sufficient system for gas cleaning from dust and alkaline compounds upstream of the gas turbine, which operates at inlet temperatures about 2,400 F, is still to be developed. Experience in fly ash precipitation can be derived from Circulating Fluidized Bed Combustion which--due to the sticky property of coal ash at higher temperatures--is restricted to temperatures below 1,700 F. At the Institute fur Warme- und Brennstofftechnik (IWBT) of the Technical University of Braunschweig a cycle has been developed that integrates a fly ash removal at these temperature into a combined cycle by means of a high temperature heat exchanger. The flue gas leaving the combustion chamber is cooled down in the heat exchanger before it is cleaned by means of ceramic filter candles. After that, the clean flue gas is heated up again in counterflow to the raw gas to drive the gas turbine. In this cycle, the heat exchanger provides acceptable temperatures for the gas cleaning. In a research project performed at the IWBT, a heat exchanger from ceramic material and the fly ash removal are tested in an atmospheric test facility. One goal of the test facility is to find out the maximum allowable operating temperature of the heat exchanger, concerning possible slagging and high temperature corrosion effects, according to the properties of the coal ash. Furthermore, the operation of the gas cleaning system in combination with the ceramic heat exchanger is investigated.

  1. Trace element emissions when firing pulverized coal in a pilot-scale combustion facility

    SciTech Connect

    Miller, S.F.; Wincek, R.T.; Miller, B.G.; Scaroni, A.W.

    1998-04-01

    Title Ed of the Clean Air Act Amendments of 1990 designates 189 hazardous air pollutants (HAPs). Fourteen of the 189 substances identified are: antimony (Sb), beryllium (Be), chlorine (0), cobalt (Co), manganese (Mn), nickel (Ni), selenium (Se), fluorine (F), arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and phosphorous (P). Eleven of these elements have been detected in the flue gas of pulverized coal-fired utility boilers. Currently there are no regulations that limit the emissions of these elements during coal combustion in utility- or industrial-scale boilers. Given the growing body of risk assessment data on these elements and their impact on the environment and human health, it is possible that regulations on emission levels for certain elements will be imposed. A knowledge of the occurrence of trace elements in coal and their behavior during combustion is essential to predict emissions and to develop control technologies for remediation. The partitioning of trace elements during combustion can be traced to their volatility within the system. For purposes of this paper, the classification of trace elements summarized by Clarke and Sloss will be used: Group I elements, i.e., elements that are not easily volatilized and form larger bottom ash and fly ash particles; Group H elements, i.e., elements that are partially or completely volatilization followed by condensation as small particles or on the surface of small particles; and Group III elements, i.e., elements that are readily volatilized and usually remain in the gas phase system.

  2. Fluorosis caused by indoor coal combustion in China: discovery and progress.

    PubMed

    Zheng, Baoshan; Wu, Daishe; Wang, Binbin; Liu, Xiaojing; Wang, Mingshi; Wang, Aimin; Xiao, Guisen; Liu, Pugao; Finkelman, Robert B

    2007-04-01

    In this study, investigations into endemic fluorosis were conducted and fluorine concentration in environmental samples determined. In an indoor coal-combustion-type fluorosis area, local clay was used to mix with coal for indoor combustion. There are two key steps in the procedure of the indoor transition of fluorine: indoor wet corns and vegetables strongly absorbed fluorine from indoor air; and fluorine strongly accumulated in clay, which was mixed with coal for combustion. Therefore, with the increasing of the percentage of clay in the clay-mixed coal as well as corn in foodstuff, the ratio of fluorosis will be increased.

  3. Co-combustion of different sewage sludge and coal: a non-isothermal thermogravimetric kinetic analysis.

    PubMed

    Otero, M; Calvo, L F; Gil, M V; García, A I; Morán, A

    2008-09-01

    The kinetics of the combustion of coal, two different sewage sludge and their blends (containing different dried weight percentages of sewage sludge) was studied by simultaneous thermogravimetric analysis. Once the weight percentage of sludge in the blend was 10%, the effects on the combustion of coal were hardly noticeable in terms of weight loss. The Arrhenius activation energy corresponding to the co-combustion of the blends was evaluated by non-isothermal kinetic analysis. This showed that, though differences between coal and sewage sludge, the combustion of their blends kept kinetically alike to that of the coal. This work illustrates how thermogravimetric analysis may be used as an easy rapid tool to asses, not only mass loss, but also kinetics of the co-combustion of sewage sludge and coal blends.

  4. Investigation on thermal and trace element characteristics during co-combustion biomass with coal gangue.

    PubMed

    Zhou, Chuncai; Liu, Guijian; Fang, Ting; Lam, Paul Kwan Sing

    2015-01-01

    The thermochemical behaviors during co-combustion of coal gangue (CG), soybean stalk (SS), sawdust (SD) and their blends prepared at different ratios have been determined via thermogravimetric analysis. The simulate experiments in a fixed bed reactor were performed to investigate the partition behaviors of trace elements during co-combustion. The combustion profiles of biomass was more complicated than that of coal gangue. Ignition property and thermal reactivity of coal gangue could be enhanced by the addition of biomass. No interactions were observed between coal gangue and biomass during co-combustion. The volatilization ratios of trace elements decrease with the increasing proportions of biomass in the blends during co-combustion. Based on the results of heating value, activation energy, base/acid ratio and gaseous pollutant emissions, the blending ratio of 20-30% biomass content is regarded as optimum composition for blending and could be applied directly at current combustion application with few modifications.

  5. Development of a coal-fired combustion system for industrial process heating applications. Phase 3 final report, November 1992--December 1994

    SciTech Connect

    1995-09-26

    A three phase research and development program has resulted in the development and commercialization of a Cyclone Melting System (CMS{trademark}), capable of being fueled by pulverized coal, natural gas, and other solid, gaseous, or liquid fuels, for the vitrification of industrial wastes. The Phase 3 research effort focused on the development of a process heater system to be used for producing value added glass products from the vitrification of boiler/incinerator ashes and industrial wastes. The primary objective of the Phase 3 project was to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential for successful commercialization. The demonstration test consisted of one test run with a duration of 105 hours, approximately one-half (46 hours) performed with coal as the primary fuel source (70% to 100%), the other half with natural gas. Approximately 50 hours of melting operation were performed vitrifying approximately 50,000 lbs of coal-fired utility boiler flyash/dolomite mixture, producing a fully-reacted vitrified product.

  6. Development of a coal-fired combustion system for industrial processing heating applications: Appendix A. Phase 3 final report, November 1992--December 1994

    SciTech Connect

    1995-09-26

    A three phase research and development program has resulted in the development and commercialization of a Cyclone Melting System (CMS{trademark}), capable of being fueled by pulverized coal, natural gas, and other solid, gaseous, or liquid fuels, for the vitrification of industrial wastes. The Phase 3 research effort focused on the development of a process heater system to be used for producing value added glass products from the vitrification of boiler/incinerator ashes and industrial wastes. The primary objective of the Phase 3 project was to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential for successful commercialization. The demonstration test consisted of one test run with a duration of 105 hours, approximately one-half (46 hours) performed with coal as the primary fuel source (70% to 100%), the other half with natural gas. Approximately 50 hours of melting operation were performed vitrifying approximately 50,000 lbs of coal-fired utility boiler flyash/dolomite mixture, producing a fully-reacted vitrified product. Appendix A contains 89 figures containing the data from the demonstration tests undertaken under Phase 3.

  7. Structure-Based Predictive model for Coal Char Combustion.

    SciTech Connect

    Hurt, R.; Colo, J; Essenhigh, R.; Hadad, C; Stanley, E.

    1997-09-24

    During the third quarter of this project, progress was made on both major technical tasks. Progress was made in the chemistry department at OSU on the calculation of thermodynamic properties for a number of model organic compounds. Modelling work was carried out at Brown to adapt a thermodynamic model of carbonaceous mesophase formation, originally applied to pitch carbonization, to the prediction of coke texture in coal combustion. This latter work makes use of the FG-DVC model of coal pyrolysis developed by Advanced Fuel Research to specify the pool of aromatic clusters that participate in the order/disorder transition. This modelling approach shows promise for the mechanistic prediction of the rank dependence of char structure and will therefore be pursued further. Crystalline ordering phenomena were also observed in a model char prepared from phenol-formaldehyde carbonized at 900{degrees}C and 1300{degrees}C using high-resolution TEM fringe imaging. Dramatic changes occur in the structure between 900 and 1300{degrees}C, making this char a suitable candidate for upcoming in situ work on the hot stage TEM. Work also proceeded on molecular dynamics simulations at Boston University and on equipment modification and testing for the combustion experiments with widely varying flame types at Ohio State.

  8. Combustion and fuel characterization of coal-water fuels

    SciTech Connect

    Beal, H.R.; Gralton, G.W.; Gronauer, T.W.; Liljedahl, G.N.; Love, B.F.

    1987-06-01

    Activities conducted under this contract include studies on the combustion and fireside behavior of numerous coal-water fuels (CWFs). The work has been broken down into the following areas: Task 1 -- Selection of Candidate Fuels; Task 2 -- Bench Scale Tests; Task 3 -- CWF Preparation and Supply; Task 4 -- Combustion Characterization; Task 5 -- Ash Deposition and Performance Testing; Task 6 -- Commercial Applications. This report covers Task 6, the study of commercial applications of CWFs as related to the technical and economic aspects of the conversion of existing boilers and heaters to CWF firing. This work involves the analysis of seven units of various sizes and configurations firing several selected CWFs. Three utility boilers, two industrial boilers, and two process heater designs are included. Each of the units was considered with four primary selected CWFs. A fifth fuel was considered for one of the utility units. A sixth fuel, a microfine grind CWF, was evaluated on two utility units and one industrial unit. The particular fuels were chosen with the objective of examining the effects of coal source, ash level, ash properties, and beneficiation on the CWF performance and economics of the seven units. 10 refs., 81 figs., 80 tabs.

  9. Co-combustion of sludge with coal or wood

    SciTech Connect

    Leckner, B.; Aamand, L.-E.

    2004-07-01

    There are several options for co-combustion of biomass or waste with coal. In all cases the fuel properties are decisive for the success of the arrangement: contents of volatile matter and of potential emission precursors, such as sulphur, nitrogen, chlorine, and heavy metals. The content of alkali in the mineral substance of the fuel is important because of the danger of fouling and corrosion. Research activities at Chalmers University of Technology include several aspects of the related problems areas. An example is given concerning emissions from co-combustion in circulating fluidized beds with coal or wood as base fuels, and with sewage sludge as additional fuel. Two aspects of the properties of sludge are studied: emissions of nitrogen and sulphur oxides as well as of chlorine, because the contents of the precursors to these emissions are high. The possibility of utilizing the phosphorus in sludge as a fertilizer is also discussed. The results show that emissions can be kept below existing emission limits if the fraction of sludge is sufficiently small but the concentration of trace elements in the sludge ash prevents the sludge from being used as a fertilizer. 15 refs., 9 figs., 2 tabs.

  10. Remediation of abandoned mines using coal combustion by-products

    SciTech Connect

    Bulusu, S.; Aydilek, A.H.; Petzrick, P.; Guynn, R.

    2005-08-01

    Acid mine drainage (AMD) is a phenomenon that occurs when pyrite that is present in abandoned coal mines comes in contact with oxygen and water, which results in the formation of sulfuric acid and iron hydroxide. Grouting of an abandoned mine with alkaline materials provides a permanent reduction in acid production. This study investigates the success of coal combustion by-product (CCB)-based grout mixtures in reducing AMD. The laboratory phase included testing of grouts with different proportions of Class F fly ash, flue gas desulfurization by-product, fluidized bed combustion by-product, and quicklime, for slump, modified flow, bleed, and strength. Then the selected optimal grout mixture was injected into the Frazee mine, located in Western Maryland. Pre- and post-injection water quality data were collected to assess the long-term success of the grouting operation by analyzing mine water, surface water, and groundwater. Overall, the results indicated that CCB-based grouts can control the acid mine drainage. However, the mechanical properties of the grout are highly critical for the construction phase, and long-term monitoring is essential for evaluating the effectiveness of the grouting process.

  11. Gel retarder for fire prevention and extinguishing -- Its application for spontaneous combustion of coal seams

    SciTech Connect

    1998-12-31

    With its unique function, gel retarder has been successfully applied to extinguish fire at coal face, roadways and stop line of upper slice extraction, and a comparably perfect set of fire extinguishing techniques has been developed. The technique gathers together characteristics of water-fixation, leak-blocking, cooling, oxidation-retarding and heat-resisting. A new agglomerating agent without amine and corrosion has been developed to replace amine-salt and acid used in the past. Gel-injection technology cooperating with the grouting system on the ground solves previous problems in which gel-injection velocity was slow and materials transport was difficult. The technique has become the main measure to extinguish spontaneous combustion in coal mines in China. The use of gel retarder as an important means of underground fire prevention will be applied more widely to prevent and extinguish spontaneous fire in coal mines.

  12. Coal combustion science quarterly progress report, October--December 1992. Task 1, Coal char combustion [and] Task 2, Fate of mineral matter

    SciTech Connect

    Hardesty, D.R.; Hurt, R.H.; Baxter, L.L.

    1993-06-01

    In the Coal Combustion Laboratory (CCL) this quarter, controlled laboratory experiments were carried out to better understand the late stages of coal combustion and its relation to unburned carbon levels in fly ash. Optical in situ measurements were made during char combustion at high carbon conversions and the optical data were related to particle morphologies revealed by optical microscopy on samples extracted under the same conditions. Results of this work are reported in detail below. In the data presented below, we compare the fraction of alkali metal loss to that of the alkaline earth metals as a function of coal rank to draw conclusions about the mechanism of release for the latter. Figure 2.1 illustrates the fractional release of the major alkali and alkaline earth metals (Na, K, Ca, Mg) as a function of coal rank for a series of coals and for several coal blends. All data are derived from combustion experiments in Sandia`s Multifuel Combustor (MFC) and represent the average of three to eight experiments under conditions where the mass loss on a dry, ash-free (daf) basis exceeds 95 %. There are no missing data in the figure. The several coals with no indicated result exhibited no mass loss of the alkali or alkaline earth metals in our experiments. There is a clear rank dependence indicated by the data in Fig. 2.1, reflecting the mode of occurrence of the material in the coal.

  13. Recent advances in the use of synchrotron radiation for the analysis of coal combustion products

    SciTech Connect

    Manowitz, B.

    1995-11-01

    Two major coal combustion problems are the formation and build-up of slag deposits on heat transfer surfaces and the production and control of toxic species in coal combustion emissions. The use of synchrotron radiation for the analysis of coal combustion products can play a role in the better understanding of both these phenomena. An understanding of the chemical composition of such slags under boiler operating conditions and as a function of the mineral composition of various coals is one ultimate goal of this program. The principal constituents in the ash of many coals are the oxides of Si, Al, Fe, Ca, K, S, and Na. The analytical method required must be able to determine the functional forms of all these elements both in coal and in coal ash at elevated temperatures. One unique way of conducting these analyses is by x-ray spectroscopy.

  14. Mercury speciation and emissions from coal combustion in Guiyang, southwest China

    SciTech Connect

    Tang, S.L.; Feng, X.B.; Qiu, H.R.; Yin, G.X.; Yang, Z.C.

    2007-10-15

    Although China has been regarded as one of the largest anthropogenic mercury emission source with coal combustion, so far the actual measurements of Hg species and Hg emissions from the combustion and the capture of Hg in Chinese emission control devices were very limited. Aiming at Hg mercury species measurements in Guiyang, the capital city of Guizhou province in Southwest China, we studied flue gases of medium-to-small-sized industrial steam coal-firing boiler (10-30 t/h) with no control devices, medium-to-small-sized industrial steam coal-firing boiler with WFGD and large-scale coal combustion with ESPs using Ontario Hytro method. We obtained mercury emission factors of the three representative coal combustion and estimated mercury emissions in Guiyang in 2003, as well as the whole province from 1986 to 2002. Coal combustion in Guiyang emitted 1898 kg mercury to the atmosphere, of which 36% Hg is released from power plants, 41% from industrial coal combustion, and 23% from domestic users, and 267 kg is Hg{sup P}, 813 kg is Hg{sup 2+} and 817 kg is Hg{sup 0}. Mercury emission in Guizhou province increased sharply from 5.8 t in 1986 to 16.4 t in 2002. With the implementation of national economic strategy of China's Western Development, the annual mercury emission from coal combustion in the province is estimated to be about 32 t in 2015.

  15. Mercury speciation and emissions from coal combustion in Guiyang, Southwest China.

    PubMed

    Tang, Shunlin; Feng, Xinbin; Qiu, Jianrong; Yin, Guoxun; Yang, Zaichan

    2007-10-01

    Although China has been regarded as one of the largest anthropogenic mercury emission source with coal combustion, so far the actual measurements of Hg species and Hg emissions from the combustion and the capture of Hg in Chinese emission control devices were very limited. Aiming at Hg mercury species measurements in Guiyang, the capital city of Guizhou province in Southwest China, we studied flue gases of medium-to-small-sized industrial steam coal-firing boiler (10-30 t/h) with no control devices, medium-to-small-sized industrial steam coal-firing boiler with WFGD and large-scale coal combustion with ESPs using Ontario Hytro method. We obtained mercury emission factors of the three representative coal combustion and estimated mercury emissions in Guiyang in 2003, as well as the whole province from 1986 to 2002. Coal combustion in Guiyang emitted 1898 kg mercury to the atmosphere, of which 36% Hg is released from power plants, 41% from industrial coal combustion, and 23% from domestic users, and 267 kg is Hg(p), 813 kg is Hg(2+) and 817 kg is Hg0. Mercury emission in Guizhou province increased sharply from 5.8 t in 1986 to 16.4 t in 2002. With the implementation of national economic strategy of China's Western Development, the annual mercury emission from coal combustion in the province is estimated to be about 32 t in 2015.

  16. Gob spontaneous combustion in a fully mechanized long-wall top-coal caving face

    SciTech Connect

    Xu, J.; Deng, J.; Zhang, X.; Guo, X.; Wen, F.

    1999-07-01

    As geological conditions allow, underground coal mines in China tend to use comprehensively mechanized roof-coal caving technique in an effort to gain a higher degree of mechanization at coal faces as well as higher coal production rates. As a face advances, a large amount of coal will be left behind in its gob area which may experience a self-enhancing process of coal oxidation and heat accumulation, ultimately leading to open fire. Such a self-enhancing coal spontaneous combustion process is a significantly impediment to mine safety and productivity. A sound mathematical model is an important step to predict the probability of spontaneous combustion so that measures against coal-heating can be adopted in time and at comparatively low cost. This paper analyzes main factors in coal spontaneous combustion process and proposes a mathematical model to describe the dynamic process of coal self-heating in the gob. This model has been applied to a coal production face in Datong Coal Region in Shangdong Province to satisfactorily predict the spontaneous combustion probability.

  17. INVESTIGATION OF PRIMARY FINE PARTICULATE MATTER FROM COAL COMBUSTION BY COMPUTER-CONTROLLED SCANNING ELECTRON MICROSCOPY

    EPA Science Inventory

    The particle size distributions, morphologies, and chemical composition distributions of 14 coal fly ash (CFA) samples produced by the combustion of four western U.S. coals (two subbituminous, one lignite, and one bituminous) and three eastern U.S. coals (all bituminous) have bee...

  18. INVESTIGATION OF PRIMARY FINE PARTICULATE MATTER FROM COAL COMBUSTION BY COMPUTER-CONTROLLED SCANNING ELECTRON MICROSCOPY

    EPA Science Inventory

    The particle size distributions, morphologies, and chemical composition distributions of 14 coal fly ash (CFA) samples produced by the combustion of four western U.S. coals (two subbituminous, one lignite, and one bituminous) and three eastern U.S. coals (all bituminous) have bee...

  19. Advances in measurements and simulation of gas-particle flows and coal combustion in burners/combustors

    NASA Astrophysics Data System (ADS)

    Zhou, L. X.

    2009-02-01

    Innovative coal combustors were developed, and measurement and simulation of gas-particle flows and coal combustion in such combustors were done in the Department of Engineering Mechanics, Tsinghua University. LDV/PDPA measurements are made to understand the behavior of turbulent gas-particle flows in coal combustors. Coal combustion test was done for the non-slagging cyclone coal combustor. The full two-fluid model developed by the present author was used to simulate turbulent gas-particle flows, coal combustion and NOx formation. It is found by measurements and simulation that the optimum design can give large-size recirculation zones for improving the combustion performance for all the combustors. The combustion test shows that the nonslagging coal combustor can burn 3-5mm coal particles with good combustion efficiency and low NO emission. Simulation in comparison with experiments indicates that the swirl number can significantly affect the NO formation in the swirl coal combustor.

  20. Solid by-products of coal combustion: Fly ash as a source of industrial minerals

    SciTech Connect

    Bhagwat, S.B.; Rapp, D.M.; Bukowski, J.M.

    1996-12-31

    Fly ash is one of the most important by-products of coal combustion. It is a complex mix of cenospheres, reactive glasses, magnetite and carbon, in addition to minor quantities of other minerals. Fly ash components are determined by the type of coal, the combustion technology, material collection system and the temperature of combustion. The changing mix of coal burned in power plants is increasingly making the fly ash characteristics independent of the locally mined coal. Fly ash is thus becoming a raw material independent of the existence of a local coal mining industry. Currently, about 65 million tons of fly ash are generated annually in the United States. This is equivalent to the crushed stone production of such highly industrialized states as Illinois. Only about twenty percent of the total fly ash are currently used, mostly in low value applications such as road building materials and concrete additions. The fly ash currently represents an environmental and financial liability to electric utilities. The increasingly competitive and boundaryless electricity market in the US increases the incentive to look at fly ash in terms of its individual components and recognize their potential as industrial minerals in the production of value added materials. For example, zeolites and other adsorbents could be produced from reactive glasses, magnetite could be used in pigments and ferrite manufacture, activated carbon could serve in pollution control and cenospheres could be used to make lightweight ceramics. If one begins to look at fly ash as a source of industrial minerals and not as a waste product, this change in perspective could turn a financial and environmental liability into an economic opportunity.

  1. Advanced staged combustion system for power generation

    SciTech Connect

    Rehmat, A.; Goyal, A.

    1993-12-31

    To respond to the increasing market need for a new generation of plants with a substantial improvement in efficiency and a reduction in capital cost, the Institute of Gas Technology has developed an advanced staged, fluidized-bed combustion system concept. The staged fluidized-bed partial combustor produces the fuel gas at about 1500 F. The fuel gas, after particulate removal, is directed to a gas turbine followed by a steam cycle. Adequate sulfur capture and solids waste stabilization are attained by separating calcination, carbonization, and gasification/combustion steps in the staged fluidized beds. Intermediate gas cooling is avoided during the process to maximize the power production. The coal-to-electricity conversion efficiency of the system approaches 49 percent, which exceeds the efficiencies of the other emerging technologies.

  2. REDUCTION OF NOx EMISSION FROM COAL COMBUSTION THROUGH OXYGEN ENRICHMENT

    SciTech Connect

    Western Research Institute

    2006-07-01

    BOC Process Gas Solutions and Western Research Institute (WRI) conducted a pilot-scale test program to evaluate the impact of oxygen enrichment on the emissions characteristics of pulverized coal. The combustion test facility (CTF) at WRI was used to assess the viability of the technique and determine the quantities of oxygen required for NOx reduction from coal fired boiler. In addition to the experimental work, a series of Computational Fluid Dynamics (CFD) simulations were made of the CTF under comparable conditions. A series of oxygen enrichment test was performed using the CTF. In these tests, oxygen was injected into one of the following streams: (1) the primary air (PA), (2) the secondary air (SA), and (3) the combined primary and secondary air. Emission data were collected from all tests, and compared with the corresponding data from the baseline cases. A key test parameter was the burner stoichiometry ratio. A series of CFD simulation models were devised to mimic the initial experiments in which secondary air was enriched with oxygen. The results from these models were compared against the experimental data. Experimental evidence indicated that oxygen enrichment does appear to be able to reduce NOx levels from coal combustion, especially when operated at low over fire air (OFA) levels. The reductions observed however are significantly smaller than that reported by others (7-8% vs. 25-50%), questioning the economic viability of the technique. This technique may find favor with fuels that are difficult to burn or stabilize at high OFA and produce excessive LOI. While CFD simulation appears to predict NO amounts in the correct order of magnitude and the correct trend with staging, it is sensitive to thermal conditions and an accurate thermal prediction is essential. Furthermore, without development, Fluent's fuel-NO model cannot account for a solution sensitive fuel-N distribution between volatiles and char and thus cannot predict the trends seen in the

  3. Evolution of Submicrometer Organic Aerosols during a Complete Residential Coal Combustion Process.

    PubMed

    Zhou, Wei; Jiang, Jingkun; Duan, Lei; Hao, Jiming

    2016-07-19

    In the absence of particulate matter (PM) control devices, residential coal combustion contributes significantly to ambient PM pollution. Characterizing PM emissions from residential coal combustion with high time resolution is beneficial for developing control policies and evaluating the environmental impact of PM. This study reports the evolution of submicrometer organic aerosols (OA) during a complete residential coal combustion process, that is, from fire start to fire extinction. Three commonly used coal types (bituminous, anthracite, and semicoke coals) were evaluated in a typical residential stove in China. For all three types of coal, the OA emission exhibited distinct characteristics in the four stages, that is, ignition, fierce combustion, relatively stable combustion, and ember combustion. OA emissions during the ignition stage accounted for 58.2-85.4% of the total OA emission of a complete combustion process. The OA concentration decreased rapidly during the fierce combustion stage and remained low during the relatively stable combustion stage. During these two stages, a significant ion peak of m/z 73 from organic acids were observed. The degree of oxidation of the OA increased from the first stage to the last stage. Implications for ambient OA source-apportionment and residential PM emission characterization and control are discussed.

  4. Coal combustion under conditions of blast furnace injection. Final technical report, September 1, 1992--August 31, 1993

    SciTech Connect

    Crelling, J.C.; Case, E.R.

    1993-12-31

    A potentially new use for Illinois coal is as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. During the first phase of this project a number of the objectives were realized, specifically: (1) a blast furnace sampling system was developed and used successfully to collect samples inside an active furnace; (2) two sets of blast furnace samples were collected and petrographic analysis showed that char derived from injected coal is entering the reduction zone of the furnace; (3) a coal/char sampling probe was designed and fabricated; (4) the completion of a program of reactivity experiments on the injected coal char, blast furnace coke and Herrin No. 6 char. The results of the reactivity experiments indicate that Herrin No. 6 coal is similar or even superior to coals now being used in blast furnace injection and that additional testing is warranted.

  5. Numerical predictions of burner performance during pulverized coal combustion

    SciTech Connect

    Zarnescu, V.; Pisupati, S.V.

    1999-07-01

    The performance of four burners in terms of temperature and velocity profiles, residence time and NO{sub x} emissions was predicted using numerical simulations and a two-dimensional model for pulverized coal combustion. Numerical predictions for two burners used in a pilot-scale 0.5 MM Btu/hr (146.5 kW) down-fired combustor (DFC) are presented. Two other burner configurations were evaluated and compared with the ones used with the DFC for attaining lower NO{sub x} levels. Simulations were conducted for both coal and coal-water slurry as primary fuels. A sensitivity analysis of predictions with respect to variations of the model parameters was performed. The results suggest that the higher NO{sub x} reduction with one of the burners used in the DFC is due to the improved near-burner aerodynamics and to better flame attachment. These improved conditions are influenced by a combination of geometric and flow parameters, such as burner dimensions, quart diameter, inlet velocity, inlet temperature and swirl number.

  6. Physicochemical characterizations of limestone for fluidized-bed coal combustion

    SciTech Connect

    Fuller, E.L. Jr.; Yoos, T.R. III; Walia, D.S.

    1981-05-01

    This study is an investigation of the physicochemical characteristics of three limestone samples, Quincy limestone (-20 + 60), Franklin limestone (-12 + 30), and Franklin limestone (-6 + 16), currently being tested at Oak Ridge National Laboratory for use in a fluidized-bed coal combustion unit. By correlating the chemistry, mineralogy, and surface area of these samples with empirical data obtained at Argonne National Laboratory, the sulfur capture ability and performance of these limestones can be loosely predicted. X-ray fluorescence and neutron activation analysis revealed a very high calcium content and very low concentrations of other elements in the three samples. X-ray diffraction patterns and petrographic examination of the limestone grains detected essentially no dolomite in the Quincy limestone or the fine Franklin limestone samples. The coarse Franklin limestone sample showed dolomite to be present in varying amounts up to maximum of 2.75%. Limited surface chemistry investigations of the samples were undertaken. Limestone and dolostone resources of the Tennessee Valley Authority region are widespread and abundant, and judged sufficient to meet industrial demand for many years. No problems are anticipated in securing limestone or dolostone supplies for a commercial fluidized-bed combustion plant in the Tennessee Valley Authority region. Transportation facilities and costs for limestone or dolostone will influence the siting of such a commercial fluidized-bed combustion plant. The most promising location in the Tennessee Valley Authority region at this time is Paducah, Kentucky.

  7. Simulation of fluidized bed combustors. I - Combustion efficiency and temperature profile. [for coal-fired gas turbines

    NASA Technical Reports Server (NTRS)

    Horio, M.; Wen, C. Y.

    1976-01-01

    A chemical engineering analysis is made of fluidized-bed combustor (FBC) performance, with FBC models developed to aid estimation of combustion efficiency and axial temperature profiles. The FBC is intended for combustion of pulverized coal and a pressurized FBC version is intended for firing gas turbines by burning coal. Transport phenomena are analyzed at length: circulation, mixing models, drifting, bubble wake lift, heat transfer, division of the FB reactor into idealized mixing cells. Some disadvantages of a coal FBC are pointed out: erosion of immersed heat-transfer tubing, complex feed systems, carryover of unburned coal particles, high particulate emission in off-streams. The low-temperature bed (800-950 C) contains limestone, and flue-gas-entrained SO2 and NOx can be kept within acceptable limits.

  8. Partitioning of sodium, chlorine and sulfur during coal and char combustion in a fluid bed

    SciTech Connect

    Bhattacharya, S.P.; He, Y.

    1998-12-31

    Advanced power generation technologies (IGCC, Advanced PFBC) using high moisture low-rank coals require gasification of coal followed by combustion of char in a fluid bed. A study was undertaken to investigate the bed behaviour of char during combustion in a fluid bed. Three high moisture Australian low-rank coals, which are currently used in Victorian power stations, were chosen for this study. These were air dried, ground and sieved to 1--4 mm size. Char was prepared from these coals by devolatilising in a 76-mm diameter spouted bed at 700 C in presence of nitrogen. Char samples were combusted in the same spouted bed under hydrodynamic conditions similar to that in an atmospheric circulating fluid bed at temperatures of 800 C and 900 C. The three coal samples were also combusted under similar conditions to compare with the combustion behaviour of the char. No significant agglomeration problems were observed during combustion of these coals for periods of up to four hours. For one char, the bed defluidized 70 minutes after combustion at 900 C, while the two remaining chars didn`t present any significant agglomeration during the test period of four hours. Ultimate and inorganic analyses were carried out for the coal and char samples before the tests. The bed materials and cyclone ash after each combustion test were analyzed for inorganics and phases using chemical analysis, XRD and DTA techniques. A significant separation of the sodium and chlorine in coal was observed during pyrolysis of the coal to char. During combustion of char, most of the sodium (in char) was captured in the bed materials. This information was used to explain the bed behaviour observed during char combustion. This paper discusses the results and suggest strategies for mitigation of defluidization, that are currently under trial.

  9. Preliminary assessment of coal-based industrial energy systems

    SciTech Connect

    Not Available

    1980-01-01

    This report presents the results of a study, performed by Mittelhauser Corp. and Resource Engineering, Inc. to identify the potential economic, environmental, and energy impacts of possible New Source Performance Standards for industrial steam generators on the use of coal and coal-derived fuels. A systems-level approach was used to take mine-mouth coal and produce a given quantity of heat input to a new boiler at an existing Chicago industrial-plant site. The technologies studied included post-combustion clean-up, atmospheric fluidized-bed combustion, solvent-refined coal liquids, substitute natural gas, and low-Btu gas. Capital and operating costs were prepared on a mid-1985 basis from a consistent set of economic guidelines. The cases studied were evaluated using three levels of air emission controls, two coals, two boiler sizes, and two operating factors. Only those combinations considered likely to make a significant impact on the 1985 boiler population were considered. The conclusions drawn in the report are that the most attractive applications of coal technology are atmospheric fluidized-bed combustion and post-combustion clean-up. Solvent-refined coal and probably substitute natural gas become competitive for the smaller boiler applications. Coal-derived low-Btu gas was found not to be a competitive boiler fuel at the sizes studied. It is recommended that more cases be studied to broaden the applicability of these results.

  10. Combustion-gas recirculation system

    DOEpatents

    Baldwin, Darryl Dean

    2007-10-09

    A combustion-gas recirculation system has a mixing chamber with a mixing-chamber inlet and a mixing-chamber outlet. The combustion-gas recirculation system may further include a duct connected to the mixing-chamber inlet. Additionally, the combustion-gas recirculation system may include an open inlet channel with a solid outer wall. The open inlet channel may extend into the mixing chamber such that an end of the open inlet channel is disposed between the mixing-chamber inlet and the mixing-chamber outlet. Furthermore, air within the open inlet channel may be at a pressure near or below atmospheric pressure.

  11. Combustion monitoring during the controlled burnout of a coal mine fire

    SciTech Connect

    Dalverny, L.E.; Chaiken, R.F.; Soroka, K.E.

    1983-07-01

    The U.S. Bureau of Mines recently (July, 1982) completed a 24 h/d, four-month field evaluation of the Burnout Control technique for converting an abandoned coal mine fire to a safe energy resource. The partial vacuum created by a surface exhaust fan draws all gases from underground combustion (accelerated by air drawn through nearby boreholes) to a central refractory-lined exhaust pipe, where a heat exchanger may be attached. Ventilation system effects on underground combustion and combustion products effects on the ventilation system were analysed. A programmable calculator was used to manipulate temperature, pressure, flow, and gas composition data acquired from two instrumentation assemblies continuously monitoring the system for combustion control and diagnostics. Flow probes (averaging and bidirectional) provided feedback from process control valve adjustments. Gas temperatures to 1,000/sup 0/ C challenged probe endurance in firebrick lined duct designed for 128 scmm (5,000 scfm) flows. Concern about condensates and loss of SO/sub 2/, H/sub 2/S, NO /SUB x/ engendered use of a heated tube bundle and porous metal and glass fiber filters. Continuous and batch samples of CO, CO/sub 2/, O/sub 2/ yielded equivalent analyses. Analytical instrumentation, reasons for choosing particular devices, and problems encountered while monitoring combustion are discussed.

  12. Energy recycling by co-combustion of coal and recovered paint solids from automobile paint operations.

    PubMed

    Suriyawong, Achariya; Magee, Rogan; Peebles, Ken; Biswas, Pratim

    2009-05-01

    During the past decade, there has been substantial interest in recovering energy from many unwanted byproducts from industries and municipalities. Co-combustion of these products with coal seems to be the most cost-effective approach. The combustion process typically results in emissions of pollutants, especially fine particles and trace elements. This paper presents the results of an experimental study of particulate emission and the fate of 13 trace elements (arsenic [As], barium [Ba], cadmium [Cd], chromium [Cr], copper [Cu], cobalt [Co], manganese [Mn], molybdenum [Mo], nickel [Ni], lead [Pb], mercury [Hg], vanadium [V], and zinc [Zn]) during combustion tests of recovered paint solids (RPS) and coal. The emissions from combustions of coal or RPS alone were compared with those of co-combustion of RPS with subbituminous coal. The distribution/partitioning of these toxic elements between a coarse-mode ash (particle diameter [dp] > 0.5 microm), a submicrometer-mode ash (dp < 0.5 microm), and flue gases was also evaluated. Submicrometer particles generated by combustion of RPS alone were lower in concentration and smaller in size than that from combustion of coal. However, co-combustion of RPS and coal increased the formation of submicrometer-sized particles because of the higher reducing environment in the vicinity of burning particles and the higher volatile chlorine species. Hg was completely volatilized in all cases; however, the fraction in the oxidized state increased with co-combustion. Most trace elements, except Zn, were retained in ash during combustion of RPS alone. Mo was mostly retained in all samples. The behavior of elements, except Mn and Mo, varied depending on the fuel samples. As, Ba, Cr, Co, Cu, and Pb were vaporized to a greater extent from cocombustion of RPS and coal than from combustion of either fuel. Evidence of the enrichment of certain toxic elements in submicrometer particles has also been observed for As, Cd, Cr, Cu, and Ni during co-combustion.

  13. Slag processing system for direct coal-fired gas turbines

    DOEpatents

    Pillsbury, Paul W.

    1990-01-01

    Direct coal-fired gas turbine systems and methods for their operation are provided by this invention. The systems include a primary combustion compartment coupled to an impact separator for removing molten slag from hot combustion gases. Quenching means are provided for solidifying the molten slag removed by the impact separator, and processing means are provided forming a slurry from the solidified slag for facilitating removal of the solidified slag from the system. The released hot combustion gases, substantially free of molten slag, are then ducted to a lean combustion compartment and then to an expander section of a gas turbine.

  14. Combustion of coal chars in oxygen-enriched atmospheres

    SciTech Connect

    Bejarano, P.A.; Levendis, Y.A.

    2007-07-01

    This work pertains to the high-temperature combustion of pulverized coal chars under oxygen-enriched atmospheres. Single char particles were burned in a drop-tube furnace, electrically-heated to 1300-1500 K, in 21%, 50% and 100% O{sub 2}, in a balance of N{sub 2}. Their luminous combustion histories were observed with two-color ratio pyrometry. A solution of the Planckian ratio-pyrometry equation for temperature was implemented, extending on Wien's approximation. The temperature and time histories for 45-53 {mu}m bituminous chars experienced wide particle-to-particle disparity, and varied depending on oxygen mole fraction and furnace temperature. Average char surface temperatures increased from 1600-1800 K in air, to 2100-2300 K in 50% O-2, to 2300-2400 K in 100% O{sub 2}, at gas temperatures of 1300-1500 K, respectively. Combustion durations decreased from 25-45 ms in air, to 8-17 ms in 50% O{sub 2}, to 6-13 in 100% O{sub 2}. Thus, average particle temperatures increased by up to 45%, whereas burnout times decreased by up to 87% as combustion was progressively enriched in O{sub 2} until 100% was attained. The apparent and intrinsic reactivity of the chars burning at 1500 K gas temperature were found to increase by factors of to 8 and 35, respectively, as the oxygen mole fraction increased by a factor of five, from 21% to 100%.

  15. Naturally Occurring Radioactive Materials in Coals and Coal Combustion Residuals in the United States.

    PubMed

    Lauer, Nancy E; Hower, James C; Hsu-Kim, Heileen; Taggart, Ross K; Vengosh, Avner

    2015-09-15

    The distribution and enrichment of naturally occurring radioactive materials (NORM) in coal combustion residuals (CCRs) from different coal source basins have not been fully characterized in the United States. Here we provide a systematic analysis of the occurrence of NORM ((232)Th, (228)Ra, (238)U, (226)Ra, and (210)Pb) in coals and associated CCRs from the Illinois, Appalachian, and Powder River Basins. Illinois CCRs had the highest total Ra ((228)Ra + (226)Ra = 297 ± 46 Bq/kg) and the lowest (228)Ra/(226)Ra activity ratio (0.31 ± 0.09), followed by Appalachian CCRs (283 ± 34 Bq/kg; 0.67 ± 0.09), and Powder River CCRs (213 ± 21 Bq/kg; 0.79 ± 0.10). Total Ra and (228)Ra/(226)Ra variations in CCRs correspond to the U and Th concentrations and ash contents of their feed coals, and we show that these relationships can be used to predict total NORM concentrations in CCRs. We observed differential NORM volatility during combustion that results in (210)Pb enrichment and (210)Pb/(226)Ra ratios greater than 1 in most fly-ash samples. Overall, total NORM activities in CCRs are 7-10- and 3-5-fold higher than NORM activities in parent coals and average U.S. soil, respectively. This study lays the groundwork for future research related to the environmental and human health implications of CCR disposal and accidental release to the environment in the context of this elevated radioactivity.

  16. Effects of Coal Combustion Additives on the Forms and Recovery of Uranium in Coal Bottom Ash

    NASA Astrophysics Data System (ADS)

    Tang, Ye; Li, Yilian

    2017-04-01

    Recovering uranium from uranium-rich coal ash is an important way to utilize unconventional uranium resource. Although it might be expected that the uranium in residual form would prevent uranium recovery from coal ash, raising the recovery rate in way of controlling residual uranium has not yet been studied. In this study, three different kinds of combustion promoting additives were investigated by coal combustion experiments, in order to decrease the proportion of residual-form uranium in ash and increase the acid leaching rate. Analytical procedures included Tessier sequential extraction, acidleaching, and characterization(ICP-MS, XRF, BET and SEM-EDS). It was showed that the effects of additives in reducing residual uranium were as the following order: alkaline earth metal compounds > transition metal compounds> alkali metal compounds. Adding alkali metal additives(KCl, NaCl, K2CO3, Na2CO3) raised the percentage of residual uranium largely. Additionally, one transition metal additive(Fe2O3) reached a decreasing amplitude of 5.15%, while the other two additives(MnO2 and Fe3O4)made the rates increased. However, coal combustion with alkaline earth metal compounds mixed had target effects. Among this kind of additives(Ca(OH)2, CaCO3, CaO, CaCl2), CaCO3displayed the best effect on restricting the rising proportion of residual uranium by 18%. Moreover, the leaching recovery research indicated that CaCO3 could raise the recovery rate by 10.8%. The XRF profiles supported that the CaCO3 could lower the concentration of SiO2 in the bottom ash from 79.76% to 49.69%. Besides, The BET and SEM revealed that the decomposition of CaCO3 brought about a variation of surface structures and area, which promoted the contact between the leaching agent and bottom ash. The uranium content increase was determined by ICP-MS and EDS. These findings suggest that CaCO3 could be a favorable additive for the controlling of residual uranium and improvement of uranium recovery rates. Key words

  17. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 17, April--June 1993

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1993-08-01

    Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the third quarter of 1993, the following technical progress was made: Completed modeling calculations of coal mineral matter transformations, deposition behavior, and heat transfer impacts of six test fuels; and ran pilot-scale tests of Upper Freeport feed coal, microagglomerate product, and mulled product.

  18. Studying the specific features pertinent to combustion of chars obtained from coals having different degrees of metamorphism and biomass chars

    NASA Astrophysics Data System (ADS)

    Bestsennyi, I. V.; Shchudlo, T. S.; Dunaevskaya, N. I.; Topal, A. I.

    2013-12-01

    Better conditions for igniting low-reaction coal (anthracite) can be obtained, higher fuel burnout ratio can be achieved, and the problem of shortage of a certain grade of coal can be solved by firing coal mixtures and by combusting coal jointly with solid biomass in coal-fired boilers. Results from studying the synergetic effect that had been revealed previously during the combustion of coal mixtures in flames are presented. A similar effect was also obtained during joint combustion of coal and wood in a flame. The kinetics pertinent to combustion of char mixtures obtained from coals characterized by different degrees of metamorphism and the kinetics pertinent to combustion of wood chars were studied on the RSK-1D laboratory setup. It was found from the experiments that the combustion rate of char mixtures obtained from coals having close degrees of metamorphism is equal to the value determined as a weighted mean rate with respect to the content of carbon. The combustion rate of char mixtures obtained from coals having essentially different degrees of metamorphism is close to the combustion rate of more reactive coal initially in the process and to the combustion rate of less reactive coal at the end of the process. A dependence of the specific burnout rate of carbon contained in the char of two wood fractions on reciprocal temperature in the range 663—833 K is obtained. The combustion mode of an experimental sample is determined together with the reaction rate constant and activation energy.

  19. Comprehensive Model of Single Particle Pulverized Coal Combustion Extended to Oxy-Coal Conditions

    DOE PAGES

    Holland, Troy; Fletcher, Thomas H.

    2017-02-22

    Oxy-fired coal combustion is a promising potential carbon capture technology. Predictive CFD simulations are valuable tools in evaluating and deploying oxy-fuel and other carbon capture technologies either as retrofit technologies or for new construction. But, accurate predictive simulations require physically realistic submodels with low computational requirements. In particular, comprehensive char oxidation and gasification models have been developed that describe multiple reaction and diffusion processes. Our work extends a comprehensive char conversion code (CCK), which treats surface oxidation and gasification reactions as well as processes such as film diffusion, pore diffusion, ash encapsulation, and annealing. In this work several submodels inmore » the CCK code were updated with more realistic physics or otherwise extended to function in oxy-coal conditions. Improved submodels include the annealing model, the swelling model, the mode of burning parameter, and the kinetic model, as well as the addition of the chemical percolation devolatilization (CPD) model. We compare our results of the char combustion model to oxy-coal data, and further compared to parallel data sets near conventional conditions. A potential method to apply the detailed code in CFD work is given.« less

  20. Comparative analysis for performance of brown coal combustion in a vortex furnace with improved design

    NASA Astrophysics Data System (ADS)

    Krasinsky, D. V.

    2016-09-01

    Comparative study of 3D numerical simulation of fluid flow and coal-firing processes was applied for flame combustion of Kansk-Achinsk brown coal in a vortex furnace of improved design with bottom injection of secondary air. The analysis of engineering performance of this furnace was carried out for several operational modes as a function of coal grinding fineness and coal input rate. The preferable operational regime for furnace was found.

  1. Computational fluid dynamics study of pulverized coal combustion in blast furnace raceway

    SciTech Connect

    Shen, Y.S.; Maldonado, D.; Guo, B.Y.; Yu, A.B.; Austin, P.; Zulli, P.

    2009-12-15

    In this work, a numerical model is used to study the flow and coal combustion along the coal plume in a large-scale setting simulating the lance-blowpipe-tuyere-raceway region of a blast furnace. The model formulation is validated against the measurements in terms of burnout for both low and high volatile coals. The typical phenomena related to coal combustion along the coal plume are simulated and analyzed. The effects of some operational parameters on combustion behavior are also investigated. The results indicate that oxygen as a cooling gas gives a higher coal burnout than methane and air. The underlying mechanism of coal combustion is explored. It is shown that under the conditions examined, coal burnout strongly depends on the availability of oxygen and residence time. Moreover, the influences of two related issues, i.e. the treatment of volatile matter (VM) and geometric setting in modeling, are investigated. The results show that the predictions of final burnouts using three different VM treatments are just slightly different, but all comparable to the measurements. However, the influence of the geometric setting is not negligible when numerically examining the combustion of pulverized coal under blast furnace conditions.

  2. Mechanisms of fouling, slagging and corrosion by pulverized coal combustion. Quarterly technical progress report No. 1, March 11-June 30, 1981

    SciTech Connect

    Gulden, M. E.; Hsu, L. L.; Stetson, A. R.

    1981-07-01

    Progress is reported on a program in which the objective is to conduct a detailed and comprehensive study of the mechanisms of fouling, slagging and corrosion in pulverized coal combustors by employing well controlled model systems which simulate the coal combustion environment. Emphasis during this period has been on design and construction of the combustion test rig. All design phases are complete. Construction of the diffuser and test sections is also complete.

  3. COMPARISON OF PARTICLE SIZE DISTRIBUTIONS AND ELEMENTAL PARTITIONING FROM THE COMBUSTION OF PULVERIZED COAL AND RESIDUAL FUEL OIL

    EPA Science Inventory

    The paper gives results of experimental efforts in which three coals and a residual fuel oil were combusted in three different systems simulating process and utility boilers. Particloe size distributions (PSDs) were determined using atmospheric and low-pressure impaction, electr...

  4. COMPARISON OF PARTICLE SIZE DISTRIBUTIONS AND ELEMENTAL PARTITIONING FROM THE COMBUSTION OF PULVERIZED COAL AND RESIDUAL FUEL OIL

    EPA Science Inventory

    The paper gives results of experimental efforts in which three coals and a residual fuel oil were combusted in three different systems simulating process and utility boilers. Particloe size distributions (PSDs) were determined using atmospheric and low-pressure impaction, electr...

  5. Some special features of combusting the coal-water fuel made of Belarussian brown coals in the fluidized bed

    NASA Astrophysics Data System (ADS)

    Borodulya, V. A.; Buchilko, E. K.; Vinogradov, L. M.

    2014-07-01

    This paper deals with the special features of combusting the coal-water fuel prepared on the basis of Belarussian brown coals and anthracite culm (Ukraine) in a fluidized bed. The sequence and the duration (calculated from the mathematical model being suggested) of the stages of the combustion of the coal-water fuel depending on the type of source solid fuel and fluidized bed temperature were experimentally confirmed. The temperature and time dependences of the content of sulfur, nitrogen, and carbon oxides in flue gases were studied.

  6. Investigation of formation of nitrogen compounds in coal combustion. Final report

    SciTech Connect

    Blair, D.W.; Crane, I.D.; Wendt, J.O.L.

    1983-10-01

    This is the final report on DOE contract number DE-AC21-80MC14061. It concerns the formation of nitrogen oxide from fuel-bound nitrogen during coal combustion. The work reported was divided into three tasks. They addressed problems of time-resolving pyrolysis rates of coal under simulated combustion conditions, the combustion of the tar that results from such pyrolysis, and theoretical modeling of the pyrolysis process. In all of these tasks, special attention was devoted to the fate of coal nitrogen. The first two tasks were performed by Exxon Research and Engineering Company. 49 references.

  7. Chromium speciation in coal and biomass co-combustion products.

    PubMed

    Stam, Arthur F; Meij, Ruud; Te Winkel, Henk; Eijk, Ronald J van; Huggins, Frank E; Brem, Gerrit

    2011-03-15

    Chromium speciation is vital for the toxicity of products resulting from co-combustion of coal and biomass. Therefore, understanding of formation processes has been studied using a combination of X-ray absorption fine structure (XAFS) spectroscopy and thermodynamic equilibrium calculations. The influence of cofiring on Cr speciation is very dependent on the type of fuel. Cr(VI) contents in the investigated fly ash samples from coal and cofiring average around 7% of the total chromium. An exception is cofiring 7-28% wood for which ashes exhibited Cr(VI) concentrations of 12-16% of the total chromium. Measurements are in line with thermodynamic predictions: RE factors of Cr around 1 are in line with volatile Cr only above 1400 °C; lower Cr(VI) concentrations with lower oxygen content and Cr(III) dissolved in aluminosilicate glass. Stability of Cr(VI) below 700 °C does not correlate with Cr(VI) concentrations found in the combustion products. It is indicated that Cr(VI) formation is a high-temperature process dependent on Cr evaporation (mode of occurrence in fuel, promoted by organic association), oxidation (local oxygen content), and formation of solid chromates (promoted by presence of free lime (CaO) in the ash). CaCrO(4)(s) is a probable chemical form but, given different leachable fractions (varying from 25 to 100%), different forms of Cr(VI) must be present. Clay-bound Cr is likely to dissolve in the aluminosilicate glass phase during melting of the clay.

  8. STRUCTURE-BASED PREDICTIVE MODEL FOR COAL CHAR COMBUSTION

    SciTech Connect

    Robert H. Hurt; Eric M. Suuberg

    2000-05-03

    This report is part on the ongoing effort at Brown University and Ohio State University to develop structure based models of coal combustion. A very fundamental approach is taken to the description of coal chars and their reaction processes, and the results are therefore expected to have broad applicability to the spectrum of carbon materials of interest in energy technologies. This quarter, our work on structure development in carbons continued. A combination of hot stage in situ and ex situ polarized light microscopy was used to identify the preferred orientational of graphene layers at gas interfaces in pitches used as carbon material precursors. The experiments show that edge-on orientation is the equilibrium state of the gas/pitch interface, implying that basal-rich surfaces have higher free energies than edge-rich surfaces in pitch. This result is in agreement with previous molecular modeling studies and TEM observations in the early stages of carbonization. The results may have important implications for the design of tailored carbons with edge-rich or basal-rich surfaces. In the computational chemistry task, we have continued our investigations into the reactivity of large aromatic rings. The role of H-atom abstraction as well as radical addition to monocyclic aromatic rings has been examined, and a manuscript is currently being revised after peer review. We have also shown that OH radical is more effective than H atom in the radical addition process with monocyclic rings. We have extended this analysis to H-atom and OH-radical addition to phenanthrene. Work on combustion kinetics focused on the theoretical analysis of the data previously gathered using thermogravametric analysis.

  9. Speciation and Attenuation of Arsenic and Selenium at Coal Combustion By-Product Management Facilities

    SciTech Connect

    K. Ladwig; B. Hensel; D. Wallschlager; L. Lee; I Murarka

    2005-10-19

    Field leachate samples are being collected from coal combustion product (CCP) management sites from several geographic locations in the United States to provide broad characterization of major and trace constituents in the leachate. In addition, speciation of arsenic, selenium, chromium, and mercury in the leachates is being determined. Through 2003, 35 samples were collected at 14 sites representing a variety of CCP types, management approaches, and source coals. Samples have been collected from leachate wells, leachate collection systems, drive-point piezometers, lysimeters, the ash/water interface at impoundments, impoundment outfalls and inlets, and seeps. Additional sampling at 23 sites has been conducted in 2004 or is planned for 2005. First-year results suggest distinct differences in the chemical composition of leachate from landfills and impoundments, and from bituminous and subbituminous coals. Concentrations of most constituents were generally higher in landfill leachate than in impoundment leachate. Sulfate, sodium, aluminum, molybdenum, vanadium, cadmium, mercury and selenium concentrations were higher in leachates for ash from subbituminous source coal. Calcium, boron, lithium, strontium, arsenic, antimony, and nickel were higher for ash from bituminous source coal. These variations will be explored in more detail when additional data from the 2004 and 2005 samples become available.

  10. Monopropellant combustion system

    NASA Technical Reports Server (NTRS)

    Berg, Gerald R. (Inventor); Mueller, Donn C. (Inventor); Parish, Mark W. (Inventor)

    2005-01-01

    An apparatus and method are provided for decomposition of a propellant. The propellant includes an ionic salt and an additional fuel. Means are provided for decomposing a major portion of the ionic salt. Means are provided for combusting the additional fuel and decomposition products of the ionic salt.

  11. Health effects of coal mining and combustion: carcinogens and cofactors.

    PubMed

    Falk, H L; Jurgelski, W

    1979-12-01

    Some polynuclear aromatics (PNA) have been found to be potent carcinogens for all tissues and organs of experimental animals that have been exposed to them, but different dose levels are needed for these effects. They have been known for decades to cause cancer at the site of application but also at certain sites distant from the area of contact. Although some hydrocarbons are potent and complete carcinogens, the majority of related hydrocarbons was originally found to be inactive. Since they generally appear together, it was important to know more about their interaction, particularly whether they would synergize, or antagonize. The polycyclic hydrocarbons have been studied by subcutaneous injection, where they prove very potent carcinogens. They are also very active on the skin of mice where they produce cancer on prolonged application. Inhalation studies, require larger doses yielded negative results until particulate matter was introduced which facilitated the development of lung tumors. Although iron oxide dust was used initially, other dusts were also capable of enhancing the response of the tissue to benzo(a)pyrene carcinogenesis. This point is of importance, particularly since the inhalation of PNA in situations of air pollution or coal mining involves particulates, although of a different type. Soot is not a homogenous substance and several factors determine its properties. Soots will lose some of the absorbed chemicals during their residence in air, but they retain their PNAs for long periods of time when they reach the soil. The carcinogenicity of PNAs in the adsorbed state may be completely absent, depending on particle size of the soot and availability of eluting capability of the tissues or cells in contact with the soot. Whenever the carcinogenic polynuclear aromatics can be eluted they will be active in producing cancer if their residence is adequate. There seems to be no reason to assume that a large increase in coal combustion in the future will

  12. Health effects of coal mining and combustion: carcinogens and cofactors.

    PubMed Central

    Falk, H L; Jurgelski, W

    1979-01-01

    Some polynuclear aromatics (PNA) have been found to be potent carcinogens for all tissues and organs of experimental animals that have been exposed to them, but different dose levels are needed for these effects. They have been known for decades to cause cancer at the site of application but also at certain sites distant from the area of contact. Although some hydrocarbons are potent and complete carcinogens, the majority of related hydrocarbons was originally found to be inactive. Since they generally appear together, it was important to know more about their interaction, particularly whether they would synergize, or antagonize. The polycyclic hydrocarbons have been studied by subcutaneous injection, where they prove very potent carcinogens. They are also very active on the skin of mice where they produce cancer on prolonged application. Inhalation studies, require larger doses yielded negative results until particulate matter was introduced which facilitated the development of lung tumors. Although iron oxide dust was used initially, other dusts were also capable of enhancing the response of the tissue to benzo(a)pyrene carcinogenesis. This point is of importance, particularly since the inhalation of PNA in situations of air pollution or coal mining involves particulates, although of a different type. Soot is not a homogenous substance and several factors determine its properties. Soots will lose some of the absorbed chemicals during their residence in air, but they retain their PNAs for long periods of time when they reach the soil. The carcinogenicity of PNAs in the adsorbed state may be completely absent, depending on particle size of the soot and availability of eluting capability of the tissues or cells in contact with the soot. Whenever the carcinogenic polynuclear aromatics can be eluted they will be active in producing cancer if their residence is adequate. There seems to be no reason to assume that a large increase in coal combustion in the future will

  13. Development & testing of industrial scale, coal fired combustion system, phase 3. Eighth quarterly technical progress report, 1 October, 1993--31 December, 1993

    SciTech Connect

    Zauderer, B.

    1994-01-31

    The primary objective of the present Phase 3 effort is to perform the final testing at a 20 MMBtu/hr commercial scale of an air cooled, slagging coal combustor for application to industrial steam boilers and power plants. The focus of the test effort will be on combustor durability, automatic control of the combustor`s operation, and optimum environmental control of emissions inside the combustor. In connection with the latter, the goal is to achieve 0.4 lb/MMBtu of SO{sub 2} emissions, 0.2 lb/MMBtu of NO{sub x} emissions, and 0.02 lb particulates/MMBtu. Meeting the particulate goal will require the use of a baghouse or electrostatic precipitator to augment the nominal slag retention in the combustor. The NO{sub x} emission goal will require a modest improvement over maximum reduction achieved to date in the combustor to a level of 0.26 lb/MMBtu. To reach the SO{sub 2} emissions goal may require a combination of sorbent injection inside the combustor and sorbent injection inside the boiler, especially in high (>3.5%) sulfur coals. Prior to the initiation of the project, SO{sub 2} levels as low as 0.6 lb/MMBtu, equal to 81% reduction in 2% sulfur coals, were measured with boiler injection of calcium hydrate. The final objective is to define suitable commercial power or steam generating systems to which the use of the air cooled combustor offers significant technical and economic benefits. In implementing this objective both simple steam generation and combined gas turbine-steam generation systems will be considered.

  14. Preparation and combustion of coal-water fuel from the Sin Pun coal deposit, southern Thailand

    SciTech Connect

    1997-05-01

    In response to an inquiry by the Department of Mineral Resources in Thailand, the Energy & Environmental Research Center (EERC) prepared a program to assess the responsiveness of Sin Pun lignite to the temperature and pressure conditions of hot-water drying. The results indicate that drying made several improvements in the coal, notably increases in heating value and carbon content and reductions in equilibrium moisture and oxygen content. The equilibrium moisture content decreased from 27 wt% for the raw coal to about 15 wt% for the hot-water-dried (HWD) coals. The energy density for a pumpable coal-water fuel (CWF) indicates an increase from 4500 to 6100 Btu/lb by hot-water drying. Approximately 650 lb of HWD Sin Pun CWF were fired in the EERC`s combustion test facility. The fuel burned extremely well, with no feed problems noted during the course of the test. Fouling and slagging deposits each indicated a very low rate of ash deposition, with only a dusty layer formed on the cooled metal surfaces. The combustor was operated at between 20% and 25% excess air, resulting in a flue gas SO{sub 2} concentration averaging approximately 6500 parts per million.

  15. Oxidation of Mercury in Products of Coal Combustion

    SciTech Connect

    Peter Walsh; Giang Tong; Neeles Bhopatkar; Thomas Gale; George Blankenship; Conrad Ingram; Selasi Blavo Tesfamariam Mehreteab; Victor Banjoko; Yohannes Ghirmazion; Heng Ban; April Sibley

    2009-09-14

    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 (HgCl{sub 2}) enables removal of mercury during wet flue gas desulfurization. The increase in mercury oxidation in a monolithic V{sub 2}O{sub 5}-WO{sub 3}/TiO{sub 2} SCR catalyst with increasing HCl at low levels of HCl (< 10 ppmv) and decrease in mercury oxidation with increasing NH{sub 3}/NO ratio during SCR were consistent with results of previous work by others. The most significant finding of the present work was the inhibition of mercury oxidation in the presence of CO during SCR of NO at low levels of HCl. In the presence of 2 ppmv HCl, expected in combustion products from some Powder River Basin coals, an increase in CO from 0 to 50 ppmv reduced the extent of mercury oxidation from 24 {+-} 3 to 1 {+-} 4%. Further increase in CO to 100 ppmv completely suppressed mercury oxidation. In the presence of 11-12 ppmv HCl, increasing CO from 0 to {approx}120 ppmv reduced mercury oxidation from {approx}70% to 50%. Conversion of SO{sub 2} to sulfate also decreased with increasing NH{sub 3}/NO ratio, but the effects of HCl and CO in flue gas on SO{sub 2} oxidation were unclear. Oxidation and adsorption of mercury by unburned carbon and fly ash enables mercury removal in a particulate control device. A chemical kinetic mechanism consisting of nine homogeneous and heterogeneous reactions for mercury oxidation and removal was developed to interpret pilot-scale measurements of mercury oxidation and adsorption by unburned carbon and fly ash in experiments at pilot

  16. Corrosion in coal and straw co-combustion environments

    SciTech Connect

    Henriksen, N.

    1997-08-01

    In order to reduce CO{sub 2} emission, ELSAM (the electric utility company of the western part of Denmark) is looking into the possibilities for using biomass--mainly straw--for combustion in high-efficiency power plants. In this connection ELSAM has investigated 3 ultra supercritical boiler concepts for combustion of straw only or together with coal: (1) pulverized fuel boilers (PF-boilers); (2) circulating fluidized bed boilers (CFB-boilers); and (3) vibrating grate boilers with 100% straw. These investigations have mainly been full-scale tests with straw fed into existing boilers. Corrosion tests have been performed in these boilers using temperature regulated probes and in-plant test tubes in existing superheaters. The corrosion has been determined by detailed measurements of wall thickness reduction and light optical microscopic measurements of the material degradation due to high temperature corrosion. Corrosion mechanisms have been evaluated using SEM/EDX together with thermodynamic considerations based on measurements of the chemical environment of the flue gas. Great differences were found in the corrosion mechanisms for superheaters in PF-boilers and the CFB-boilers fired with almost the same share of straw and at the same metal temperatures.

  17. Toxic substances from coal combustion -- A comprehensive assessment

    SciTech Connect

    Senior, C.L.; Huggins, F.E.; Huffman, G.P.; Shan, N.; Yap, N.; Wendt, J.O.L.; Seames, W.; Ames, M.R.; Sarofim, A.F.; Swenson, S.; Lighty, J.; Kolker, A.; Finkelman, R.; Palmer, C.; Mroczkowski, S.; Helble, J.; Mamani-Paco, R.; Sterling, R.; Dunham, G.; Miller, S.

    2000-08-17

    The final program review meeting of Phase II was held on June 22 in Salt Lake City. The goals of the meeting were to present work in progress and to identify the remaining critical experiments or analyses, particularly those involving collaboration among various groups. The information presented at the meeting is summarized in this report. Remaining fixed bed, bench-scale experiments at EERC were discussed. There are more ash samples which can be run. Of particular interest are high carbon ash samples to be generated by the University of Arizona this summer and some ash-derived sorbents that EERC has evaluated on a different program. The use of separation techniques (electrostatic or magnetic) was also discussed as a way to understand the active components in the ash with respect to mercury. XAFS analysis of leached and unleached ash samples from the University of Arizona was given a high priority. In order to better understand the fixed bed test results, CCSEM and Moessbauer analyses of those ash samples need to be completed. Utah plans to analyze the ash from the single particle combustion experiments for those major elements not measured by INAA. USGS must still complete mercury analyses on the whole coals and leaching residues. Priorities for further work at the SHRIMP-RG facility include arsenic on ash surfaces and mercury in sulfide minerals. Moessbauer analyses of coal samples from the University of Utah were completed; samples from the top and bottom layers of containers of five different coals showed little oxidation of pyrite in the top relative to the bottom except for Wyodak.

  18. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 6, July 1990--September 1990

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1990-11-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a three-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are being run at the cleaning facility in Homer City, Pennsylvania, to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CVVT) or a dry microfine pulverized coal (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors to CE to perform parts of the test work are the Massachusetts Institute of Technology (MIT), Physical Science, Inc. Technology Company (PSIT) and the University of North Dakota Energy and Environmental Research Center (UNDEERC). Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFS, and two conventionally cleaned coals for full-scale tests. Approximately, nine BCFs will be in dry microfine coal (DMPC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements.

  19. Emission characteristics of coal combustion in different O2/N2, O2/CO2 and O2/RFG atmosphere.

    PubMed

    Chen, Jyh-Cherng; Liu, Zhen-Shu; Huang, Jian-Sheng

    2007-04-02

    This study investigates the emission characteristics of CO(2), SO(2) and NOx in the flue gas of coal combustion by varying the compositions and concentrations of feed gas (O(2)/CO(2)/N(2)) and the ratios of recycled flue gas. The differences between O(2)/recycled flue gas (O(2)/RFG) combustion and general air combustion are also discussed. Experimental results indicate that the maximum concentration of CO(2) in O(2)/CO(2) combustion system is 95% as the feed gas is 30% O(2)/70% CO(2). The average concentration of CO(2) in the flue gas of O(2)/CO(2) coal combustion system is higher than 90% and much higher than that of O(2)/N(2) coal combustion system. This high concentration of CO(2) is beneficial for the separation of CO(2) from the flue gas by adsorption or absorption technologies. The maximum concentration of CO(2) in O(2)/N(2) combustion system is only 34% at the feed gas 50% O(2)/50% N(2), the concentration of CO(2) is increased with the concentration of O(2) in feed gas. By O(2)/CO(2) combustion technology, higher concentration of SO(2) is produced as the feed gas is 30% O(2)/70% CO(2) or 40% O(2)/60% CO(2), while higher concentration of NOx is produced as the feed gas is 20% O(2)/80% CO(2) or 50% O(2)/50% CO(2). The mass flow rates of CO(2), SO(2) and NOx in the flue gas are all increased with the ratio of recycled flue gas except for the feed gas 20% O(2)/80% CO(2). The enhanced mass flow rates of air pollutants in such O(2)/RFG combustion system are also beneficial for improving the control efficiencies of air pollution control devices. By O(2)/N(2) combustion technology, higher concentrations of SO(2) and NOx are produced as the feed gas is 21% O(2)/79% N(2). The results also indicate that the formation of NOx in general air combustion system is higher than that in O(2)/RFG or O(2)/CO(2) combustion system.

  20. Carbon and oxygen isotopic composition of coal and carbon dioxide derived from laboratory coal combustion: A preliminary study

    USGS Publications Warehouse

    Warwick, Peter; Ruppert, Leslie F.

    2016-01-01

    The concentration of carbon dioxide (CO2) in the atmosphere has dramatically increased from the start of the industrial revolution in the mid-1700s to present levels exceeding 400 ppm. Carbon dioxide derived from fossil fuel combustion is a greenhouse gas and a major contributor to on-going climate change. Carbon and oxygen stable isotope geochemistry is a useful tool to help model and predict the contributions of anthropogenic sources of CO2 in the global carbon cycle. Surprisingly few studies have addressed the carbon and oxygen isotopic composition of CO2 derived from coal combustion. The goal of this study is to document the relationships between the carbon and oxygen isotope signatures of coal and signatures of the CO2 produced from laboratory coal combustion in atmospheric conditions.Six coal samples were selected that represent various geologic ages (Carboniferous to Tertiary) and coal ranks (lignite to bituminous). Duplicate splits of the six coal samples were ignited and partially combusted in the laboratory at atmospheric conditions. The resulting coal-combustion gases were collected and the molecular composition of the collected gases and isotopic analyses of δ13C of CO2, δ13C of CH4, and δ18O of CO2 were analysed by a commercial laboratory. Splits (~ 1 g) of the un-combusted dried ground coal samples were analyzed for δ13C and δ18O by the U.S. Geological Survey Reston Stable Isotope Laboratory.The major findings of this preliminary work indicate that the isotopic signatures of δ13C (relative to the Vienna Pee Dee Belemnite scale, VPDB) of CO2 resulting from coal combustion are similar to the δ13CVPDB signature of the bulk coal (− 28.46 to − 23.86 ‰) and are not similar to atmospheric δ13CVPDB of CO2 (~ − 8 ‰, see http://www.esrl.noaa.gov/gmd/outreach/isotopes/c13tellsus.html). The δ18O values of bulk coal are strongly correlated to the coal dry ash yields and appear to have little or no influence on the δ18O values of CO2

  1. Study on trace metal partitioning in pulverized combustion of bituminous coal and dry sewage sludge

    SciTech Connect

    Cenni, R.; Gerhardt, T.; Spliethoff, H.; Hein, K.R.G.; Frandsen, F.

    1998-12-31

    In Germany, the feasibility of co-combustion of sewage sludge in power plants is under evaluation. A study of the influence of co-firing of dry municipal sewage sludge on the behavior of the metals Cr, Hg, Mn, Ni, Pb, zn during pulverized coal combustion is presented. Sewage sludge contains higher concentrations of the metals listed above than the reference coal, but a lower concentration of Cl, that enhances the volatility of many metals. Experiments were performed in a semi-industrial scale pulverized fuel combustion chamber. Ash was collected at four locations: bottom hopper, air preheater, cyclone, and bag filter. From the bottom hopper to the filter, the particle size decreased and ash particles were progressively enriched in volatile elements. Mass balances of the metals were performed and the enrichment trends on the ash collected at the different locations were calculated. Increasing the sewage sludge share in the blend caused a significant increase in the recovery rate in the solid phase. In spite of that, the calculated concentrations in the flue gas of Hg and zn increased. Sewage sludge co-firing influences the combustion process and the post-combustion environment in many ways. This study focuses on the effect of the different flue gas composition on the condensation temperature of metal species. The system was modeled by assuming thermodynamic equilibrium. The results indicated that the increasing recovery of Zn might be caused by enhanced condensation and the increasing recovery of Hg by adsorption on ash particles. The increasing recovery of the other metals seemed referable to failure in vaporization and it cannot be studied with an equilibrium approach.

  2. Evaluation of the behavior of Colombian coals during the combustion in fixed bed

    SciTech Connect

    Giraldo, M.; Chejne, F.; Hill, A.

    2000-07-01

    The improvements in the technological processes that have coal as energy source must be based on the knowledge of physical and chemical properties of coal and in the knowledge of its evolution during the combustion process. These characteristics are involved in the coal behavior. Moreover, the coal porosity has an important relevance on the reaction rate and in diverse physical and chemical properties, and therefore, is a key parameter in the usefulness of coal. This project includes studies about Colombian coal combustion and its kinetic behavior. The coal was characterized and classified by particle size,and origin. In this research project, the physical and chemical properties of coal that affect its applicability in different kinds of technological processes have been studied as well as the characteristics that could be related to pollutant generation. The study considers the following issues: the types and level of criteria pollutant precursor compounds such as sulfur and nitrogen in coal, the influence of particle size and porosity in the generation of pollutant species, the participation of pollutant species in the combustion process, and basic properties such as heat capacity, and heat effects related to the conversion of coal during heating test. Coal from Antioquia, Valle del Cauca and Cundinamarca Regions were used. These coals are used domestically by the industrial and power sector. Particle sizes of 4, 2.5 and 1 cm were used from each one of these coals. The combustion tests were done in a fixed bed pilot furnace. The amount of air used was controlled during the experiment. In addition, air and gas flow, concentration and temperatures were registered. This paper presents a description of: characteristics of each test, composition of generated gases, and the influence of the particle size and coal origin in the pollutant emissions, also includes the results of test done in different samples took along each test.

  3. Pulverized-coal combustion. Semi-annual report, September 18, 1980-March 31, 1981

    SciTech Connect

    Not Available

    1981-04-01

    A flow tube reactor for the study of the reactivity of pulverized coal under controlled conditions has been developed at Stanford University. The reactor system incorporates advanced optical diagnostics as well as probe sampling techniques to measure the reactivity of coals with differing physical and chemical properties. The aim of the research is to provide fundamental data that can be used in the design and development of coal combustion systems. Reactor characterization measurements with a number of diagnostics have shown that the system performs according to design specifications. In recent experiments, Montana Rosebud coal was found to have a relatively high oxidation reactivity. Marked qualitative differences in oxidation behavior, associated with the rate of volatile evolution, were observed as the gas temperaute was increased from about 1100/sup 0/K to 1500/sup 0/K. Electron microscopy analysis showed the development of a complex macropore structure during burnout. The existence of this structure is consistent with preliminary data indicating a dependence of reactivity on particle size differing from that predicted by some theories.

  4. Coal Combustion Residual Beneficial Use Evaluation: Fly Ash Concrete and FGD Gypsum Wallboard

    EPA Pesticide Factsheets

    This page contains documents related to the evaluation of coal combustion residual beneficial use of fly ash concrete and FGD gypsum wallboard including the evaluation itself and the accompanying appendices

  5. Fact Sheet: Final Rule on Coal Combustion Residuals Generated by Electric Utilities

    EPA Pesticide Factsheets

    This fact sheet describes the final rule signed on December 19, 2014 establishing a comprehensive set of requirements for the disposal of coal combustion residuals generated by electric utilities in landfills and surface impoundments.

  6. Measurement of air toxic emissions from a coal-fired boiler equipped with a tangentially-fired low NOx combustion system

    SciTech Connect

    Dismukes, E.B.; Clarkson, R.J.; Hardman, R.R.; Elia, G.G.

    1993-11-01

    This paper presents the results of measurements of chemical emissions from a coal-burning, tangentially-fired, utility boiler equipped with a hot-side electrostatic precipitator and a low NOx firing system. The tests were conducted in response to Title III of the 1990 Amendments to the Clean Air Act which lists 189 chemicals to be evaluated as {open_quotes}Air Toxics.{close_quotes} The project was jointly funded by the Electric Power Research Institute and the US Department of Energy under an existing Innovative Clean Coal Technology Cooperative Agreement managed by Southern Company Services. Field chemical emissions monitoring was conducted in two phases: a baseline {open_quotes}pre-low NOx burner{close_quotes} condition in September 1991 and in the LNCFS Level III low NOx firing condition in January 1992. In addition to stack emissions measurements of both organic and inorganic chemicals, plant material balance evaluations were performed to determine the efficiency of the hot-side ESP at controlling emissions of air toxics and to determine the fate of the target chemicals in various plant process streams.

  7. Development and testing of industrial scale, coal fired combustion system, Phase 3. Second quarterly technical progress report, April 1, 1992--June 30, 1992

    SciTech Connect

    Zauderer, B.

    1992-07-10

    In the second quarter of calendar year 1992, work continued on Task 1.1. ``DESIGN MODIFICATIONS TO THE 20 MMBTU/HR AIR COOLED COMBUSTOR AND BOILER COMPONENTS``. This consisted of specifying and designing the changes needed to prepare the 20 MMBtu/hr air cooled combustor at the Tampella boiler house site in Williamsport, PA. In depth review of the technical status of the combustor showed that no major design changes were necessary in order to implement the effort of task 2 testing and part of the task 3 testing. Among the major planned changes eliminated were replacement of the inlet swirl air flow section of the combustor. The major changes undertaken were to improve the coal and sorbent injection into the combustor; refurbishing various components and controls systems such as the stack particle scrubber and temperature probes; automating key elements of the combustor, such as the slag tap, upgrading the computer control and automatic data acquisition; and upgrading the long duration capability of the exit nozzle. To support this effort advanced analytical modeling was used to provide guidance for the design changes. A multi-dimensional computer code was used to analyze the combustor performance for different combustor stoichiometries and geometry. A heat transfer analysis of the exit nozzle was performed to determine the best method of adding cooling capacity to the exit nozzle to allow its use for multi-day, round-the-clock coal testing.

  8. Combustion characteristics of blends of lignite and bituminous coal with different binder materials

    SciTech Connect

    Haykiri-Acma, H.; Ersoy-Mericboyu, A.; Kuecuekbayrak, S.

    2000-05-01

    In this study, the combustion characteristics of blends of a Turkish lignite and a Siberian bituminous coal with and without binder materials were investigated. Sunflower shell, sawdust, and molasses were used as binder materials. The combustion curves of the coal and binder material samples and of the blends were obtained using differential thermal analysis (DTA). The differences observed in the DTA curves of the samples are discussed in detail.

  9. Investigation of the devolatilization of coal under combustion conditions. Seventh quarterly report, 1 April-30 June, 1980

    SciTech Connect

    Seery, D.J.

    1980-04-01

    This report describes progress during the seventh quarter of a two year contract to study pyrolysis of coal under combustion conditions. Major accomplishments of this quarter have been the infrared analysis of two new coals, heated grid devolatilization of these coals over the entire available temperature range, quantitative measurements of tar and char nitrogen contents, measurements of NO formation during early phase of combustion of coal, high speed photography of tar release from a Pittsburgh bituminous coal, relating the early tar release of the bituminous coal to its voltatiles combustion behavior.

  10. Effects of calcium magnesium acetate on the combustion of coal-water slurries. Final project report, 1 September 1989--28 February 1993

    SciTech Connect

    Levendis, Y.A.; Wise, D.; Metghalchi, H.; Cumper, J.; Atal, A.; Estrada, K.R.; Murphy, B.; Steciak, J.; Hottel, H.C.; Simons, G.

    1993-07-01

    To conduct studies on the combustion of coal water fuels (CWFs) an appropriate facility was designed and constructed. The main components were (1) a high-temperature isothermal laminar flow furnace that facilitates observation of combustion events in its interior. The design of this system and its characterization are described in Chapter 1. (2) Apparatus for slurry droplet/agglomerate particle generation and introduction in the furnace. These devices are described in Chapters 1 and 3 and other attached publications. (3) An electronic optical pyrometer whose design, construction theory of operation, calibration and performance are presented in Chapter 2. (4) A multitude of other accessories, such as particle fluidization devices, a suction thermometer, a velocimeter, high speed photographic equipment, calibration devices for the pyrometer, etc., are described throughout this report. Results on the combustion of CWF droplets and CWF agglomerates made from micronized coal are described in Chapter 3. In the same chapter the combustion of CWF containing dissolved calcium magnesium acetate (CMA) axe described. The combustion behavior of pre-dried CWF agglomerates of pulverized grain coal is contrasted to that of agglomerates of micronized coal in Chapter 4. In the same chapter the combustion of agglomerates of carbon black and diesel soot is discussed as well. The effect of CMA on the combustion of the above materials is also discussed. Finally, the sulfur capture capability of CMA impregnated micronized and pulverized bituminous coals is examined in Chapter 5.

  11. Energy recycling by co-combustion of coal and recovered paint solids from automobile paint operations

    SciTech Connect

    Achariya Suriyawong; Rogan Magee; Ken Peebles; Pratim Biswas

    2009-05-15

    This paper presents the results of an experimental study of particulate emission and the fate of 13 trace elements (arsenic (As), barium (Ba), cadmium (Cd), chromium (Cr), copper (Cu), cobalt (Co), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), mercury (Hg), vanadium (V), and zinc (Zn)) during combustion tests of recovered paint solids (RPS) and coal. The emissions from combustions of coal or RPS alone were compared with those of co-combustion of RPS with subbituminous coal. The distribution/partitioning of these toxic elements between a coarse-mode ash (particle diameter (d{sub p}) > 0.5 {mu}m), a submicrometer-mode ash (d{sub p} < 0.5 {mu}m), and flue gases was also evaluated. Submicrometer particles generated by combustion of RPS alone were lower in concentration and smaller in size than that from combustion of coal. However, co-combustion of RPS and coal increased the formation of submicrometer-sized particles because of the higher reducing environment in the vicinity of burning particles and the higher volatile chlorine species. Hg was completely volatilized in all cases; however, the fraction in the oxidized state increased with co-combustion. Most trace elements, except Zn, were retained in ash during combustion of RPS alone. Mo was mostly retained in all samples. The behavior of elements, except Mn and Mo, varied depending on the fuel samples. As, Ba, Cr, Co, Cu, and Pb were vaporized to a greater extent from cocombustion of RPS and coal than from combustion of either fuel. Evidence of the enrichment of certain toxic elements in submicrometer particles has also been observed for As, Cd, Cr, Cu, and Ni during co-combustion. 27 refs., 6 figs., 5 tabs.

  12. Co-combustion of coal and solid waste (municipal and industrial solid wastes)

    SciTech Connect

    Ketlogetswe, C.

    1996-12-31

    This work determines the thermal characteristics of various mixtures of carpet waste as an illustrative solid waste. Generally the results revealed that combustion of a mixture of coal with carpet waste yields high fuel bed temperature, in comparison with the combustion of pure solid waste. High fuel bed temperatures of 1,340 C to 1,520 C obtained during the combustion of a mixture of coal with PVC carpet waste would be ideal for energy recovery. The fuel bed temperature of 1,290 C obtained during the combustion of 100% PVC carpet waste suggests that the combustion of general industrial solid waste may be expected to yield a fuel bed temperature of about 1,400 C which would be suitable for energy recovery in the form of power generation or steam generation for general use. The results also revealed that combustion of a mixture of coal and municipal solid waste may require 30% to 35% coal to achieve a fuel bed temperature of about 1,300 C. From economical viewpoint, the % of coal must be kept to a minimum, at least 20% coal or less.

  13. Trace metal capture by various sorbents during fluidized bed coal combustion

    SciTech Connect

    Ho, T.C.; Ghebremeskel, A.; Wang, K.S.; Hopper, J.R.

    1997-07-01

    This study investigated the potential of employing suitable sorbents to capture toxic trace metallic substances during fluidized bed coal combustion. Metal capture experiments were carried out in a 25.4 mm (1 inch) quartz fluidized bed combustor enclosed in an electric furnace. The metals involved were cadmium, lead, chromium, arsenic and selenium, and the sorbents tested included bauxite, zeolite and lime. In addition to the experimental investigations, potential metal-sorbent reactions were also identified through chemical equilibrium calculations based on the minimization of system free energy. The observed experimental results indicated that metal capture by sorbents can be as high as 88% depending on the metal species and sorbent involved. Results from thermodynamic equilibrium simulations suggested the formation of metal-sorbent compounds such as Pb{sub 2}SiO{sub 4}(s), CdAl{sub 2}O{sub 4}(s) and CdSiO{sub 3}(s) under the combustion conditions.

  14. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 12, January--March 1992

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1992-08-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the third quarter of 1992, the following technical progress was made: Continued analyses of drop tube furnace samples to determine devolatilization kinetics; completed editing of the fifth quarterly report and sent it to the publishing office; and prepared two technical papers for conferences.

  15. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 14, July--September 1992

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1993-02-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the third quarter of 1992, the following technical progress was made: Continued analyses of drop tube furnace samples to determine devolatilization kinetics; published two technical papers at conferences; and prepared for upcoming tests of new BCFs being produced.

  16. Coal slurry solids/coal fluidized bed combustion by-product mixtures as plant growth media

    USGS Publications Warehouse

    Darmody, R.G.; Green, W.P.; Dreher, G.B.

    1998-01-01

    Fine-textured, pyritic waste produced by coal cleaning is stored in slurry settling ponds that eventually require reclamation. Conventionally, reclamation involves covering the dewatered coal slurry solids (CSS) with 1.3 m of soil to allow plant growth and prevent acid generation by pyrite oxidation. This study was conducted to determine the feasiblity of a less costly reclamation approach that would eliminate the soil cover and allow direct seeding of plants into amended CSS materials. Potential acidity of the CSS would be neutralized by additions of fluidized-bed combustion by-product (FBCB), an alkaline by-product of coal combustion. The experiment involved two sources of CSS and FBCB materials from Illinois. Birdsfoot trefoil (Lotus corniculatus L.), tall fescue (Festuca arundinacea Schreb.), and sweet clover (Melilotus officinalis (L.) Lam.) were seeded in the greenhouse into pots containing mixtures of the materials. CSS-1 had a high CaCO3:FeS2 ratio and needed no FBCB added to compensate for its potential acidity. CSS-2 was mixed with the FBCB materials to neutralize potential acidity (labeled Mix A and B). Initial pH was 5.6, 8.8, and 9.2 for the CSS-1, Mix A, and Mix B materials, respectively. At the end of the 70-day experiment, pH was 5.9 for all mixtures. Tall fescue and sweet clover grew well in all the treatments, but birdsfoot trefoil had poor emergence and survival. Elevated tissue levels of B, Cd, and Se were found in some plants. Salinity, low moisture holding capacity, and potentially phytotoxic B may limit the efficacy of this reclamation method.

  17. Advanced coal-fueled gas turbine systems

    SciTech Connect

    Not Available

    1992-04-24

    No combustion tests for this program were conducted during this reporting period of January 1 to March 31, 1992. DOE-sponsored slogging combustor tests have been suspended since December 1991 in order to perform combustion tests on Northern States Power Company (NSP) coals. The NSP coal tests were conducted to evaluate combustor performance when burning western sub bituminous coals. The results of these tests will guide commercialization efforts, which are being promoted by NSP, Westinghouse Electric, and Textron Defense Systems. The NSP testing has been completed and preparation of the final report for that effort is underway. Although the NSP testing program has been completed, the Westinghouse/DOE program will not be resumed immediately. The reason for this is that Textron Defense Systems (TDS) has embarked on an internally funded program requiring installation of a new liquid fuel combustor system at the Haverhill site. The facility modifications for this new system are significant and it is not possible to continue the Westinghouse/DOE testing while these modifications are being made. These facility modifications are being performed during the period February 15, 1992 through May 31, 1992. The Westinghouse/DOE program can be resumed upon completion of this work.

  18. CHAR CRYSTALLINE TRANSFORMATIONS DURING COAL COMBUSTION AND THEIR IMPLICATIONS FOR CARBON BURNOUT

    SciTech Connect

    ROBERT H. HURT

    1998-09-08

    temperatures approaching 3000 o C. For the measurement of temperature histories an optical diagnostic is being developed that offers sufficient spatial resolution to distinguish the sample temperature from the substrate temperature. The optical diagnostic is based on a CID camera, a high-power lens, and movable mirrors to projecting multiple, filtered images onto a single chip. Oxidation kinetics are measured on the heat treated samples by a nonisothermal TGA technique. Task 2 Thermal deactivation kinetics. The goal of this task is to quantify thermal char deactivation as a function of temperature history and parent coal, with an emphasis on inert environments at temperatures and times found in combustion systems. The results are to be cast in the form of deactivation kinetics useful for incorporation in combustion models. Task 3 Crystal structure characterization. Crystal structure characterization provides important insight into the mechanisms of thermal char deactivation, and the degree of crystalline transformations has shown a strong correlation with reactivity changes in recent combustion studies [Davis et al., 1992, Beeley et al., 1996]. This task seeks to improve our understanding of char carbon crystalline transformations under combustion conditions by analyzing a large set of HRTEM fringe images for a series of flame-generated chars whose reactivities have been previously reported [Hurt et al., 1995, Beeley et al., 1996]. As a first step, a new technique is being developed for the quantitative analysis of fringe images, extending previous work to allow measurement of a complete set of crystal structure parameters including mean layer size, mean stacking height, interlayer spacing, layer curvature, amorphous fraction, and degree of anisotropy. The resulting database will revealing, at a very fundamental level, the basic differences in char crystal structure due to parent coal rank and to temperature history in the range of interest to combustion systems.

  19. Characterization of Coal Combustion Residues from Electric Utilities--Leaching and Characterization Data

    EPA Science Inventory

    This report evaluates changes in composition and constituent release by leaching that may occur to fly ash and other coal combustion residues (CCRs) in response to changes in air pollution control technology at coal-fired power plants. The addition of flue-gas desulfurization (FG...

  20. Digital image processing applications in the ignition and combustion of char/coal particles

    SciTech Connect

    Annamalai, K.; Kharbat, E.; Goplakrishnan, C.

    1992-12-01

    Digital image processing, is employed in this remarch study in order to visually investigate the ignition and combustion characteristics of isolated char/coal particles as well as the effect of interactivecombustion in two-particle char/coal arrays. Preliminary experiments are conducted on miniature isolated candles as well as two-candle arrays.

  1. Characterization of Coal Combustion Residues from Electric Utilities Using Wet Scrubbers for Multi-Pollutant Control

    EPA Science Inventory

    This report evaluates changes that may occur to coal combustion residues (CCRs) in response to changes in air pollution control technology at coal-fired power plants, which will reduce emissions from the flue gas stack by transferring pollutants to fly ash and other air pollution...

  2. Characterization of Coal Combustion Residues from Electric Utilities--Leaching and Characterization Data

    EPA Science Inventory

    This report evaluates changes in composition and constituent release by leaching that may occur to fly ash and other coal combustion residues (CCRs) in response to changes in air pollution control technology at coal-fired power plants. The addition of flue-gas desulfurization (FG...

  3. Characterization of Coal Combustion Residues from Electric Utilities Using Wet Scrubbers for Multi-Pollutant Control

    EPA Science Inventory

    This report evaluates changes that may occur to coal combustion residues (CCRs) in response to changes in air pollution control technology at coal-fired power plants, which will reduce emissions from the flue gas stack by transferring pollutants to fly ash and other air pollution...

  4. ASSESSING SPECIATION AND RELEASE OF HEAVY METALS FROM COAL COMBUSTION PRODUCTS

    EPA Science Inventory

    In this study, the speciation of heavy metals such as arsenic, selenium, lead, zinc and mercury in coal combustion products (CCPs) was evaluated using sequential extraction procedures. Coal fly ash, bottom ash and flue gas desulphurization (FGD) sludge samples were used in the ex...

  5. RELATIONSHIPS BETWEEN COMPOSITION AND PULMONARY TOXICITY OF PROTOTYPE PARTICLES FROM COAL COMBUSTION AND PYROLYSIS (MONTREAL, CANADA)

    EPA Science Inventory

    The hypothesis that health effects associated with coal combustion fly-ash particles are exacerbated by the simultaneous presence of iron and soot was tested through two sets of experiments. The first set created prototype particles from complete and partial combustion, or oxygen...

  6. Relationships between composition and pulmonary toxicity of prototype particles from coal combustion and pyrolysis

    EPA Science Inventory

    The hypothesis that health effects associated with coal combustion fly-ash particles are exacerbated by the simultaneous presence of iron and soot was tested through two sets of experiments. The first set created prototype particles from complete and partial combustion, or oxygen...

  7. Relationships between composition and pulmonary toxicity of prototype particles from coal combustion and pyrolysis

    EPA Science Inventory

    The hypothesis that health effects associated with coal combustion fly-ash particles are exacerbated by the simultaneous presence of iron and soot was tested through two sets of experiments. The first set created prototype particles from complete and partial combustion, or oxygen...

  8. VARIATION OF ELEMENT SPECIATION IN COAL COMBUSTION AEROSOLS WITH PARTICLE SIZE

    EPA Science Inventory

    The speciation of sulfur, iron and key trace elements (Cr, As, Se, Zn) in combustion ash aerosols has been examined as a function of size from experimental combustion units burning Utah and Illinois bituminous coals. Although predominantly present as sulfate, sulfur was also pre...

  9. Effects of calcium magnesium acetate on the combustion of coal-water slurries

    SciTech Connect

    Levendis, Y.A.

    1991-01-01

    The general objective of the project is to investigate the combustion behavior of single and multiple Coal-Water Fuel (CWF) particles burning at high temperature environments. Both uncatalyzed as well as catalyzed CWF drops with Calcium Magnesium Acetate (CMA) catalyst will be studies. Emphasis will also be given in the effects of CMA on the sulfur capture during combustion.

  10. RELATIONSHIPS BETWEEN COMPOSITION AND PULMONARY TOXICITY OF PROTOTYPE PARTICLES FROM COAL COMBUSTION AND PYROLYSIS (MONTREAL, CANADA)

    EPA Science Inventory

    The hypothesis that health effects associated with coal combustion fly-ash particles are exacerbated by the simultaneous presence of iron and soot was tested through two sets of experiments. The first set created prototype particles from complete and partial combustion, or oxygen...

  11. VARIATION OF ELEMENT SPECIATION IN COAL COMBUSTION AEROSOLS WITH PARTICLE SIZE

    EPA Science Inventory

    The speciation of sulfur, iron and key trace elements (Cr, As, Se, Zn) in combustion ash aerosols has been examined as a function of size from experimental combustion units burning Utah and Illinois bituminous coals. Although predominantly present as sulfate, sulfur was also pre...

  12. Development and testing of an industrial scale coal fired slagging combustion system, Phase 3. Task 2.1, Preliminary systems test plan

    SciTech Connect

    Not Available

    1992-09-11

    The planned effort for the task 2 tests has four major objectives. They are computer controlled combustor operation, optimization of SO2 reduction, combustor materials durability, and testing focused on application to industrial coal fired boilers. Several major advances in the combustor development have occurred since this original plan was proposed in 1991. Some of these advances occurred in tests performed in a project that was completed in June 1992, while others occurred during the design and shakedown tests of equipment that was installed in task I of this project. Therefore, the present test plan is based on the current status of the combustor technology, and it differs somewhat from the preliminary test plan that was prepared in April 1992. Depending on the results in the early tests in this task, further test plan modifications may be required. However, the general objectives will most probably remain unchanged.

  13. Coal Cleaning Using Resonance Disintegration for Mercury and Sulfur Reduction Prior to Combustion

    SciTech Connect

    Andrew Lucero

    2005-04-01

    Coal-cleaning processes have been utilized to increase the heating value of coal by extracting ash-forming minerals in the coal. These processes involve the crushing or grinding of raw coal followed by physical separation processes, taking advantage of the density difference between carbonaceous particles and mineral particles. In addition to the desired increase in the heating value of coal, a significant reduction of the sulfur content of the coal fed to a combustion unit is effected by the removal of pyrite and other sulfides found in the mineral matter. WRI is assisting PulseWave to develop an alternate, more efficient method of liberating and separating the undesirable mineral matter from the carbonaceous matter in coal. The approach is based on PulseWave's patented resonance disintegration technology that reduces that particle size of materials by application of destructive resonance, shock waves, and vortex generating forces. Illinois No.5 coal, a Wyodak coal, and a Pittsburgh No.8 coal were processed using the resonance disintegration apparatus then subjected to conventional density separations. Initial microscopic results indicate that up to 90% of the pyrite could be liberated from the coal in the machine, but limitations in the density separations reduced overall effectiveness of contaminant removal. Approximately 30-80% of the pyritic sulfur and 30-50% of the mercury was removed from the coal. The three coals (both with and without the pyritic phase separated out) were tested in WRI's 250,000 Btu/hr Combustion Test Facility, designed to replicate a coal-fired utility boiler. The flue gases were characterized for elemental, particle bound, and total mercury in addition to sulfur. The results indicated that pre-combustion cleaning could reduce a large fraction of the mercury emissions.

  14. NOx EMISSIONS PRODUCED WITH COMBUSTION OF POWDER RIVER BASIN COAL IN A UTILITY BOILER

    SciTech Connect

    John S. Nordin; Norman W. Merriam

    1997-04-01

    The objective of this report is to estimate the NOx emissions produced when Powder River Basin (PRB) coal is combusted in a utility boiler. The Clean Air Act regulations specify NOx limits of 0.45 lb/mm Btu (Phase I) and 0.40 lb/mm Btu (Phase II) for tangentially fired boilers, and 0.50 lb/mm 13tu (Phase II) and 0.46 lb/mm Btu (Phase II) for dry-bottom wall-fired boilers. The Clean Air Act regulations also specify other limits for other boiler types. Compliance for Phase I has been in effect since January 1, 1996. Compliance for Phase II goes into effect on January 1, 2000. Emission limits are expressed as equivalent NO{sub 2} even though NO (and sometimes N{sub 2}O) is the NOx species emitted during combustion. Regulatory agencies usually set even lower NOx emission limits in ozone nonattainment areas. In preparing this report, Western Research Institute (WRI) used published test results from utilities burning various coals, including PRB coal, using state-of-the art control technology for minimizing NOx emissions. Many utilities can meet Clean Air Act NOx emission limits using a combination of tight combustion control and low-NOx burners and by keeping furnaces clean (i.e., no slag buildup). In meeting these limits, some utilities also report problems such as increased carbon in their fly ash and excessive furnace tube corrosion. This report discusses utility experience. The theory of NOx emission formation during coal combustion as related to coal structure and how the coal is combusted is also discussed. From this understanding, projections are made for NOx emissions when processed PRB coal is combusted in a test similar to that done with other coals. As will be shown, there are a lot of conditions for achieving low NOx emissions, such as tight combustion control and frequent waterlancing of the furnace to avoid buildup of deposits.

  15. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 7, October 1990--December 1990

    SciTech Connect

    Hargrove, M.J.; Chow, O.K.; Nsakala, N.Y.

    1991-02-01

    During the fourth quarter of 1990, the following technical progress was made: (1) Calculated the kinetic characteristics of chars from the combustion of microbubble flotation beneficiated products; (2) continued drop tube combustion tests of the spherical oil agglomeration beneficiated products; (3) analyzed the data from three (MIT) pilot-scale combustion tests of the Upper Freeport feed coal; and (4) continued analyses of the data from the CE pilot-scale tests of nine fuels.

  16. Experimental and Numerical Study on Combustion of Secondary Pyrolysis Products from Various Coals.

    NASA Astrophysics Data System (ADS)

    Cho, Sunghwan

    In burning coal suspensions, non-uniform mixing and particle dispersion promote secondary pyrolysis and soot formation. The changes in volatile compositions affect volatiles combustion, which is responsible for flame propagation and pollutant formation during pulverized coal combustion. The lack of kinetic data on volatiles combustion is attributed to the complexity of fuel compositions and its close association with devolatilization and char oxidation, which cause difficulties in the isolation of volatiles combustion. This work attempts to determine global combustion rates of noncondensible volatiles by measuring laminar burning velocities. A radiant coal flow reactor generates combustible mixtures of noncondensibles, which are combusted in a constant volume combustion bomb to generate laminar burning velocities for the noncondensibles from Pit. #8 bituminous and Low. Kit. lv bituminous coals. The laminar burning velocities of noncondensible volatiles increase with the extent of secondary pyrolysis for both coals because the molar yields of H_2 and C_2H_2 increase during the conversion of tar into soot. For noncondensibles from Pit. #8 coal, the burning velocity at a fuel equivalence ratio of 1.2 and (N_2 + CO_2 + H_2 O):O_2 = 6.8, is quadrupled from 55 to 215 cm/s as the extent of sooting increases from 0.66 to 1.0. The combustion in air shows a similar variation. A correlation is developed using the equivalent concentrations of H_2 and CO with the adjustment of O_2 concentrations to convert hydrocarbons into CO: rm S_{u}^2 = Cxi_{O _2}(xi_{H_2} - alphaxi_{CO})exp({- }{Eover RT_{f}}) A single set of parameters describes the variation of burning velocities on the extent of sooting and coal types for four coals including Ill. #6 bituminous and Dietz subbituminous coals. Correlation parameters are C = 13.2 times 10^8 cm^2/s^2 , alpha = 1.0, and E = 27.4 kcal/mole. Numerical predictions of burning velocities with sensitivity analyses are performed using a detailed C

  17. Fluidized bed combustion of low-grade coal and wastes: Research and development

    SciTech Connect

    Borodulya, V.A.; Dikalenko, V.I.; Palchonok, G.I.; Vinogradov, L.M.; Dobkin, S.M.; Telegin, E.M.

    1994-12-31

    Experimental studies were carried out to investigate devolatilization of fuel as single spherical particles of wood, hydrolytic lignin, leather sewage sludge and Belarussian brown coals in a fluidized bed of sand. It is found that the devolatilization process depends on moisture and ash contents in fuel and on the external heat and mass transfer rate. The char combustion occurs largely in the intermediate region. Kinetic parameters of the devolatilization and char combustion are obtained. A low-capacity fluidized bed boiler suitable for combustion of coal and different wastes is described.

  18. List of Publicly Accessible Internet Sites Hosting Compliance Data and Information Required by the Disposal of Coal Combustion Residuals Rule

    EPA Pesticide Factsheets

    This page is to make accessible a list of the websites coal-fired power plants have created to post for the public to view with respect to their compliance with the disposal of coal combustion residuals final rule.

  19. Application of Foam-gel Technique to Control CO Exposure Generated During Spontaneous Combustion of Coal in Coal Mines.

    PubMed

    Ren, Xing W; Wang, Feng Z; Guo, Qing; Zuo, Zhao B; Fang, Qi S

    2015-01-01

    In China, 47.3% of state-owned coal mines are located in coal seams that are prone to spontaneous combustion. The spontaneous combustion of coal is the main cause of the generation of a large amount of carbon monoxide, which can cause serious health issues to miners. A new technique using foam-gel formation was developed to effectively control the spontaneous combustion of coal. The gel can capture more than 90% of the water in the grout and at the same time the foam can cover dangerous areas in the goaf by stacking and cooling of foam in all directions. In this study, a mechanism of foam-gel formation was introduced and the optimal proportions of additives were defined based on experiments of different foaming properties, gelling time and water loss rate as the main index parameters. The results of a field application in a coal mine promise that this new technique would effectively prevent coal oxidation in the goaf and reduce the generation of carbon monoxide.

  20. Analysis of Coals with Different Spontaneous Combustion Characteristics Using Infrared Spectrometry

    NASA Astrophysics Data System (ADS)

    Tang, Y.

    2015-05-01

    The relationship between the spontaneous combustion characteristics and the functional group distributions of coal was studied by analyzing different samples of coals using infrared spectroscopy. The analysis demonstrated that coal with a higher content of oxygen-containing functional groups and aliphatic hydrocarbons is more likely to spontaneously combust. Compared with coal which showed little spontaneous combustion tendency, coal, which is prone to spontaneous combustion, presented stretching bands of aromatic C=C at 1.604 cm-1, -CH2 at ~2857-2851 and 1443 cm-1, and C-O at 1030 cm-1 with the absorption peaks at those stretching bands showing the greatest difference. After being oxidized at low temperature, the aliphatic hydrocarbons and oxygen-containing functional groups changed significantly, while the absorption peak intensity of aromatic rings exhibited only slight changes. The results verified that diffuse reflectance Fourier transform infrared spectroscopy is an efficient method for investigating the spontaneous combustion characteristics and the variation of the active groups in the oxidation of coal at low temperature.

  1. A numerical analysis of pulverized coal combustion in a multiburner furnace

    SciTech Connect

    Nozomu Hashimoto; Ryoichi Kurose; Hirofumi Tsuji; Hiromi Shirai

    2007-08-15

    A three-dimensional numerical simulation is applied to a pulverized coal combustion field in a furnace equipped with three burners, and the trajectories of the coal particles with respect to each burner, which are hardly obtained experimentally, are also investigated in detail. Simulation results are compared with experimental results. The results show that the numerical and experimental results are consistent generally. Also, the examination of the particle trajectories shows that most of the unburned carbon originates from the upper-stage burner. This result suggests that the overall unburned fraction can be reduced by supplying coal with a low combustibility to lower- or middle-stage burners and supplying coal with a high combustibility to the upper-stage burner. 50 refs., 14 figs., 4 tabs.

  2. Analysis of the dynamics of coal char combustion with ignition and extinction phenomena: Shrinking core model

    SciTech Connect

    Sadhukhan, A.K.; Gupta, P.; Saha, R.K.

    2008-09-15

    Single-particle combustion of coal char is analyzed using a generalized shrinking core model. Finite volume method, which was earlier employed by the authors in solving moving boundary problems involving fluid-solid noncatalytic reactions in general, is used to solve fully transient mass and energy equations. The model takes into account convection and diffusion inside the particle as well as in the boundary layer. The computed results are compared with the experimental data of the authors for combustion of coal char in a fluidized bed combustor. The effects of parameters such as bulk temperature and initial particle radius on the combustion dynamics are examined. The phenomena of ignition and extinction are also investigated. Finally, the importance of Stefan flow, originating due to nonequimolar counterdiffusion, on combustion of coal char is analyzed.

  3. Physical structure changes of Canadian coals during combustion

    SciTech Connect

    Gentzis, T.; Chambers, A.

    1995-01-01

    A subbituminous (Coal A), and both high-volatile (Coal B) and low-volatile bituminous (Coal C) coals were chosen to examine coals of different rank and reactivity. Coal A and Coal B were very reactive, with burnouts of 95% and 88% achieved under stable operating conditions. Coal C was relatively unreactive. It was not possible to achieve a stable flame with the burnout decreasing below 50% in less than 1 h. Direct comparison of the partially burnt samples from the three coals was difficult because of the different reactivities. Coals A and B burned so rapidly that it was not possible to collect samples below 70% burnout. Conversely, it was not possible to generate samples of Coal C char at burnouts above 72%. Coal A showed a continuous decrease in particle size with burnout. Coal B showed a significant size decrease only before 70% burnout, whereas coal C actually increased in size up to 60% burnout, followed by a slight decrease. Surface area analysis of Coal A indicated a large surface area contained in micropores. At high levels of burnout (above 90%), the surface area decreased. The same behavior was observed for coal B. While coal C also showed this large increase in surface area, the decrease occurred at about 50% burnout, much earlier than for the other coals. Results of mercury porosimetry tests on the partially burnt samples revealed a significant change in the pore volume for both Coals A and B, while no large changes were observed for Coal C. It was difficult to draw any conclusions from the porosimetry results due to the different particle size of the chars and wide variance in the measurements.

  4. Characterizing the Leaching Behavior of Coal Combustion Residues using the Leaching Environmental Assessment Framework (LEAF) to Inform Future Management Decisions

    EPA Science Inventory

    Abstract for presentation on Characterizing the Leaching Behavior of Coal Combustion Residues using the Leaching Environmental Assessment Framework (LEAF) to Inform Future Management Decisions. The abstract is attached.

  5. Characterizing the Leaching Behavior of Coal Combustion Residues using the Leaching Environmental Assessment Framework (LEAF) to Inform Future Management Decisions

    EPA Science Inventory

    Abstract for presentation on Characterizing the Leaching Behavior of Coal Combustion Residues using the Leaching Environmental Assessment Framework (LEAF) to Inform Future Management Decisions. The abstract is attached.

  6. Nanominerals, fullerene aggregates, and hazardous elements in coal and coal combustion-generated aerosols: An environmental and toxicological assessment.

    PubMed

    Saikia, Jyotilima; Narzary, Bardwi; Roy, Sonali; Bordoloi, Manobjyoti; Saikia, Prasenjit; Saikia, Binoy K

    2016-12-01

    Studies on coal-derived nanoparticles as well as nano-minerals are important in the context of the human health and the environment. The coal combustion-generated aerosols also affect human health and environmental quality aspects in any coal-fired station. In this study, the feed coals and their combustion-generated aerosols from coal-fired boilers of two tea industry facilities were investigated for the presence of nanoparticles/nano minerals, fullerene aggregates, and potentially hazardous elements (PHEs). The samples were characterized by using X-ray diffraction (XRD), Time-of-flight secondary ion mass spectroscopy (TOF-SIMS), High resolution-transmission electron microscopy/energy dispersive spectroscopy (HR-TEM/EDS) and Ultra Violet-visible spectroscopy (UV-Vis) to know their extent of environmental risks to the human health when present in coals and aerosols. The feed coals contain mainly clay minerals, whilst glass fragments, spinel, quartz, and other minerals occur in lesser quantities. The PM samples contain potentially hazardous elements (PHEs) like As, Pb, Cd and Hg. Enrichment factor of the trace elements in particulate matters (PMs) was calculated to determine their sources. The aerosol samples were also found to contain nanomaterials and ultrafine particles. The fullerene aggregates along with potentially hazardous elements were also detected in the aerosol samples. The cytotoxicity studies on the coal combustion-generated PM samples show their potential risk to the human health. This detailed investigation on the inter-relationship between the feed coals and their aerosol chemistry will be useful for understanding the extent of environmental hazards and related human health risk.

  7. Development and testing of industrial scale, coal fired combustion system, Phase 3. Thirteenth quarterly technical progress report, January 1, 1995--March 31, 1995

    SciTech Connect

    Zauderer, B.

    1995-04-18

    The present report is a summary of the activities in February and March 1995. The primary activities during these two months was to monitor the fabricator of the combustor extension in order to assure completion of the work according to the design, to procure the additional components needed to install the combustor-boiler system at the Arsenal test site, and on initial installation of auxiliary components at the site. Welding of the combustor extension major sections began in mid-January. However, the quality of the welds was poor and a number of non-critical flanges were warped during welding. As a result the fabricator replaced the welders and the quality assurance personnel in early February. To assure that the welded sections would properly mate with the existing combustor, Coal Tech personnel regularly visited the fabricator until the end of March. The combustor extension section was completed and delivered to the Arsenal at the end of March. To meet the Philadelphia particulate emission standard of 0.06 lb/MMBtu a baghouse was procured in February. Competitive procurement of the stack ducting from the boiler to the baghouse and to the atmosphere was initiated. Pneumatically controlled valves for the combustor extension section`s air cooling sub-system were ordered and delivered.

  8. Air toxic emissions from the combustion of coal: Identifying and quantifying hazardous air pollutants from US coals

    SciTech Connect

    Szpunar, C.B.

    1992-09-01

    This report addresses the key air toxic emissions likely to emanate from continued and expanded use of domestic coal. It identifies and quantifies those trace elements specified in the US 1990 Clean Air Act Amendments, by tabulating selected characterization data on various source coals by region, state, and rank. On the basis of measurements by various researchers, this report also identifies those organic compounds likely to be derived from the coal combustion process (although their formation is highly dependent on specific boiler configurations and operating conditions).

  9. Air toxic emissions from the combustion of coal: Identifying and quantifying hazardous air pollutants from US coals

    SciTech Connect

    Szpunar, C.B.

    1992-09-01

    This report addresses the key air toxic emissions likely to emanate from continued and expanded use of domestic coal. It identifies and quantifies those trace elements specified in the US 1990 Clean Air Act Amendments, by tabulating selected characterization data on various source coals by region, state, and rank. On the basis of measurements by various researchers, this report also identifies those organic compounds likely to be derived from the coal combustion process (although their formation is highly dependent on specific boiler configurations and operating conditions).

  10. Environmental effects of increased coal utilization: ecological effects of gaseous emissions from coal combustion.

    PubMed Central

    Glass, N R

    1979-01-01

    This report is limited to an evaluation of the ecological and environmental effects of gaseous emissions and aerosols of various types which result from coal combustion. It deals with NOx, SOx, fine particulate, photochemical oxidant and acid precipitation as these pollutants affect natural and managed resources and ecosystems. Also, synergistic effects involving two or more pollutants are evaluated as well as ecosystem level effects of gaseous pollutants. There is a brief summary of the effects on materials and atmospheric visibility of increased coal combustion. The economic implications of ecological effects are identified to the extent they can be determined within acceptable limits. Aquatic and terrestrial effects are distinguished where the pollutants in question are clearly problems in both media. At present, acid precipitation is most abundant in the north central and northeastern states. Total SOx and NOx emissions are projected to remain high in these regions while increasing relatively more in the western than in the eastern regions of the country. A variety of ecological processes are affected and altered by air pollution. Such processes include community succession and retrogression, nutrient biogeochemical cycling, photosynthetic activity, primary and secondary productivity, species diversity and community stability. Estimates of the non health-related cost of air pollutants range from several hundred million dollars to $1.7 billion dollars per year. In general, these estimates include only those relatively easily measured considerations such as the known losses to cultivate crops from acute air pollution episodes or the cost of frequent repainting required as a result of air pollution. No substantial nationwide estimates of losses to forest productivity, natural ecosystem productivity which is tapped by domestic grazing animals and wildlife, and other significant dollar losses are available. PMID:44247

  11. Advanced coal-fueled gas turbine systems

    SciTech Connect

    Not Available

    1992-09-01

    Westinghouse's Advanced Coal-Fueled Gas Turbine System Program (DE-AC2l-86MC23167) was originally split into two major phases - a Basic Program and an Option. The Basic Program also contained two phases. The development of a 6 atm, 7 lb/s, 12 MMBtu/hr slagging combustor with an extended period of testing of the subscale combustor, was the first part of the Basic Program. In the second phase of the Basic Program, the combustor was to be operated over a 3-month period with a stationary cascade to study the effect of deposition, erosion and corrosion on combustion turbine components. The testing of the concept, in subscale, has demonstrated its ability to handle high- and low-sulfur bituminous coals, and low-sulfur subbituminous coal. Feeding the fuel in the form of PC has proven to be superior to CWM type feed. The program objectives relative to combustion efficiency, combustor exit temperature, NO[sub x] emissions, carbon burnout, and slag rejection have been met. Objectives for alkali, particulate, and SO[sub x] levels leaving the combustor were not met by the conclusion of testing at Textron. It is planned to continue this testing, to achieve all desired emission levels, as part of the W/NSP program to commercialize the slagging combustor technology.

  12. Advanced coal-fueled gas turbine systems

    SciTech Connect

    Not Available

    1991-09-01

    The combustion system discussed here incorporates a modular three- stage slagging combustor concept. Fuel-rich conditions inhibit NO{sub x} formation from fuel nitrogen in the first stage; also in the first stage, sulfur is captured with sorbent; coal ash and sulfated sorbent are removed from the combustion gases by inertial means in the second stage by the use of an impact separator and slagging cyclone separator in series. Final oxidation of the fuel-rich gases, and dilution to achieve the desired turbine inlet conditions are accomplished in the third stage, which is maintained sufficiently lean so that here, too, NO{sub x} formation is inhibited. The objective of this contract is to establish the technology required for subsequent commercial development and application by the private sector of utility-size direct coal-fueled gas turbines. Emissions from these units are to meet or be lower than the Environment Protection Agency's (EPA's) New Source Performance Standards (NSPS) for a pulverized coal-=fired steam turbine generator plant.

  13. Char Crystalline Transformations During Coal Combustion and Their Implication for Carbon Burnout

    SciTech Connect

    Hurt, Robert H

    1997-12-30

    temperatures approaching 3000 o C. For the measurement of temperature histories an optical diagnostic is being developed that offers sufficient spatial resolution to distinguish the sample temperature from the substrate temperature. The optical diagnostic is based on a CID camera, a high-power lens, and movable mirrors to projecting multiple, filtered images onto a single chip. Oxidation kinetics are measured on the heat treated samples by a nonisothermal TGA technique. Task 2 Thermal deactivation kinetics. The goal of this task is to quantify thermal char deactivation as a function of temperature history and parent coal, with an emphasis on inert environments at temperatures and times found in combustion systems. The results are to be cast in the form of deactivation kinetics useful for incorporation in combustion models.

  14. Combustion and emissions characterization of pelletized coal fuels. [Quarterly] technical report, March 1--May 31, 1993

    SciTech Connect

    Rajan, S.

    1993-09-01

    Pelletization of coal offers a means of utilizing coal fines which otherwise would be difficult to use. Other advantages of coal pelletization include: (a) utilization of low grade fuels such as preparation plant waste, (b) impregnation of pellets with calcium carbonate or calcium hydroxide sorbent for efficient sulfur removal, and (c) utilization of coal fines of low quality in combination with different types of binders. The objective of this project is to investigate the carbon conversion efficiency and SO{sub 2} and NO{sub x} emissions from combusting pelletized coal fuels made from preparation plant waste streams using both limestone and calcium hydroxide as sorbent and cornstarch and gasification tar as binders. The combustion performance of these pelletized fuels is compared with equivalent data from a reference run-of-mine coal. Six different samples of coal pellets have been secured from ISGS researchers. Combustion and emissions characterization of these pellets in the laboratory scale 4-inch diameter circulating fluidized bed have been performed on some of the pellet samples. The pellets burn readily, and provide good bed temperature control. Preliminary results show good carbon conversion efficiencies. Oxides of nitrogen emissions are quite low and sulfur dioxide emissions are as good as or lower than those from a representative run-of-mine coal.

  15. Statistical modeling of spontaneous combustion in industrial-scale coal stockpiles

    SciTech Connect

    Ozdeniz, H

    2009-07-01

    Companies consuming large amounts of coal should work with coal stocks in order to not face problems due to production delays. The industrial-scale stockpiles formed for the aforementioned reasons cause environmental problems and economic losses for the companies. This study was performed in a coal stock area of a large company in Konya, which uses large amounts of coal in its manufacturing units. The coal stockpile with 5 m width, 10 m length, 3 m height, and having 120 tons of weight was formed in the coal stock area of the company. The inner temperature data of the stockpile was recorded by 17 temperature sensors placed inside the stockpile at certain points. Additionally, the data relating to the air temperature, air humidity, atmospheric pressure, wind velocity, and wind direction that are the parameters affecting the coal stockpile were also recorded. A statistical model applicable for a spontaneous combustion event was developed during this study after applying multi-regression analyses to the data recorded in the stockpile during the spontaneous combustion event. The correlation coefficients obtained by the developed statistical model were measured approximately at a 0.95 level. Thus, the prediction of temperature variations influential in the spontaneous combustion event of the industrial-scale coal stockpiles will be possible.

  16. Prevention of trace and major element leaching from coal combustion products by hydrothermally-treated coal ash

    SciTech Connect

    Adnadjevic, B.; Popovic, A.; Mikasinovic, B.

    2009-07-01

    The most important structural components of coal ash obtained by coal combustion in 'Nikola Tesla A' power plant located near Belgrade (Serbia) are amorphous alumosilicate, alpha-quartz, and mullite. The phase composition of coal ash can be altered to obtain zeolite type NaA that crystallizes in a narrow crystallization field (SiO{sub 2}/Al{sub 2}O{sub 3}; Na{sub 2}O/SiO{sub 2}; H{sub 2}O/Na{sub 2}O ratios). Basic properties (crystallization degree, chemical composition, the energy of activation) of obtained zeolites were established. Coal ash extracts treated with obtained ion-exchange material showed that zeolites obtained from coal ash were able to reduce the amounts of iron, chromium, nickel, zinc, copper, lead, and manganese in ash extracts, thus proving its potential in preventing pollution from dump effluent waters.

  17. Development and testing of industrial scale, coal-fired combustion system, Phase 3. Nineteenth quarterly technical progress report, July 1, 1996--September 30, 1996

    SciTech Connect

    Zauderer, B.

    1996-10-27

    In the third quarter of calendar year 1996, 13 days of combust-boiler tests were performed, including 3 days of tests on a parallel DOE sponsored project on sulfur retention in a stagging combustor. Between tests, modifications and improvements that were indicated by these tests were implemented. This brings the total number of test days to the end of September in the task 5 effort to 41, increased to 46 as of the date of this Report, 10/27/96. This compares with a total of 63 test days needed to complete the task 5 test effort. As reported previously, the only major modification to the Williamsport combustor has been the addition of a new downstream section, which lengthens the combustor and improves the combustor-boiler interface. The original combustor section, which includes the fuel, air, and cooling water delivery systems remained basically unchanged. Only the refractory liner was completely replaced, a task which occurs on an annual basis in all commercial stagging utility combustors. Therefore, this combustor has been operated since 1988 without replacement.

  18. Influence of sulfur in coals on char morphology and combustion. Technical report, 1 September 1991--30 November 1991

    SciTech Connect

    Marsh, H.

    1991-12-31

    During coal carbonization (pyrolysis), as during the combustion process of pulverized coal in a combustor, not all of the sulfur is released. Significant proportions become pat of the structure of the resultant coke and char. The combustion process of the char within the flames of the combustor in influenced dominantly by char morphology. This, in turn, controls the accessibility of oxidizing gases to the surfaces of the carbonaceous substance of the char. Mineral matter content, its extent and state of distribution, also exerts an influence on char morphology created during pyrolysis/carbonization. This complexity of coal renders it a very difficult material to study, systematically, to distinguish and separate out the contributing factors which influence combustion characteristics. Therefore, in such circumstances, it is necessary to simplify the systems by making use of model chars/cokes/carbons which can be made progressively more complex, but in a controlled way. In this way complicating influence in chars from coals can be eliminated, so enabling specific influences to be studied independently. It is important to note that preliminary work by Marsh and Gryglewicz (1990) indicated that levels of sulfur of about 3 to 5 wt % can reduce reactivities by 10 to 25%. The overall purpose of the study is to provide meaningful kinetic data to establish, quantitatively, the influence of organically-bound sulfur on the reactivity of carbons, and to ascertain if gasification catalysts are effective in the preferential removal of sulfur from the chars.

  19. Co-combustion of coal and sewage sludge: chemical and ecotoxicological properties of ashes.

    PubMed

    Barbosa, Rui; Lapa, Nuno; Boavida, Dulce; Lopes, Helena; Gulyurtlu, Ibrahim; Mendes, Benilde

    2009-10-30

    The co-combustion of sewage sludge (SS) and coal is widely used for the treatment and thermal valorization of SS produced in wastewater treatment plants. The chemical and ecotoxicological properties of the ashes produced in this thermal treatment have not been fully studied. Two combustion tests were performed in a fluidized bed combustor. Colombian coal was used as fuel in test A. A blend (1+1) of this coal and a stabilized SS (Biogran) was used in a second test B. Samples of the bottom and fly ashes trapped in two sequential cyclones were collected. The characterization of the ashes was focused