A Model for Nitrogen Chemistry in Oxy-Fuel Combustion of Pulverized Coal

DEFF Research Database (Denmark)

Hashemi, Hamid; Hansen, Stine; Toftegaard, Maja Bøg

2011-01-01

, heating and devolatilization of particles, and gas–solid reactions. The model is validated by comparison with entrained flow reactor results from the present work and from the literature on pulverized coal combustion in O2/CO2 and air, covering the effects of fuel, mixing conditions, temperature......In this work, a model for the nitrogen chemistry in the oxy-fuel combustion of pulverized coal has been developed. The model is a chemical reaction engineering type of model with a detailed reaction mechanism for the gas-phase chemistry, together with a simplified description of the mixing of flows......, stoichiometry, and inlet NO level. In general, the model provides a satisfactory description of NO formation in air and oxy-fuel combustion of coal, but under some conditions, it underestimates the impact on NO of replacing N2 with CO2. According to the model, differences in the NO yield between the oxy...

Fluidized bed and pulverized coal combustion residues for secondary pavements

International Nuclear Information System (INIS)

Ghafoori, N.; Diawara, H.; Wang, L.

2009-01-01

The United States produced nearly 125 million tons of coal combustion products in 2006. These by-products include fly ash, flue gas desulphurization materials, bottom ash, boiler slag, and other power plant by-products. The expense associated with waste disposal, lack of disposal sites, and significant environmental damage linked with the disposal of coal combustion residues have encouraged innovative utilization strategies such as the fluidized bed combustion (FBC) unit. This paper presented the results of a laboratory investigation that examined the properties of composites developed with different proportions of pre-conditioned FBC spent bed, pulverized coal combustion fly ash, natural fine aggregate, and Portland cement. The purpose of the study was to examine the extent to which the by-product composites could replace currently used materials in secondary roads. The paper presented the research objectives and experimental programs, including matrix constituent and proportions; mixture proportions; and mixing, curing, sampling, and testing. The discussion of results centered around compressive strength and expansion by internal sulfate attack. It was concluded that with proper proportioning, by-products of pulverized and fluidized bed combustion promote binding of sand particles and provide adequate strength under various curing and moisture conditions 4 refs., 6 tabs.

Pyrolysis of superfine pulverized coal. Part 4. Evolution of functionalities in chars

International Nuclear Information System (INIS)

Liu, Jiaxun; Ma, Yang; Luo, Lei; Ma, Junfang; Zhang, Hai; Jiang, Xiumin

2017-01-01

Highlights: • A combination of XPS and NMR is adopted for analyzing char chemical structures during superfine pulverized coal pyrolysis. • The chemisorbed NO can be transformed into pyridine N with the favor of adjacent oxygenated groups in chars. • Particle size has significant influence on oxygen-containing configurations in chars. - Abstract: The properties of the coal-derived char play crucial roles in coal conversion reactions and the formation of air pollutants. The nascent char is highly reactive due to the existence of numerous free radicals, active sites, and organic functional groups on its surface. Here, we showed that a combination of nuclear magnetic resonance spectroscopy (NMR) and X-ray photoelectron spectroscopy (XPS) techniques is an effective and precise way to characterize the occurrence, distribution, and evolution of organic functionalities in coal chars. Using these methods, we explored detailed information about chemical features of superfine pulverized coal chars in different atmospheres, and we also discussed the influence of particle size on the evolutionary behavior of functionalities. Results indicate that, in both N_2 and CO_2 atmospheres, the content of C−O species increases with the reduction in char particle sizes. This increment facilitates the heterogeneous reduction of NOx on char surfaces. The chemisorbed NO is susceptible to being incorporated into chars, and being transformed into pyridine-type nitrogen with the favor of adjacent oxygen-containing groups. Moreover, the significant increment in oxygen-containing groups with the reduction of particle size is further confirmed through "1"3C NMR analysis. It was shown that there is an excellent correlation between estimates derived from XPS and NMR for oxygen configuration. The findings from this work provide some new insights into NOx reduction mechanisms and shed light on the practical application of superfine pulverized coal in the future.

Combustion of pulverized coal in counter-current flow

Energy Technology Data Exchange (ETDEWEB)

Timnat, Y M; Goldman, Y [Technion-Israel Inst. of Tech., Haifa (Israel). Faculty of Aerospace Engineering

1991-01-01

In this report we describe the results obtained with two prototypes of pulverized coal combustors operating in counter-current flow, one at atmospheric pressure, the other at higher pressure and compare them to the predictions of a theoretical-numerical model, we have developed. The first prototype treats a vertical configuration, eight times larger than the one treated before (Hazanov et al. 1985), while in the second a horizontal arrangement with a smaller volume is studied. Attention was focused on particle trajectories, burnout, angle of injection, ash separation by rotational motion, effects of initial particle size and temperature, impingement velocity and the effect of gravity. Main development activity was directed to achieving stable and reliable coal burning in the combustors.

Online X-ray Fluorescence (XRF) Analysis of Heavy Metals in Pulverized Coal on a Conveyor Belt.

Science.gov (United States)

Yan, Zhang; XinLei, Zhang; WenBao, Jia; Qing, Shan; YongSheng, Ling; DaQian, Hei; Da, Chen

2016-02-01

Heavy metals in haze episode will continue to threaten the quality of public health around the world. In order to decrease the emission of heavy metals produced from coal burning, an online X-ray fluorescence (XRF) analyzer system, consisting of an XRF analyzer with data acquisition software and a laser rangefinder, was developed to carry out the measurement of heavy metals in pulverized coal. The XRF analyzer was mounted on a sled, which can effectively smooth the surface of pulverized coal and reduce the impact of surface roughness during online measurement. The laser rangefinder was mounted over the sled for measuring the distance between a pulverized coal sample and the analyzer. Several heavy metals and other elements in pulverized coal were online measured by the XRF analyzer directly above a conveyor belt. The limits of detection for Hg, Pb, Cr, Ti, Fe, and Ca by the analyzer were 44 ± 2, 34 ± 2, 17 ± 3, 41 ± 4, 19 ± 3, and 65 ± 2 mg·kg(-1), respectively. The relative standard deviation (%RSD) for the elements mentioned was less than 7.74%. By comparison with the results by inductively-coupled plasma mass spectrometry (ICP-MS), relative deviation (%D) of the online XRF analyzer was less than 10% for Cr, Ti, and Ca, in the range of 0.8-24.26% for Fe, and greater than 20% for Hg and Pb. © The Author(s) 2016.

Relationship between Particle Size Distribution of Low-Rank Pulverized Coal and Power Plant Performance

Directory of Open Access Journals (Sweden)

Rajive Ganguli

2012-01-01

Full Text Available The impact of particle size distribution (PSD of pulverized, low rank high volatile content Alaska coal on combustion related power plant performance was studied in a series of field scale tests. Performance was gauged through efficiency (ratio of megawatt generated to energy consumed as coal, emissions (SO2, NOx, CO, and carbon content of ash (fly ash and bottom ash. The study revealed that the tested coal could be burned at a grind as coarse as 50% passing 76 microns, with no deleterious impact on power generation and emissions. The PSD’s tested in this study were in the range of 41 to 81 percent passing 76 microns. There was negligible correlation between PSD and the followings factors: efficiency, SO2, NOx, and CO. Additionally, two tests where stack mercury (Hg data was collected, did not demonstrate any real difference in Hg emissions with PSD. The results from the field tests positively impacts pulverized coal power plants that burn low rank high volatile content coals (such as Powder River Basin coal. These plants can potentially reduce in-plant load by grinding the coal less (without impacting plant performance on emissions and efficiency and thereby, increasing their marketability.

Enhanced Combustion Low NOx Pulverized Coal Burner

Energy Technology Data Exchange (ETDEWEB)

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

Pyrolysis of superfine pulverized coal. Part 3. Mechanisms of nitrogen-containing species formation

International Nuclear Information System (INIS)

Liu, Jiaxun; Jiang, Xiumin; Shen, Jun; Zhang, Hai

2015-01-01

Highlights: • NH 3 and NO formation mechanisms during superfine pulverized coal pyrolysis are investigated. • Influences of temperature, heating rate, particle size, atmosphere, and acid wash on the NH 3 and NO formation are analyzed. • Transformations of nitrogen-containing structures in coal/char during pyrolysis are recognized through XPS observation. • Relationships among nitrogen-containing gaseous species during pyrolysis are discussed. - Abstract: With more stringent regulations being implemented, elucidating the formation mechanisms of nitrogen-containing species during the initial pyrolysis step becomes important for developing new NO x control strategies. However, there is a lack of agreement on the origins of NO x precursors during coal pyrolysis, in spite of extensive investigations. Hence, it is important to achieve a more precise knowledge of the formation mechanisms of nitrogen-contain species during coal pyrolysis. In this paper, pyrolysis experiments of superfine pulverized coal were performed in a fixed bed at low heating rates. The influences of temperature, coal type, particle size and atmosphere on the NH 3 and NO evolution were discussed. There is a central theme to develop knowledge of the relationship between particle sizes and evolving behaviors of nitrogen-containing species. Furthermore, the catalytic role of inherent minerals in coal was proved to be effective on the partitioning of nitrogen during coal pyrolysis. In addition, the conversion pathways of heteroaromatic nitrogen structures in coal/char during pyrolysis were recognized through the X-ray photoelectron spectroscopy (XPS) analysis. Large quantities of pyridinic and quanternary nitrogen functionalities were formed during the thermal degradation. Finally, the relationships among the nitrogen-containing gaseous species during coal pyrolysis were discussed. In brief, a comprehensive picture of the volatile-nitrogen partitioning during coal pyrolysis is obtained in this

Deposit formation in a full-scale pulverized wood-fired power plant with and without coal fly ash addition

DEFF Research Database (Denmark)

Wu, Hao; Shafique Bashir, Muhammad; Jensen, Peter Arendt

2013-01-01

Ash transformation and deposition in a pulverized wood-fired power plant boiler of 800 MWth were studied with and without the addition of coal fly ash. The transient ash deposition behavior was investigated by using an advanced deposit probe system at two different boiler locations with flue gas...... at the low-temperature location showed a slow initial build-up and a stable mass of deposits after approximately 1-5 h. The deposits collected during pulverized wood combustion contained a considerable amount of K2SO4, KCl, and KOH/K2CO3. With the addition of coal fly ash (~4 times of the mass flow of wood...... ash) to the boiler, these alkali species were effectively removed both in the fly ash and in the deposits, and a more frequent shedding of the deposits was observed. The results imply that coal fly ash can be an effective additive to reduce ash deposition and corrosion problems in a pulverized wood...

Low NO{sub x} burner modifications to front-fired pulverized coal boilers

Energy Technology Data Exchange (ETDEWEB)

Broderick, R G; Wagner, M

1998-07-01

Madison Gas and Electric Blount Street Station Units 8 and 9 are Babcock and Wilcox pulverized coal fired and natural gas fired boilers. These boilers were build in the late 1950's and early 1960's with each boiler rated at 425,000 lb./hr of steam producing 50 MW of electricity. The boilers are rated at 9,500 F at 1,350 psig. Each unit is equipped with one Ljungstroem air heater and two B and W EL pulverizers. These units burn subbituminous coal with higher heating value of 10,950 Btu/LB on an as-received basis. The nitrogen content is approximately 1.23% with 15% moisture. In order to comply with the new Clean Air Act Madison Gas and Electric needs to reduce NO{sub x} on these units to less than .5 LB/mmBtu. Baseline NO{sub x} emissions on these units range between .8--.9 lb./mmBtu. LOIs average approximately 8%. Madison Gas and Electric contracted with RJM Corporation to modify the existing burners to achieve this objective. These modifications consisted of adding patented circumferentially and radially staged flame stabilizers, modifying the coal pipe, and replacing the coal impeller with a circumferentially staged coal spreader. RJM Corporation utilized computational fluid dynamics modeling in order to design the equipment to modify these burners. The equipment was installed during the March 1997 outage and start-up and optimization was conducted in April 1997. Final performance results and economic data will be included in the final paper.

Physical and chemical characterization of 50 pulverized coal ashes with respect to partial cement replacement in concrete

Energy Technology Data Exchange (ETDEWEB)

Van der Sloot, H A; Weijers, E G

1986-04-01

Physical and chemical characterization of 50 pulverized coal ashes from Dutch, Belgian and German installations has been carried out to identify the parameters that have to be kept under control, when pulverized coal ashes are to be used as partial cement replacement in concrete. For a good workability of fly ash/cement mortars the particle size and the carbon content are important. By performing a mortar flow test (Heagermann) upon delivery exterme ashes can be easily eliminated. The compressive strength is largely determined by the fineness of the ash (weight fraction below 20 micron). A direct effect of carbon content on strength development is not observed, but a reduction in mortar slow due to carbon leads to loss in strength, while the workability has to be adjusted. Size distribution measurement by optical methods is recommended as the relevant part of the ash size distribution cannot be properly assessed by sieve methods. The net contribution of fly ash to the compressive strength of a fly ash/cement (20/80) mortar exhibits a minimum at 14 days curing, which is common to all 50 ashes studied. Improvements in ash quality as obtained from pulverized-coal fired installations can be achieved by improvements in coal milling and optimizing ash collection. 6 figs., 4 tabs., 19 refs.

Numerical simulation of pulverized coal combustion to reduce pollutants

International Nuclear Information System (INIS)

Mohammad Bagher Ayani; Behnam Rahmanian

2010-01-01

Full text: In this research, the numerical simulation of pollutant reduction and in a pulverized coal combustion at 2D combustion chamber have been studied. Finite volume method using structured grid arrangement was utilized for modeling the pulverized coal combustion. The pressure base algorithm and implicit solver has been employed to simulate non-premix combustion model. The air was diluted by some participative gaseous such as whose percentages varied from 0 % to 20 %. Participative gases and air were preheated by a high-temperature gas generator, and the preheated oxidizer temperature could achieve. The combustion simulation with the generalized finite rate chemistry model, referred to as the Magnussen model and the reacting flow with the mixture fraction PDF/ equilibrium chemistry model, referred to as the PDF model are studied. Quick scheme was adopted for the discretization of all convective terms of the advective transport equations. So, as a result of addition participative gases into oxidizer the rate of formation of pollutants as well as NO x suppressed. The addition only a few percent of halogen components can make some systems nonflammable. The effects of addition halogen components and non-reaction gaseous such as Helium and Argon are fuel dilution and its acts as catalysts in reducing the H atom concentration necessary for the chain branching reaction sequence. Moreover, they act like surface and they make the increment of surface ratio versus volume. Because of this, the number of radical conflicts and hence destruction them will be increase. Furthermore, the rate of formation of pollutants will be decreased if the halogen components and non-reaction gaseous injection will be increased. However, as a result of this research, in the case of injection in pulverized coal combustion the flame temperature is lower than Steam, Argon and Helium. So, the emission levels of carbon dioxide is significantly lower than other participative gases, but in this

Gasification in pulverized coal flames. Final report (Part I). Pulverized coal combustion and gasification in a cyclone reactor: experiment and model

Energy Technology Data Exchange (ETDEWEB)

Barnhart, J. S.; Laurendeau, N. M.

1979-05-01

A unified experimental and analytical study of pulverized coal combustion and low-BTU gasification in an atmospheric cyclone reactor was performed. Experimental results include several series of coal combustion tests and a coal gasification test carried out via fuel-rich combustion without steam addition. Reactor stability was excellent over a range of equivalence ratios from .67 to 2.4 and air flowrates from 60 to 220 lb/hr. Typical carbon efficiencies were 95% for air-rich and stoichiometric tests and 80% for gasification tests. The best gasification results were achieved at an equivalence ratio of 2.0, where the carbon, cold gas and hot gas efficiencies were 83, 45 and 75%, respectively. The corresponding product gas heating value was 70 BTU/scf. A macroscopic model of coal combustion in the cyclone has been developed. Fuel-rich gasification can also be modeled through a gas-phase equilibrium treatment. Fluid mechanics are modeled by a particle force balance and a series combination of a perfectly stirred reactor and a plug flow reactor. Kinetic treatments of coal pyrolysis, char oxidation and carbon monoxide oxidation are included. Gas composition and temperature are checked against equilibrium values. The model predicts carbon efficiency, gas composition and temperature and reactor heat loss; gasification parameters, such as cold and hot gas efficiency and make gas heating value, are calculated for fuel-rich conditions. Good agreement exists between experiment and theory for conditions of this investigation.

Novel fragmentation model for pulverized coal particles gasification in low temperature air thermal plasma

Directory of Open Access Journals (Sweden)

Jovanović Rastko D.

2016-01-01

Full Text Available New system for start-up and flame support based on coal gasification by low temperature air thermal plasma is planned to supplement current heavy oil system in Serbian thermal power plants in order to decrease air pollutions emission and operational costs. Locally introduced plasma thermal energy heats up and ignites entrained coal particles, thus starting chain process which releases heat energy from gasified coal particles inside burner channel. Important stages during particle combustion, such as particle devolatilisation and char combustion, are described with satisfying accuracy in existing commercial CFD codes that are extensively used as powerful tool for pulverized coal combustion and gasification modeling. However, during plasma coal gasification, high plasma temperature induces strong thermal stresses inside interacting coal particles. These stresses lead to “thermal shock” and extensive particle fragmentation during which coal particles with initial size of 50-100 m disintegrate into fragments of at most 5-10 m. This intensifies volatile release by a factor 3-4 and substantially accelerates the oxidation of combustible matter. Particle fragmentation, due to its small size and thus limited influence on combustion process is commonly neglected in modelling. The main focus of this work is to suggest novel approach to pulverized coal gasification under high temperature conditions and to implement it into commercial comprehensive code ANSYS FLUENT 14.0. Proposed model was validated against experimental data obtained in newly built pilot scale D.C plasma burner test facility. Newly developed model showed very good agreement with experimental results with relative error less than 10%, while the standard built-in gasification model had error up to 25%.

Volatile release and particle formation characteristics of injected pulverized coal in blast furnaces

International Nuclear Information System (INIS)

Chen, Wei-Hsin; Du, Shan-Wen; Yang, Tsung-Han

2007-01-01

Volatiles release and particle formation for two kinds of pulverized coals (a high volatile bituminous coal and a low volatile bituminous coal) in a drop tube furnace are investigated to account for the reactions of pulverized coal injected in blast furnaces. Two different sizes of feed particles are considered; one is 100-200 mesh and the other is 200-325 mesh. By evaluating the R-factor, the devolatilization extent of the larger feed particles is found to be relatively poor. However, the swelling behavior of individual or two agglomerated particles is pronounced, which is conducive to gasification of the chars in blast furnaces. In contrast, for the smaller feed particles, volatiles liberated from the coal particles can be improved in a significant way as a result of the amplified R-factor. This enhancement can facilitate the performance of gas phase combustion. Nevertheless, the residual char particles are characterized by agglomeration, implying that the reaction time of the char particles will be lengthened, thereby increasing the possibility of furnace instability. Double peak distributions in char particle size are observed in some cases. This possibly results from the interaction of the plastic state and the blowing effect at the particle surface. Considering the generation of tiny aerosols composed of soot particles and tar droplets, the results indicate that their production is highly sensitive to the volatile matter and elemental oxygen contained in the coal. Comparing the reactivity of the soot to that of the unburned char, the former is always lower than the latter. Consequently, the lower is the soot formation, the better is the blast furnace stability

Reconstruction of the aero-mixture channels of the pulverized coal plant of the 100MW power plant unit

Directory of Open Access Journals (Sweden)

Ivanovic Vladan B.

2011-01-01

Full Text Available After the last revitalization of thermal power block of 100 MW in TPP “Kostolac A”, made in the year 2004, during the operation of the plant, pulverized coal deposition often occurred in horizontal sections of the aero-mixture channels. Deposition phenomenon manifested itself in places ahead of spherical compensators in the direction of flow of pulverized coal to the burners, due to unfavorable configuration of these channels. Coal dust deposited in the channels dried and spontaneously combusted, causing numerous damage to channels and its isolation as well as the frequent stoppage of the operation for necessary interventions. The paper presents the original solution of reconstruction of aero-mixture channels which prevented deposition of coal dust and its eventual ignition. In this way the reliability of the mill plant is maximized and higher availability of boiler and block as a whole is achieved.

Pulverized coal burnout in blast furnace simulated by a drop tube furnace

Energy Technology Data Exchange (ETDEWEB)

Du, Shan-Wen [Steel and Aluminum Research and Development Department, China Steel Corporation, Kaohsiung 812 (China); Chen, Wei-Hsin [Department of Greenergy, National University of Tainan, Tainan 700 (China); Lucas, John A. [School of Engineering of the University of Newcastle, Callaghan, NSW 2308 (Australia)

2010-02-15

Reactions of pulverized coal injection (PCI) in a blast furnace were simulated using a drop tube furnace (DTF) to investigate the burnout behavior of a number of coals and coal blends. For the coals with the fuel ratio ranging from 1.36 to 6.22, the experimental results indicated that the burnout increased with decreasing the fuel ratio, except for certain coals departing from the general trend. One of the coals with the fuel ratio of 6.22 has shown its merit in combustion, implying that the blending ratio of the coal in PCI operation can be raised for a higher coke replacement ratio. The experiments also suggested that increasing blast temperature was an efficient countermeasure for promoting the combustibility of the injected coals. Higher fuel burnout could be achieved when the particle size of coal was reduced from 60-100 to 100-200 mesh. However, once the size of the tested coals was in the range of 200 and 325 mesh, the burnout could not be improved further, resulting from the agglomeration of fine particles. Considering coal blend reactions, the blending ratio of coals in PCI may be adjusted by the individual coal burnout rather than by the fuel ratio. (author)

Examination of flame length for burning pulverized coal in laminar flow reactor

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Dong; Kim, Gyu Bo; Chang, Young June; Song, Ju Hun; Jeon, Chung Hwan [Pusan National University, Busan (Korea, Republic of)

2010-12-15

Because there has been a recent increase in the use of low calorific coal compared to standard coal, it is crucial to control the char flame length governing the burning life-time of coal in a coal-fired utility boiler. The main objective of this study is to develop a simplified model that can theoretically predict the flame length for burning coal in a laboratory-scale entrained laminar flow reactor (LFR) system. The char burning behavior was experimentally observed when sub-bituminous pulverized coal was fed into the LFR under burning conditions similar to those in a real boiler: a heating rate of 1000 K/s, an oxygen molar fraction of 7.7 %, and reacting flue gas temperatures ranging from 1500 to 2000 K. By using the theoretical model developed in this study, the effect of particle size on the coal flame length was exclusively addressed. In this model, the effect of particle mass was eliminated to compare with the experimental result performed under a constant mass feeding of coal. Overall, the computed results for the coal flame length were in good agreement with the experimental data, particularly when the external oxygen diffusion effect was considered in the model

Examination of flame length for burning pulverized coal in laminar flow reactor

International Nuclear Information System (INIS)

Kim, Jae Dong; Kim, Gyu Bo; Chang, Young June; Song, Ju Hun; Jeon, Chung Hwan

2010-01-01

Because there has been a recent increase in the use of low calorific coal compared to standard coal, it is crucial to control the char flame length governing the burning life-time of coal in a coal-fired utility boiler. The main objective of this study is to develop a simplified model that can theoretically predict the flame length for burning coal in a laboratory-scale entrained laminar flow reactor (LFR) system. The char burning behavior was experimentally observed when sub-bituminous pulverized coal was fed into the LFR under burning conditions similar to those in a real boiler: a heating rate of 1000 K/s, an oxygen molar fraction of 7.7 %, and reacting flue gas temperatures ranging from 1500 to 2000 K. By using the theoretical model developed in this study, the effect of particle size on the coal flame length was exclusively addressed. In this model, the effect of particle mass was eliminated to compare with the experimental result performed under a constant mass feeding of coal. Overall, the computed results for the coal flame length were in good agreement with the experimental data, particularly when the external oxygen diffusion effect was considered in the model

Modeling and optimization of processes for clean and efficient pulverized coal combustion in utility boilers

Directory of Open Access Journals (Sweden)

Belošević Srđan V.

2016-01-01

Full Text Available Pulverized coal-fired power plants should provide higher efficiency of energy conversion, flexibility in terms of boiler loads and fuel characteristics and emission reduction of pollutants like nitrogen oxides. Modification of combustion process is a cost-effective technology for NOx control. For optimization of complex processes, such as turbulent reactive flow in coal-fired furnaces, mathematical modeling is regularly used. The NOx emission reduction by combustion modifications in the 350 MWe Kostolac B boiler furnace, tangentially fired by pulverized Serbian lignite, is investigated in the paper. Numerical experiments were done by an in-house developed three-dimensional differential comprehensive combustion code, with fuel- and thermal-NO formation/destruction reactions model. The code was developed to be easily used by engineering staff for process analysis in boiler units. A broad range of operating conditions was examined, such as fuel and preheated air distribution over the burners and tiers, operation mode of the burners, grinding fineness and quality of coal, boiler loads, cold air ingress, recirculation of flue gases, water-walls ash deposition and combined effect of different parameters. The predictions show that the NOx emission reduction of up to 30% can be achieved by a proper combustion organization in the case-study furnace, with the flame position control. Impact of combustion modifications on the boiler operation was evaluated by the boiler thermal calculations suggesting that the facility was to be controlled within narrow limits of operation parameters. Such a complex approach to pollutants control enables evaluating alternative solutions to achieve efficient and low emission operation of utility boiler units. [Projekat Ministarstva nauke Republike Srbije, br. TR-33018: Increase in energy and ecology efficiency of processes in pulverized coal-fired furnace and optimization of utility steam boiler air preheater by using in

EXPERIMENTS AND COMPUTATIONAL MODELING OF PULVERIZED-COAL IGNITION; FINAL

International Nuclear Information System (INIS)

Samuel Owusu-Ofori; John C. Chen

1999-01-01

Under typical conditions of pulverized-coal combustion, which is characterized by fine particles heated at very high rates, there is currently a lack of certainty regarding the ignition mechanism of bituminous and lower rank coals as well as the ignition rate of reaction. furthermore, there have been no previous studies aimed at examining these factors under various experimental conditions, such as particle size, oxygen concentration, and heating rate. Finally, there is a need to improve current mathematical models of ignition to realistically and accurately depict the particle-to-particle variations that exist within a coal sample. Such a model is needed to extract useful reaction parameters from ignition studies, and to interpret ignition data in a more meaningful way. The authors propose to examine fundamental aspects of coal ignition through (1) experiments to determine the ignition temperature of various coals by direct measurement, and (2) modeling of the ignition process to derive rate constants and to provide a more insightful interpretation of data from ignition experiments. The authors propose to use a novel laser-based ignition experiment to achieve their first objective. Laser-ignition experiments offer the distinct advantage of easy optical access to the particles because of the absence of a furnace or radiating walls, and thus permit direct observation and particle temperature measurement. The ignition temperature of different coals under various experimental conditions can therefore be easily determined by direct measurement using two-color pyrometry. The ignition rate-constants, when the ignition occurs heterogeneously, and the particle heating rates will both be determined from analyses based on these measurements

A theoretical approach to the restoration of azulejos by re-firing

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João Manuel Mimoso

2016-01-01

Full Text Available LNEC found, as a by-product of another research project, that in at least some cases, glazed ceramic tiles (azulejos could be restored by re-firing. The re-firing of façade glazed tiles as a viable alternative to their outright dumping should, in principle, present no doubts. However the mere idea of restoring in the kiln brings forth methodologic arguments unparalleled in other restoration techniques. The present communication discusses the re-firing of azulejos based on theoretical restoration principles, aiming to demonstrate that it cannot be discarded straightforwardly without considering individually its advantages and possible applications. However, and although no damaging consequences where identified, the eventual application of this method to azulejos that are not considered as industrial products still requires complementary studies regarding its long-term dangerousness.

Flat-flame burner studies of pulverized-coal combustion. Experimental results on char reactivity

Energy Technology Data Exchange (ETDEWEB)

Peck, R.E.; Shi, L.

1996-12-01

Structure of laminar, premixed pulverized-coal flames in a 1-D reactor has been studied with emphasis on char reactivity. A 1.1-meter-long tube furnace accommodated high-temperature environments and long residence times for the laminar flames produced by a flat-flame, coal-dust burner. Experiments were conducted at different operating conditions (fuel type/size, fuel-air ratio). Measurements included solid sample composition, major gas species and hydrocarbon species concentrations, and gas- and particle-phase line-of-sight temperatures at different axial locations in flames. Degree of char burnout increased with coal volatiles content and decreased with coal particle size. Combustion in furnace was in oxidizer-deficient environment and higher burnout was achieved as the fuel-air ratio neared stoichiometric. For 0-45 {mu}m particles most of the fixed carbon mass loss occurred within 5 cm of the furnace inlet, and char reaction was slow downstream due to low oxidizer concentrations. Fixed carbon consumption of the 45-90 {mu}m particles generally was slower than for the small particles. About 40%-80% of the fixed carbon was oxidized in the furnace. Primary volatiles mass loss occurred within the first 4.5 cm, and more than 90% of the volatiles were consumed in the flames. The flames stabilized in the furnace produced less CH{sub 4} and H{sub 2} in the burnt gas than similar unconfined flames. NO concentrations were found to decrease along the furnace and to increase with decreasing fuel/air ratio. Temperature measurement results showed that gas-phase temperatures were higher than solid-phase temperatures. Temperatures generally decreased with decreasing volatiles content and increased as the equivalence ratio approached one. The results can be used to interpret thermochemical processes occurring in pulverized-coal combustion. (au) 15 refs.

A Pulverized Coal-Fired Boiler Optimized for Oxyfuel Combustion Technology

Directory of Open Access Journals (Sweden)

Tomáš Dlouhý

2012-01-01

Full Text Available This paper presents the results of a study on modifying a pulverized coal-fired steam boiler in a 250 MWe power plant for oxygen combustion conditions. The entry point of the study is a boiler that was designed for standard air combustion. It has been proven that simply substituting air by oxygen as an oxidizer is not sufficient for maintaining a satisfactory operating mode, not even with flue gas recycling. Boiler design optimization aggregating modifications to the boiler’s dimensions, heating surfaces and recycled flue gas flow rate, and specification of a flue gas recycling extraction point is therefore necessary in order to achieve suitable conditions for oxygen combustion. Attention is given to reducing boiler leakage, to which external pre-combustion coal drying makes a major contribution. The optimization is carried out with regard to an overall power plant conception for which a decrease in efficiency due to CO2 separation is formulated.

Simulation of blast furnace operation during the substitution of coke and pulverized coal with granulated waste plastic

Directory of Open Access Journals (Sweden)

Kovačević Tihomir M.

2014-01-01

Full Text Available The possibility of using the waste plastic as reducing agent in blast furnace for obtaining pig iron is in focus for the past couple year. The simulation of blast furnace process in BFC software has been performed in order to analyze the coke and coals saving, CO2 emission and determining the economic benefits. Three different batches were made for comparative analysis, depending on the batch composition and input of batch components into the blast furnace: case 1 (C1, case 2 (C2 and case 3 (C3. The base case, C1 contains sinter (bulk material which is needed for obtaining 1 tone of pig iron, quartz which provides slag alkalinity and coke as reducing and energy agent. C2 has the same components as C1, but contains pulverized coal instead one part of coke and C3 contains granulated waste plastic instead coke in an approximately the same amount as pulverized coal. The substitution of coke with pulverized coal and waste plastic is 18.6 % and 25.2 %, respectively. The economic, productivity and ecologic aspects have been analyzed. The consumption of each tone of waste plastic in blast furnace saves 360 $, which is 18 times more than its price, bearing in mind that the market price of coke is 380 $/t % and waste plastic 20 $/t. Regarding the specific productivity, it decreases from 2.13 for C1 to 1.87 for C3. From an environmental aspect there are two main benefits: reduction of CO2 emission and impossibility of dioxin formation. The CO2 emission was 20.18, 19.46 and 17.21 for C1, C2 and C3, respectively.

A simple numerical model to estimate the effect of coal selection on pulverized fuel burnout

Energy Technology Data Exchange (ETDEWEB)

Sun, J.K.; Hurt, R.H.; Niksa, S.; Muzio, L.; Mehta, A.; Stallings, J. [Brown University, Providence, RI (USA). Division Engineering

2003-06-01

The amount of unburned carbon in ash is an important performance characteristic in commercial boilers fired with pulverized coal. Unburned carbon levels are known to be sensitive to fuel selection, and there is great interest in methods of estimating the burnout propensity of coals based on proximate and ultimate analysis - the only fuel properties readily available to utility practitioners. A simple numerical model is described that is specifically designed to estimate the effects of coal selection on burnout in a way that is useful for commercial coal screening. The model is based on a highly idealized description of the combustion chamber but employs detailed descriptions of the fundamental fuel transformations. The model is validated against data from laboratory and pilot-scale combustors burning a range of international coals, and then against data obtained from full-scale units during periods of coal switching. The validated model form is then used in a series of sensitivity studies to explore the role of various individual fuel properties that influence burnout.

Conceptual designs of pressurized fluidized bed and pulverized coal fired power plants

International Nuclear Information System (INIS)

Doss, H.S.; Bezella, W.A.; Hamm, J.R.; Pietruszkiewicz, J.

1984-01-01

This paper presents the major technical and economic characteristics of steam and air-cooled pressurized fluidized bed (PFB) power plant concepts, along with the characteristics of a pulverized coal fired power plant equipped with an adipic acid enhanced wet-limestone flue gas desulfurization system. Conceptual designs for the three plants were prepared to satisfy a set of common groundrules developed for the study. Grassroots plants, located on a generic plant site were assumed. The designs incorporate technologies projected to be commercial in the 1990 time frame. Power outputs, heat rates, and costs are presented

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

International Nuclear Information System (INIS)

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

2017-01-01

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 (CO 2 , H 2 O, 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. - Highlights: • A Monte Carlo–based nongray radiation solver is developed to study effects of radiation. • Radiation alters the lift-off height, and the distribution of temperature andspecies for the target flame. • Radiation alters the heat transfer mechanism of medium

Determining the radiative properties of pulverized-coal particles from experiments. Final report

Energy Technology Data Exchange (ETDEWEB)

Menguec, M.P.

1992-02-01

A comprehensive coupled experimental-theoretical study has been performed to determine the effective radiative properties of pulverized-coal/char particles. The results obtained show that the ``effective`` scattering phase function of coal particles are highly forward scattering and show less sensitivity to the size than predicted from the Lorenz-Mie theory. The main reason for this is the presence of smaller size particles associated with each larger particle. Also, the coal/char particle clouds display more side scattering than predicted for the same size range spheres, indicating the irregular shape of the particles and fragmentation. In addition to these, it was observed that in the visible wavelength range the coal absorption is not gray, and slightly vary with the wavelength. These two experimental approaches followed in this study are unique in a sense that the physics of the problem are not approximated. The properties determined include all uncertainties related to the particle shape, size distribution, inhomogeneity and spectral complex index of refraction data. In order to obtain radiative property data over a wider wavelength spectrum, additional ex-situ experiments have been carried out using a Fourier Transform Infrared (FT-IR) Spectrometer. The spectral measurements were performed over the wavelength range of 2 to 22 {mu}m. These results were interpreted to obtain the ``effective`` efficiency factors of coal particles and the corresponding refractive index values. The results clearly show that the coal/char radiative properties display significant wavelength dependency in the infrared spectrum.

Effect of the Reburning Zone Stoichiometry on the Nox Concentration at the Three-Stage Combustion of Pulverized Coal

Directory of Open Access Journals (Sweden)

Chernetskaya Nelya

2016-01-01

Full Text Available Numerical study of heat and mass transfer taking into account the combustion of coal particles in the furnace at the three-stage combustion of pulverized coal was performed. Analysis of the reburning zone stoichiometry on the concentration of nitrogen oxides at the furnace outlet was made. The values of excess air in the primary and reburning combustion zones, providing for the concentration of nitrogen oxides at the furnace outlet is not more than 350 mg/m3 and unburned carbon not more than 1 % when burning coal with a high content of nitrogen were established.

Experimental investigation on NO{sub x} emission and carbon burnout from a radially biased pulverized coal whirl burner

Energy Technology Data Exchange (ETDEWEB)

Xue, Shan; Hui, Shi' en; Zhou, Qulan; Xu, Tongmo; Hu, Hongli [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Liu, Taisheng [Dongfang Boiler Group Co., Ltd., Zigong, Sichuan 643001 (China)

2009-09-15

Experiments have been performed on 1 MW pulverized coal (pc) furnace in order to investigate the characteristics of coal combustion and NO{sub x} emission from a new type of radially biased dual register whirl burner. The burner is characterized by a primary air pipe with a continuously changing cross-section and an impact ring. The mixture of pulverized coal and air inside the primary pipe is split into two streams, which are the outer pc rich annular jet and the inner pc lean annular jet respectively. Three Chinese coals, which are high rank bituminous coal, low rank bituminous coal and meager coal respectively, are used in the experiments. We examine the influences of various parameters such as the relative position of the over-fire air (OFA) nozzle, over-fire air ratio (19.1%), primary air ratio, inner secondary air ratio, outer secondary air ratio, inner secondary air swirling intensity, and outer secondary air swirling intensity on NO{sub x} formation and unburned carbon in fly ash. With the primary air ratio increasing from 13.4% to 23.4%, the value of the NO{sub x} emission of the SH coal decreases by 26.7% at first, and then increases by 21.7%. In contrast, the value of the carbon in fly ash (C{sub FA}) increases by 40.1% at first, and then decreases by 58.3%. According to the experimental results, the influence of each individual parameter on NO{sub x} formation and unburned carbon in fly ash agrees well with the existing literature. In this study, the influences of various combinations of these parameters are also examined, thus providing some reference for the design of the radial biased whirl burner, the configuration of the furnace and the distribution of the air. (author)

REDUCING THE INTENSITY OF TAKEAWAY PULVERIZED COAL BY USING SPECIAL SOLUTION

Directory of Open Access Journals (Sweden)

M. M. Biliaiev

2017-04-01

Full Text Available Purpose. The article is aimed: 1 to develop the coal coating solution in open railway cars or to cover coal piles to minimize the coal dust losses; 2 creating a mathematical model of the process of the solution feeding to the surface of coal. Methodology. To solve this problem, it was developed a special solution containing cheap industrial wastes and semiproducts of chemical industries. It was conducted a physical experiment to assess the intensity of coal dust loss when using the developed solution. A mathematical model based on the use of the motion equations of the ideal fluid and mass transfer was developed. The developed numerical models are the basis of the application program package created for assessing the quality of processing the coal surface by special solution. Findings. The results of the conducted physical experiment to assess the magnitude of the coal dust loss on the model of the coal pile in the processing of its surface with a special solution and without processing are presented in the article. It is shown that the application of the proposed solution for surface processing of coal can significantly reduce the coal dust loss. This makes it possible to reduce the amount of economic losses and reduce the level of air dust pollution in work areas. The results of computational experiments carried out on the basis of the constructed numerical models are presented in the article. Originality. Authors proposed a new solution for the coal surface processing in order to minimize the removal of pulverized coal from the coal pile, which substantially reduces the coal losses. There were created numerical models to take into account the relevant factors influencing the solution dispersion process in the atmosphere from coal processing in gondola cars. Practical value. Solution, proposed in the article has a low price, because it can be created on the basis of industrial production wastes. Application of this solution can significantly

CFD modelling and analysis of pulverized coal injection in blast furnace: an overview

Energy Technology Data Exchange (ETDEWEB)

Shen, Yansong; Yu, Aibing [Laboratory for Simulation and Modelling of Particulate Systems, School of Materials Science and Engineering, The University of New South Wales (UNSW), Sydney, NSW 2052 (Australia); Zulli, Paul [BlueScope Steel Research (BSR), P.O. Box 202, Port Kembla, NSW 2505 (Australia)

2011-05-15

In order to understand the complicated phenomena of pulverized coal injection (PCI) process in blast furnace (BF), several mathematical models have been developed by the UNSW and BSR cooperation. These models are featuring from coal combustion in a pilot-scale test rig, to coal combustion in a real BF, and then to coal/coke combustion in a real BF, respectively. This paper reviews these PCI models in aspects of model developments and model applicability. The model development is firstly discussed in terms of model formulation, their new features and geometry/regions considered. The model applicability is then discussed in terms of main findings followed by the model evaluation on their advantages and limitations. It is indicated that the three PCI models are all able to describe PCI operation qualitatively. The model of coal/coke combustion in a real BF is more reliable for simulating in-furnace phenomena of PCI operation qualitatively and quantitatively. Such model gives a more reliable burnout prediction over the raceway surface, which could better represent the amount of unburnt char entering the coke bed. These models are useful for understanding the flow-thermo-chemical behaviours and then optimising the PCI operation in practice. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Pulverized coal burner

Science.gov (United States)

Sivy, J.L.; Rodgers, L.W.; Koslosy, J.V.; LaRue, A.D.; Kaufman, K.C.; Sarv, H.

1998-11-03

A burner is described having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO{sub x} burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO{sub x} back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing. 8 figs.

Transformations and affinities for sulfur of Chinese Shenmu coal ash in a pulverized coal-fired boiler

Energy Technology Data Exchange (ETDEWEB)

Cheng, J.; Zhou, J.H.; Liu, J.Z.; Cao, X.Y.; Cen, K.F. [Zhejiang University, Hangzhou (China)

2009-07-01

The self-desulfurization efficiency of Shenmu coal with a high initial Ca/S molar ratio of 2.02 was measured in a 1,025 t/h pulverized coal-fired boiler. It increases from 29% to 32% when the power capacity decreases from 100% to 70%. About 60% of the mineral matter and calcium element fed into the furnace is retained in the fly ash, while less than 10% is retained in the bottom ash. About 70% of the sulfur element fed into the furnace is emitted as SO{sub 2} in the flue gas, while less than 10% is retained in the fly ash and less than 1% is retained in the bottom ash. The mineralogical compositions of feed coal, fly ash, and bottom ash were obtained by X-ray diffraction analysis. It is found that the initial amorphous phase content is 91.17% and the initial CaCO{sub 3} phase content is 2.07% in Shenmu coal. The vitreous phase and sulfation product CaSO{sub 4} contents are, respectively, 70.47% and 3.36% in the fly ash obtained at full capacity, while the retained CaCO{sub 3} and CaO contents are, respectively, 4.73% and 2.15%. However, the vitreous phase content is only 25.68% and no CaSO{sub 4} is detected in the bottom ash obtained at full capacity. When the power capacity decreases from 100% to 70%, the vitreous phase content in fly ash decreases from 70.47% to 67.41% and that in bottom ash increases from 25.68% to 28.10%.

Impact of Coal Fly Ash Addition on Combustion Aerosols (PM2.5) from Full-Scale Suspension-Firing of Pulverized Wood

DEFF Research Database (Denmark)

Damø, Anne Juul; Wu, Hao; Frandsen, Flemming

2014-01-01

The formation of combustion aerosols was studied in an 800 MWth suspension-fired power plant boiler, during combustion of pulverized wood pellets with and without addition of coal fly ash as alkali capture additive. The aerosol particles were sampled and characterized by a low-pressure cascade im...

REFIR/BB initial observations in the water vapour rotational band: Results from a field campaign

International Nuclear Information System (INIS)

Esposito, F.; Grieco, G.; Leone, L.; Restieri, R.; Serio, C.; Bianchini, G.; Palchetti, L.; Pellegrini, M.; Cuomo, V.; Masiello, G.; Pavese, G.

2007-01-01

There is a growing interest in the far infrared spectral region 17-50 μm as a remote sensing tool in atmospheric sciences, since this portion of the spectrum contains the characteristic molecular rotational band for water vapour. Much of the Earth energy lost to space is radiated through this spectral region. The Radiation Explorer in the Far InfraRed Breadboard (REFIR/BB) spectrometer was born because of the quest to make observations in the far infrared. REFIR/BB is a Fourier Transform Spectrometer with a sampling resolution of 0.5 cm -1 and it was tested for the first time in the field to check its reliability and radiometric performance. The field campaign was held at Toppo di Castelgrande (40 o 49' N, 15 o 27' E, 1258 m a. s. l.), a mountain site in South Italy. The spectral and radiometric performance of the instrument and initial observations are shown in this paper. Comparisons to both (1) BOMEM MR100 Fourier Transform spectrometer observations and (2) line-by-line radiative transfer calculations for selected clear sky are presented and discussed. These comparisons (1) show a very nice agreement between radiance measured by REFIR/BB and by BOMEM MR100 and (2) demonstrate that REFIR/BB accurately observes the very fine spectral structure in the water vapour rotational band

The effects of re-firing process under oxidizing atmosphere and temperatures on the properties of strontium aluminate phosphors

International Nuclear Information System (INIS)

Karacaoglu, Erkul; Karasu, Bekir

2013-01-01

Graphical abstract: The comparative emission spectra of standard and re-fired Phosphor A under oxidizing atmosphere at various temperatures. The colour of Phosphor A re-fired at higher temperatures above 900 °C shifted from yellowish-green to bluish-green in the dark. But, the bluish-green emission could only be seen when it was exposed to UV and disappeared as soon as the light source was removed. Moreover, the emission intensities decreased as the re-firing temperatures increased. This could be attributed to the oxidation of Eu 2+ during the re-firing process. It is well known fact from the literature that the reduction of Eu 3+ to Eu 2+ in appropriate host materials needs an annealing process in a reducing atmosphere such as H 2 , H 2 /N 2 mixture or CO. Up to now, the reduction phenomena of Eu 3+ → Eu 2+ in air have been found in phosphates (Ba 3 (PO 4 ) 2 :Eu), sulphates (BaSO 4 :Eu), borates (SrB 4 O 7 :Eu, SrB 6 O 10 :Eu and BaB 8 O 13 :Eu) and aluminates (Sr 4 Al 14 O 25 :Eu). Interestingly, an apparent blue shift in the phosphorescence spectrum was observed in the samples re-fired at 1000 °C and above, indicating a minimal effect on the oxidation state or the electronic energy levels of the co-doped Dy 3+ ions, which were thought to act as long-lived hole traps resulting in long afterglow. - Highlights: • This study examines the effects re-firing at oxidizing atmosphere of photoluminescence of three different commercial SrAl 2 O 4 :Eu 2+ ,Dy 3+ -phosphors. • All the commercial SrAl 2 O 4 :Eu 2+ ,Dy 3+ -phosphors completely lost their phosphorescence after being re-fired at 1300 °C. • Oxidizing environment and re-firing temperature naturally affecting the valance of Eu 2+ may cause the basic lattice structure to be modified and also limit their applications at higher temperatures, such as third firing vetrosa décor or glaze applications in ceramic industry. • It was thought that this kind of study may be promising to provide many outcome

PASSIVE CONTROL OF PARTICLE DISPERSION IN A PARTICLE-LADEN CIRCULAR JET USING ELLIPTIC CO-ANNULAR FLOW: A MEANS FOR IMPROVING UTILIZATION AND EMISSION REDUCTIONS IN PULVERIZED COAL BURNER

Energy Technology Data Exchange (ETDEWEB)

Ahsan R. Choudhuri

2003-06-01

A passive control technology utilizing elliptic co-flow to control the particle flinging and particle dispersion in a particle (coal)-laden flow was investigated using experimental and numerical techniques. Preferential concentration of particles occurs in particle-laden jets used in pulverized coal burner and causes uncontrollable NO{sub x} formation due to inhomogeneous local stoichiometry. This particular project was aimed at characterizing the near-field flow behavior of elliptic coaxial jets. The knowledge gained from the project will serve as the basis of further investigation on fluid-particle interactions in an asymmetric coaxial jet flow-field and thus is important to improve the design of pulverized coal burners where non-homogeneity of particle concentration causes increased NO{sub x} formation.

Aspects on prediction of two-phase reacting flow in a swirl-stabilized pulverized coal flame

Energy Technology Data Exchange (ETDEWEB)

Wennerberg, D. (LSTM, Erlangen (Germany))

1991-01-01

Knowledge of NO{sub x} formation routes in a pulverized coal flame is essential for understanding the problematics. Coal-bound N is the dominated source of NO{sub x} in a pf flame. The so-called 'thermal' NO{sub x} plays a minor role, since the temperature level is lower in a pf flame than in a gas - or oilfired flame. The coalbound N is mainly released along with the volatiles in the coal as HCN. This release takes place in the central recirculation zone when the coal is first heated up. The continued reaction processes of the HCN take different paths, dependent on whether the burner near field zone is fuel-rich or fuel-lean: Under fuel-rich conditions: HCN {yields} CN {yields} N{sub 2}. Under fuel-lean conditions: HCN {yields} NH/NCO {yields} NO. This reaction scheme is strongly simplified in order to clarify the main influence of the aerodynamics on the NO{sub x} formation. Concentration of radicals O, OH, H are also important for the reaction routes as well as the residence time for the coal particles under respective conditions. The conditions for reactions are however determined largely by the aerodynamics of the near-field burner zone. (orig./GL).

Detailed model for practical pulverized coal furnaces and gasifiers

Energy Technology Data Exchange (ETDEWEB)

Philips, S.D.; Smoot, L.D.

1989-08-01

The need to improve efficiency and reduce pollutant emissions commercial furnaces has prompted energy companies to search for optimized operating conditions and improved designs in their fossil-fuel burning facilities. Historically, companies have relied on the use of empirical correlations and pilot-plant data to make decisions about operating conditions and design changes. The high cost of collecting data makes obtaining large amounts of data infeasible. The main objective of the data book is to provide a single source of detailed three-dimensional combustion and combustion-related data suitable for comprehensive combustion model evaluation. Five tasks were identified as requirements to achieve the main objective. First, identify the types of data needed to evaluate comprehensive combustion models, and establish criteria for selecting the data. Second, identify and document available three-dimensional combustion data related to pulverized coal combustion. Third, collect and evaluate three-dimensional data cases, and select suitable cases based on selection criteria. Fourth, organize the data sets into an easy-to-use format. Fifth, evaluate and interpret the nature and quality of the data base. 39 refs., 15 figs., 14 tabs.

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

Science.gov (United States)

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%.

Distribution of trace elements in selected pulverized coals as a function of particle size and density

Science.gov (United States)

Senior, C.L.; Zeng, T.; Che, J.; Ames, M.R.; Sarofim, A.F.; Olmez, I.; Huggins, Frank E.; Shah, N.; Huffman, G.P.; Kolker, A.; Mroczkowski, S.; Palmer, C.; Finkelman, R.

2000-01-01

Trace elements in coal have diverse modes of occurrence that will greatly influence their behavior in many coal utilization processes. Mode of occurrence is important in determining the partitioning during coal cleaning by conventional processes, the susceptibility to oxidation upon exposure to air, as well as the changes in physical properties upon heating. In this study, three complementary methods were used to determine the concentrations and chemical states of trace elements in pulverized samples of four US coals: Pittsburgh, Illinois No. 6, Elkhorn and Hazard, and Wyodak coals. Neutron Activation Analysis (NAA) was used to measure the absolute concentration of elements in the parent coals and in the size- and density-fractionated samples. Chemical leaching and X-ray absorption fine structure (XAFS) spectroscopy were used to provide information on the form of occurrence of an element in the parent coals. The composition differences between size-segregated coal samples of different density mainly reflect the large density difference between minerals, especially pyrite, and the organic portion of the coal. The heavy density fractions are therefore enriched in pyrite and the elements associated with pyrite, as also shown by the leaching and XAFS methods. Nearly all the As is associated with pyrite in the three bituminous coals studied. The sub-bituminous coal has a very low content of pyrite and arsenic; in this coal arsenic appears to be primarily organically associated. Selenium is mainly associated with pyrite in the bituminous coal samples. In two bituminous coal samples, zinc is mostly in the form of ZnS or associated with pyrite, whereas it appears to be associated with other minerals in the other two coals. Zinc is also the only trace element studied that is significantly more concentrated in the smaller (45 to 63 ??m) coal particles.

Kinetic extruder - a dry pulverized solid material pump

Science.gov (United States)

Meyer, J. W.; Bonin, J. H.; Daniel, A. D. Jr.

1983-03-15

Method and apparatus are shown for the continuous feeding of pulverized material to a high pressure container. A rotor is located within the high pressure container. The pulverized material is fed from a feed hopper through a stationary feed pipe to a vented spin-up chamber to a plurality of two-stage sprues mounted in the rotor. Control nozzles downstream from the sprues meter the flow of coal through the sprues. 19 figs.

Numerical analysis of loads effect on combustion performance and NO{sub x} emissions of a 220 MW pulverized coal boiler

Energy Technology Data Exchange (ETDEWEB)

Li, Jun; Yang, Weihong; Blasiak, Wlodzimierz [Royal Institute of Technology (KTH), Stockholm (Sweden). Div. of Energy and Furnace Technology; Jankowski, Radoslaw; Kotecki, Michal; Szewczyk, Dariusz [Industrial Combustion Systems (ICS) Company, Poznan (Poland); Brzdekiewicz, Artur [Remak-Rozruch SA, Opole (Poland)

2013-07-01

This paper presents numerical study on the combustion performance and NO{sub x} emissions of a 220 MW pulverized coal boiler. Three different loads have been simulated with combusting coal, 200, 170 and 140 MW, respectively. In order to get as precise as possible numerical analysis results, two-step simulation method has been adopted in this work, namely, air supply system simulation and furnace simulation. After air supply system simulation, the results have been taken as the initial and boundary conditions for furnace simulation. The comparison between the measured values and predicted results from 200 MW case shows much better agreement. According to the simulation results, the adopted two-step simulation method is reasonable and suitable for predicting the characters of the flow and combustion process. It is concluded that the distributions of temperature, O{sub 2} and CO concentration inside furnace with different loads shows good similarly. The total NOx emissions decreased with the boiler load reducing, and fuel NO{sub x} has the same trend as total NO{sub x}, and fuel NO{sub x} account for about 66% in total NO{sub x} in all the three cases. More important, thermal NO{sub x} slowly decreased with the rise of boiler load. More detailed results presented in this paper enhance the understanding of combustion processes and complex flow patterns of front-wall pulverized coal boilers.

Effect of the parameters of a straight-through pulverized coal spray on formation of nitrogen oxides

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.

1987-04-01

Experiments were conducted on varying the parameters affecting intensity of the mixing process at the starting point of a pulverized coal spray. Investigations were carried out using Donetsk black coal in a BKZ-210-140FZhSh steam generator equipped with a tangential combustion chamber. The plant featured liquid slag removal and direct blow-in as well as a medium-speed model VSM-140 mill. Four experiments were conducted in which gas samples were taken from the combustion chamber and analyzed for RO/sub 2/ and O/sub 2/ as well as CO and H/sub 2/. A relationship between reducing gases at the starting point of the torch and the initial air feed factor was demonstrated. Experiments were conducted to determine a relationship between NO/sub x/ concentrations in exhaust gases and the initial air feed factor. 5 refs.

Computational Fluid Dynamics (CFD) Modeling for High Rate Pulverized Coal Injection (PCI) to Blast Furnaces

International Nuclear Information System (INIS)

Zhou, Chenn

2008-01-01

Pulverized coal injection (PCI) into the blast furnace (BF) has been recognized as an effective way to decrease the coke and total energy consumption along with minimization of environmental impacts. However, increasing the amount of coal injected into the BF is currently limited by the lack of knowledge of some issues related to the process. It is therefore important to understand the complex physical and chemical phenomena in the PCI process. Due to the difficulty in attaining trus BF measurements, Computational fluid dynamics (CFD) modeling has been identified as a useful technology to provide such knowledge. CFD simulation is powerful for providing detailed information on flow properties and performing parametric studies for process design and optimization. In this project, comprehensive 3-D CFD models have been developed to simulate the PCI process under actual furnace conditions. These models provide raceway size and flow property distributions. The results have provided guidance for optimizing the PCI process

Risk management of energy efficiency projects in the industry - sample plant for injecting pulverized coal into the blast furnaces

OpenAIRE

Jovanović Filip P.; Berić Ivana M.; Jovanović Petar M.; Jovanović Aca D.

2016-01-01

This paper analyses the applicability of well-known risk management methodologies in energy efficiency projects in the industry. The possibilities of application of the selected risk management methodology are demonstrated within the project of the plants for injecting pulverized coal into blast furnaces nos. 1 and 2, implemented by the company US STEEL SERBIA d.o.o. in Smederevo. The aim of the project was to increase energy efficiency through the reductio...

Exergetic and environmental analysis of a pulverized coal power plant

International Nuclear Information System (INIS)

Restrepo, Álvaro; Miyake, Raphael; Kleveston, Fábio; Bazzo, Edson

2012-01-01

This paper presents the results of exergetic and environmental analysis of a typical pulverized coal power plant located in Brazil. The goal was to quantify both the exergy destruction and the environmental impact associated with a thermal power plant. The problem boundary consists of the entire coal delivery route, including mining and beneficiation, transport, pre-burning processes and the power plant. The used data were obtained mainly from field measurements taken in all system processes, from mining to the power plant. The study focused only on the operation period. Previous works have shown that the construction and decommissioning periods contribute less than 1% of the environmental impact. The exergetic analysis was based on the second law of thermodynamics while the environmental analysis was based on life cycle assessment (LCA) using SimaPro 7.2, focussing on the climate change and acidification impact categories. The CO 2 -eq emission was 1300 kg per MWh. The highest degree of environmental impact occurred during the combustion process. The exergetic and environmental analysis provides a tool to evaluate irreversibilities and the environmental impact, identifying the most significant stages and equipment of the entire power generation process. -- Highlights: ► Exergetic and environmental analysis of a typical Brazilian PC power plant. ► Environmental impact associated with the mining, transport and thermal power plant. ► Life cycle assessment used for environmental analysis. ► Acidification impact category evaluated using Eco-indicator 99. ► Climate change impact evaluation using (Global Warming Potential) GWP 100a.

Burning characteristics and gaseous/solid emissions of blends of pulverized coal with waste tire-derived fuel

Energy Technology Data Exchange (ETDEWEB)

Levendis, Y.A.; Atal, A.; Courtemanche, B.; Carlson, J.B. [Northeastern University, Boston, MA (United States). Dept. of Mechanical, Industrial and Manufacturing Engineering

1998-10-01

The combustion behaviour and the emissions from blends of a pulverized bituminous coal and ground waste automobile tires were investigated. Combustion took place under steady flow conditions, in an electrically-heated drop-tube furnace in air at a gas temperature of 1150{degree}C and a particle heating rate of approximate to 10{sup 5}{degree}C/s. Combustion observations were conducted with simultaneous pyrometry and cinematography. Interparticle flame interactions were visually observed in the near-stoichiometric and fuel-rich regions. Volatile flame interactions were apparent at a lower phi for tire crumb particles than for coal particles and became progressively more intense with increasing phi until at sufficiently high phi`s large group flames formed for tire particles. As particle flame interactions increased, average maximum temperatures in the flame decreased. Coal particles resisted the formation of group flames, even at high phi`s. Such observations correlated with the trends observed for the PAH emissions of the two fuels, those of tire crumb being much higher than those of coal Some stratification in the combustion of blends of particles of the two fuels was observed. This kept the PAH emissions lower levels than expected. NO{sub x} emissions from tires were much lower than those of coal, while those of the blends were close to the weighted average emissions. SO{sub 2} emissions from the blends were close to the weighted average emissions of the two fuels. Blending coal with tire reduced the CO{sub 2} emissions of coal but increased the CO emissions. Particulate emissions (soot and ash), measured in the range of 0.4 to 8{mu}m, increased with phi. Generally, tire produced more mass of submicron particulates than coal. Particulate emissions of blends of the two fuels were close to those expected based on weighted average of the two fuels.

Achievement report for fiscal 1999 on project for supporting the formation of energy/environmental technology verification project. International joint verification research project (Verification project relative to ignition and NOx reduction using plasma sub-burner in pulverized coal-fired furnace); 1999 nendo plasma sabubana ni yoru bifuntan nenshoro ni okeru chakka oyobi NO{sub x} teigen gijutsu ni kansuru jissho project seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

This project is executed through the cooperation of a Russian research institute, Akita Prefectural University, and the Ishikawajima-Harima Heavy Industries Co., Ltd. In the development of a plasma sub-burner and the basic research for its verification, a pulverized coal burning plasma sub-burner is designed and fabricated, a basic burning experiment is conducted for the plasma sub-burner, and plasma stabilization in a pulverized coal flow is simulated. In the verification study of the ignition by the plasma sub-burner in a pulverized coal-fired furnace, it is found that the newly-developed plasma sub-burner satisfies the prescribed operating conditions in the system and that the ignition of pulverized coal takes place across the air ratio range of 0.5-1.5 when pulverized coal is fed to the sub-burner. It is also found that NOx is reduced a great deal when a plasma operating on an orifice gas of air or nitrogen is generated in a gas which contains NOx. (NEDO)

Coal pump

Science.gov (United States)

Bonin, John H.; Meyer, John W.; Daniel, Jr., Arnold D.

1983-01-01

A device for pressurizing pulverized coal and circulating a carrier gas is disclosed. This device has utility in a coal gasification process and eliminates the need for a separate collection hopper and eliminates the separate compressor.

Means and apparatus for throttling a dry pulverized solid material pump

Science.gov (United States)

Meyer, J. W.; Daniel, Jr, A. D.; Bonin, J. H.

1982-12-07

Method and apparatus are shown for control of continuous feeding of pulverized material to a high pressure container. A rotor is located within the high pressure container. The pulverized material is fed from a feed hopper through a stationary feed pipe to a vented spin-up zone chamber to a plurality of sprues mounted in the rotor. Control of the pressure within control nozzles downstream from the sprues adjusts the flow rate of coal through the sprues. 9 figs.

Estimation of Moisture Content in Coal in Coal Mills

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Mataji, B.

the moisture content of the coal is proposed based on a simple dynamic energy model of a coal mill, which pulverizes and dries the coal before it is burned in the boiler. An optimal unknown input observer is designed to estimate the moisture content based on an energy balance model. The designed moisture...

Estimation of Moisture Content in Coal in Coal Mills

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Mataji, Babak

2006-01-01

the moisture content of the coal is proposed based on a simple dynamic energy model of a coal mill, which pulverizes and dries the coal before it is burned in the boiler. An optimal unknown input observer is designed to estimate the moisture content based on an energy balance model. The designed moisture...

Development of I and C system for the coal feeder of coal firing plant

Energy Technology Data Exchange (ETDEWEB)

Kim, Teak Soo; Park, Chan Ho [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

1996-12-31

KECC(Kepco Coal Feeder Control System) receives coal weight, conveyor speed and boiler demand signals. It controls coal flow by generating speed signal of feeder which conveys coal in hopper to pulverizer, displaying measured coal quantity and providing local auto and manual manipulator (author). 33 figs.

The application of RANS CFD for design of SNCR technology for a pulverized coal-fired boiler

Directory of Open Access Journals (Sweden)

Ruszak Monika

2017-06-01

Full Text Available The article describes the technology of NOx emission abatement by SNCR method. The scope of research included CDF simulations as well as design and construction of the pilot plant and tests of NOx reduction by urea in the plant located in industrial pulverized-coal fired boiler. The key step of research was to determine the appropriate temperature window for the SNCR process. The proposed solution of the location of injection lances in the combustion chamber enabled to achieve over a 30% reduction of NOx. It is possible to achieve higher effectiveness of the proposed SNCR technology and meet the required emission standards via providing prior reduction of NOx to the level of 350 mg/um3 using the primary methods.

DEVELOPMENT OF A NOVEL RADIATIVELY/CONDUCTIVELY STABILIZED BURNER FOR SIGNIFICANT REDUCTION OF NOx EMISSIONS AND FOR ADVANCING THE MODELING AND UNDERSTANDING OF PULVERIZED COAL COMBUSTION AND EMISSIONS

Energy Technology Data Exchange (ETDEWEB)

Noam Lior; Stuart W. Churchill

2003-10-01

The primary objective of the proposed study was the study and analysis of, and design recommendations for, a novel radiatively-conductively stabilized combustion (RCSC) process for pulverized coal, which, based on our prior studies with both fluid fuels and pulverized coal, holds a high promise to reduce NO{sub x} production significantly. We have primarily engaged in continuing and improving our process modeling and analysis, obtained a large amount of quantitative information about the effects of the major parameters on NO{sub x} production, conducted an extensive exergy analysis of the process, evaluated the practicalities of employing the Radiatively-Conductively Stabilized Combustor (RCSC) to large power and heat plants, and improved the experimental facility. Prior experimental work has proven the feasibility of the combustor, but slagging during coal combustion was observed and should be dealt with. The primary outcomes and conclusions from the study are: (1) we developed a model and computer program that represents the pulverized coal combustion in the RCSC, (2) the model predicts that NO{sub x} emissions can be reduced by a number of methods, detailed in the report. (3) the exergy analysis points out at least a couple of possible ways to improve the exergetic efficiency in this combustor: increasing the effectiveness of thermal feedback, and adjusting the combustor mixture exit location, (4) because of the low coal flow rates necessitated in this study to obtain complete combustion in the burner, the size of a burner operating under the considered conditions would have to be up to an order of magnitude, larger than comparable commercial burners, but different flow configurations of the RCSC can yield higher feed rates and smaller dimensions, and should be investigated. Related to this contract, eleven papers were published in journals and conference proceedings, and ten invited presentations were given at university and research institutions, as well as at

Oxy-coal Combustion Studies

Energy Technology Data Exchange (ETDEWEB)

Wendt, J. [Univ. of Utah, Salt Lake City, UT (United States); Eddings, E. [Univ. of Utah, Salt Lake City, UT (United States); Lighty, J. [Univ. of Utah, Salt Lake City, UT (United States); Ring, T. [Univ. of Utah, Salt Lake City, UT (United States); Smith, P. [Univ. of Utah, Salt Lake City, UT (United States); Thornock, J. [Univ. of Utah, Salt Lake City, UT (United States); Y Jia, W. Morris [Univ. of Utah, Salt Lake City, UT (United States); Pedel, J. [Univ. of Utah, Salt Lake City, UT (United States); Rezeai, D. [Univ. of Utah, Salt Lake City, UT (United States); Wang, L. [Univ. of Utah, Salt Lake City, UT (United States); Zhang, J. [Univ. of Utah, Salt Lake City, UT (United States); Kelly, K. [Univ. of Utah, Salt Lake City, UT (United States)

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.

Pulverized coal devolatilization prediction

International Nuclear Information System (INIS)

Rojas, Andres F; Barraza, Juan M

2008-01-01

The aim of this study was to predict the two bituminous coals devolatilization at low rate of heating (50 Celsius degrade/min), with program FG-DVC (functional group Depolymerization. Vaporization and crosslinking), and to compare the devolatilization profiles predicted by program FG-DVC, which are obtained in the thermogravimetric analyzer. It was also study the volatile liberation at (10 4 k/s) in a drop-tube furnace. The tar, methane, carbon monoxide, and carbon dioxide, formation rate profiles, and the hydrogen, oxygen, nitrogen and sulphur, elemental distribution in the devolatilization products by FG-DVC program at low rate of heating was obtained; and the liberation volatile and R factor at high rate of heating was calculated. it was found that the program predicts the bituminous coals devolatilization at low rate heating, at high rate heating, a volatile liberation around 30% was obtained

CFD analysis of the pulverized coal combustion processes in a 160 MWe tangentially-fired-boiler of a thermal power plant

Energy Technology Data Exchange (ETDEWEB)

Silva, Cristiano V. da; Beskow, Arthur B. [Universidade Regional Integrada do Alto Uruguai e das Misses (LABSIM/GEAPI/URI), Erechim, RS (Brazil). Dept. de Engenharia e Ciencia da Computacao. Grupo de Engenharia Aplicada a Processos Industriais], Emails: cristiano@uricer.edu.br, Arthur@uricer.edu.br; Indrusiak, Maria Luiza S. [Universidade do Vale do Rio dos Sinos (UNISINOS), Sao Leopoldo, RS (Brazil). Programa de Engenharia Mecanica], E-mail: sperbindrusiak@via-rs.net

2010-10-15

The strategic role of energy and the current concern with greenhouse effects, energetic and exegetic efficiency of fossil fuel combustion greatly enhance the importance of the studies of complex physical and chemical processes occurring inside boilers of thermal power plants. The state of the art in computational fluid dynamics and the availability of commercial codes encourage numeric studies of the combustion processes. In the present work the commercial software CFX Ansys Europe Ltd. was used to study the combustion of coal in a 160 MWe commercial thermal power plant with the objective of simulating the operational conditions and identifying factors of inefficiency. The behavior of the flow of air and pulverized coal through the burners was analyzed, and the three-dimensional flue gas flow through the combustion chamber and heat exchangers was reproduced in the numeric simulation. (author)

Assessing coal burnout

Energy Technology Data Exchange (ETDEWEB)

Lowe, A. [Pacific Power, Sydney, NSW (Australia)

1999-11-01

Recent research has allowed a quantitative description of the basic process of burnout for pulverized coals to be made. The Cooperative Research Centre for Black Coal Utilization has built on this work to develop a coal combustion model which will allow plant engineers and coal company representatives to assess their coals for combustion performance. The paper describes the model and its validation and outlines how it is run. 2 figs.

Ignition and devolatilization of pulverized coals in lower oxygen content O{sub 2}/CO{sub 2} atmosphere

Energy Technology Data Exchange (ETDEWEB)

Huang, Xiaohong; Li, Jing; Liu, Zhaohui; Yang, Ming; Wang, Dingbang; Zheng, Chuguang [Huazhong Univ. of Science and Technology, Wuhan (China). State Key Lab. of Coal Combustion

2013-07-01

High speed camera is employed to capture the transient images of the burning particle in a flat-flame entrained flow reactor, some information of the burning particle, such as the optical intensity and the residence time, are obtained through analysis of transient images. The ignition and devolatilization behavior of different rank coals at 1,670, 1,770 and 1,940 K over a range of 2-30% O{sub 2} in both N{sub 2} and CO{sub 2} diluent gases are researched. The results indicate that the laws of ignition and devolatilization of pulverized coals in low oxygen O{sub 2}/CO{sub 2} atmosphere are consistent with the literature, which focus on the environments of high oxygen contents (10-30%) or lower temperate (900-1,500 K). With the gas temperature and oxygen content increased, the ignition delay time and devolatilization time for the lower oxygen content cases decreased for both N{sub 2} and CO{sub 2} atmosphere. With the use CO{sub 2} in place of N{sub 2} in low oxygen content, the ignition delay was retarded and the duration of devolatilization was increased. The effect of CO{sub 2} on coal particle ignition is explained by its higher molar specific heat. And the effect of CO{sub 2} on devolatilization results from its effect on the diffusion rates of volatile fuel and oxygen.

Mercury emissions from polish pulverized coalfired boiler

Directory of Open Access Journals (Sweden)

Wichliński Michał

2017-01-01

Full Text Available The current paper presents the research results carried out at one of Polish power plants at a pulverized hard coal-fired 225 MW unit. The research was carried out at full load of the boiler (100% MCR and focused on analysis of mercury content in the input fuel and limestone sorbent for wet flue gas desulfurization (FGD system, as well as investigation of mercury content in the combustion products, i.e. fly ash, slag, FGD product (gypsum and FGD effluents (waste. Within the framework of the present study the concentration of mercury vapor in the exhaust gas was also investigated. The analysis was performed using Lumex RA-915+ spectrometer with an attachment (RP-91C. The measurements were carried out at three locations, i.e. before the electrostatic precipitator (ESP, downstream the ESP, and downstream the wet FGD plant. Design of the measurement system allowed to determine both forms of mercury in the flue gas (Hg0 and Hg2+ at all measurement locations.Based on the measurement results the balance of mercury for a pulverized coal (PC boiler was calculated and the amount of mercury was assessed both in the input solids (fuel and sorbent, as well as the gaseous and solids products (flue gas, slag, ash, gypsum and FGD waste.

Firing a sub-bituminous coal in pulverized coal boilers configured for bituminous coals

Energy Technology Data Exchange (ETDEWEB)

N. Spitz; R. Saveliev; M. Perelman; E. Korytni; B. Chudnovsky; A. Talanker; E. Bar-Ziv [Ben-Gurion University of the Negev, Beer-Sheva (Israel)

2008-07-15

It is important to adapt utility boilers to sub-bituminous coals to take advantage of their environmental benefits while limiting operation risks. We discuss the performance impact that Adaro, an Indonesian sub-bituminous coal with high moisture content, has on opposite-wall and tangentially-fired utility boilers which were designed for bituminous coals. Numerical simulations were made with GLACIER, a computational-fluid-dynamic code, to depict combustion behavior. The predictions were verified with full-scale test results. For analysis of the operational parameters for firing Adaro coal in both boilers, we used EXPERT system, an on-line supervision system developed by Israel Electric Corporation. It was concluded that firing Adaro coal, compared to a typical bituminous coal, lowers NOx and SO{sub 2} emissions, lowers LOI content and improves fouling behavior but can cause load limitation which impacts flexible operation. 21 refs., 7 figs., 3 tabs.

Report on 1980 result of R and D under Sunshine Project. Development of solvent extraction liquefaction technology and demonstrative investigation on development of brown coal liquefaction technology (studies on high-temperature in-oil pulverization); 1980 nendo yozai chushutsu ekika gijutsu no kaihatsu / kattan ekika gijutsu kaihatsu jissho chosa seika hokokusho. Koon'yuchu funsai no kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-01

This paper explains the results of development of coal liquefaction technology under the Sunshine Project in fiscal 1980. As a part of the development of brown coal liquefaction technology, pulverization of the first-dehydration brown coal was technologically established, as were adjustment of slurry and equipment for the second-dehydration process. A 20kg/h high temperature in-oil pulverizer was designed, constructed and made ready for the studies. A high temperature mill was a wet type ball mill, 500mm{phi}(diameter) x 1,500 mm length and 2.2kw. Coal was fully pulverized even in a solvent such as creosote oil and anthracene oil freed from crystal, and was adjustable to a prescribed particle size distribution. The wet type slurry adjustment method offered prospects that solvent/coal slurry moisture could be controlled to a prescribed value. An analysis was made on the mill outlet gas and drain collection liquid at the time of high temperature in-oil pulverization, which provided knowledge of securing safety. An analysis was also made on the influence of the heating temperature rise of the mill on the strength, which provided basic data for examining the strength of the mill. Using brown coal as the raw material, slurry was prepared, which confirmed that the device had functions as planned. (NEDO)

Assessment of ecotoxicological risks of element leaching from pulverized coal ashes

International Nuclear Information System (INIS)

Jenner, H.A.

1995-05-01

The main objective of this study was to assess the effects on representative organisms, after exposure to pulverized fuel ashes (PFA) or leachates of PFA. The studies dealt primarily with toxic effects and focused on the impact of PFA on single species and groups of related species including their acute effects, bioconcentration and ultimate body burden. Emphasis was placed on reproductive effects in this study. Crawling behaviour of mussels was also studied to reflection to the physical differences of PFA from other substrates. A newly developed device was therefore used for valve movement monitoring. A phytomonitoring system with duckweed was developed for assessing effects on yield, using image processing. The results are presented in three parts according to the environmental compartments concerned i.e. marine, freshwater and terrestrial. In Part 1, marine studies with benthic invertebrates were carried out in model ecosystems with different compositions of PFA and Waddensea sediment. In Part 2, the freshwater studies were carried out in flow chambers using the painters mussel Unio pictorum. Besides behavioural studies with PFA specific research was carried out with selenium on body burden and effects on reproduction. Selenium is a prominent constituent of PFA. In Part 3 research is described on the monitoring of leachates of PFA with duckweed. A separate chapter deals with growth, mortality and accumulation in plants and worms exposed to coal gasification slag. figs., tabs., refs

Numerical study on NO formation in a pulverized coal-fired furnace using oxy-fuel combustion

Energy Technology Data Exchange (ETDEWEB)

Zhang, Aiyue; Chen, Yuan; Sheng, Changdong [Southeast Univ., Nanjing (China). School of Energy and Environment

2013-07-01

Computational fluid dynamics (CFD) approach was employed to numerically investigate NO formation in a 600 MW wall-fired pulverized coal-fired furnace retrofitted for oxy-coal combustion, aimed at the impacts of flue gas recycle ratio, O{sub 2} staging and recycled NO with the recycled flue gas (RFG) on NO formation and emission. An in-house CFD research code for conventional air combustion was developed and extended to simulate O{sub 2}/RFG combustion with specific considerations of the change of gas properties and its impact on coal particle combustion processes. The extended De Soete mechanisms including NO reburning mechanism were applied to describe transformations of fuel nitrogen. It was shown that CFD simulation represented the significant reduction of NO formation during O{sub 2}/RFG combustion compared to that during air combustion. The in-burner and particularly the in-furnace O{sub 2} staging were confirmed still to play very important roles in NO formation control. Changing the recycle ratio had significant impact on the combustion performance and consequently on NO formation and emission. With the combustion performance ensured, decreasing the flue gas recycle ratio or increasing the inlet O{sub 2} concentration of combustion gas led to reduction of NO formation and emission. Although NO formation and emission was found to increase with increasing the inlet NO concentration of combustion gas, CFD simulation indicated that {proportional_to}74% of the inlet NO was reduced in the furnace, consistent with the experimental data reported in the literature. This demonstrated the significant contribution of reburning mechanism to the reduction of the recycled NO in the furnace.

Observer-based Coal Mill Control using Oxygen Measurements

DEFF Research Database (Denmark)

Andersen, Palle; Bendtsen, Jan Dimon; S., Tom

2006-01-01

This paper proposes a novel approach to coal flow estimation in pulverized coal mills, which utilizes measurements of oxygen content in the flue gas. Pulverized coal mills are typically not equipped with sensors that detect the amount of coal injected into the furnace. This makes control...... of the coal flow difficult, causing stability problems and limits the plant's load following capabilities. To alleviate this problem without having to rely on expensive flow measurement equipment, a novel observer-based approach is investigated. A Kalman filter based on measurements of combustion air flow led...... into the furnace and oxygen concentration in the flue gas is designed to estimate the actual coal flow injected into the furnace. With this estimate, it becomes possible to close an inner loop around the coal mill itself, thus giving a better disturbance rejection capability. The approach is validated against...

Use of image analysis on the prediction of coal burnout performance in a drop tube furnace

Energy Technology Data Exchange (ETDEWEB)

R. Barranco; M. Cloke; E. Lester [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, SChEME

2003-07-01

An experimental investigation in a drop-tube furnace (DTF) into the combustion burnout performance of some South American coals was carried out. The coal samples, mainly from Colombia, were crushed and screened into three size fractions: 53-75 {mu}m, 106-125 {mu}m, and 150-180 {mu}m. These samples were characterised by standard tests along with a specially developed image analysis technique (grey-scale histogram). Pyrolysis of these samples was performed at a temperature of 1300{sup o}C, in a 1% of oxygen in nitrogen atmosphere for 200 ms. The chars obtained were then re-fired in the same apparatus, at the same temperature, at various residence times, in an atmosphere containing 5% of oxygen in nitrogen. The changes in the characteristics of the chars produced were assessed using a number of different techniques including intrinsic reactivity test and automatic char analysis. Despite the fact that all the coals used in this study were vitrinite-rich, variations in char morphology were evident. This demonstrated that it was impossible to assign any one char type to a single maceral group. It was apparent that vitrinite generates a wide range of char types depending upon the rank of the parent coal and on the maceral associations within the coal. In addition, a reactivity parameter, derived from the grey-scale histogram obtained by image analysis of the coal, was found to be important in the prediction of coal combustion behaviour. Some properties of the re-fired chars were compared with morphology and intrinsic reactivity data of the pyrolysed chars. The results showed that the poor burnout of one of the coals was clearly due to the formation of some particular chars during pyrolysis. This confirms the usefulness of high temperature pyrolysis chars as a predictor of burnout performance. 18 refs., 8 figs., 2 tabs.

Improved coal grinding and fuel flow control in thermal power plants

DEFF Research Database (Denmark)

Niemczyk, Piotr; Bendtsen, Jan Dimon

2011-01-01

A novel controller for coal circulation and pulverized coal flow in a coal mill is proposed. The design is based on optimal control theory for bilinear systems with additional integral action. The states are estimated from the grinding power consumption and the amount of coal accumulated in the m......A novel controller for coal circulation and pulverized coal flow in a coal mill is proposed. The design is based on optimal control theory for bilinear systems with additional integral action. The states are estimated from the grinding power consumption and the amount of coal accumulated...... as well as when parameter uncertainties and noise are present. The proposed controller lowers the grinding power consumption while in most cases exhibiting superior performance in comparison with the PID controller....

Fiscal 2001 achievement report. Development of coal gas production technology for fuel cells - Research using pilot test facility - for public release (Test result report - 2/3); 2001 nendo seika hokokusho (Kokai you). Nenryo denchi you sekitan gas seizo gijutsu kaihatsu - Pilot shiken setsubi ni yoru kenkyu (Shiken kekka hokokusho 2/3)

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-03-01

For the development of a coal gasification furnace optimum for fuel cells, a pilot test facility was constructed, and the results of tests and inspections conducted therefor are put together. They include an individual test of the receiving pit hopper vibrator, individual test of the pulverized coal related rotary valve, individual test of the pretreatment compressed air fan, individual test of the coal pulverizer lubricating device, individual test of the coal pulverizer pressure device, individual test of the coal pulverizer, individual test of the coal pulverizer motor, individual test of the coal feeder, individual test of the pulverized coal bunker exhaust fan, individual test of the pulverized coal bunker exhaust fan motor, test of capacity for pulverized coal, individual test of the pulverized coal conveyer blower, test of the sequence of the same, test of pulverizer inert clearing, individual test of the pretreatment condensed water pump in the coal pretreatment device, test of airborne conveyance in the same, verification test of inter-hopper transfer in the same, test of coal pulverization in the same, test operation of the raw material air/low pressure nitrogen compressor in the air separation facility, test operation of the raw material air freezer in the same, and a test operation of the MS adsorber/MS regeneration electric heater. (NEDO)

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

Energy Technology Data Exchange (ETDEWEB)

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.

An update on blast furnace granular coal injection

Energy Technology Data Exchange (ETDEWEB)

Hill, D.G. [Bethlehem Steel Corp., Burns Harbor, IN (United States); Strayer, T.J.; Bouman, R.W. [Bethlehem Steel Corp., PA (United States)

1997-12-31

A blast furnace coal injection system has been constructed and is being used on the furnace at the Burns Harbor Division of Bethlehem Steel. The injection system was designed to deliver both granular (coarse) and pulverized (fine) coal. Construction was completed on schedule in early 1995. Coal injection rates on the two Burns Harbor furnaces were increased throughout 1995 and was over 200 lbs/ton on C furnace in September. The injection rate on C furnace reached 270 lbs/ton by mid-1996. A comparison of high volatile and low volatile coals as injectants shows that low volatile coal replaces more coke and results in a better blast furnace operation. The replacement ratio with low volatile coal is 0.96 lbs coke per pound of coal. A major conclusion of the work to date is that granular coal injection performs very well in large blast furnaces. Future testing will include a processed sub-bituminous coal, a high ash coal and a direct comparison of granular versus pulverized coal injection.

Influence of high-energy impact on the physical and technical characteristics of coal fuels

Science.gov (United States)

Mal'tsev, L. I.; Belogurova, T. P.; Kravchenko, I. V.

2017-08-01

Currently, in the world's large-scale coal-fired power industry, the combustion of pulverized coal is the most widely spread technology of combusting the coals. In recent years, the micropulverization technology for preparation and combustion of the coal has been developed in this field. As applied to the small-scale power industry, the method of combusting the coal in the form of a coal-water slurry has been explored for years. Fine coal powders are produced and used in the pulverized-coal gasification. Therefore, the coal preparation methods that involve high-dispersion disintegration of coals attract the greatest interest. The article deals with the problems of high-energy impact on the coal during the preparation of pulverized-coal fuels and coal-water slurries, in particular, during the milling of the coal in ball drum mills and the subsequent regrinding in disintegrators or the cavitation treatment of the coal-water slurries. The investigations were conducted using samples of anthracite and lignite from Belovskii open-pit mine (Kuznetsk Basin). It is shown that both the disintegration and the cavitation treatment are efficient methods for controlling the fuel characteristics. Both methods allow increasing the degree of dispersion of the coal. The content of the small-sized particles reground by cavitation considerably exceeds the similar figure obtained using the disintegrator. The specific surface area of the coal is increased by both cavitation and disintegration with the cavitation treatment producing a considerably greater effect. Being subjected to the cavitation treatment, most coal particles assume the form of a split characterized by the thermodynamically nonequilibrium state. Under external action, in particular, of temperature, the morphological structure of such pulverized materials changes faster and, consequently, the combustion of the treated coal should occur more efficiently. The obtained results are explained from the physical point of view.

Coal combustion technology in China

International Nuclear Information System (INIS)

Huang, Z.X.

1994-01-01

Coal is the most important energy source in China, the environmental pollution problem derived from coal burning is rather serious in China. The present author discusses coal burning technologies both in boilers and industrial furnaces and their relations with environmental protection problems in China. The technological situations of Circulating Fluidized Bed Coal Combustor, Pulverized Coal Combustor with Aerodynamic Flame Holder and Coal Water Slurry Combustion have been discussed here as some of the interesting problems in China only. (author). 3 refs

Combustion of wet pulverized coal in reactor flow; Combustao de particulas de carvao pulverizado contendo umidade em seu interior

Energy Technology Data Exchange (ETDEWEB)

Costa, Valdeci Jose [Universidade do Planalto Catarinense (UNIPLAC), Lages, SC (Brazil). Dept. de Ciencias Exatas e Tecnologicas]. E-mail: vcosta@iscc.com.br; Krioukov, Viktor [Universidade Regional do Estado do Rio Grande do Sul (UNIJUI), Ijui, RS (Brazil). Programa de Pos-Graduacao em Modelagem Matematica]. E-mail: krioukov@main.unijui.tche.br; Maliska, Clovis Raimundo [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica]. E-mail: maliska@sinmec.ufsc.br

2000-07-01

In this work I propose a numeric study destined to the combustion of wet pulverized coal in reacting flow. The mathematical model is composed by equations for the concentration of the substances in the reacting flow, written based in the chemical kinetics and exponential form, conservation equations and devolatilization equations, combustion of the carbon and residues. The study detects fluctuation among the temperatures of the gas and of the particles. The inclusion of the humidity as constituent part of the volatile matter doesn't affect the performance of the model, however, its presence alters the temperature profiles and the gaseous composition. With the increase of the humidity in the coal have a slight reduction in the time of combustion of the particle, what agrees with experimental data. The model foresees an increment in the difference Tp-Tg and a smaller production of CO with the increase of the wetness rate. The volatile ones, in spite of they have its fraction relatively reduced with the wetness presence they are liberated more slowly with its increment, provoking change in the position of front flame. (author)

Influence of staged-air on airflow, combustion characteristics and NO(x) emissions of a down-fired pulverized-coal 300 MW(e) utility boiler with direct flow split burners.

Science.gov (United States)

Li, Zhengqi; Kuang, Min; Zhang, Jia; Han, Yunfeng; Zhu, Qunyi; Yang, Lianjie; Kong, Weiguang

2010-02-01

Cold airflow experiments were conducted to investigate the aerodynamic field in a small-scale furnace of a down-fired pulverized-coal 300 MW(e) utility boiler arranged with direct flow split burners enriched by cyclones. By increasing the staged-air ratio, a deflected flow field appeared in the lower furnace; larger staged-air ratios produced larger deflections. Industrial-sized experiments on a full-scale boiler were also performed at different staged-air damper openings with measurements taken of gas temperatures in the burner region and near the right-side wall, wall heat fluxes, and gas components (O(2), CO, and NO(x)) in the near-wall region. Combustion was unstable at staged-air damper openings below 30%. For openings of 30% and 40%, late ignition of the pulverized coal developed and large differences arose in gas temperatures and heat fluxes between the regions near the front and rear walls. In conjunction, carbon content in the fly ash was high and boiler efficiency was low with high NO(x) emission above 1200 mg/m(3) (at 6% O(2) dry). For fully open dampers, differences in gas temperatures and heat fluxes, carbon in fly ash and NO(x) emission decreased yielding an increase in boiler efficiency. The optimal setting is fully open staged-air dampers.

Weighted sum of gray gases model optimization for numerical investigations of processes inside pulverized coal-fired furnaces

Science.gov (United States)

Crnomarkovic, Nenad; Belosevic, Srdjan; Tomanovic, Ivan; Milicevic, Aleksandar

2017-12-01

The effects of the number of significant figures (NSF) in the interpolation polynomial coefficients (IPCs) of the weighted sum of gray gases model (WSGM) on results of numerical investigations and WSGM optimization were investigated. The investigation was conducted using numerical simulations of the processes inside a pulverized coal-fired furnace. The radiative properties of the gas phase were determined using the simple gray gas model (SG), two-term WSGM (W2), and three-term WSGM (W3). Ten sets of the IPCs with the same NSF were formed for every weighting coefficient in both W2 and W3. The average and maximal relative difference values of the flame temperatures, wall temperatures, and wall heat fluxes were determined. The investigation showed that the results of numerical investigations were affected by the NSF unless it exceeded certain value. The increase in the NSF did not necessarily lead to WSGM optimization. The combination of the NSF (CNSF) was the necessary requirement for WSGM optimization.

Chemical forms of the fluorine and carbon in fly ashes recovered from electrostatic precipitators of pulverized coal-fired plants

Energy Technology Data Exchange (ETDEWEB)

Naoto Tsubouchi; Hidekazu Hayashi; Akiyuki Kawashima; Masahide Sato; Noboru Suzuki; Yasuo Ohtsuka [Tohoku University, Sendai (Japan). Institute of Multidisciplinary Research for Advanced Materials

2011-01-15

The functionalities of the fluorine and carbon present in fly ashes formed in pulverized coal combustion have been studied with X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption (TPD) techniques. The ash samples include 20-130 {mu}g/g-dry and 0.4-4.1 mass%-dry of fluorine and carbon elements, respectively, and these components are enriched at the outermost layer of the ash surface. The F consists of both inorganic and organic functionalities, and the proportion of the latter is as high as 84-98 mol%. The C has different types of surface oxygen species, such as carboxyl, lactone/acid anhydride and phenolic groups, and most of these groups decompose to CO{sub 2} or CO up to 700{sup o}C to yield carbon active sites. When the amount of the O-functional forms increases, the content of organic C-F forms tends to increase almost linearly. On the basis of the above results, it may be speculated as one possibility that the formation of covalent C-F bonds takes place mainly through secondary reactions between gaseous F-containing compounds (HF and/or F{sub 2}) in flue gas and carbon active sites produced below 700{sup o}C downstream of coal-fired boilers. 30 refs., 8 figs., 4 tabs.

Observer-Based Fuel Control Using Oxygen Measurement. A study based on a first-principles model of a pulverized coal fired Benson Boiler

Energy Technology Data Exchange (ETDEWEB)

Andersen, Palle; Bendtsen, Jan Dimon; Mortensen, Jan Henrik; Just Nielsen, Rene; Soendergaard Pedersen, Tom [Aalborg Univ. (Denmark). Dept. of Control Engineering

2005-01-01

This report describes an attempt to improve the existing control of coal mills used at the Danish power plant Nordjyllandsvaerket Unit 3. The coal mills pulverize raw coal to a fine-grained powder, which is injected into the furnace of the power plant. In the furnace the coal is combusted, producing heat, which is used for steam production. With better control of the coal mills, the power plant can be controlled more efficiently during load changes, thus improving the overall availability and efficiency of the plant. One of the main difficulties from a control point of view is that the coal mills are not equipped with sensors that detect how much coal is injected into the furnace. During the project, a fairly detailed, non-linear differential equation model of the furnace and the steam circuit was constructed and validated against data obtained at the plant. It was observed that this model was able to capture most of the important dynamics found in the data. Based on this model, it is possible to extract linearized models in various operating points. The report discusses this approach and illustrates how the model can be linearized and reduced to a lower-order linear model that is valid in the vicinity of an operating point by removing states that have little influence on the overall response. A viable adaptive control strategy would then be to design controllers for each of these simplified linear models, i.e., the control loop that sets references to the coal mills and feedwater, and use the load as a separate input to the control. The control gains should then be scheduled according to the load. However, the variations and uncertainties in the coal mill are not addressed directly in this approach. Another control approach was taken in this project, where a Kalman filter based on measurements of air flow blown into the furnace and the oxygen concentration in the flue gas is designed to estimate the actual coal flow injected into the furnace. With this estimate

JV Task 106 - Feasibility of CO2 Capture Technologies for Existing North Dakota Lignite-Fired Pulverized Coal Boilers

Energy Technology Data Exchange (ETDEWEB)

Michael L. Jones; Brandon M. Pavlish; Melanie D. Jensen

2007-05-01

The goal of this project is to provide a technical review and evaluation of various carbon dioxide (CO{sub 2}) capture technologies, with a focus on the applicability to lignite-fired facilities within North Dakota. The motivation for the project came from the Lignite Energy Council's (LEC's) need to identify the feasibility of CO{sub 2} capture technologies for existing North Dakota lignite-fired, pulverized coal (pc) power plants. A literature review was completed to determine the commercially available technologies as well as to identify emerging CO{sub 2} capture technologies that are currently in the research or demonstration phase. The literature review revealed few commercially available technologies for a coal-fired power plant. CO{sub 2} separation and capture using amine scrubbing have been performed for several years in industry and could be applied to an existing pc-fired power plant. Other promising technologies do exist, but many are still in the research and demonstration phases. Oxyfuel combustion, a technology that has been used in industry for several years to increase boiler efficiency, is in the process of being tailored for CO{sub 2} separation and capture. These two technologies were chosen for evaluation for CO{sub 2} separation and capture from coal-fired power plants. Although oxyfuel combustion is still in the pilot-scale demonstration phase, it was chosen to be evaluated at LEC's request because it is one of the most promising emerging technologies. As part of the evaluation of the two chosen technologies, a conceptual design, a mass and energy balance, and an economic evaluation were completed.

Burnout of pulverized biomass particles in large scale boiler - Single particle model approach

Energy Technology Data Exchange (ETDEWEB)

Saastamoinen, Jaakko; Aho, Martti; Moilanen, Antero [VTT Technical Research Centre of Finland, Box 1603, 40101 Jyvaeskylae (Finland); Soerensen, Lasse Holst [ReaTech/ReAddit, Frederiksborgsveij 399, Niels Bohr, DK-4000 Roskilde (Denmark); Clausen, Soennik [Risoe National Laboratory, DK-4000 Roskilde (Denmark); Berg, Mogens [ENERGI E2 A/S, A.C. Meyers Vaenge 9, DK-2450 Copenhagen SV (Denmark)

2010-05-15

Burning of coal and biomass particles are studied and compared by measurements in an entrained flow reactor and by modelling. The results are applied to study the burning of pulverized biomass in a large scale utility boiler originally planned for coal. A simplified single particle approach, where the particle combustion model is coupled with one-dimensional equation of motion of the particle, is applied for the calculation of the burnout in the boiler. The particle size of biomass can be much larger than that of coal to reach complete burnout due to lower density and greater reactivity. The burner location and the trajectories of the particles might be optimised to maximise the residence time and burnout. (author)

Numerical study of furnace process of a 600 MW pulverized coal boiler under low load with SNCR application

Energy Technology Data Exchange (ETDEWEB)

Cao, Q.X.; Shi, Y.; Liu, H.; Yang, C.H.; Wu, S.H. [Harbin Institute of Technology, Harbin (China)

2013-07-01

Numerical simulation of flow, heat transfer, and combustion process in a 600MW pulverized coal boiler under low load is performed using Computational Fluid Dynamics (CFD) code Fluent. The distributions of temperature and species were obtained and their influences on Selective non-catalytic reduction (SNCR) were analyzed. The results indicate that the furnace temperature changed significantly as the operation load declines. The furnace space with proper temperature for SNCR reaction becomes lower with decreasing of operation load. As the load falls off, the available O{sub 2}concentration for SNCR reactions rises gently and the initial NOx concentration for SNCR reactions debases slightly. These variations can have some influence on the SNCR process. For the upper furnace where the temperature is suitable for SNCR reactions, the CO concentration is close to 0 under different load. Consequently, the SNCR process will not be affected by CO based on the calculation in this work.

Coal Calorific Value Prediction Based on Projection Pursuit Principle

OpenAIRE

QI Minfang; FU Zhongguang; JING Yuan

2012-01-01

The calorific value of coal is an important factor for the economic operation of coal-fired power plant. However, calorific value is tremendous difference between the different coal, and even if coal is from the same mine. Restricted by the coal market, most of coal fired power plants can not burn the designed-coal by now in China. The properties of coal as received are changing so frequently that pulverized coal firing is always with the unexpected condition. Therefore, the researches on the...

Catalytic activity of pyrite for coal liquefaction reaction; Tennen pyrite no shokubai seino ni kansuru kento

Energy Technology Data Exchange (ETDEWEB)

Hirano, K.; Kozu, M.; Okada, T.; Kobayashi, M. [Nippon Coal Oil Co. Ltd., Tokyo (Japan)

1996-10-28

Since natural pyrite is easy to obtain and cheap as coal liquefaction catalyst, it is to be used for the 150 t/d scale NEDOL process bituminous coal liquefaction pilot plant. NEDO and NCOL have investigated the improvement of catalytic activity of pulverized natural pyrite for enhancing performance and economy of the NEDOL process. In this study, coal liquefaction tests were conducted using natural pyrite catalyst pulverized by dry-type bowl mill under nitrogen atmosphere. Mechanism of catalytic reaction of the natural pyrite was discussed from relations between properties of the catalyst and liquefaction product. The natural pyrite provided an activity to transfer gaseous hydrogen into the liquefaction product. It was considered that pulverized pyrite promotes the hydrogenation reaction of asphaltene because pulverization increases its contact rate with reactant and the amount of active points on its surface. It was inferred that catalytic activity of pyrite is affected greatly by the chemical state of Fe and S on its surface. 3 refs., 4 figs., 1 tab.

Pulverized straw combustion in a low-NOx multifuel burner

DEFF Research Database (Denmark)

Mandø, Matthias; Rosendahl, Lasse; Yin, Chungen

2010-01-01

A CFD simulation of pulverized coal and straw combustion using a commercial multifuel burner have been undertaken to examine the difference in combustion characteristics. Focus has also been directed to development of the modeling technique to deal with larger non-spherical straw particles...... and to determine the relative importance of different modeling choices for straw combustion. Investigated modeling choices encompass the particle size and shape distribution, the modification of particle motion and heating due to the departure from the spherical ideal, the devolatilization rate of straw......, the influence of inlet boundary conditions and the effect of particles on the carrier phase turbulence. It is concluded that straw combustion is associated with a significantly longer flame and smaller recirculation zones compared to coal combustion for the present air flow specifications. The particle size...

Coal combustion aerothermochemistry research. Final report

Energy Technology Data Exchange (ETDEWEB)

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.

Dry pulverized solid material pump

Science.gov (United States)

Meyer, John W.; Bonin, John H.; Daniel, Jr., Arnold D.

1984-07-31

Apparatus is shown for substantially increasing the feed rate of pulverized material into a pressurized container. The apparatus includes a rotor that is mounted internal to the pressurized container. The pulverized material is fed into an annular chamber defined by the center of the rotor. A plurality of impellers are mounted within the annular chamber for imparting torque to the pulverized material.

Influence of the gray gases number in the weighted sum of gray gases model on the radiative heat exchange calculation inside pulverized coal-fired furnaces

Directory of Open Access Journals (Sweden)

Crnomarković Nenad Đ.

2016-01-01

Full Text Available The influence of the number of gray gases in the weighted sum in the gray gases model on the calculation of the radiative heat transfer is discussed in the paper. A computer code which solved the set of equations of the mathematical model describing the reactive two-phase turbulent flow with radiative heat exchange and with thermal equilibrium between phases inside the pulverized coal-fired furnace was used. Gas-phase radiative properties were determined by the simple gray gas model and two combinations of the weighted sum of the gray gases models: one gray gas plus a clear gas and two gray gases plus a clear gas. Investigation was carried out for two values of the total extinction coefficient of the dispersed phase, for the clean furnace walls and furnace walls covered by an ash layer deposit, and for three levels of the approximation accuracy of the weighting coefficients. The influence of the number of gray gases was analyzed through the relative differences of the wall fluxes, wall temperatures, medium temperatures, and heat transfer rate through all furnace walls. The investigation showed that there were conditions of the numerical investigations for which the relative differences of the variables describing the radiative heat exchange decrease with the increase in the number of gray gases. The results of this investigation show that if the weighted sum of the gray gases model is used, the complexity of the computer code and calculation time can be reduced by optimizing the number of gray gases. [Projekat Ministarstva nauke Republike Srbije, br. TR-33018: Increase in energy and ecology efficiency of processes in pulverized coal-fired furnace and optimization of utility steam boiler air preheater by using in-house developed software tools

Study on the combustion properties of bio-coal briquette blends of ...

African Journals Online (AJOL)

This study was carried out to investigate the properties of bio-coal briquette produced from blending cassava stalk and coal. The cassava stalk and coal lumps were carbonized at 160 oC, pulverized and used to produce biocoal briquettes of 10 %, 20 %, 30 %, 40 %, 50 %, 60 %,70 %, 80 %, 90 % and 100 % biomasses.

Kinetics of devolatilization and oxidation of a pulverized biomass in an entrained flow reactor under realistic combustion conditions

Energy Technology Data Exchange (ETDEWEB)

Jimenez, Santiago [LITEC-CSIC (Spanish Council for Scientific Research), Maria de Luna 10, 50018 Zaragoza (Spain); Remacha, Pilar; Ballester, Javier [LITEC-CSIC (Spanish Council for Scientific Research), Maria de Luna 10, 50018 Zaragoza (Spain); Fluid Mechanics Group, University of Zaragoza, Maria de Luna 3, 50018 Zaragoza (Spain); Ballesteros, Juan C.; Gimenez, Antonio [ENDESA GENERACION, S.A., Ribera del Loira 60, 28042 Madrid (Spain)

2008-03-15

In this paper the results of a complete set of devolatilization and combustion experiments performed with pulverized ({proportional_to}500 {mu}m) biomass in an entrained flow reactor under realistic combustion conditions are presented. The data obtained are used to derive the kinetic parameters that best fit the observed behaviors, according to a simple model of particle combustion (one-step devolatilization, apparent oxidation kinetics, thermally thin particles). The model is found to adequately reproduce the experimental trends regarding both volatile release and char oxidation rates for the range of particle sizes and combustion conditions explored. The experimental and numerical procedures, similar to those recently proposed for the combustion of pulverized coal [J. Ballester, S. Jimenez, Combust. Flame 142 (2005) 210-222], have been designed to derive the parameters required for the analysis of biomass combustion in practical pulverized fuel configurations and allow a reliable characterization of any finely pulverized biomass. Additionally, the results of a limited study on the release rate of nitrogen from the biomass particle along combustion are shown. (author)

On gas and particle radiation in pulverized fuel combustion furnaces

DEFF Research Database (Denmark)

Yin, Chungen

2015-01-01

Radiation is the principal mode of heat transfer in a combustor. This paper presents a refined weighted sum of gray gases model for computational fluid dynamics modelling of conventional air-fuel combustion, which has greater accuracy and completeness than the existing gaseous radiative property...... models. This paper also presents new conversion-dependent models for particle emissivity and scattering factor, instead of various constant values in literature. The impacts of the refined or new models are demonstrated via computational fluid dynamics simulation of a pulverized coal-fired utility boiler...

Burnout prediction using advance image analysis coal characterization techniques

Energy Technology Data Exchange (ETDEWEB)

Edward Lester; Dave Watts; Michael Cloke [University of Nottingham, Nottingham (United Kingdom). School of Chemical Environmental and Mining Engineering

2003-07-01

The link between petrographic composition and burnout has been investigated previously by the authors. However, these predictions were based on 'bulk' properties of the coal, including the proportion of each maceral or the reflectance of the macerals in the whole sample. Combustion studies relating burnout with microlithotype analysis, or similar, remain less common partly because the technique is more complex than maceral analysis. Despite this, it is likely that any burnout prediction based on petrographic characteristics will become more accurate if it includes information about the maceral associations and the size of each particle. Chars from 13 coals, 106-125 micron size fractions, were prepared using a Drop Tube Furnace (DTF) at 1300{degree}C and 200 millisecond and 1% Oxygen. These chars were then refired in the DTF at 1300{degree}C 5% oxygen and residence times of 200, 400 and 600 milliseconds. The progressive burnout of each char was compared with the characteristics of the initial coals. This paper presents an extension of previous studies in that it relates combustion behaviour to coals that have been characterized on a particle by particle basis using advanced image analysis techniques. 13 refs., 7 figs.

A newer concept of setting up coal refineries in coal utilising industries through environmentally sound clean coal technology of organosuper refining of coals

International Nuclear Information System (INIS)

Sharma, D.K.

1994-01-01

In order to reduce the losses of premium organic matter of coal and its immense potential energy which is present in the form of stronger interatomic and intramolecular bonding energies, a newer and convenient technique of recovering the premium organic matter from low grade coals by organosuper-refining technique which operates under ambient pressure conditions has been developed. The residual coal obtained can be used as environmentally clean fuel or as a feedstock for the industries based on carbonization and gasification. It is suggested that a beginning be made by setting up coal refineries in coal utilizing industries on the basis of the presently developed new technology of organosuper-refining of coals to recover premium grade organic chemical feed stocks from coals before utilizing coal by techniques such as bubble bed or recirculatory fluidized bed or pulverized coal combustion in thermal power stations, carbonization in steel plants or other carbonization units, gasification in fertilizer industries or in integrated coal gasification combined cycle power generation. Thus, coal refineries may produce value added aromatic chemical feed stocks, formed coke or coke manufacturing; and carbon fillers for polymers. (author). 100 refs., 1 fig

Comparative bioleaching of metals from pulverized and non-pulverized PCBs of cell phone charger: advantages of non-pulverized PCBs.

Science.gov (United States)

Joshi, Vyenkatesh; Shah, Neha; Wakte, Prashant; Dhakephalkar, Prashant; Dhakephalkar, Anita; Khobragade, Rahul; Naphade, Bhushan; Shaikh, Sajid; Deshmukh, Arvind; Adhapure, Nitin

2017-12-01

Sample inhomogeneity is a severe issue in printed circuit boards especially when we are comparing the bioleaching efficiency. To avoid the ambiguous results obtained due to inhomogeneity in PCBs, 12 similar cell phone chargers (of renowned company) having same make and batch number were collected from scrap market. PCBs obtained from them were used in present studies. Out of these 12, three PCBs were used separately for chemical analysis of PCBs with prior acid digestion in aqua regia. It was found that, 10.8, 68.0, and 710.9 mg/l of Zn, Pb, and Cu were present in it, respectively. Six PCBs were used for bioleaching experiment with two variations, pulverized and non-pulverized. Though the pulverized sample have shown better leaching than non-pulverized one, former has some disadvantages if overall recycling of e-waste (metallic and nonmetallic fraction) is to be addressed. At the end of leaching experiments, copper was recovered using a simple setup of electrodeposition and 92.85% recovery was attained. The acidophiles involved in bioleaching were identified by culture dependent and culture independent techniques such as DGGE and species specific primers in PCR.

Transformations of inorganic coal constituents in combustion systems

Energy Technology Data Exchange (ETDEWEB)

Helble, J.J. (ed.); Srinivasachar, S.; Wilemski, G.; Boni, A.A. (PSI Technology Co., Andover, MA (United States)); Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. (Massachusetts Inst. of Tech., Cambridge, MA (United States)); Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L. (Arizona Univ., Tucson, AZ (United States)); 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.

Result of design and test operation of a coal boiler at Hyogo Refinery

Energy Technology Data Exchange (ETDEWEB)

Miura, Yasuhiko; Sato, Noriyuki

1987-05-01

This boiler is the first coal boiler for the oil refineries in Japan (Installed in Oct., 1986 at Idemitsu Petrochemical Co.) Causes for using coal as a fuel are a conversion to less expensive fuel and offering a technical service to the users of coal through the combustion of coal and learning of a handling technique. The type of boiler is Babcock single barrel radiant type and has 150 t/d capacity with single fuel combustion of coal. Auxiliary equipments are a pulverizer, a transportation and storage unit, a denitration unit, a dust collector, a desulfurization unit, and an ash disposal unit. Main considerations in the design are measures for the security of finely pulverized coal, clogging prevention for coal and ash. A test operation revealed 7 % of combustible loss and 160 - 250 ppm of NOx content at a charge inlet of denitration unit. Actual operation exhibited no clogging at the denitration unit of troubles due to scaling. Design for raw materials is to blend 4 imported coals (from Australia and Canada, etc) and 3 Japanese ones. (7 figs, 2 tabs)

Clean coal reference plants: Pulverized coal boiler with flue gas desulfurization. Topical report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-09-01

The Clean Coal Technology Demonstration Program (CCT) is a government and industry cofunded technology development effort to demonstrate a new generation of innovative coal utilization processes in a series of full-scale facilities. The goal of the program is to provide the U.S. energy marketplace with a number of advanced, more efficient, and environmentally responsive coal-using technologies. To achieve this goal, a multiphased effort consisting of five separate solicitations has been completed. The Morgantown Energy Technology Center (METC) has the responsibility for monitoring the CCT Projects within certain technology categories, which, in general, correspond to the center`s areas of technology development. Primarily the categories of METC CCT projects are: atmospheric fluid bed combustion, pressurized fluidized bed combustion, integrated gasification combined cycle, mild gasification, and industrial applications.

Risk management of energy efficiency projects in the industry - sample plant for injecting pulverized coal into the blast furnaces

Directory of Open Access Journals (Sweden)

Jovanović Filip P.

2016-01-01

Full Text Available This paper analyses the applicability of well-known risk management methodologies in energy efficiency projects in the industry. The possibilities of application of the selected risk management methodology are demonstrated within the project of the plants for injecting pulverized coal into blast furnaces nos. 1 and 2, implemented by the company US STEEL SERBIA d.o.o. in Smederevo. The aim of the project was to increase energy efficiency through the reduction of the quantity of coke, whose production requires large amounts of energy, reduction of harmful exhaust emission and increase productivity of blast furnaces through the reduction of production costs. The project was complex and had high costs, so that it was necessary to predict risk events and plan responses to identified risks at an early stage of implementation, in the course of the project design, in order to minimise losses and implement the project in accordance with the defined time and cost limitations. [Projekat Ministarstva nauke Republike Srbije, br. 179081: Researching contemporary tendencies of strategic management using specialized management disciplines in function of competitiveness of Serbian economy

Burnout synergic or inhibiting effects in combustion assays of coal/sawdust blends

Energy Technology Data Exchange (ETDEWEB)

Ximena Garcia; Ximena Matus; Claudia Ulloa; Alfredo L. Gordon [University of Concepcion, Concepcion (Chile). Dept. of Chemical Engineering

2007-07-01

Characterization of chars and charcoal and combustion assays of coal/ pine sawdust blends were carried on to evaluate the burnout, under conditions similar to those found in pulverized coal combustion. A drop tube furnace (DTF) was used to generate chars from three coals of different rank (Bitsch, a lignite; Lemington, a bituminous HV coal; and LD, a semianthracite) and charcoal from sawdust (S). Burning profiles, as well as morphological and optical characterization of these chars were obtained and discussed. Pulverized samples of pure constituents and sawdust/coal blends (5, 10 and 20%wt of S) were burned in the DTF reactor. Samples of combustion residues were collected for characterization. Depending on blend composition and the rank of the coal being blended, positive and negative deviations with respect to the expected weighted average value of the burnout were measured. This behavior is related both, to the duration of the step by which simultaneous burning of char and charcoal take place, and to the sawdust content in the blend. The optical analysis of combustion residues supports this conclusion. 7 refs., 6 figs., 3 tabs.

The power of Indonesian coal

Energy Technology Data Exchange (ETDEWEB)

Rosiak, T. [Duke/Fluor Daniel (United States)

2003-02-01

The paper presents three Indonesian projects carried out by Duke/Fluor Daniel whose unique construction and operation have demonstrated the versatility and value of coal-fired power generation. These are: the construction of units 7 and 8 of the Paiton Private Power Project, a 1230 MW pulverised coal plant in Paiton, East Java; construction of a coal fired generation plant and transmission system to provide power for the expansion of a copper and gold mine on the island of Papua; and construction of four 28 MW pulverized coal units to provide 'heavy lifting' for a new mine at Batu Hijau on the island of Sumbawa. Coal was found to cost less than diesel for power generation. 2 photos.

Evaluation of dense-phase ultrafine coal (DUC) as a fuel alternative for oil- and gas-designed boilers and heaters. Final report

Energy Technology Data Exchange (ETDEWEB)

1986-12-01

Utility and industrial firms currently using oil- and gas-fired boilers have an interest in substitution of coal for oil and gas as the primary boiler fuel. This interest stems from coal`s two main advantages over oil and gas-lower cost and security of supply. Recent efforts in the area of coal conversion have been directed to converting oil- and gas- fired boilers which were originally designed for coal-firing or were designed with some coal-firing capability. Boilers designed exclusively for oil- or gas-firing have not been considered viable candidates for coal conversion because they generally require a significant capacity derating and extensive and costly modifications. As a result, conversion of boilers in this class to coal-firing has generally been considered unattractive. Renewed interest in the prospects for converting boilers designed exclusively for oil- and gas-firing to coal firing has centered around the concept of using ``ultra fine`` coal as opposed to ``conventional grind`` pulverized coal. The main distinction being the finer particle size to which the former is ground. This fuel type may have characteristics which ameliorate many of the boiler problems normally associated with pulverized coal-firing. The overall concept for ultrafine coal utilization is based on a regional large preparation plant with distribution of a ready to fire fuel directly to many small users. This differs from normal practice in which final coal sizing is performed in pulverizers at the user`s site.

The influence of near burner region aerodynamics on the formation and emission of nitrogen oxides in a pulverized coal-fired furnace

International Nuclear Information System (INIS)

Abbas, T.; Costen, P.; Lockwood, F.C.

1992-01-01

This paper reports that detailed measurements have been performed for two distinct pulverized-coal-fired burners in a large-scale laboratory furnace. Comparative in-flame data are archived and include gas temperature, O 2 , CO concentration, and an inventory of stable fuel nitrogen species and solids (HCN, NH 3 , N 2 O, NO, nitrogen release, mass flux, and particle burnout). A significant decrease in the NO concentration in the near burner region and a substantial decrease in the furnace exit values are observed when the central tube from a single annular orifice burner jet (normally the location of a gas or oil burner for light-up purposes) is replaced with a single central orifice burner jet of same cross-sectional area. The latter burner exhibits the delayed combustion phenomena normally associated with a tangentially fired system. The particle burnout remains unaffected due to the longer particles' residence time in the all-important oxygen lean internal recirculation zone

Effects of moisture release and radiation properties in pulverized fuel combustion

DEFF Research Database (Denmark)

Yin, Chungen

2016-01-01

and impacts via a computational fluid dynamics (CFD) study of a 609 MWe pulverized coal-fired utility boiler. Overall speaking, it is suggested to add the free moisture in the fuel to the primary air stream while lump the bound moisture with volatiles in PF combustion modelling, although different methods.......g., oxy-fuel or air–fuel), account for the variations in CO2 and H2O concentrations in a flame, and include the impacts of other participating gases (e.g., CO and hydrocarbons) needs to be derived for combustion CFD community....

Technology for beneficiation of non-coking coals

Energy Technology Data Exchange (ETDEWEB)

Bose, S.K.

1987-04-01

This article outlines the need for efficient non-coking coal beneficiation plants in India to cope with mass production from opencast coal mines. The existing use of magnetite in heavy medium separation processes is expensive and not very efficient in respect to removing shales from opencast lump coals. Instead a new technique is proposed using a ROMJIG washing plant developed in the Federal Republic of Germany. This provides a very efficient, low cost washing system for the coals and allows the continued integration with the coal blending plants. This simplified technology allows for flexible working hours to meet demand and will allow new developments to continue including fuel slurry pipelines, automated testing of coals and new pulverized boiler fuels.

Optimization of a lignite-fired open pulverizing system boiler process based on variations in the drying agent composition

International Nuclear Information System (INIS)

Ma, Youfu; Zhang, Hua; Yuan, Yichao; Wang, Zhiyun

2015-01-01

This paper evaluates three lignite-fired OPSB (open pulverizing system boiler) processes, named OPSB-A, OPSB-B and OPSB-C, corresponding to three options of drying agents used for the pulverizing systems. OPSB-B is similar to our previous work [18] on drying agent composition. Performances of the three OPSBs were calculated and compared with a 600 MW lignite-fired boiler as the reference. The results showed that the coal savings of OPSB-A and OPSB-C were 5.41% and 4.06% in comparison with the reference boiler, whereas for OPSB-B, the savings was 2.57%. Accordingly, emissions of each OPSB could be reduced in proportion to the coal savings. Among the three OPSBs, OPSB-C showed the best performance of water recovery from mill-exhausts because it had the highest mill-exhaust water dew point of 73.2 °C, whereas the exhaust dew points of OPSB-A and OPSB-B were 63.9 °C and 70.9 °C, respectively. Both OPSB-C and OPSB-B are beneficial for achieving a high mill-exhaust humidity ratio, which facilitates water recovery from the mill-exhaust, and a low oxygen content in mill-exhaust, which improves the operating safety of the pulverizing systems, whereas OPSB-A is relatively inferior in these respects. The OPSB-C process is recommended for engineering applications because of its favorable overall performances. - Highlights: • Three lignite-fired OPSB processes are analyzed based on a conventional 600 MW boiler. • OPSB-A, OPSB-B and OPSB-C show coal savings of 5.41%, 2.57 and 4.06%, respectively. • All OPSBs have a great advantage of water recovery from the flue gas, especially OPSB-C. • OPSB-C process is recommended in view of its favorable overall performances

Power generation from chemically cleaned coals: do environmental benefits of firing cleaner coal outweigh environmental burden of cleaning?

DEFF Research Database (Denmark)

Ryberg, Morten W.; Owsianiak, Mikolaj; Laurent, Alexis

2015-01-01

Power generation from high-ash coals is a niche technology for power generation, but coal cleaning is deemed necessary to avoid problems associated with low combustion efficiencies and to minimize environmental burdens associated with emissions of pollutants originating from ash. Here, chemical...... beneficiation of coals using acid and alkali–acid leaching procedures is evaluated as a potential coal cleaning technology employing life cycle assessment (LCA). Taking into account the environmental benefits from firing cleaner coal in pulverized coal power plants and the environmental burden of the cleaning...... itself, it is demonstrated that for a wide range of cleaning procedures and types of coal, chemical cleaning generally performs worse than combustion of the raw coals and physical cleaning using dense medium separation. These findings apply for many relevant impact categories, including climate change...

Thermal coal utilization for the ESCAP region

Energy Technology Data Exchange (ETDEWEB)

1982-01-01

A selection of papers is presented originating from talks to coal utilization workshops for the ASEAN region in 1981. The papers cover: planning aspects - economic and technical aspects of coal usage, long term planning for fuel coal needs, planning and coal selection for coal-fired power plants, coal availability and marketing, and economic aspects of coal usage in developing countries; combustion and plant - changing from coal to oil, principles and problems of coal combustion, use of indigenous and imported coals and their effects on plant design, coal pulverizing mills, ash and dust disposal, environmental aspects of coal combustion, industrial sized coal-fired boilers; transport and storage -ocean shipment, coal receival facilities and associated operations, shipping and rail transport, coal handling and transport, environmental issue in the transport and handling of coal, coal preparation and blending; testing and properties - coal types, characterization properties and classification; training power plant operators; the cement industry and coal, the Australian black coal industry.

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

Science.gov (United States)

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...

Microfine coal firing results from a retrofit gas/oil-designed industrial boiler

Energy Technology Data Exchange (ETDEWEB)

Patel, R.; Borio, R.W.; Liljedahl, G. [Combustion Engineering, Inc., Windsor, CT (United States)] [and others

1995-11-01

Under US Department of Energy, Pittsburgh Energy Technology Center (PETC) support, the development of a High Efficiency Advanced Coal Combustor (HEACC) has been in progress since 1987 at the ABB Power Plant Laboratories. The initial work on this concept produced an advanced coal firing system that was capable of firing both water-based and dry pulverized coal in an industrial boiler environment.

Utilization of pulverized fuel ash in Malta

International Nuclear Information System (INIS)

Camilleri, Josette; Sammut, Michael; Montesin, Franco E.

2006-01-01

In Malta all of the waste produced is mixed and deposited at various sites around the island. None of these sites were purpose built, and all of the waste is above groundwater level. The landfills are not engineered and do not contain any measures to collect leachate and gases emanating from the disposal sites. Another waste, which is disposed of in landfills, is pulverized fuel ash (PFA), which is a by-product of coal combustion by the power station. This has been disposed of in landfill, because its use has been precluded due to the radioactivity of the ashes. The aim of this study was to analyze the chemical composition of the pulverized fuel ash and to attempt to utilize it as a cement replacement in normal concrete mixes in the construction industry. The levels of radiation emitted from the ashes were measured by gamma spectrometry. The results of this study revealed that although at early ages cement replacement by PFA resulted in a reduction in compressive strength (P = 0), when compared to the reference concrete at later ages the strengths measured on concrete cores were comparable to the reference concrete (P > 0.05). The utilization of PFA up to 20% cement replacement in concrete did not raise the radioactivity of the concrete. In conclusion, utilization of PFA in the construction industry would be a better way of disposing of the ashes rather than controlling the leachate and any radioactivity emitted by the landfilled ashes

Advanced technique for computing fuel combustion properties in pulverized-fuel fired boilers

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R. (Vsesoyuznyi Teplotekhnicheskii Institut (Russian Federation))

1992-03-01

Reviews foreign technical reports on advanced techniques for computing fuel combustion properties in pulverized-fuel fired boilers and analyzes a technique developed by Combustion Engineering, Inc. (USA). Characteristics of 25 fuel types, including 19 grades of coal, are listed along with a diagram of an installation with a drop tube furnace. Characteristics include burn-out intensity curves obtained using thermogravimetric analysis for high-volatile bituminous, semi-bituminous and coking coal. The patented LFP-SKM mathematical model is used to model combustion of a particular fuel under given conditions. The model allows for fuel particle size, air surplus, load, flame height, and portion of air supplied as tertiary blast. Good agreement between computational and experimental data was observed. The method is employed in designing new boilers as well as converting operating boilers to alternative types of fuel. 3 refs.

Pulverizing Portraits

DEFF Research Database (Denmark)

Elias, Camelia

Pulverizing Portraits provides the first book-length study of contemporary American poet Lynn Emanuel. Emanuel's poetry is significant because it situates itself in relation to current debates about the state of poetry, creative writing in the academia, and the importance of drawing on interdisci......Pulverizing Portraits provides the first book-length study of contemporary American poet Lynn Emanuel. Emanuel's poetry is significant because it situates itself in relation to current debates about the state of poetry, creative writing in the academia, and the importance of drawing...... been increasingly concerned with poetry as a tool for cultural criticism which constantly redefines our poetic discourse. Elias traces the power of Emanuel's writing and looks at her subtleties in combining intrinsic and formal constraints in poetry with extrinsic and socio-historical methodologies...

Influence of process parameters on coal combustion performance. Review, experiments and engineering modeling

Energy Technology Data Exchange (ETDEWEB)

Lans, R.P. van der

1997-04-01

The objective of this study is to improve the understanding of nitrogen oxide formation and carbon burnout during the combustion of pulverized coal, and to contribute to addressing the potential of chemical engineering models for the prediction of furnace temperatures, NO emissions and the amount of carbon in ash. To this purpose, the effect of coal quality on NO and burnout has been investigated experimentally, a radiation heat balance has been developed based on a simple chemical engineering methodology, and a mixing study has been conducted in order to describe the near burner macro mixing in terms of a reactor configuration. The influence of coal type and process conditions on NO formation and carbon burnout has been investigated experimentally in a 400 MW{sub e} corner fired boiler with over fire air, a 350 MW{sub e} opposed fired boiler, and in a 160 kW{sub t} pilot scale test rig. Three different coals were fired in each of the furnaces as part of the activities in group 3 of the European Union JOULE 2 Extension project `Atmospheric Pressure Combustion of Pulverized Coal and Coal Based Blends for Power Generation`. On the pilot scale test both single stage and air staged tests were performed. A simple, one-dimensional combustion and radiation heat transfer model has been developed for the furnace of full scale boilers. The model has been applied to the two boilers mentioned above, and is validated against measured temperatures and carbon in ash concentrations. A mixing study has been performed in order to initiate an investigation of the potential of chemical engineering models to predict NO from pulverized fuel burners. (EG) 11 refs.

High pressure MHD coal combustors investigation, phase 2

Science.gov (United States)

Iwata, H.; Hamberg, R.

1981-05-01

A high pressure MHD coal combustor was investigated. The purpose was to acquire basic design and support engineering data through systematic combustion experiments at the 10 and 20 thermal megawatt size and to design a 50 MW/sub t/ combustor. This combustor is to produce an electrically conductive plasma generated by the direct combustion of pulverized coal with hot oxygen enriched vitiated air that is seeded with potassium carbonate. Vitiated air and oxygen are used as the oxidizer, however, preheated air will ultimately be used as the oxidizer in coal fired MHD combustors.

Prediction of the burnout performance of some South American coals using a drop-tube furnace

Energy Technology Data Exchange (ETDEWEB)

Richelieu Barranco; Michael Cloke; Edward Lester [University of Nottingham, Nottingham (United Kingdom). Fuel Technology Centre, School of Chemical, Environmental and Mining Engineering

2003-10-01

An experimental investigation into the combustion burnout behaviour of some South American coals was carried out in a drop-tube furnace. The samples, in two size fractions, were initially pyrolysed at a temperature of 1300{sup o}C, in a 1% of oxygen in nitrogen atmosphere for 200 ms. The re-firing of these pyrolysed chars was performed in the same apparatus, at the same temperature, during 400 ms, in an atmosphere containing 5% of oxygen in nitrogen. The coal samples used in this study were characterised by standard tests along with a specially developed image analysis technique (grey-scale histogram). Data of intrinsic reactivity, morphology, and burnout of the chars were correlated with maceral content of the feed coal by mean of linear regressions. In most cases, the results showed a poor correlation. Subsequently, when the rank of the coals was included in the regressions, the correlations remarkably improved in all cases. When further regressions of char properties with the grey-scale histogram of the coals were carried out, much better correlations were achieved. Therefore, the results indicate that the grey-scale histogram analysis provides a simple and objective technique to predict the combustion behaviour of these coals. 17 refs., 6 figs., 4 tabs.

Process to improve combustion and coalescing characteristics of coal pellets

Energy Technology Data Exchange (ETDEWEB)

Ban, T.E.; Marlowe, W.H.

1980-10-23

Baking types of coal, which occur mainly in the Midwestern States of the USA, tend to form solid layers when heated to remove tar. In order to prevent this, it is proposed to pulverize the coal, to form small pellets and to coat these pellets. A suitable coating material mentioned here is sodium carbonate. Variants of the coating process are given. The coated pellets are heated.

Brayton Point coal conversion project (NEPCO)

Energy Technology Data Exchange (ETDEWEB)

Sullivan, W.F. Jr.

1982-05-01

The New England Power Company (NEPCO) recently converted Brayton Point Power Station Units 1, 2, and 3 from oil to coal. The coal conversion project is the largest coal conversion project in the nation to date. Stone and Webster Engineering Corporation (SWEC) was hired as the engineer/constructor for the project. Units 1 and 2 are 250-MW Combustion Engineering boilers, and Unit 3 is a 650-MW Babcock and Wilcox boiler. All three units were originally designed to burn pulverized coal but were converted to oil during the years of low oil prices. Studies performed by NEPCO and SWEC indicated that the areas discussed in the following paragraphs required upgrading before the units could efficiently burn coal and meet Federal and State environmental requirements. All units have been converted and are operating. This paper discusses design modifications required to burn coal, startup, and initial operating problems, and solutions.

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

Data.gov (United States)

U.S. Environmental Protection Agency — Pulverized bituminous coal was burned in a 10W externally heated entrained flow furnace under air-combustion and three oxy-combustion inlet oxygen conditions (28,...

Overview of current and future - clean coal technologies

International Nuclear Information System (INIS)

Darthenay, A.

1995-01-01

A new generation of advanced coal technology, environmentally cleaner and in many cases more efficient, has been developed: flue gas treatment of pulverized coal combustion, circulating fluidized bed (CFB), integrated gasification with combined cycle (IGCC) and pressurized fluidized bed combustion (PFBC). These techniques are described, giving a balance of their references and of the steps which are still to be got over in order to have industrial processes applicable to large size power plants. 4 tabs

A MACHINE FOR PULVERIZING AND SIFTING GARI MASH

African Journals Online (AJOL)

Dr Obe

O.75kw electric motor. Fig. 2.Photograph of prototype gari pulverizing/sifting machine. A Side view of the Prototype Gari mash Pulverize/sifting machine. 1. Vee-belt drives; 2. Head pulley; 3 belt conveyor; 4, cake breaker, 5. tail pulley; 6. lump or cake of' gari mash;7hopper; 8pulverizing roller; 9. Side gaurds; 10.brush 11.

A model of the enhancement of coal combustion using high intensity acoustic fields

International Nuclear Information System (INIS)

Yavuzkurt, S.; Ha, M.Y.; Koopmann, G.H.; Scaroni, A.

1989-01-01

In this paper a model for the enhancement of coal combustion in the presence of high intensity acoustics is developed. A high intensity acoustic field induces an oscillating velocity over pulverized coal particles otherwise entrained in the main gas stream, resulting in increased heat and mass transfer. The augmented heat and mass transfer coefficients, expressed as space- and time-averaged Nusselt and Sherwood numbers for the oscillating flow, were implemented in an existing computer code (PCGC-2) capable of predicting various aspects of pulverized coal combustion and gasification. Increases in the Nusselt and Sherwood numbers of about 45, 60 and 82.5% at sound pressure levels of 160, 165, and 170 dB for 100 μm coal particles were obtained due to increases in the acoustic slop velocity associated with the increased sound pressure levels. The main effect of the acoustic field was observed during the char combustion phase in a diffusionally controlled situation. A decrease in the char burnout length (time) of 15.7% at 160 dB and 30.2% at 170 dB was obtained compared to the case with no sound for the 100 μm coal particles

The development of clean coal technology is the main way to control of atmospheric pollution in China

Energy Technology Data Exchange (ETDEWEB)

Wu Lixin; Xu Hong [Clean Coal Engineering & Research Center of Coal Industry (China)

1999-11-01

Atmospheric pollution in China and its causes are analysed. Power stations, industrial boilers and kilns and domestic coal combustion are the main pollution sources. Clean coal technologies are urgently needed. Main clean coal technologies which can improve the present situation of industrial coal combustion are coal cleaning, blending and briquetting; boiler retrofitting; advanced technologies to improve combustion efficiency and reduce pollution - fluidized bed combustion and pulverized coal desulfurization; and advanced desulfurization and dedusting technologies and equipment.

ULTRA LOW NOx INTEGRATED SYSTEM FOR NOx EMISSION CONTROL FROM COAL-FIRED BOILERS

Energy Technology Data Exchange (ETDEWEB)

Galen H. Richards; Charles Q. Maney; Richard W. Borio; Robert D. Lewis

2002-12-30

ALSTOM Power Inc.'s Power Plant Laboratories, working in concert with ALSTOM Power's Performance Projects Group, has teamed with the U.S. Department of Energy's National Energy Technology Laboratory (DOE NETL) to conduct a comprehensive study to develop/evaluate low-cost, efficient NOx control technologies for retrofit to pulverized coal fired utility boilers. The objective of this project was to develop retrofit NOx control technology to achieve less than 0.15 lb/MMBtu NOx (for bituminous coals) and 0.10 lb/MMBtu NOx (for subbituminous coals) from existing pulverized coal fired utility boilers at a cost which is at least 25% less than SCR technology. Efficient control of NOx is seen as an important, enabling step in keeping coal as a viable part of the national energy mix in this century, and beyond. Presently 57% of U.S. electrical generation is coal based, and the Energy Information Agency projects that coal will maintain a lead in U.S. power generation over all other fuel sources for decades (EIA 1998 Energy Forecast). Yet, coal-based power is being strongly challenged by society's ever-increasing desire for an improved environment and the resultant improvement in health and safety. The needs of the electric-utility industry are to improve environmental performance, while simultaneously improving overall plant economics. This means that emissions control technology is needed with very low capital and operating costs. This project has responded to the industry's need for low NOx emissions by evaluating ideas that can be adapted to present pulverized coal fired systems, be they conventional or low NOx firing systems. The TFS 2000{trademark} firing system has been the ALSTOM Power Inc. commercial offering producing the lowest NOx emission levels. In this project, the TFS 2000{trademark} firing system served as a basis for comparison to other low NOx systems evaluated and was the foundation upon which refinements were made to further

Perancangan Sistem Pemeliharaan Menggunakan Metode Reliability Centered Maintenance (RCM Pada Pulverizer (Studi Kasus: PLTU Paiton Unit 3

Directory of Open Access Journals (Sweden)

RATNA BHAKTI PUSPITA SARI

2017-03-01

Full Text Available PLTU Paiton Unit 3 merupakan perusahaan yang bergerak di bidang produksi listrik menggunakan bahan baku batubara yang terletak di Paiton, Probolinggo. Untuk mencapai target, proses produksi dilakukan 24 jam selama 1 tahun tanpa henti. Program pemeliharaan mesin sangat penting untuk kelancaran proses produksi. Dalam rangka mencapai target tersebut dituntut adanya kelancaran batubara dari silo hingga surface burner menggunakan pulverizer. Data dari Departemen Engineering menunjukkan bahwa beberapa subsistem pulverizer sering mengalami kerusakan yang dapat menimbulkan kegagalan pada sistem tersebut. Penelitian tugas akhir ini menggunakan metode Reliability Centered Maintenance (RCM untuk menurunkan tingkat breakdown mesin dan downtime produksi. Data historis kerusakan pulverizer dianalisa. Kemudian kegagalan dari suatu komponen yang dapat menyebabkan kegagalan fungsi dari sistem diidentifikasi menggunakan metode Failure Mode and Effect Analysis (FMEA. Selanjutnya menggunakan RCM Decision Worksheet untuk mengetahui bagian dari sistem yang gagal dan perlu dilakukan tindakan perbaikan dan pencegahan berdasarkan kegagalan yang ada agar kejadian yang sama tidak terulang dan menentukan kegiatan perancang perawatan yang tepat pada setiap komponen Berdasarkan analisis data secara Reliability Centered Maintenance (RCM terdapat 12 failure mode yang terjadi pada pulverizer. 3 failure mode dapat dicegah dengan scheduled restoration task, 8 failure mode dapat dicegah dengan scheduled discard task, dan 1 failure mode dapat dicegah dengan redesign. Analisis kuantitatif menggunakan distribusi kegagalan dengan perangkat lunak Weibull++6 didapatkan MTBF grinding roller 2880,66 jam, MTBF hydraulic pump 5075,06 jam, MTBF gearbox 5381,65 jam dan MTBF coal feeder 525,17 jam.

Life Cycle Assessment of Coal-fired Power Production

Energy Technology Data Exchange (ETDEWEB)

Spath, P. L.; Mann, M. K.; Kerr, D. R.

1999-09-01

Coal has the largest share of utility power generation in the US, accounting for approximately 56% of all utility-produced electricity (US DOE, 1998). Therefore, understanding the environmental implications of producing electricity from coal is an important component of any plan to reduce total emissions and resource consumption. A life cycle assessment (LCA) on the production of electricity from coal was performed in order to examine the environmental aspects of current and future pulverized coal boiler systems. Three systems were examined: (1) a plant that represents the average emissions and efficiency of currently operating coal-fired power plants in the US (this tells us about the status quo), (2) a new coal-fired power plant that meets the New Source Performance Standards (NSPS), and (3) a highly advanced coal-fired power plant utilizing a low emission boiler system (LEBS).

Co-firing straw with coal in a swirl-stabilized dual-feed burner: modelling and experimental validation

DEFF Research Database (Denmark)

Yin, Chungen; Kær, Søren Knudsen; Rosendahl, Lasse

2010-01-01

This paper presents a comprehensive computational fluid dynamics (CFD) modelling study of co-firing wheat straw with coal in a 150 kW swirl-stabilized dual-feed burner flow reactor, in which the pulverized straw particles (mean diameter of 451μm) and coal particles (mean diameter of 110.4μm...... conversion. It is found that for pulverized biomass particles of a few hundred microns in diameter the intra-particle heat and mass transfer is a secondary issue at most in their conversion, and the global four-step mechanism of Jones and Lindstedt may be better used in modelling volatiles combustion......-lean core zone; whilst the coal particles are significantly affected by secondary air jet and swirled into the oxygen-rich outer radius with increased residence time (in average, 8.1s for coal particles vs. 5.2s for straw particles in the 3m high reactor). Therefore, a remarkable difference in the overall...

Next-generation coal utilization technology development study. Environmentally-friendly coal combustion technology; O2/CO2 combustion technology; Sekitan riyo jisedai gijutsu kaihatsu chosa. Kankyo chowagata sekitan nensho gijutsu (sanso nensho gijutsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

For the purpose of developing combustion systems in which environmental pollutants are less emitted from coal-fired boilers, conducted in fiscal 1994 were a study of load followability of oxygen producing equipment, and element and basic tests on oxygen combustion systems. Dynamic simulations were made to confirm load followability of low-purity oxygen producing equipment. Further, a test was made on starting time of oxygen producing equipment. As a result of the simulation, favorable load followability was confirmed except for some of the process. The width of variation of the product oxygen purity was {plus_minus} 0.7% at maximum. In the element test on oxygen combustion systems, an experiment on the oxygen combustion using pulverized coal was conducted to study heat collection characteristics of furnace and response to multi-kind of coal. A study of balance of S content, experiments on characteristics of crushing/transporting pulverized coal, etc. were added. There were seen no peculiar differences in CO2 transport and air transport. 216 figs., 31 tabs.

Coal liquefaction in an inorganic-organic medium. [DOE patent application

Science.gov (United States)

Vermeulen, T.; Grens, E.A. II; Holten, R.R.

Improved process for liquefaction of coal by contacting pulverized coal in an inorganic-organic medium solvent system containing a ZnCl/sub 2/ catalyst, a polar solvent with the structure RX where X is one of the elements O, N, S, or P, and R is hydrogen or a lower hydrocarbon radical; the solvent system can contain a hydrogen donor solvent (and must when RX is water) which is immiscible in the ZnCl/sub 2/ and is a hydroaromatic hydrocarbon selected from tetralin, dihydrophenanthrene, dihydroanthracene or a hydrogenated coal derived hydroaromatic hydrocarbon distillate fraction.

Coal-fired power plants and the causes of high temperature corrosion

Energy Technology Data Exchange (ETDEWEB)

Oakey, J E; Simms, N J [British Coal Corporation, Coal Technology Development Div., Cheltenham, Glos (United Kingdom); Tomkings, A B [ERA Technology Ltd., Leatherhead, Surrey (United Kingdom)

1996-12-01

The heat exchangers in all types of coal-fired power plant operate in aggressive, high temperature environments where high temperature corrosion can severely limit their service lives. The extent of this corrosion is governed by the combined effects of the operating conditions of the heat exchanger and the presence of corrosive species released from the coal during operation. This paper reviews the coal-related factors, such as ash deposition, which influence the operating environments of heat exchangers in three types of coal-fired power plant - conventional pulverized coal boilers, fluidized bed boilers and coal gasification systems. The effects on the performance of the materials used for these heat exchangers are then compared. (au) 35 refs.

Combustion behaviors and kinetics of sewage sludge blended with pulverized coal: With and without catalysts.

Science.gov (United States)

Wang, Zhiqiang; Hong, Chen; Xing, Yi; Li, Yifei; Feng, Lihui; Jia, Mengmeng

2018-04-01

The combustion behaviors of sewage sludge (SS), pulverized coal (PC), and their blends were studied using a thermogravimetric analyzer. The effect of the mass ratio of SS to PC on the co-combustion characteristics was analyzed. The experiments showed that the ignition performance of the blends improved significantly as the mass percentage of SS increased, but its combustion intensity decreased. The burnout temperature (T b ) and comprehensive combustibility index (S) of the blends were almost unchanged when the mass percentage of SS was less than 10%. However, a high mass percentage of SS (>10%) resulted in a great increase in T b and a notable decrease in S. Subsequently, the effects of different catalysts (CaO, CeO 2 , MnO 2 , and Fe 2 O 3 ) on the combustion characteristics and activation energy of the SS/PC blend were investigated. The four catalysts promoted the release and combustion of volatile matters in the blended fuels and shifted their combustion profiles to a low temperature. In addition, their peak separating tendencies were obvious at 350-550 C, resulting in high peak widths. All the catalysts improved combustion activity of the blended fuel and accelerated fixed carbon combustion, which decreased the ignition temperature and burnout temperature of the fuels. CeO 2 had the best catalytic effects in terms of the comprehensive combustion performance and activation energy, followed closely by Fe 2 O 3 . However, the rare-earth compounds are expensive to be applied in the catalytic combustion process of SS/PC blend at present. Based on both catalytic effects and economy, Fe 2 O 3 was potentially an optimal option for catalytic combustion among the tested catalysts. Copyright © 2018 Elsevier Ltd. All rights reserved.

Identification and quantification of priority species from coal combustion

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E.; Zheng, L.; Hlavacek, T. [Canada Centre for Mineral and Energy Technology, Ottawa, ON (Canada). Energy Research Laboratories

1996-07-01

The objective is to quantify and characterize emissions from pulverized coal combustion of seven coals and the circulating fluidized bed combustion of four coals. The species of particular interest are sulphur, nitrogen, chlorine, arsenic, mercury, lead, cadmium, potassium, and sodium. The Facility for Analysis of Chemical Thermodynamics (F{asterisk}A{asterisk}C{asterisk}T) method is used to predict type and amount of priority species. Prediction is made for combustion with and without the presence of limestone. The results show that the combustion technology used influences the amount of priority species emitted. 16 tabs., 3 apps.

γ-ray activity in bituminous, subbituminous and lignite coals

International Nuclear Information System (INIS)

Barber, D.E.; Giorgio, H.R.

1977-01-01

Specimens of three different types of coal from four different geographical locations (Montana, North Dakota, Illinois and Pennsylvania) were examined by γ-ray spectrometry. Some samples were ashed in a muffle furnace. Other samples included pulverized coal, slag and fly ash from an electric power generating station. Activity from the 232 Th and 238 U series was present in all samples. Activity varied widely depending upon the source of the coal. The results indicate a need for additional examination of activity in coal to: (1) establish more precisely the relative environmental impact of coal-fired power stations compared with nuclear ones, (2) indicate the degree of sophistication required in environmental surveillance programs involving areas where both nuclear and coal-fired power stations are operational, and (3) determine the occupational exposure risks in mining operations. (author)

Thermal analysis evaluation of the reactivity of coal mixtures for injection in the blast furnace

Directory of Open Access Journals (Sweden)

Maria de Lourdes Ilha Gomes

2006-03-01

Full Text Available Pulverized Coal Injection (PCI is an important standard technology replacing coke partially by pulverized coal into the blast furnace that allows a significant reduction of hot metal costs and environmental impact, contributing to a decrease of coke requirements for ironmaking. Coals typically used in this process in Brazil are, at current time, exclusively imported from many countries, although economic important coal-measures occur in the southern part of the country. The Brazilian coals have a low rank, higher contents of inert components, proportioning nocoking properties and an expected high reactivity. Due to these caractheristics, these coals could be used for injection in the blast furnaces in order to decrease the dependency on high cost imported coals. The efficiency in the combustion and the coal reactivity are considered important parameters in the blast furnace, since a larger amount of char (unburned coal causes severe problems to the furnace operation. The aim of the present work is to compare the reactivity of a south Brazilian coal, obtained from Faxinal mine, with two imported coals and the blends of the Brazilian coal with the imported ones. The reactivity of these coals and their blends were evaluated in a thermogravimetric analyzer. In the experiments, various mass ratios of Faxinal coal and the imported coals were used to compose the blends. The gasification reaction with pure CO2 was conducted under isothermal conditions at 1050 °C and atmospheric pressure. The experimental results show the greater reactivity of the Faxinal coal. The additive behavior was confirmed. The blends with a composition of up to 50% Faxinal coal have parameters according to the usual limits used for PCI.

Investigation of air gasification of micronized coal, mechanically activated using the plasma control of the process

Directory of Open Access Journals (Sweden)

Butakov Evgenii

2017-01-01

Full Text Available Combination of the processes of coal combustion and gasification into a single technology of mechano-chemical and plasma-chemical activation is of a considerable scientific and technological interest. Enhancement of coal reactivity at their grinding with mechanical activation is associated with an increase in the reaction rate of carbon material, and at plasma-chemical effect, the main is an increase in reactivity of the oxidizing agent caused by the high plasma temperatures of atomic oxygen. The process of gasification was studied on the 1-MW setup with tangential scroll supply of pulverized coal-air mixture and cylindrical reaction chamber. Coal ground by the standard boiler mill is fed to the disintegrator, then, it is sent to the scroll inlet of the burner-reactor with the transport air. Pulverized coal is ignited by the plasmatron of 10-kW power. In experiments on air gasification of micronized coal, carried out at the temperature in the reaction chamber of 1000-1200°C and air excess α = 0.3-1, the data on CO concentration of 11% and H2 concentration of up to 6% were obtained. Air and air-steam gasification of mechanically-activated micronized coals with plasma control was calculated using SigmaFlow software package.

Investigation of air gasification of micronized coal, mechanically activated using the plasma control of the process

Science.gov (United States)

Butakov, Evgenii; Burdukov, Anatoly; Chernetskiy, Mikhail; Kuznetsov, Victor

2017-10-01

Combination of the processes of coal combustion and gasification into a single technology of mechano-chemical and plasma-chemical activation is of a considerable scientific and technological interest. Enhancement of coal reactivity at their grinding with mechanical activation is associated with an increase in the reaction rate of carbon material, and at plasma-chemical effect, the main is an increase in reactivity of the oxidizing agent caused by the high plasma temperatures of atomic oxygen. The process of gasification was studied on the 1-MW setup with tangential scroll supply of pulverized coal-air mixture and cylindrical reaction chamber. Coal ground by the standard boiler mill is fed to the disintegrator, then, it is sent to the scroll inlet of the burner-reactor with the transport air. Pulverized coal is ignited by the plasmatron of 10-kW power. In experiments on air gasification of micronized coal, carried out at the temperature in the reaction chamber of 1000-1200°C and air excess α = 0.3-1, the data on CO concentration of 11% and H2 concentration of up to 6% were obtained. Air and air-steam gasification of mechanically-activated micronized coals with plasma control was calculated using SigmaFlow software package.

Exergetic analysis of a steam power plant using coal and rice straw in a co-firing process

Energy Technology Data Exchange (ETDEWEB)

Restrepo, Alvaro; Miyake, Raphael Guardini; Bazzo, Edson [Federal University of Santa Catarina (UFSC), Dept. of Mechanical Engineering, Florianopolis, SC (Brazil)], e-mails: arestrep@labcet.ufsc.br, miyake@labcet.ufsc.br, ebazzo@emc.ufsc.br; Bzuneck, Marcelo [Tractebel Energia S.A., Capivari de Baixo, SC (Brazil). U.O. Usina Termeletrica Jorge Lacerda C.], e-mail: marcelob@tractebelenergia.com.br

2010-07-01

This paper presents an exergetic analysis concerning an existing 50 M We steam power plant, which operates with pulverized coal from Santa Catarina- Brazil. In this power plant, a co-firing rice straw is proposed, replacing up to 10% of the pulverized coal in energy basis required for the boiler. Rice straw has been widely regarded as an important source for bio-ethanol, animal feedstock and organic chemicals. The use of rice straw as energy source for electricity generation in a co-firing process with low rank coal represents a new application as well as a new challenge to overcome. Considering both scenarios, the change in the second law efficiency, exergy destruction, influence of the auxiliary equipment and the greenhouse gases emissions such as CO{sub 2} and SO{sub 2} were considered for analysis. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Helble, J.J. [ed.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. [PSI Technology Co., Andover, MA (United States); Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L. [Arizona Univ., Tucson, AZ (United States); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. [Kentucky Univ., Lexington, KY (United States)

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.

Increasing coal-fired power generation efficiency to reduce electric cost and environmental emissions

International Nuclear Information System (INIS)

Torrens, I.M.; Stenzel, W.C.

1997-01-01

New generating capacity required globally between 1993 and 2010 is estimated to be around 1500 GW, of which some two-thirds will be outside the OECD, and some 40 % in the Asian non-OECD countries. Coal is likely to account for a substantial fraction of this new generation. Today's state-of-the-art supercritical coal-fired power plant has a conversion efficiency of some 42-45 %. The capital cost increase associated with the supercritical or ultra-supercritical pulverized coal power plant compared to a conventional subcritical plant is small to negligible. The increased efficiency associated with the supercritical plant leads to an actual reduction in the total cost of electricity generated in cents/kWh, relative to a conventional plant. Despite this, the power sector continues to build subcritical plants and has no near term plans to increase the efficiency of power plants in the projects it is developing. Advanced clean coal technologies such as integrated gasification combined cycle and pressurized fluidized bed combustion will be selected for independent power projects only in very specific circumstances. Advanced clean coal plants can be operated reliably and with superior performance, and specifically that their present estimated capital costs can be reduced substantially to a point where they are competitive with state-of-the-art pulverized coal technologies. (R.P.)

Anatomy of an upgraded pulverized coal facility: Combustion modification through flue gas scrubbing

Energy Technology Data Exchange (ETDEWEB)

Watts, J.U. [Dept. of Energy, Pittsburgh, PA (United States). Federal Energy Technology Center; Savichky, W.J.; O`Dea, D.T. [New York State Electric and Gas Corp., Binghamton, NY (United States)

1997-12-31

Regeneration is a biological term for formation or creating anew. In the case of Milliken station, a species of steam generation (Tangentus coali) regeneration refers to refitting critical systems with the latest technological advances to reduce emissions while maintaining or improving performance. The plant has undergone a series of operations which provided anatomical changes as well as a face lift. Each of the two units were place in suspended animation (outage) to allow these changes to be made. The paper describes the project which includes retrofitting combustion systems, pulverizers, boiler liners, scrubbers, and control room. This retrofit is meant to increase thermal efficiency while reducing the formation of nitrogen oxides.

Coal-water fuels - a clean coal solution for Eastern Europe

International Nuclear Information System (INIS)

Ljubicic, B.; Willson, W.; Bukurov, Z.; Cvijanovic, P.; Stajner, K.; Popovic, R.

1993-01-01

Eastern Europe currently faces great economic and environmental problems. Among these problems is energy provision. Coal reserves are large but cause pollution while oil and gas need to be used for export. Formal 'clean coal technologies' are simply too expensive to be implemented on a large scale in the current economic crisis. The promised western investment and technological help has simply not taken place, western Europe must help eastern Europe with coal technology. The cheapest such technology is coal-water fuel slurry. It can substitute for oil, but research has not been carried out because of low oil prices. Coal-water fuel is one of the best methods of exploiting low rank coal. Many eastern European low rank coals have a low sulfur content, and thus make a good basis for a clean fuel. Italy and Russia are involved in such a venture, the slurry being transported in a pipeline. This technology would enable Russia to exploit Arctic coal reserves, thus freeing oil and gas for export. In Serbia the exploitation of sub-Danube lignite deposits with dredging mining produced a slurry. This led to the use and development of hot water drying, which enabled the removal of many of the salts which cause problems in pulverized fuel combustion. The system is economic, the fuel safer to transport then oil, either by rail or in pipelines. Many eastern European oil facilities could switch. 24 refs

Characteristics of carbonized sludge for co-combustion in pulverized coal power plants

International Nuclear Information System (INIS)

Park, Sang-Woo; Jang, Cheol-Hyeon

2011-01-01

Co-combustion of sewage sludge can destabilize its combustion profile due to high volatility, which results in unstable flame. We carried out fuel reforming for sewage sludge by way of carbonization at pyrolysis temperature of 300-500 deg. C. Fuel characteristics of carbonized sludge at each temperature were analyzed. As carbonization temperature increased, fuel ratio increased, volatile content reduced, and atomic ratio relation of H/C and O/C was similar to that of lignite. The analysis result of FT-IR showed the decrease of aliphatic C-H bond and O-C bond in carbonization. In the analysis result of TG-DTG, the thermogravimetry reduction temperature of carbonized sludge (CS400) was proven to be higher than that of dried sludge, but lower than that of sub-bituminous coal. Hardgrove grindability index increased in proportion to fuel ratio increase, where the carbonized sludge value of 43-110 was similar or higher than the coal value of 49-63. As for ash deposits, slagging and fouling index were higher than that of coal. When carbonized sludge (CS400) and coal were co-combusted in 1-10% according to calorific value, slagging tendency was low in all conditions, and fouling tendency was medium or high according to the compositions of coal.

Numerical Simulation of Gas-Solid Two-Phase Flow for Four-Channels Pulverized Swirling Burner

Directory of Open Access Journals (Sweden)

Defu LI

2013-05-01

Full Text Available This article presents a mathematical model of cold gas-solid two-phase flow which is based on the cement rotary kiln in service. By altering the parameters of air supply system of four- channels pulverized burner, investigations are taken of that motion trajectory and particle distributions in the very turbulent field. The results show that motion trail of most particles in rotary kiln is a combination process of gradual diffusion and slow sedimentation; increasing internal flow velocity would aggravate coal particles to diffuse; external flow velocity should be controlled in a reasonable range.

Exploring evaluation to influence the quality of pulverized coal fly ash. Co-firing of biomass in a pulverized coal plant or mixing of biomass ashes with pulverized coal fly ash; Verkennende evaluatie kwaliteitsbeinvloeding poederkoolvliegas. Bijstoken van biomassa in een poederkoolcentrale of bijmenging van biomassa-assen met poederkoolvliegas

Energy Technology Data Exchange (ETDEWEB)

Van der Sloot, H.A.; Cnubben, P.A.J.P [ECN Schoon Fossiel, Petten (Netherlands)

2000-08-01

In this literature survey the consequences of co-firing of biomass and mixing of biomass ash with coal fly ash on the coal fly ash quality is evaluated. Biomass ash considered in this context is produced by gasification, pyrolysis or combustion in a fluidized bed. The irregular shape of biomass ash obtained from gasification, pyrolysis or combustion has a negative influence on the water demand in concrete applications of the coal fly ash resulting from mixing biomass ash and coal fly ash. In case of co-firing, high concentrations of elements capable of lowering the ash melting point (e.g., Ca and Mg) may lead to more ash agglomeration. This leads to a less favourable particle size distribution of the coal fly ash, which has a negative impact on the water demand in cement bound applications. Gasification, pyrolysis and combustion may lead to significant unburnt carbon levels (>10%). The unburnt carbon generally absorbs water and thus has a negative influence on the water demand in cement-bound applications. The contribution of biomass ash to the composition of coal fly ash will not be significantly different, whether the biomass is co-fired or whether the biomass ash is mixed off-line with coal fly ash. The limit values for Cl, SO4 and soluble salts can form a limitation for the use of coal fly ash containing biomass for cement-bound applications. As side effects of biomass co-firing, the level of constituents such as Na, K, Ca and Mg may lead to slagging and fouling of the boiler. In addition, a higher emission of flue gas contaminants As, Hg, F, Cl and Br may be anticipated in case more contaminated biomass streams are applied. This may also lead to a higher contamination level of gypsum produced from flue gas cleaning residues. Relatively clean biomass streams (clean wood, cacao shells, etc.) will hardly lead to critical levels of elements from a leaching point of view. More contaminated streams, such as sewage sludge, used and preserved wood, petcoke and RDF

Slagging behavior of upgraded brown coal and bituminous coal in 145 MW practical coal combustion boiler

Energy Technology Data Exchange (ETDEWEB)

Akiyama, Katsuya; Pak, Haeyang; Takubo, Yoji [Kobe Steel, Ltd, Kobe (Japan). Mechanical Engineering Research Lab.; Tada, Toshiya [Kobe Steel, Ltd, Takasago (Japan). Coal and Energy Technology Dept.; Ueki, Yasuaki [Nagoya Univ. (Japan). Energy Science Div.; Yoshiie, Ryo; Naruse, Ichiro [Nagoya Univ. (Japan). Dept. of Mechanical Science and Engineering

2013-07-01

The purpose of this study is to quantitatively evaluate behaviors of ash deposition during combustion of Upgraded Brown Coal (UBC) and bituminous coal in a 145 MW practical coal combustion boiler. A blended coal consisting 20 wt% of the UBC and 80 wt% of the bituminous coal was burned for the combustion tests. Before the actual ash deposition tests, the molten slag fractions of ash calculated by chemical equilibrium calculations under the combustion condition was adopted as one of the indices to estimate the tendency of ash deposition. The calculation results showed that the molten slag fraction for UBC ash reached approximately 90% at 1,523 K. However, that for the blended coal ash became about 50%. These calculation results mean that blending the UBC with a bituminous coal played a role in decreasing the molten slag fraction. Next, the ash deposition tests were conducted, using a practical pulverized coal combustion boiler. A water-cooled stainless-steel tube was inserted in locations at 1,523 K in the boiler to measure the amount of ash deposits. The results showed that the mass of deposited ash for the blended coal increased and shape of the deposited ash particles on the tube became large and spherical. This is because the molten slag fraction in ash for the blended coal at 1,523 K increased and the surface of deposited ash became sticky. However, the mass of the deposited ash for the blended coal did not greatly increase and no slagging problems occurred for 8 days of boiler operation under the present blending conditions. Therefore, appropriate blending of the UBC with a bituminous coal enables the UBC to be used with a low ash melting point without any ash deposition problems in a practical boiler.

Preventing performance drops of coal mills due to high moisture content

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Stoustrup, Jakob; Mataji, B.

2007-01-01

Coal mills pulverize and dry the coal dust before it is blown into the furnace in coal-fired power plants. The coal mills can only deliver the requested coal flow if certain conditions are fulfilled. These are normally considered as constraints on individual variables. However, combinations of more...... than one variable might cause problems even though these individually variables are in an acceptable region. This paper deals with such a problem. The combination of a high load of the power plant, a large load change and high moisture content in the coal, can force the coal mill into a state where...... coal is accumulated instead of being blown into the furnace. This paper suggests a simple method for preventing the accumulation of the coal in the mill, by limiting the requested coal flow considering the coal moisture content and the temperature outside the mill.  ...

Measurement and modeling of advanced coal conversion processes, Volume II

Energy Technology Data Exchange (ETDEWEB)

Solomon, P.R.; Serio, M.A.; Hamblen, D.G. [and others

1993-06-01

A two dimensional, steady-state model for describing a variety of reactive and nonreactive flows, including pulverized coal combustion and gasification, is presented. The model, referred to as 93-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 a discrete ordinates method. The particle phase is modeled in a lagrangian framework, such that mean paths of particle groups are followed. A new coal-general devolatilization submodel (FG-DVC) with coal swelling and char reactivity submodels has been added.

Comprehensive report to Congress Clean Coal Technology Program

International Nuclear Information System (INIS)

1992-06-01

This project will provide a full-scale demonstration of Micronized Coal Reburn (MCR) technology for the control of NO x on a wall-fired steam generator. This demonstration is expected to reduce NO x emissions by 50 to 60%. Micronized coal is coal that has been very finely pulverized (80% less than 325 mesh). This micronized coal, which may comprise up to 30% of the total fuel fired in the furnace, is fired high in the furnace in a fuel-rich reburn zone at a stoichiometry of 0.8. Above the reburn zone, overfire air is injected into the burnout zone at high velocity for good mixing to ensure complete combustion. Overall excess air is 15%. MCR technology reduces NO x emissions with minimal furnace modifications, and the improved burning characteristics of micronized coal enhance boiler performance

Characteristics of carbonized sludge for co-combustion in pulverized coal power plants.

Science.gov (United States)

Park, Sang-Woo; Jang, Cheol-Hyeon

2011-03-01

Co-combustion of sewage sludge can destabilize its combustion profile due to high volatility, which results in unstable flame. We carried out fuel reforming for sewage sludge by way of carbonization at pyrolysis temperature of 300-500°C. Fuel characteristics of carbonized sludge at each temperature were analyzed. As carbonization temperature increased, fuel ratio increased, volatile content reduced, and atomic ratio relation of H/C and O/C was similar to that of lignite. The analysis result of FT-IR showed the decrease of aliphatic C-H bond and O-C bond in carbonization. In the analysis result of TG-DTG, the thermogravimetry reduction temperature of carbonized sludge (CS400) was proven to be higher than that of dried sludge, but lower than that of sub-bituminous coal. Hardgrove grindability index increased in proportion to fuel ratio increase, where the carbonized sludge value of 43-110 was similar or higher than the coal value of 49-63. As for ash deposits, slagging and fouling index were higher than that of coal. When carbonized sludge (CS400) and coal were co-combusted in 1-10% according to calorific value, slagging tendency was low in all conditions, and fouling tendency was medium or high according to the compositions of coal. Copyright © 2010 Elsevier Ltd. All rights reserved.

The Charfuel coal refining process

International Nuclear Information System (INIS)

Meyer, L.G.

1991-01-01

The patented Charfuel coal refining process employs fluidized hydrocracking to produce char and liquid products from virtually all types of volatile-containing coals, including low rank coal and lignite. It is not gasification or liquefaction which require the addition of expensive oxygen or hydrogen or the use of extreme heat or pressure. It is not the German pyrolysis process that merely 'cooks' the coal, producing coke and tar-like liquids. Rather, the Charfuel coal refining process involves thermal hydrocracking which results in the rearrangement of hydrogen within the coal molecule to produce a slate of co-products. In the Charfuel process, pulverized coal is rapidly heated in a reducing atmosphere in the presence of internally generated process hydrogen. This hydrogen rearrangement allows refinement of various ranks of coals to produce a pipeline transportable, slurry-type, environmentally clean boiler fuel and a slate of value-added traditional fuel and chemical feedstock co-products. Using coal and oxygen as the only feedstocks, the Charfuel hydrocracking technology economically removes much of the fuel nitrogen, sulfur, and potential air toxics (such as chlorine, mercury, beryllium, etc.) from the coal, resulting in a high heating value, clean burning fuel which can increase power plant efficiency while reducing operating costs. The paper describes the process, its thermal efficiency, its use in power plants, its pipeline transport, co-products, environmental and energy benefits, and economics

Influence of rank and macerals on the burnout behaviour of pulverized Indian coal

Energy Technology Data Exchange (ETDEWEB)

Choudhury, Nandita; Biswas, S.; Sarkar, P.; Kumar, Manish; Mukherjee, A.; Choudhury, A. [Central Institute of Mining and Fuel Research, Digwadih Campus (Formerly Central Fuel Research Institute), P.O. FRI, Dhanbad-828 108, Jharkhand (India); Ghosal, Sujit; Mitra, Tandra [Jadavpur University, Kolkata-700 032, West Bengal (India)

2008-04-03

The combustion behaviour of coal is significantly influenced by its rank and maceral and microlithotype compositions. Different macerals, due to their distinct and unique physical properties and chemical makeup, have different burning characteristics. This paper deals with the burning behaviour of coals of Indian origin by thermo gravimetric analysis (TGA) and in drop tube furnace (DTF) with particular emphasis on the role of macerals and their associations. Four coals of different rank and petrographic makeup, along with their two density fractions, with enriched vitrinite and inertinites, respectively,were studied in both TGA and DTF. The burnout behaviour was estimated from the chemical analyses of the char samples collected from the DTF. The burning characteristics of one of the coals deviate from the trend expected with the variations of rank. The behaviour of the density fractions in DTF was found to be different from that observed in TGA analyses. An attempt has been made to correlate the burnout with the petrographic macerals and microlithotypes present in the coals. The morphology of the residual chars indicates the contributions of the inertinites towards the formation of cenospheres and network types of reactive chars. The superior burning behaviour of the higher density inertinite-rich fractions over the raw coals and also some vitrinite-rich fractions indicate the better reactivity of the inertinites towards combustion. (author)

Report on Seminar on Clean Coal Technology '93; Clean coal technology kokusai seminar hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-11-01

The program of the above clean coal technology (CCT) event is composed of 1) Coal energy be friendly toward the earth, 2) Research on CCT in America (study of coal structure under electron microscope), and 3) Research on CCT in Australia (high intensity combustion of ultrafine coal particles in a clean way). Remarks under item 1) are mentioned below. As for SO{sub 2} emissions base unit, Japan's is 1 at its coal-fired thermal power station while that of America is 7.8. As for the level of SO{sub 2}/NOx reduction attributable to coal utilization technologies, it rises in the order of flue gas desulfurizer-aided pulverized coal combustion, normal pressure fluidized bed combustion, pressurized fluidized bed combustion, integrated coal gasification combined cycle power generation, and integrated coal gasification combined cycle power generation/fuel cell. As for the level of CO2 reduction attributable to power generation efficiency improvement, provided that Japan's average power generation efficiency is 39% and if China's efficiency which is now 28% is improved to be similar to that of Japan, there will be a 40% reduction in CO2 emissions. Under item 2) which involves America's CCT program, reference is made to efforts at eliminating unnecessary part from the catalytic process and at reducing surplus air, to the export of CCT technology, and so forth. Under item 3), it is stated that coal cleaning may govern reaction efficiency in a process of burning coal particles for gasification. (NEDO)

The use of mechanically activated micronized coal in thermal power engineering

Directory of Open Access Journals (Sweden)

Burdukov Anatoliy P.

2016-01-01

Full Text Available Coal is one of the main energy resources and development of new promising technologies on its basis is certainly topical. This article discusses the use of new technology of gas and fuel oil replacement by mechanically activated micronized coal in power engineering: ignition and stabilization of pulverized coal flame combustion, as well as gasification of micronized coal in the flow. The new technology coal combustion with two stages of grinding is suggested. Optimization of the scheme of two-stage combustion is calculated. The first experimental data on the combustion process are obtained. The first demonstration tests on gas and heavy oil replacement by micronized coal during boiler ignition were carried out in the real power boiler with the capacity of 320 tons of steam per hour.

Research on pyrolysis characteristics and kinetics of super fine and conventional pulverized coal

International Nuclear Information System (INIS)

Zhang Chaoqun; Jiang Xiumin; Wei Lihong; Wang Hui

2007-01-01

Based on isothermal thermogravimetric analysis (TGA) and kinetic equations, the optimization toolbox of MATLAB was applied to study the effects of particle size and heating rate on the pyrolysis characteristics and kinetics and to obtain the mechanism function and kinetic parameters of Yuanbaoshan coal at four different particle sizes and heating rates. The pyrolysis characteristics of the samples were analyzed using thermogravimetric (TG) curves and differential thermogravimetric (DTG) curves. The results show that the coal pyrolysis process is strongly affected by heating rate and particle size. As the heating rate increases, the temperature of volatile matter initiation increases, the total volatile matter evolved decreases and the DTG peak shifts toward higher temperature. As the particle size decreases, the temperature of volatile matter initiation of the coal sample decreases and the maximum rate of mass loss increases. In the pyrolysis of coal, the activation energies of the samples were found to increase with growing particle size and decreasing heating rate for both of the devolatilization temperature stages. In the lower temperature stage, the coal samples show a great difference in mechanism function at different particle sizes and heating rates

Characteristic Study of Shenmu Bituminous Coal Combustion with Online TG-MS-FTIR

Science.gov (United States)

Pan, Guanfu

2018-01-01

The combustion characteristics of Shenmu bituminous pulverized coal (SBC) were comprehensively investigated with a combined TG-MS-FTIR system by considering the effect of particle size, heating rate and total flowrate. The combustion products were accurately quantified by normalization and numerical analysis of MS results. The results indicate that the decrease of the particle size, heating rate and total flowrate result in lower ignition and burnout temperatures. The activation energy tends to be lower with smaller particle size, lower heating rate and total flowrate. The MS and FTIR results demonstrate that lower concentrations of different products, such as NO, NO2, HCN, CH4 and SO2 were produced with smaller particle size, slower heating rate and lower total flowrate. The decrease of particle size would lead to more contact area with oxygen and slower heating rate could provide more sufficient time for the diffusion. High total flowrate would reduce the oxygen adsorbability on the coal particle surface and shorten the residence time of oxygen, which makes the ignition difficult to occur. This work will guide to understand the combustion kinetics of pulverized coals and be beneficial to control the formation of pollutants.

Use of coal-water mixtures in blast furnaces

Energy Technology Data Exchange (ETDEWEB)

Malgarini, G; Giuli, M; Davide, A; Carlesi, C [Centro Sviluppo Materiali, Rome (Italy); Italsider, Genoa [Italy; Deltasider, Piombino [Italy

1989-03-01

At the present time, an ironworks blast furnace employing a pulverized coal injection (PCI) system is in operation at the Piombino Works (Italy). A wide development, within this industry, of PCI techniques is expected in the near future to limit, as much as possible, the rebuilding of coke ovens. Research activities and industrial trials aimed at maximizing the use of coal injection into blast furnaces are in course of development. This paper uses flowsheets to illustrate such a system and provides graphs to indicate the economic convenience of PCI systems as compared with systems using naphtha as an injected fuel.

Environmental characteristics of clean coal technologies

International Nuclear Information System (INIS)

Bossart, S.J.

1992-01-01

The Department of Energy's (DOE) Clean Coal Technology (CCT) Program is aimed at demonstrating the commercial readiness of advanced coal-based technologies. A major goal of the CCT program is to introduce into the US energy marketplace those coal-based power generation technologies that have superior economic and environmental performance over the current suite of commercial coal-based power generation technologies. The commercialization of CCTs will provide the electric utility industry with technology options for replacing aging power plants and meeting future growth in electricity demand. This paper discusses the environmental advantages of two CCTs used for electric power generation: pressurized fluidized-bed combustion (PFBC) and integrated gasification combined-cycle (IGCC). These CCTs are suitable for repowering existing power plants or for grassroots construction. Due to their high efficiency and advanced environmental control systems, they emit less sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), particulate matter, and carbon dioxide (CO 2 ) than a state-of-the-art, pulverized coal power plant with flue gas desulfurization (PC/FGD)

Basic studies on coal liquefaction reaction, reforming and utilization of liquefaction products

Energy Technology Data Exchange (ETDEWEB)

Shiraishi, M. (National Institute for Resources and Environment, Tsukuba (Japan))

1993-09-01

This report describes the achievement of research and development of coal liquefaction technologies in the Sunshine Project for FY 1992, regarding the coal liquefaction reaction, reforming and utilization of liquefaction products. For the fundamental study on coal liquefaction reaction, were investigated effect of asphaltene in petroleum residue on coprocessing, pretreatment effect in coprocessing of Taiheiyo coal and tarsand bitumen using oil soluble catalyst, solubilization and liquefaction of Taiheiyo coal at mild conditions with the aid of super acid, and flash hydropyrolysis of finely pulverized swollen coal under high hydrogen pressure. On the other hand, for the study on hydrotreatment of coal derived liquid, were investigated catalytic hydroprocessing of Wandoan coal liquids, production of gasoline from coal liquids by fluid catalytic cracking, solvent extraction of phenolic compounds from coal liquids, and separation of hetero compounds in coal liquid by means of high pressure crystallization. Further progress in these studies has been confirmed. 9 figs., 6 tabs.

Pilot-Scale Demonstration of ALTA for NOx Control in Pulverized Coal-Fired Boilers

Energy Technology Data Exchange (ETDEWEB)

Andrew Fry; Devin Davis; Marc Cremer; Bradley Adams

2008-04-30

This report describes computational fluid dynamics (CFD) modeling and pilot-scale testing conducted to demonstrate the ability of the Advanced Layered Technology Approach (ALTA) to reduce NO{sub x} emissions in a pulverized coal (PC) boiler. Testing specifically focused on characterizing NO{sub x} behavior with deep burner staging combined with Rich Reagent Injection (RRI). Tests were performed in a 4 MBtu/hr pilot-scale furnace at the University of Utah. Reaction Engineering International (REI) led the project team which included the University of Utah and Combustion Components Associates (CCA). Deep burner staging and RRI, combined with selective non-catalytic reduction (SNCR), make up the Advanced Layered Technology Approach (ALTA) for NO{sub x} reduction. The application of ALTA in a PC environment requires homogenization and rapid reaction of post-burner combustion gases and has not been successfully demonstrated in the past. Operation of the existing low-NO{sub x} burner and design and operation of an application specific ALTA burner was guided by CFD modeling conducted by REI. Parametric pilot-scale testing proved the chemistry of RRI in a PC environment with a NOx reduction of 79% at long residence times and high baseline NOx rate. At representative particle residence times, typical operation of the dual-register low-NO{sub x} burner provided an environment that was unsuitable for NO{sub x} reduction by RRI, showing no NOx reduction. With RRI, the ALTA burner was able to produce NO{sub x} emissions 20% lower than the low-NO{sub x} burner, 76 ppmv vs. 94 ppmv, at a burner stoichiometric ratio (BSR) of 0.7 and a normalized stoichiometric ratio (NSR) of 2.0. CFD modeling was used to investigate the application of RRI for NO{sub x} control on a 180 MW{sub e} wall-fired, PC boiler. A NO{sub x} reduction of 37% from baseline (normal operation) was predicted using ALTA burners with RRI to produce a NO{sub x} emission rate of 0.185 lb/MBtu at the horizontal nose of

Ash transformation during co-firing coal and straw

DEFF Research Database (Denmark)

Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn

2007-01-01

Co-firing straw with coal in pulverized fuel boilers can cause problems related to fly ash utilization, deposit formation, corrosion and SCR catalyst deactivation due to the high contents of Cl and K in the ash. To investigate the interaction between coal and straw ash and the effect of coal...... quality on fly ash and deposit properties, straw was co-fired with three kinds of coal in an entrained flow reactor. The compositions of the produced ashes were compared to the available literature data to find suitable scaling parameters that can be used to predict the composition of ash from straw...... and coal co-firing. Reasonable agreement in fly ash compositions regarding total K and fraction of water soluble K was obtained between co-firing in an entrained flow reactor and full-scale plants. Capture of potassium and subsequent release of HCl can be achieved by sulphation with SO2 and more...

Far-IR measurements at Cerro Toco, Chile: FIRST, REFIR, and AERI

Science.gov (United States)

Cageao, Richard P.; Alford, J. Ashley; Johnson, David G.; Kratz, David P.; Mlynczak, Martin G.

2010-09-01

In mid-2009, the Radiative Heating in the Underexplored Bands Campaign II (RHUBC-II) was conducted from Cerro Toco, Chile, a high, dry, remote mountain plateau, 23°S , 67.8°W at 5.4km, in the Atacama Desert of Northern Chile. From this site, dominant IR water vapor absorption bands and continuum, saturated when viewed from the surface at lower altitudes, or in less dry locales, were investigated in detail, elucidating infrared (IR) absorption and emission in the atmosphere. Three Fourier Transform InfraRed (FTIR) instruments were at the site, the Far-Infrared Spectroscopy of the Troposphere (FIRST), the Radiation Explorer in the Far Infrared (REFIR), and the Atmospheric Emitted Radiance Interferometer (AERI). In a side-by-side comparison, these measured atmospheric downwelling radiation, with overlapping spectral coverage from 5 to 100μm (2000 to 100cm-1), and instrument spectral resolutions from 0.5 to 0.643cm-1, unapodized. In addition to the FTIR and other ground-based IR and microwave instrumentation, pressure/temperature/relative humidity measuring sondes, for atmospheric profiles to 18km, were launched from the site several times a day. The derived water vapor profiles, determined at times matching the FTIR measurement times, were used to model atmospheric radiative transfer. Comparison of instrument data, all at the same spectral resolution, and model calculations, are presented along with a technique for determining adjustments to line-by-line calculation continuum models. This was a major objective of the campaign.

Processing woody debris biomass for co-milling with pulverized coal

Science.gov (United States)

Dana Mitchell; Bob Rummer

2007-01-01

The USDA, Forest Service, Forest Products Lab funds several grants each year for the purpose of studying woody biomass utilization. One selected project proposed removing small diameter stems and unmerchantable woody material from National Forest lands and delivering it to a coal-fired power plant in Alabama for energy conversion. The Alabama Power Company...

Simulation of pulverized coal fired boiler: reaction chamber

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, C.P.; Lansarin, M.A.; Secchi, A.R.; Mendes, T.F. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Dept. de Engenharia Quimica. Grupo de Modelagem, Simulacao, Controle e Otimizacao de Processos)]. E-mail: {cperdomo, marla, arge, talita}@enq.ufrgs.br

2005-06-15

This work is part of a joint project to built a computational tool for power plant simulation, dealing specifically with the reaction chamber (place of the boiler where the fuel is burned). In order to describe the conversion of chemical energy to thermal energy, an one dimensional pseudo-homogeneous mathematical model, with variable physical properties, and based on mass and energy balances, was developed. The equations were implemented in the gPROMS simulator and the model parameters were estimated using the module gEST of this software, with experimental data from a large-scale coal-fired utility boiler and kinetic data from the open literature. The results showed that the model predicts the composition of the outlet combustion gas satisfactorily. (author)

Coal as a source of energy to alleviate the crisis facing the cement industry

Energy Technology Data Exchange (ETDEWEB)

Reinert, N

1979-01-01

After recalling the importance of coal in the cement industry up until the end of the 1950s, and the regeneration of interest in this fuel, the author presents some views on the stocking of coal, on its preparation and on its application for firing. The advantages of linear stocking and of de-stocking by the 'front slice' method to ensure good homogenization are described. The precautions to be taken during the fine-grinding process and the transport of the pulverized coal in order to prevent coal-dust explosions are discussed. The main firing systems (direct, semi-direct and indirect) are discussed and their respective advantages and drawbacks examined. (In French)

Assessment of inhalation risk due to radioactivity released from coal-based thermal power plant

International Nuclear Information System (INIS)

Sahu, S.K.; Pandit, G.G.; Shukla, V.K.; Puranik, V.D.; Kushwaha, H.S.

2006-01-01

In India, the coal based thermal power plants have been the major source of power generation in the past and would continue for decades to come. As the coal contains naturally occurring primordial radionuclides the burning of pulverized coal to produce energy for generation of electricity in thermal power plants will result in the emission of a variety of natural radioactive elements into the environment in the vicinity of thermal power plants. In this paper we have used two different methods for characterization of uncertainty in inhalation risk to the general public around 10 Kms radius in the neighborhood of a coal-fired thermal power plant. (author)

Problem of formation of nitrogen oxides during coal combustion in power plant steam generators

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.; Kuvaev, Yu.V.

1992-07-01

Analyzes a study of physical and chemical processes of nitrogen oxide formation during coal combustion conducted at Stanford University (USA). Experimental installation, pulverized coal feeding as well as measuring techniques and equipment are described. Experiments were conducted with 55 micron particles of semibituminous coal. An equation for the percentage of coal carbon converted to gaseous products is given. Active formation of NO from nitrogen content in the fuel was observed when oxygen content was under 4%. Conversion of the fuel nitrogen to NO[sub x] in the 1,350-1,850 K temperature range did not depend on gas temperature but rather on oxygen content. 2 refs.

Apparatus and method to pulverize rock using a superconducting electromagnetic linear motor

Science.gov (United States)

Ignatiev, Alex (Inventor)

2009-01-01

A rock pulverizer device based on a superconducting linear motor. The superconducting electromagnetic rock pulverizer accelerates a projectile via a superconducting linear motor and directs the projectile at high speed toward a rock structure that is to be pulverized by collision of the speeding projectile with the rock structure. The rock pulverizer is comprised of a trapped field superconducting secondary magnet mounted on a movable car following a track, a wire wound series of primary magnets mounted on the track, and the complete magnet/track system mounted on a vehicle used for movement of the pulverizer through a mine as well as for momentum transfer during launch of the rock breaking projectile.

A STUDY ON THE GRINDABILITY OF SERBIAN COALS

Directory of Open Access Journals (Sweden)

Dragoslava D Stojiljković

2011-01-01

Full Text Available Thermal power plants in the Republic of Serbia are making considerable efforts and even more considerable investments, not only to maintain electricity production at maximum design levels, but even to additionally increase the power output of existing generating units. Capacities of mills used in pulverized coal preparation are identified as one of the main constraints to achieving maximum mill plant capacity, while coal grindability is seen as one of the factors that directly affect capacities of the coal mills utilized in thermal power plants. The paper presents results of experimental investigation conducted for the purpose of determining Hardgrove grindability index of coal. The investigation was conducted in accordance with ISO 5074 and included analysis of approximately 70 coal samples taken from the open pit mine of Kolubara coal basin. Research results obtained indicate that coal rich in mineral matter and thus, of lower heating value is characterized by higher grindability index. Therefore, analyses presented in the paper suggest that characteristics of solid fuels analyzed in the research investigation conducted are such that the use coals less rich in mineral matter i. e. coals characterized by lower grindability index will cause coal mills to operate at reduced capacity. This fact should be taken into account when considering a potential for electricity production increase.

Coal preparation and coal cleaning in the dry process; Kanshiki sentaku to coal cleaning

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Z; Morikawa, M; Fujii, Y [Okayama University, Okayama (Japan). Faculty of Engineering

1996-09-01

Because the wet process has a problem such as waste water treatment, coal cleaning in the dry process was discussed. When a fluidized bed (using glass beads and calcium carbonate) is utilized instead of the heavy liquid, the fluidized bed will have apparent density as the liquid does, whereas the relative relationship therewith determines whether a substance having been put into the fluidized bed will float or sink. This is utilized for coals. In addition, two powder constituents of A and B may be wanted to be separated using the fluidized extraction process (similar to the liquid-liquid extraction process). In such a case, a fluidized bed in which both constituents are mixed is added with a third constituent C (which will not mix with A, but mix well with B), where the constituents are separated into A and (B + C), and the (B + C) constituent is separated further by using a sieve. If coal has the coal content mixed with ash content and pulverized, it turns into particle groups which have distributions in grain size and density. Groups having higher density may contain more ash, and those having lower density less ash. In addition, the ash content depends also on the grain size. The ash content may be classified by using simultaneously wind classification (for density and grain size) and a sieve (for grain size). This inference may be expanded to consideration of constructing a multi-stage fluidized bed classification tower. 12 figs., 5 tabs.

Coal reburning technology for cyclone boilers

International Nuclear Information System (INIS)

Yagiela, A.S.; Maringo, G.J.; Newell, R.J.; Farzan, H.

1990-01-01

Babcock and Wilcox has obtained encouraging results from engineering feasibility and pilot-scale proof-of-concept studies of coal reburning for cyclone boiler NO x control. Accordingly, B and W completed negotiations for a clean coal cooperative agreement with the Department of Energy to demonstrate coal reburning technology for cyclone boilers. The host site for the demonstration is the Wisconsin Power and Light (WP and L) Company's 100MWe Nelson Dewey Station. Reburning involves the injection of a supplemental fuel (natural gas, oil, or coal) into the main furnace to produce locally reducing stoichiometric conditions which convert the NO x produced therein to molecular nitrogen, thereby reducing overall NO x emissions. There are currently no commercially-demonstrated combustion modification techniques for cyclone boilers which reduce NO x emissions. The emerging reburning technology offers cyclone boiler operators a promising alternative to expensive flue gas cleanup techniques for NO x emission reduction. This paper reviews baseline testing results at the Nelson Dewey Station and pilot-scale results simulating Nelson Dewey operation using pulverized coal (PC) as the reburning fuel. Outcomes of the model studies as well as the full-scale demonstration preliminary design are discussed

Update of progress for Phase II of B&W`s advanced coal-fired low-emission boiler system

Energy Technology Data Exchange (ETDEWEB)

McDonald, D.K. [Babcock & Wilcox, Barberton, OH (United States); Madden, D.A.; Rodgers, L.W. [Babcock & Wilcox, Alliance, OH (United States)] [and others

1995-11-01

Over the past five years, advances in emission control techniques at reduced costs and auxiliary power requirements coupled with significant improvements in steam turbine and cycle design have significantly altered the governing criteria by which advanced technologies have been compared. With these advances, it is clear that pulverized coal technology will continue to be competitive in both cost and performance with other advanced technologies such as Integrated Gasification Combined Cycle (IGCC) or first generation Pressurized Fluidized Bed Combustion (PFBC) technologies for at least the next decade. In the early 1990`s it appeared that if IGCC and PFBC could achieve costs comparable to conventional pulverized coal plants, their significantly reduced NO{sub x} and SO{sub 2} emissions would make them more attractive. A comparison of current emission control capabilities shows that all three technologies can already achieve similarly low emissions levels.

Effects of bluff-body burner and coal particle size on NOx emissions and burnout

Energy Technology Data Exchange (ETDEWEB)

Xiao, L.S.; Cheng, J.F.; Zeng, H.C. [Huazhong University of Science and Technology, Wuhan (China). National Coal Combustion Lab.

1999-12-01

Investigations on air staging have been carried out using various coals with different degrees of fineness and a variety of burners with a 92.9 kw h{sup -1} tunnel furnace burning pulverized coal. It has been observed that using the bluff-body burner can reduce both the unburned carbon in fly ash and NOx emissions in the case of air staging. The experimental results show that air-staging combustion has a more remarkable effect on NOx reduction for higher-volatile coal than for lower-volatile coal. The results also show that there is a strong influence of coal particle size on NOx emissions and unburned carbon in the fly ash in the case of air staging. 13 refs., 12 figs., 2 tabs.

SVM-based multisensor data fusion for phase concentration measurement in biomass-coal co-combustion

Science.gov (United States)

Wang, Xiaoxin; Hu, Hongli; Jia, Huiqin; Tang, Kaihao

2018-05-01

In this paper, the electrical method combines the electrostatic sensor and capacitance sensor to measure the phase concentration of pulverized coal/biomass/air three-phase flow through data fusion technology. In order to eliminate the effects of flow regimes and improve the accuracy of the phase concentration measurement, the mel frequency cepstrum coefficient features extracted from electrostatic signals are used to train the Continuous Gaussian Mixture Hidden Markov Model (CGHMM) for flow regime identification. Support Vector Machine (SVM) is introduced to establish the concentration information fusion model under identified flow regimes. The CGHMM models and SVM models are transplanted on digital signal processing (DSP) to realize on-line accurate measurement. The DSP flow regime identification time is 1.4 ms, and the concentration predict time is 164 μs, which can fully meet the real-time requirement. The average absolute value of the relative error of the pulverized coal is about 1.5% and that of the biomass is about 2.2%.

Prospects for advanced coal-fuelled fuel cell power plants

International Nuclear Information System (INIS)

Jansen, D.; Laag, P.C. van der; Oudhuis, A.B.J.; Ribberink, J.S.

1994-01-01

As part of ECN's in-house R and D programmes on clean energy conversion systems with high efficiencies and low emissions, system assessment studies have been carried out on coal gasification power plants integrated with high-temperature fuel cells (IGFC). The studies also included the potential to reduce CO 2 emissions, and to find possible ways for CO 2 extraction and sequestration. The development of this new type of clean coal technology for large-scale power generation is still far off. A significant market share is not envisaged before the year 2015. To assess the future market potential of coal-fuelled fuel cell power plants, the promise of this fuel cell technology was assessed against the performance and the development of current state-of-the-art large-scale power generation systems, namely the pulverized coal-fired power plants and the integrated coal gasification combined cycle (IGCC) power plants. With the anticipated progress in gas turbine and gas clean-up technology, coal-fuelled fuel cell power plants will have to face severe competition from advanced IGCC power plants, despite their higher efficiency. (orig.)

Coking coal consumption of POSCO

International Nuclear Information System (INIS)

Yoo, B.C.

1991-01-01

Pohang Iron and Steel Company Limited (POSCO) was established in 1968. Molten iron was first produced in July 1973 after a 3 year construction period. The long awaited start up of Korea's first integrated steel works provided the momentum for the fast growth of our steel industry. In 1973, the first year of operation, POSCO purchased 770,000 tons of coal from the United States and Australia. The import tonnage was more than doubled in 1976 when we completed the second stage of Pohang Works and has continued to increase reaching 13.1 million tons last year. POSCO's coal consumption will increase one more time next year as the fourth stage of Kwangyang works starts to operate a new blast furnace with an annual molten iron production capacity of 2.8 million tons. Even though the new blast furnace will have the same capacity as the other 3 in Kwangyang, the additional coking coal requirement will be much smaller than the tonnages we needed for the other stages of the works. This paper reports that this is due to the increased use of pulverized coal

Economic comparison of clean coal generating technologies with natural gas-combined cycle systems

International Nuclear Information System (INIS)

Sebesta, J.J.; Hoskins, W.W.

1990-01-01

This paper reports that there are four combustion technologies upon which U.S. electric utilities are expected to rely for the majority of their future power generating needs. These technologies are pulverized coal- fired combustion (PC); coal-fired fluidized bed combustion (AFBC); coal gasification, combined cycle systems (CGCC); and natural gas-fired combined cycle systems (NGCC). The engineering and economic parameters which affect the choice of a technology include capital costs, operating and maintenance costs, fuel costs, construction schedule, process risk, environmental and site impacts, fuel efficiency and flexibility, plant availability, capacity factors, timing of startup, and the importance of utility economic and financial factors

Physicochemical characterization of Baizhi particles by ultrafine pulverization

Science.gov (United States)

Yang, Lian-Wei; Sun, Peng; Gai, Guo-Sheng; Yang, Yu-Fen; Wang, Yu-Rong

2011-04-01

Baizhi, as a medicinal plant, has been demonstrated to be useful for the treatment of aches and pains in China. The physicochemical characterization of Baizhi particles is greatly influenced by ultrafine pulverization. To study the physicochemical characterization of Baizhi, the raw plant material of Baizhi was ground to 6 μm particles by a high speed centrifugal sheering (HSCS) pulverizer. The micron particles were characterized by optical microscopy and scanning electron microscopy (SEM). Imperatorin is one of the active ingredients of Baizhi, and its extraction yield is determined to evaluate the chemical characterization of Baizhi powder. Imperatorin was analyzed by high performance liquid chromatography (HPLC). The results show that after ultrafine pulverization, the plant cell walls are broken into pieces and the extraction yield of imperatorin is increased by 11.93% compared with the normal particles.

Advanced pulverized-coal power plants: A U.S. export opportunity

International Nuclear Information System (INIS)

Ruth, L.A.; Ramezan, M.; Izsak, M.S.

1995-01-01

This paper provides an overview of Low Emission Boiler System (LEBS) power generation systems and its potential for generating power worldwide. Based on the fuel availability, power requirements, and environmental regulations, countries have been identified that need to build advanced, clean, efficient, and economical power generation, systems. It is predicted that ''more electrical generation capacity will be built over the next 25 years than was built in the previous century''. For example, China and India alone, with less than 10% of today's demand, plan to build what would amount to a quarter of the world's new capacity. For the near- to mid-term, the LEBS program of Combustion 2000 has the promise to fill some of the needs of the international coal-fired power generation market. The high efficiency of LEBS, coupled with the use of advanced, proven technologies and low emissions, make it a strong candidate for export to those areas whose need for additional power is greatest. LEBS is a highly advanced version of conventional coal-based power plants that have been utilized throughout the world for decades. LEBS employs proven technologies and doesn't require gasification and/or an unconventional combustion environment (e.g., fluidized bed). LEBS is viewed by the utility industry as technically acceptable and commercially feasible

Change in surface characteristics of coal in upgrading of low-rank coals; Teihin`itan kaishitsu process ni okeru sekitan hyomen seijo no henka

Energy Technology Data Exchange (ETDEWEB)

Oki, A.; Xie, X.; Nakajima, T.; Maeda, S. [Kagoshima University, Kagoshima (Japan). Faculty of Engineering

1996-10-28

With an objective to learn mechanisms in low-rank coal reformation processes, change of properties on coal surface was discussed. Difficulty in handling low-rank coal is attributed to large intrinsic water content. Since it contains highly volatile components, it has a danger of spontaneous ignition. The hot water drying (HWD) method was used for reformation. Coal which has been dry-pulverized to a grain size of 1 mm or smaller was mixed with water to make slurry, heated in an autoclave, cooled, filtered, and dried in vacuum. The HWD applied to Loy Yang and Yallourn coals resulted in rapid rise in pressure starting from about 250{degree}C. Water content (ANA value) absorbed into the coal has decreased largely, with the surface made hydrophobic effectively due to high temperature and pressure. Hydroxyl group and carbonyl group contents in the coal have decreased largely with rising reformation treatment temperature (according to FT-IR measurement). Specific surface area of the original coal of the Loy Yang coal was 138 m{sup 2}/g, while it has decreased largely to 73 m{sup 2}/g when the reformation temperature was raised to 350{degree}C. This is because of volatile components dissolving from the coal as tar and blocking the surface pores. 2 refs., 4 figs.

Soot, unburned carbon and ultrafine particle emissions from air- and oxy-coal flames

International Nuclear Information System (INIS)

Morris, W.J.; Yu, Dunxi; Wendt, J.O.L.

2010-01-01

Oxy-coal combustion is one possible solution for the mitigation of greenhouse gases. In this process coal is burned in oxygen, rather than air, and the temperatures in the boiler are mitigated by recycling flue gases, so that the inlet mixture may contain either 27 % O 2 to match adiabatic flame temperatures, or 32 % O 2 to match gaseous radiation heat fluxes in the combustion chamber. However, a major issue for heat transfer from coal combustion is the radiative heat transmission from soot. For this research, air and oxy coal firing were compared regarding the emission of soot. A 100 kW down-fired laboratory combustor was used to determine effects of switching from air to oxy-firing on soot, unburned carbon and ultrafine particle emissions from practical pulverized coal flames. Of interest here were potential chemical effects of substitution of the N 2 in air by CO 2 in practical pulverized coal flames. The oxy-coal configuration investigated used once-through CO 2 , simulating cleaned flue gas recycle with all contaminants and water removed. Three coals were each burned in: a) air, b) 27 % O 2 / 73 % CO 2 , c) 32 % O 2 / 68 % CO 2 . Tests were conducted at (nominally) 3 %, 2 %, 1 % and 0 % O 2 in the exhaust (dry basis). For each condition, particulate samples were iso kinetically withdrawn far from the radiant zone, and analyzed using a photoacoustic analyzer (PA) for black carbon, a scanning mobility particle sizer (SMPS) for ultrafine particles, and a total sample loss on ignition (LOI) method for unburned carbon in ash. Data suggest that at low stoichiometric ratios, ultrafine particles consist primarily of black carbon, which, for the bituminous coal, is produced in lesser amounts under oxy-fired conditions than under the air-fired condition, even when adiabatic flame temperatures are matched. However, significant changes in mineral matter vaporization were not observed unless the flames were hotter. These and other results are interpreted in the light of

Particle-based characterisation of pulverised coals and chars for carbon burnout studies

Energy Technology Data Exchange (ETDEWEB)

Gibbins, J.R.; Seitz, M.H.; Kennedy, S.M.; Beeley, T.J.; Riley, G.S. [Imperial College of Science, Technology and Medicine, London (United Kingdom). Mechanical Engineering Department

1999-07-01

The study of individual particle properties, as opposed to averaged behaviour of differing particles, was carried out for the combustion of coals and chars using optical microscopy and digital image processing. Chars from entrained flow reactors and corresponding pulverized fuel samples were characterized to examine possible char particle origins for real heterogeneous particles. 7 refs., 5 figs., 1 tab.

Assessment of ecotoxicological risks of element leaching from pulverized coal ashes

NARCIS (Netherlands)

Jenner, H.A.

1995-01-01

This thesis describes the consequences of the disposal of the combustion residues of coal, especially the uptake of elements from such residues and their effects on various organisms. The effects on benthic organisms in fresh and in seawater are considered in the first two parts. The third

Research, development, demonstration, and early deployment policies for advanced-coal technology in China

International Nuclear Information System (INIS)

Zhao Lifeng; Gallagher, Kelly Sims

2007-01-01

Advanced-coal technologies will increasingly play a significant role in addressing China's multiple energy challenges. This paper introduces the current status of energy in China, evaluates the research, development, and demonstration policies for advanced-coal technologies during the Tenth Five-Year Plan, and gives policy prospects for advanced-coal technologies in the Eleventh Five-Year Plan. Early deployment policies for advanced-coal technologies are discussed and some recommendations are put forward. China has made great progress in the development of advanced-coal technologies. In terms of research, development, and demonstration of advanced-coal technologies, China has achieved breakthroughs in developing and demonstrating advanced-coal gasification, direct and indirect coal liquefaction, and key technologies of Integrated Gasification Combined Cycle (IGCC) and co-production systems. Progress on actual deployment of advanced-coal technologies has been more limited, in part due to insufficient supporting policies. Recently, industry chose Ultra Super Critical (USC) Pulverized Coal (PC) and Super Critical (SC) PC for new capacity coupled with pollution-control technology, and 300 MW Circulating Fluidized Bed (CFB) as a supplement

A FUEL-RICH PRECOMBUSTOR. FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS - VOLUME IV. ALTERNATE CON- CEPTS FOR SOX, NOX, AND PARTICULATE EMISSIONS CONTROL FROM

Science.gov (United States)

The report gives results a study of the use of precombustors for the simultaneous control of S02, NOx, and ash emissions from coal combustion. In Phase 1, exploratory testing was conducted on a small pilot scale--293 kW (million Btu/hr)-pulverized-coal-fired precombustor to ident...

Non-slag co-gasification of biomass and coal in entrained-bed furnace

Science.gov (United States)

Itaya, Yoshinori; Suami, Akira; Kobayashi, Nobusuke

2018-02-01

Gasification is a promising candidate of processes to upgrade biomass and to yield clean gaseous fuel for utilization of renewable energy resources. However, a sufficient amount of biomass is not always available to operate a large scale of the plant. Co-gasification of biomass with coal is proposed as a solution of the problem. Tar emission is another subject during operation in shaft or kiln type of gasifiers employed conventionally for biomass. The present authors proposed co-gasification of biomass and coal in entrained-bed furnace, which is a representative process without tar emission under high temperature, but operated so to collect dust as flyash without molten slag formation. This paper presents the works performed on co-gasification performance of biomass and pulverized coal to apply to entrained-bed type of furnaces. At first, co-gasification of woody powder and pulverized coal examined using the lab-scale test furnace of the down-flow entrained bed showed that the maximum temperatures in the furnace was over 1500 K and the carbon conversion to gas achieved at higher efficiency than 80-90 percent although the residence time in the furnace was as short as a few seconds. Non-slag co-gasification was carried out successfully without slag formation in the furnace if coal containing ash with high fusion temperature was employed. The trend suggesting the effect of reaction rate enhancement of co-gasification was also observed. Secondary, an innovative sewage sludge upgrading system consisting of self-energy recovery processes was proposed to yield bio-dried sludge and to sequentially produce char without adding auxiliary fuel. Carbonization behavior of bio-dried sludge was evaluated through pyrolysis examination in a lab-scale quartz tube reactor. The thermal treatment of pyrolysis of sludge contributed to decomposition and removal of contaminant components such as nitrogen and sulfur. The gasification kinetics of sludge and coal was also determined by a

Formation of fine particles in co-combustion of coal and solid recovered fuel in a pulverized coal-fired power station

DEFF Research Database (Denmark)

Wu, Hao; Pedersen, Anne Juul; Glarborg, Peter

2011-01-01

showed an ultrafine mode centered at approximately 0.1 μm. Compared with coal combustion, co-combustion of coal and SRF increased the formation of submicron particles, especially ultrafine particles below 0.2 μm. The morphology of the particles indicated that supermicron particles were primarily formed...... by the melting of minerals. The ultrafine particles were generated through nucleation and coagulation of vaporized inorganic species, while for the particles in between supermicron and ultrafine particles, condensation of vaporized species or aggregation of nucleates on the existing spherical submicron particles...... appear to be an important formation mechanism. The elemental composition of the particles from coal combustion showed that S and Ca were significantly enriched in ultrafine particles and P was also enriched considerably. However, compared with supermicron particles, the contents of Al, Si and K were...

Coal Direct Chemical Looping Retrofit to Pulverized Coal Power Plants for In-Situ CO2 Capture

Energy Technology Data Exchange (ETDEWEB)

Zeng, Liang; Li, Fanxing; Kim, Ray; Bayham, Samuel; McGiveron, Omar; Tong, Andrew; Connell, Daniel; Luo, Siwei; Sridhar, Deepak; Wang, Fei; Sun, Zhenchao; Fan, Liang-Shih

2013-09-30

A novel Coal Direct Chemical Looping (CDCL) system is proposed to effectively capture CO2 from existing PC power plants. The work during the past three years has led to an oxygen carrier particle with satisfactory performance. Moreover, successful laboratory, bench scale, and integrated demonstrations have been performed. The proposed project further advanced the novel CDCL technology to sub-pilot scale (25 kWth). To be more specific, the following objectives attained in the proposed project are: 1. to further improve the oxygen carrying capacity as well as the sulfur/ash tolerance of the current (working) particle; 2. to demonstrate continuous CDCL operations in an integrated mode with > 99% coal (bituminous, subbituminous, and lignite) conversion as well as the production of high temperature exhaust gas stream that is suitable for steam generation in existing PC boilers; 3. to identify, via demonstrations, the fate of sulfur and NOx; 4. to conduct thorough techno-economic analysis that validates the technical and economical attractiveness of the CDCL system. The objectives outlined above were achieved through collaborative efforts among all the participants. CONSOL Energy Inc. performed the techno-economic analysis of the CDCL process. Shell/CRI was able to perform feasibility and economic studies on the large scale particle synthesis and provide composite particles for the sub-pilot scale testing. The experience of B&W (with boilers) and Air Products (with handling gases) assisted the retrofit system design as well as the demonstration unit operations. The experience gained from the sub-pilot scale demonstration of the Syngas Chemical Looping (SCL) process at OSU was able to ensure the successful handling of the solids. Phase 1 focused on studies to improve the current particle to better suit the CDCL operations. The optimum operating conditions for the reducer reactor such as the temperature, char gasification enhancer type, and flow rate were identified. The

Dispersion of pollutants, environmental externalities due to a pulverized coal power plant and their effect on the cost of electricity

International Nuclear Information System (INIS)

Czarnowska, Lucyna; Frangopoulos, Christos A.

2012-01-01

Energy conversion systems generate pollution that causes damages to the environment and the society. The objective of this work is to study the dispersion of pollutants and assess the environmental and social cost due to pollution from such a system. For this purpose, a pulverized coal power plant is selected. Using thermodynamic principles combined with empirical techniques, the quantities of pollutants emitted by the plant are estimated. Then, using the EcoSenseWeb software, which is based on the results of the ExternE project, the external environmental cost (externalities) of pollution is assessed. The plant is considered as located in four different cities in Poland and the externalities are calculated for each city separately. It is shown that the external environmental cost has a strong influence on the unit cost of electricity. In addition, the dispersion of pollutants is presented for the plant located in Olsztyn city. Furthermore, the plant is considered as located near the capitals of European countries and the environmental externalities are calculated for each city. The neighboring countries that are strongly affected by the plant in each particular city are identified. The sensitivity of the unit cost of electricity to certain important parameters is investigated. -- Highlights: ► The external cost of pollution has a significant impact on the cost of electricity. ► The results depend on the particular plant, location and level (local-global). ► Externalities make the installation of abatement equipment economical. ► The source location of emissions has a significant effect on the external cost. ► The transboundary pollution has a strong effect on the environmental cost.

6th Conference on Coal Utilization Technology; Dai 6 kai sekitan riyo gijutsu kaigi koenshu

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-09-01

The paper compiled the papers presented in the 6th Conference on Coal Utilization Technology held in September 1996. With relation to the fluidized bed boiler, reported were Field operation test of Wakamatsu PFBC combined cycle power plant and Development of pressurized internally circulating fluidized bed combustion technology. Regarding the coal reformation, Development of advanced coal cleaning process, Coal preparation and coal cleaning in the dry process, etc. Concerning the combustion technology, Study of the O2/CO2 combustion technology, Development of pressurized coal partial combustor, etc. About the CWM, Development of low rank coals upgrading and their CWM producing technology, Technique of CWM distribution system, etc. Relating to the coal ash, Engineering characteristics of the improved soil by deep mixing method using coal ash, Employment of fluidized bed ash as a basecourse material, On-site verification trials using fly ash for reclamation behind bulkheads, Water permeabilities of pulverized fuel ash, Separation of unburned carbon from coal fly ash through froth flotation, Practical use technology of coal ash (POZ-O-TEC), etc

Research program for an environmentally-friendly coal utilization system in the Philippines

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

Feasibility studies are conducted on the introduction of an environmentally-friendly coal utilization system into the Filipino electric power industry, cement industry, and domestic fuel sector. The studies cover the current status of economy and energy in that country, supply and demand of coal, environmental protection and Government's policy, study of the above-said system relative to its application to the fields of electric power industry, cement industry, and domestic fuel sector, and a study about the effective utilization of Filipino domestic coal by the use of the system. Imported coal is used in the electric power industry because of its cost and quality. It is learned after research, however, that domestic coal will be able to compete against imported coal when some technologies are resorted to, such as those pertinent to denitrification in the furnace, novel low-NOx burner, coal pulverization, and combustion diagnosis. As for the treatment of flue gas, it is concluded that the simplified wet lime/gypsum process will be suitable. It is inferred that the CWM (coal-water mixture) process technology will be effective for the utilization of domestic low-grade coal. (NEDO)

Research program for an environmentally-friendly coal utilization system in the Philippines

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

Feasibility studies are conducted on the introduction of an environmentally-friendly coal utilization system into the Filipino electric power industry, cement industry, and domestic fuel sector. The studies cover the current status of economy and energy in that country, supply and demand of coal, environmental protection and Government's policy, study of the above-said system relative to its application to the fields of electric power industry, cement industry, and domestic fuel sector, and a study about the effective utilization of Filipino domestic coal by the use of the system. Imported coal is used in the electric power industry because of its cost and quality. It is learned after research, however, that domestic coal will be able to compete against imported coal when some technologies are resorted to, such as those pertinent to denitrification in the furnace, novel low-NOx burner, coal pulverization, and combustion diagnosis. As for the treatment of flue gas, it is concluded that the simplified wet lime/gypsum process will be suitable. It is inferred that the CWM (coal-water mixture) process technology will be effective for the utilization of domestic low-grade coal. (NEDO)

PROTOTYPE SCALE TESTING OF LIMB TECHNOLOGY FOR A PULVERIZED-COAL-FIRED BOILER

Science.gov (United States)

The report summarizes results of an evaluation of furnace sorbent injection (FSI) to control sulfur dioxide (SO2) emissions from coal-fired utility boilers. (NOTE: FSI of calcium-based sorbents has shown promise as a moderate SO2 removal technology.) The Electric Power Research I...

Influence of Process Parameters on Coal Combustion Performance

DEFF Research Database (Denmark)

Lans, Robert Pieter Van Der

investigated experimentally in a 400 MWe corner fired boiler with over fire air, a 350 MWe opposed fired boiler, and in a 160 kWt pilot scale test rig. Three different coals were fired in each of the furnaces as part of the activities in group 3 of the European Union JOULE 2 Extension project "Atmospheric......The objective of this study is to improve the understanding of nitrogen oxide formation and carbon burnout during the combustion of pulverized coal, and to contribute to addressing the potential of chemical engineering models for the prediction of furnace temperatures, NO emissions and the amount...... of carbon in ash. To this purpose, the effect of coal quality on NO and burnout has been investigated experimentally, a radiation heat balance has been developed based on simple chemical engineering methodology, and a mixing study has been conducted in order to describe the near burner macro mixing in terms...

PROJECT OF COAGULANT DISPENSER IN PULVERIZATION AERATOR WITH WIND DRIVE

Directory of Open Access Journals (Sweden)

Ewa Osuch

2017-09-01

Full Text Available Lakes are one of most important freshwater ecosystems, playing significant role in functioning of nature and human economy. Swarzędzkie Lake is good example of ecosystem, which in last half-century was exposed to the influence of strong anthropopressure. Direct inflow of sewage with large number of biogens coming to the lake with water of inflows caused distinct disturbance of its functioning. In autumn 2011 restoration begined on Swarzędzkie Lake for reduction of lake trophy and improvement of water quality. For achieving better and quicker effect, simultaneously combination of some methods was applied, among others method of oxygenation of over-bottom water with help of pulverization aerator and method of precise inactivation of phosphorus in water depths. Characterization and analysis of improved coagulant dispenser applying active substance only during work of pulverization aerator is the aim of this thesis. Principle of dispenser work, its structure and location in pulverization aerator were explained. It was stated, that introduction to water a factor initiating process of phosphorus inactivation causes significant reduction of mineral phosphorus in water and size of coagulant dose correlates with intensity of work of pulverization aerator with wind drive.

Numerical investigation of influence thermal preparation coal on nitric oxides formation in combustion process

Energy Technology Data Exchange (ETDEWEB)

Chernetskaya, N. [Siberian Federal Univ., Krasnoyarsk (Russian Federation); Chernetsky, M.; Dekterev, A. [Siberian Federal Univ., Krasnoyarsk (Russian Federation); Kutateladze Institute of Thermophysics, Novosibirsk (Russian Federation)

2013-07-01

Emissions of nitrogen oxides from coal combustion are a major environmental problem because they have been shown to contribute to the formation of acid rain and photochemical smog. Coal thermalpreparation before furnace delivery is effective method to reduce NOx emissions, shown by experiments in small-scale facilities (Babiy VI, Alaverdov PI, Influence of thermal preparation pulverized coal on nitric oxides outlet for combustion different metamorphized coal. ATI, 1983). This paper presents the mathematical model of burning thermal preparation coal. Validation of the model was carried out on laboratory-scale plant of All-Russia thermal engineering institute. Modeling of low-emissive burner with preliminary heating coal dust is made for the purpose of search of burner optimal constructions which provides low concentration of nitric oxides in the boiler. For modeling are used in-house CFD code ''{sigma}Flow'' (Dekterev AA, Gavrilov AA, Harlamov EB, Litvintcev KY, J Comput Technol 8(Part 1):250-255, 2003).

ASPEN Plus simulation of coal integrated gasification combined blast furnace slag waste heat recovery system

International Nuclear Information System (INIS)

Duan, Wenjun; Yu, Qingbo; Wang, Kun; Qin, Qin; Hou, Limin; Yao, Xin; Wu, Tianwei

2015-01-01

Highlights: • An integrated system of coal gasification with slag waste heat recovery was proposed. • The goal of BF slag heat saving and emission reduction was achieved by this system. • The optimal parameters were obtained and the waste heat recovery rate reached 83.08%. • About 6.64 kmol/min syngas was produced when using one ton BF slag to provide energy. - Abstract: This article presented a model for the system of coal gasification with steam and blast furnace slag waste heat recovery by using the ASPEN Plus as the simulating and modeling tool. Constrained by mass and energy balance for the entire system, the model included the gasifier used to product syngas at the chemical equilibrium based on the Gibbs free energy minimization approach and the boiler used to recover the heat of the blast furnace slag (BF slag) and syngas. Two parameters of temperature and steam to coal ratio (S/C) were considered to account for their impacts on the Datong coal (DT coal) gasification process. The carbon gasification efficiency (CE), cold gasification efficiency (CGE), syngas product efficiency (PE) and the heating value of syngas produced by 1 kg pulverized coal (HV) were adopted as the indicators to examine the gasification performance. The optimal operating temperature and S/C were 800 °C and 1.5, respectively. At this condition, CE reached above 90% and the maximum values of the CGE, PE and HV were all obtained. Under the optimal operating conditions, 1000 kg/min BF slag, about 40.41 kg/min DT pulverized coal and 77.94 kg/min steam were fed into the gasifier and approximate 6.64 kmol/min syngas could be generated. Overall, the coal was converted to clean syngas by gasification reaction and the BF slag waste heat was also recovered effectively (reached up to 83.08%) in this system, achieving the objective of energy saving and emission reduction

The Technology of Nitrogen Oxide Emissions Reduction at Pulverized Coal Burning

Directory of Open Access Journals (Sweden)

Dunaevska, N.I.

2016-11-01

Full Text Available To assess the effectiveness of the influence of thermochemical preparation of anthracite on the formation of nitrogen oxides the three-dimensional numerical model of the TPP-210A boiler`s furnace for standard and modified burners was created. The calculation results are shown the decrease of NOx concentration across the height of the furnace and reduce of the unburnt coal for the modified burners in comparison with standard ones.

Trace elements in co-combustion of solid recovered fuel and coal

DEFF Research Database (Denmark)

Wu, Hao; Glarborg, Peter; Jappe Frandsen, Flemming

2013-01-01

Trace element partitioning in co-combustion of a bituminous coal and a solid recovered fuel (SRF) was studied in an entrained flow reactor. The experiments were carried out at conditions similar to pulverized coal combustion, with SRF shares of 7.9 wt.% (wet basis), 14.8 wt.% and 25.0 wt.......%. In addition, the effect of additives such as NaCl, PVC, ammonium sulphate, and kaolinite on trace element partitioning was investigated. The trace elements studied were As, Cd, Cr, Pb, Sb and Zn, since these elements were significantly enriched in SRF as compared to coal. During the experiments, bottom ash...... was collected in a chamber, large fly ash particles were collected by a cyclone with a cut-off diameter of ~2.5 μm, and the remaining fly ash particles were gathered in a filter. It was found that when coal was co-fired with SRF, the As, Cd, Pb, Sb and Zn content in filter ash/cyclone ash increased almost...

Wireless vibration monitoring in a US coal-fired plant

Energy Technology Data Exchange (ETDEWEB)

Gbur, G.L.; Wier, W.; Bark, T.

2006-07-15

Choosing a reliable wireless systems able to provide data on vibration magnitudes in a coal pulveriser was never going to be easy, so two systems were tested alongside each other. One was the Wireless MCT System produced by SKF Reliability Systems; the other was from an alternative vendor. A replacement wireless vibration monitor was required at the Baldwin Energy Complex near Decartar, Illinois, USA. A single CE-Raymond model 923.RP pulverizer equipped with eight Wilcox on 786A accelerometers was chosen for monitoring. Five days after installation, the pulverizer experienced a failure. The wireless system provided vibration magnitudes to Dynegy's OSI PI Historian software. Analysis of this data coupled with an unsuccessful attempt to adjust the grinding roll, revealed that the number two grinding roll bearing had failed. The SKF Reliability System proved to detect the fault earlier than the non-SKF system and was chosen for the plant. 10 figs., 1 tab.

Coal Combustion Behavior in New Ironmaking Process of Top Gas Recycling Oxygen Blast Furnace

Science.gov (United States)

Zhou, Zhenfeng; Xue, Qingguo; Tang, Huiqing; Wang, Guang; Wang, Jingsong

2017-10-01

The top gas recycling oxygen blast furnace (TGR-OBF) is a new ironmaking process which can significantly reduce the coke ratio and emissions of carbon dioxide. To better understand the coal combustion characteristics in the TGR-OBF, a three dimensional model was developed to simulate the lance-blowpipe-tuyere-raceway of a TGR-OBF. The combustion characteristics of pulverized coal in TGR-OBF were investigated. Furthermore, the effects of oxygen concentration and temperature were also analyzed. The simulation results show that the coal burnout increased by 16.23% compared to that of the TBF. The oxygen content has an obvious effect on the burnout. At 70% oxygen content, the coal burnout is only 21.64%, with a decrease of 50.14% compared to that of TBF. Moreover, the effect of oxygen temperature is also very obvious.

Influence of wheat kernel physical properties on the pulverizing process.

Science.gov (United States)

Dziki, Dariusz; Cacak-Pietrzak, Grażyna; Miś, Antoni; Jończyk, Krzysztof; Gawlik-Dziki, Urszula

2014-10-01

The physical properties of wheat kernel were determined and related to pulverizing performance by correlation analysis. Nineteen samples of wheat cultivars about similar level of protein content (11.2-12.8 % w.b.) and obtained from organic farming system were used for analysis. The kernel (moisture content 10 % w.b.) was pulverized by using the laboratory hammer mill equipped with round holes 1.0 mm screen. The specific grinding energy ranged from 120 kJkg(-1) to 159 kJkg(-1). On the basis of data obtained many of significant correlations (p kernel physical properties and pulverizing process of wheat kernel, especially wheat kernel hardness index (obtained on the basis of Single Kernel Characterization System) and vitreousness significantly and positively correlated with the grinding energy indices and the mass fraction of coarse particles (> 0.5 mm). Among the kernel mechanical properties determined on the basis of uniaxial compression test only the rapture force was correlated with the impact grinding results. The results showed also positive and significant relationships between kernel ash content and grinding energy requirements. On the basis of wheat physical properties the multiple linear regression was proposed for predicting the average particle size of pulverized kernel.

Relevance of Clean Coal Technology for India’s Energy Security: A Policy Perspective

Science.gov (United States)

Garg, Amit; Tiwari, Vineet; Vishwanathan, Saritha

2017-07-01

Climate change mitigation regimes are expected to impose constraints on the future use of fossil fuels in order to reduce greenhouse gas (GHG) emissions. In 2015, 41% of total final energy consumption and 64% of power generation in India came from coal. Although almost a sixth of the total coal based thermal power generation is now super critical pulverized coal technology, the average CO2 emissions from the Indian power sector are 0.82 kg-CO2/kWh, mainly driven by coal. India has large domestic coal reserves which give it adequate energy security. There is a need to find options that allow the continued use of coal while considering the need for GHG mitigation. This paper explores options of linking GHG emission mitigation and energy security from 2000 to 2050 using the AIM/Enduse model under Business-as-Usual scenario. Our simulation analysis suggests that advanced clean coal technologies options could provide promising solutions for reducing CO2 emissions by improving energy efficiencies. This paper concludes that integrating climate change security and energy security for India is possible with a large scale deployment of advanced coal combustion technologies in Indian energy systems along with other measures.

Distinctive features of high-ash bituminuos coals combution with low milling fineness in furnace chambers with bottom blowing

Science.gov (United States)

Zroychikov, N. A.; Kaverin, A. A.; Biryukov, Ya A.

2017-11-01

Nowadays the problem of improvement of pulverized coal combustion schemes is an actual one for national power engineering, especially for combustion of coals with low milling fineness with significant portion of moisture or mineral impurities. In this case a big portion of inert material in the fuel may cause impairment of its ignition and combustion. In addition there are a lot of boiler installations on which nitrogen oxides emission exceeds standard values significantly. Decreasing of milling fineness is not without interest as a way of lowering an electric energy consumption for pulverization, which can reach 30% of power plant’s auxiliary consumption of electricity. Development of a combustion scheme meeting the requirements both for effective coal burning and environmental measures (related to NOx emission) is a complex task and demands compromising between these two factors, because implementation of NOx control by combustion very often leads to rising of carbon-in-ash loss. However widespread occurrence of such modern research technique as computer modeling allows to conduct big amount of variants calculations of combustion schemes with low cost and find an optimum. This paper presents results of numerical research of combined schemes of coal combustion with high portion of inert material based on straight-flow burners and nozzles. Several distinctive features of furnace aerodynamics, heat transfer and combustion has been found. The combined scheme of high-ash bituminouos coals combustion with low milling fineness, which allows effective combustion of pointed type of fuels with nitrogen oxides emission reduction has been proposed.

Subtask 3.9 - Direct Coal Liquefaction Process Development

Energy Technology Data Exchange (ETDEWEB)

Aulich, Ted; Sharma, Ramesh

2012-07-01

The Energy and Environmental Research Center (EERC), in partnership with the U.S. Department of Energy (DOE) and Accelergy Corporation, an advanced fuels developer with technologies exclusively licensed from ExxonMobil, undertook Subtask 3.9 to design, build, and preliminarily operate a bench-scale direct coal liquefaction (DCL) system capable of converting 45 pounds/hour of pulverized, dried coal to a liquid suitable for upgrading to fuels and/or chemicals. Fabrication and installation of the DCL system and an accompanying distillation system for off-line fractionation of raw coal liquids into 1) a naphtha middle distillate stream for upgrading and 2) a recycle stream was completed in May 2012. Shakedown of the system was initiated in July 2012. In addition to completing fabrication of the DCL system, the project also produced a 500-milliliter sample of jet fuel derived in part from direct liquefaction of Illinois No. 6 coal, and submitted the sample to the Air Force Research Laboratory (AFRL) at Wright Patterson Air Force Base, Dayton, Ohio, for evaluation. The sample was confirmed by AFRL to be in compliance with all U.S. Air Force-prescribed alternative aviation fuel initial screening criteria.

An artificial intelligence treatment of devolatilization for pulverized coal and biomass in co-fired flames

Energy Technology Data Exchange (ETDEWEB)

Abbas, T.; Awais, M.M.; Lockwood, F.C. [Lahore University of Management & Science, Lahore (Pakistan)

2003-02-01

In most of the existing predictive procedures for devolatilization, combustion and emissions are modeled by a single-step, global chemical reaction, with the yield of volatile matter presumed to experience mixing-controlled combustion. Several more detailed multi-step coal devolatilization models have recently emerged. A common shortcoming of these models is that they require a large set of input data, involving kinetic parameters, gas precursor compositions, and additional parameters describing the coal's polymeric structure. The input data must be generated from an extensive series of experimental measurements for each coal of interest. Very significant computational expense and application restricted to coals, which have already been studied, are implied. All of these problems are exacerbated when coal blending or co-firing with renewable solid fuels, such as forest and agricultural waste, and sewage sludge, is considered. In this paper, a new approach based on neural networks is proposed; it is capable of handling a range of solid fuels. The model considers heating rate, fuel atomic ratios, and the temperature of the fuel particles to predict the volatiles released by the particles. The 'learning' properties of the model implicitly facilitate all the physical conditions, of devolatilization experiments, which were used during its training and validation phases. The neural-network model was implemented into an existing 3D CFD combustion code. The predictions for high- and low-NOx burners demonstrate improved prediction of in-flame data for reduced computational effort, one-fifth of that with the standard single-global-reaction devolatilization model. Its devolatilization predictions have also been compared with a detailed devolatilization model (FLASHCHAIN) and were found to be comparable.

Innovative clean coal technology (ICCT): demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NOx) emission from high-sulfur, coal-fired boilers - economic evaluation of commercial-scale SCR applications for utility boilers

International Nuclear Information System (INIS)

Healy, E.C.; Maxwell, J.D.; Hinton, W.S.

1996-09-01

This report presents the results of an economic evaluation produced as part of the Innovative Clean Coal Technology project, which demonstrated selective catalytic reduction (SCR) technology for reduction of NO x emissions from utility boilers burning U.S. high-sulfur coal. The document includes a commercial-scale capital and O ampersand M cost evaluation of SCR technology applied to a new facility, coal-fired boiler utilizing high-sulfur U.S. coal. The base case presented herein determines the total capital requirement, fixed and variable operating costs, and levelized costs for a new 250-MW pulverized coal utility boiler operating with a 60-percent NO x removal. Sensitivity evaluations are included to demonstrate the variation in cost due to changes in process variables and assumptions. This report also presents the results of a study completed by SCS to determine the cost and technical feasibility of retrofitting SCR technology to selected coal-fired generating units within the Southern electric system

CFD simulation of coal and straw co-firing

DEFF Research Database (Denmark)

Junker, Helle; Hvid, Søren L.; Larsen, Ejvind

This paper presents the results of a major R&D program with the objective to develop CFD based tools to assess the impact of biomass co-firing in suspension fired pulverized coal power plants. The models have been developed through a series of Danish research projects with the overall objective...... to collect results from fundamental research and make it operational in boiler design through implementation in a Computational Fluid Dynamics based simulation tool. This paper summarizes the developments in modeling of; particle motion, particle conversion, ash deposition on heat transfer surfaces, and NOx...

Large eddy simulations of coal jet flame ignition using the direct quadrature method of moments

Science.gov (United States)

Pedel, Julien

The Direct Quadrature Method of Moments (DQMOM) was implemented in the Large Eddy Simulation (LES) tool ARCHES to model coal particles. LES coupled with DQMOM was first applied to nonreacting particle-laden turbulent jets. Simulation results were compared to experimental data and accurately modeled a wide range of particle behaviors, such as particle jet waviness, spreading, break up, particle clustering and segregation, in different configurations. Simulations also accurately predicted the mean axial velocity along the centerline for both the gas phase and the solid phase, thus demonstrating the validity of the approach to model particles in turbulent flows. LES was then applied to the prediction of pulverized coal flame ignition. The stability of an oxy-coal flame as a function of changing primary gas composition (CO2 and O2) was first investigated. Flame stability was measured using optical measurements of the flame standoff distance in a 40 kW pilot facility. Large Eddy Simulations (LES) of the facility provided valuable insight into the experimentally observed data and the importance of factors such as heterogeneous reactions, radiation or wall temperature. The effects of three parameters on the flame stand-off distance were studied and simulation predictions were compared to experimental data using the data collaboration method. An additional validation study of the ARCHES LES tool was then performed on an air-fired pulverized coal jet flame ignited by a preheated gas flow. The simulation results were compared qualitatively and quantitatively to experimental observations for different inlet stoichiometric ratios. LES simulations were able to capture the various combustion regimes observed during flame ignition and to accurately model the flame stand-off distance sensitivity to the stoichiometric ratio. Gas temperature and coal burnout predictions were also examined and showed good agreement with experimental data. Overall, this research shows that high

Water use at pulverized coal power plants with postcombustion carbon capture and storage.

Science.gov (United States)

Zhai, Haibo; Rubin, Edward S; Versteeg, Peter L

2011-03-15

Coal-fired power plants account for nearly 50% of U.S. electricity supply and about a third of U.S. emissions of CO(2), the major greenhouse gas (GHG) associated with global climate change. Thermal power plants also account for 39% of all freshwater withdrawals in the U.S. To reduce GHG emissions from coal-fired plants, postcombustion carbon capture and storage (CCS) systems are receiving considerable attention. Current commercial amine-based capture systems require water for cooling and other operations that add to power plant water requirements. This paper characterizes and quantifies water use at coal-burning power plants with and without CCS and investigates key parameters that influence water consumption. Analytical models are presented to quantify water use for major unit operations. Case study results show that, for power plants with conventional wet cooling towers, approximately 80% of total plant water withdrawals and 86% of plant water consumption is for cooling. The addition of an amine-based CCS system would approximately double the consumptive water use of the plant. Replacing wet towers with air-cooled condensers for dry cooling would reduce plant water use by about 80% (without CCS) to about 40% (with CCS). However, the cooling system capital cost would approximately triple, although costs are highly dependent on site-specific characteristics. The potential for water use reductions with CCS is explored via sensitivity analyses of plant efficiency and other key design parameters that affect water resource management for the electric power industry.

Effects of calcium magnesium acetate on the combustion of coal-water slurries. Final project report, 1 September 1989--28 February 1993

Energy Technology Data Exchange (ETDEWEB)

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.

Pilot plant development of a new catalytic process for improved electrostatic separation of fly-ash in coal fired power plants

Energy Technology Data Exchange (ETDEWEB)

Olivares del Valle, J.; Salvador Martinez, L.; Muniz Baum, B.; Cortes Galeano, V. [University of Seville, Seville (Spain). Chemical and Environmental Engineering Dept.

1996-12-31

A new catalytic process for flue gas conditioning in pulverized coal fired power plants is outlined. Vanadium and platinum catalysts specifically prepared on ceramic honeycomb monoliths to oxidize SO{sub 2} into SO{sub 3} have been tested and evaluated at pilot scale. 10 refs., 3 figs., 2 tabs.

Field test corrosion experiences when co-firing straw and coal: 10 year status within Elsam

DEFF Research Database (Denmark)

Frandsen, Rasmus Berg; Montgomery, Melanie; Larsen, Ole Hede

2007-01-01

and straw at the 150 MW pulverized coal fired boiler Studstrup unit 1. Two exposure series lasting 3000 hours each were performed for co-firing 10 and 20% of straw (% energy basis) with coal. Using built in test tubes in the hot end of the actual superheaters and air/water cooled corrosion probes...... to 575 degrees C and for the flue gas from 1025 to 1300 degrees C. All these test tubes have been removed during the last three years at one year intervals for corrosion studies. The corrosion studies performed on all investigated tubes included measurements of the corrosion attack, light optical...

Quality and environmental aspects in relation to the application of pulverized fuel ash

International Nuclear Information System (INIS)

Berg, J.W. van den

1991-01-01

In the Netherlands pulverised coal from different parts of the world is used in 5 coalfired power stations which each have 1 to 3 boilers, which in turn are equipped with various types of burners. This causes a large variation in the composition of the pulverized fuel ash (PFA). The PFA is marketed in several areas, each of which has its own specific quality requirements. These requirements are partially dictated in standard specifications. In order to obtain insight into the quality of the PFA, samples are taken and analysed daily. Rules for certification, concerning the quality and the quality control of PFA for use in concrete in The Netherlands have been agreed upon. The environmental aspects in relation to the application of PFA concern the working conditions and health aspects during processing and the environmental impact when PFA is used as a building material. The Dutch legislation concerning the environmental consequences of the application of PFA and other secondary materials is currently under review. 3 tabs

Applying environmental externalities to US Clean Coal Technologies for Asia

International Nuclear Information System (INIS)

Szpunar, C.B.; Gillette, J.L.

1993-01-01

The United States is well positioned to play an expanding role in meeting the energy technology demands of the Asian Pacific Basin, including Indonesia, Thailand, and the Republic of China (ROC-Taiwan). The US Department of Energy Clean Coal Technology (CCT) Demonstration Program provides a proving ground for innovative coal-related technologies that can be applied domestically and abroad. These innovative US CCTs are expected to satisfy increasingly stringent environmental requirements while substantially improving power generation efficiencies. They should also provide distinct advantages over conventional pulverized coal-fired combustors. Finally, they are expected to be competitive with other energy options currently being considered in the region. This paper presents potential technology scenarios for Indonesia, Thailand, and the ROC-Taiwan and considers an environmental cost-benefit approach employing a newly developed method of applying environmental externalities. Results suggest that the economic benefits from increased emission control can indeed be quantified and used in cost-benefit comparisons, and that US CCTs can be very cost effective in reducing emissions

Combustion and gasification of coal and straw under pressurized conditions. Task 2: Determination of kinetic parameters in PTGA

Energy Technology Data Exchange (ETDEWEB)

Rathmann, O; Hald, P; Bak, J; Boll Illerup, J; Gjernes, E; Fjellerup, J; Olsen, A

1995-10-01

The reactivities of pulverized coal and straw fuels were investigated regarding pyrolysis, combustion and gasification with CO{sub 2} and H{sub 2}O by thermogravimetric analysis under pressurized conditions. The fuels were a Colombian coal, pulverized to 45-90 {mu}m particles, and wheat straw pulverized to 0-200 {mu}m particles. The pyrolysis studies were performed at 150-1000 deg. C in pure N{sub 2} at 1.5 to 40 bar. The combustion studies were performed at 300-550 deg. C, 1.5-40 bar total pressure with 0.08-0.8 bar of O{sub 2} partial pressure. The CO{sub 2} gasification studies were performed at 850-1200 deg. C, 4-40 bar of total pressure with 0.7-4 bar of CO{sub 2} partial pressure, also including studies with CO in combination with CO{sub 2}. A minor H{sub 2}O gasification study with straw was performed at 900-1050 deg. C at 1.5-2.0 bar of total pressure in an atmosphere containing partial pressures up to 0.32 bar of H{sub 2}O, o.2 bar of CO{sub 2}, 0.28 bar of CO and 0.12 bar of H{sub 2}. For combustion and CO{sub 2} gasification the results were analyzed with regard to reaction kinetics, and kinetic parameters that represent the experimental results were found. (AU) 11 tabs., 26 ills., 10 refs.

Briquetting of coal fines and sawdust. Part 1: binder and briquetting-parameters evaluations

Energy Technology Data Exchange (ETDEWEB)

D. Taulbee; D.P. Patil; Rick Q. Honaker; B.K. Parekh [University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

2009-01-15

Various technical and economic aspects relating to the briquetting of fine coal with sawdust have been evaluated with the results for two segments of that study presented here: binder and briquetting-parameter evaluations. Approximately 50 potential binder formulations were subjected to a series of screening evaluations to identify three formulations that were the most cost effective for briquetting fine coal with sawdust. Two of the binders, guar gum and wheat starch, were selected as most suitable for the pulverized coal market while the third formulation, lignosulfonate/lime, was targeted for the stoker market. Following binder selection, a number of briquetting parameters including binder and sawdust concentration, sawdust type, briquetting pressure and dwell time, coal and sawdust particle size, clay content, moisture content, and cure temperature and cure time were evaluated. Briquetting pressure and dwell time have the least impact while binder and sawdust concentrations, sawdust type, and curing conditions exerted the greatest influence on briquette quality. 7 refs.

Nitrogen oxide suppression by using a new design of pulverized-coal burners

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.; Cameron, S.D.; Grekhov, L.L. [All-Russian Thermal Engineering Institute, Moscow (Russian Federation)

1996-07-01

The results of testing a low-NO{sub x} swirl burner are presented. This burner was developed by Babcock Energy Ltd., for reducing nitrogen oxide emissions when burning Ekibastuz and Kuznetsk low-caking coals in power boilers. The tests conducted at a large plant of the BEL Technological Center showed that the new burner reduces NO{sub x} emissions by approximately two times. 6 refs., 6 figs., 1 tab.

CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS (CFB AND CLB) FUELS IN PULVERIZED FUEL AND FIXED BED BURNERS

Energy Technology Data Exchange (ETDEWEB)

Kalyan Annamalai; John Sweeten; Saqib Mukhtar; Ben Thein; Gengsheng Wei; Soyuz Priyadarsan; Senthil Arumugam; Kevin Heflin

2003-08-28

Intensive animal feeding operations create large amounts of animal waste that must be safely disposed of in order to avoid environmental degradation. Cattle feedlots and chicken houses are two examples. In feedlots, cattle are confined to small pens and fed a high calorie grain-diet diet in preparation for slaughter. In chicken houses, thousands of chickens are kept in close proximity. In both of these operations, millions of tons of manure are produced every year. The manure could be used as a fuel by mixing it with coal in a 90:10 blend and firing it in an existing coal suspension fired combustion systems. This technique is known as co-firing, and the high temperatures produced by the coal will allow the biomass to be completely combusted. Reburn is a process where a small percentage of fuel called reburn fuel is injected above the NO{sub x} producing, conventional coal fired burners in order to reduce NO{sub x}. The manure could also be used as reburn fuel for reducing NO{sub x} in coal fired plants. An alternate approach of using animal waste is to adopt the gasification process using a fixed bed gasifier and then use the gases for firing in gas turbine combustors. In this report, the cattle manure is referred to as feedlot biomass (FB) and chicken manure as litter biomass (LB). The report generates data on FB and LB fuel characteristics. Co-firing, reburn, and gasification tests of coal, FB, LB, coal: FB blends, and coal: LB blends and modeling on cofiring, reburn systems and economics of use of FB and LB have also been conducted. The biomass fuels are higher in ash, lower in heat content, higher in moisture, and higher in nitrogen and sulfur (which can cause air pollution) compared to coal. Small-scale cofiring experiments revealed that the biomass blends can be successfully fired, and NO{sub x} emissions will be similar to or lower than pollutant emissions when firing coal. Further experiments showed that biomass is twice or more effective than coal when

Study of mobilization and speciation of trace elements in coal pyrolysis

International Nuclear Information System (INIS)

Ting, B.T.G.

1979-01-01

Various types of coal contain high levels of a number of trace elements. Little is known of the fates of these trace elements during the conversion of coal to liquid and gaseous products. Studies were undertaken of mobilization and speciation of trace elements in coal pyrolysis, one of the major coal conversion processes. The bituminous coal was pyrolyzed to produce liquid and gaseous products. The pyrolysis products were collected in traps in an inert gas stream. In addition mildly hydrogenated coal was prepared by mixing with tetralin, a hydrogen donor solvent, at boiling temperature. In order to characterize each element specifically during pyrolysis, base samples of coal and mildly hydrogenated coal (H-coal) were spiked with heavy metal sulfides, trace metals bound to partially oxidized coal (coal humates), and halide salts prior to carrying out pyrolysis. Eight elements were investigated in this research. They are As, Br, Cl, Co, Cr, Mn, Se, and V. Pre-spiked hydrogenated coal, i.e., pulverized coal spiked with halide salts and heavy metal sulfides then hydrogenated with tetralin, was prepared and studied for the fates of these elements during pyrolysis. Chlorinated and brominated coals were also prepared to compare the volatility differences between organically and inorganically bound halogens during the pyrolysis reaction. These products and the coal char residues were analyzed for the spiked elements mainly by neutron activation analysis for the spiked elements to determine their degree of volatility. Volatility and recovery (mass balance) will be discussed for those elements that appeared highly volatile during pyrolysis. In order to understand the halogenated compounds in the pyrolysis products, gas chromatograms were taken to the collected pyrolysis products of coal, hydrogenated coal, NaCl spiked coal, NaBr spiked coal, chlorinated coal, and brominated coal

Development of automobile brake lining using pulverized cow hooves

Directory of Open Access Journals (Sweden)

Katsina C. BALA

2016-06-01

Full Text Available Asbestos has been used for so long as automobile brake lining material because of its good physical and chemical properties. However, due to the health hazard associated with its handling, it has lost favour and several alternative materials are being increasingly used. Asbestos-free brake lining was developed in this work using pulverized cow hooves along with epoxy resin, barium sulphate, graphite and aluminium oxide. This was with a view to exploiting the characteristics of cow hooves, which are largely discarded as waste materials to replace asbestos which has been found to be carcinogenic. Samples of brake linings were produced using compressive moulding in which the physical and mechanical properties of the samples were studied. The results obtained showed that proper bonding was achieved as the percentage by weight of epoxy resin increased and percentage by weight of pulverized cow hooves decreased. The hardness, compressive strength, coefficient of friction, water and oil absorption, relative density and wear rate of the brake linings were determined and compared with existing brake lining properties. The result indicates that pulverized cow hooves can be used as brake lining material for automobiles.

Recovery of iron oxide from coal fly ash

Science.gov (United States)

Dobbins, Michael S.; Murtha, Marlyn J.

1983-05-31

A high quality iron oxide concentrate, suitable as a feed for blast and electric reduction furnaces is recovered from pulverized coal fly ash. The magnetic portion of the fly ash is separated and treated with a hot strong alkali solution which dissolves most of the silica and alumina in the fly ash, leaving a solid residue and forming a precipitate which is an acid soluble salt of aluminosilicate hydrate. The residue and precipitate are then treated with a strong mineral acid to dissolve the precipitate leaving a solid residue containing at least 90 weight percent iron oxide.

Oxy-fuel combustion of pulverized fuels

DEFF Research Database (Denmark)

Yin, Chungen; Yan, Jinyue

2016-01-01

Oxy-fuel combustion of pulverized fuels (PF), as a promising technology for CO2 capture from power plants, has gained a lot of concerns and also advanced considerable research, development and demonstration in the last past years worldwide. The use of CO2 or the mixture of CO2 and H2O vapor as th...

Impact of co-combustion of petroleum coke and coal on fly ash quality: Case study of a Western Kentucky power plant

International Nuclear Information System (INIS)

Hower, James C.; Thomas, Gerald A.; Mardon, Sarah M.; Trimble, Alan S.

2005-01-01

Petroleum coke has been used as a supplement or replacement for coal in pulverized-fuel combustion. At a 444-MW western Kentucky power station, the combustion of nearly 60% petroleum coke with moderate- to high-sulfur Illinois Basin coal produces fly ash with nearly 50% uncombusted petroleum coke and large amounts of V and Ni when compared to fly ash from strictly pulverized coal burns. Partitioning of the V and Ni, known from other studies to be concentrated in petroleum coke, was noted. However, the distribution of V and Ni does not directly correspond to the amount of uncombusted petroleum coke in the fly ash. Vanadium and Ni are preferentially associated with the finer, higher surface area fly ash fractions captured at lower flue gas temperatures. The presence of uncombusted petroleum coke in the fly ash doubles the amount of ash to be disposed, makes the fly ash unmarketable because of the high C content, and would lead to higher than typical (compared to other fly ashes in the region) concentrations of V and Ni in the fly ash even if the petroleum coke C could be beneficiated from the fly ash. Further studies of co-combustion ashes are necessary in order to understand their behavior in disposal

Coal-water slurries containing petrochemicals to solve problems of air pollution by coal thermal power stations and boiler plants: An introductory review.

Science.gov (United States)

Dmitrienko, Margarita A; Strizhak, Pavel A

2018-02-01

This introductory study presents the analysis of the environmental, economic and energy performance indicators of burning high-potential coal water slurries containing petrochemicals (CWSP) instead of coal, fuel oil, and natural gas at typical thermal power stations (TPS) and a boiler plant. We focus on the most hazardous anthropogenic emissions of coal power industry: sulfur and nitrogen oxides. The research findings show that these emissions may be several times lower if coal and oil processing wastes are mixed with water as compared to the combustion of traditional pulverized coal, even of high grades. The study focuses on wastes, such as filter cakes, oil sludge, waste industrial oils, heavy coal-tar products, resins, etc., that are produced and stored in abundance. Their deep conversion is very rare due to low economic benefit. Effective ways are necessary to recover such industrial wastes. We present the cost assessment of the changes to the heat and power generation technologies that are required from typical power plants for switching from coal, fuel oil and natural gas to CWSPs based on coal and oil processing wastes. The corresponding technological changes pay off after a short time, ranging from several months to several years. The most promising components for CWSP production have been identified, which provide payback within a year. Among these are filter cakes (coal processing wastes), which are produced as a ready-made coal-water slurry fuel (a mixture of flocculants, water, and fine coal dust). These fuels have the least impact on the environment in terms of the emissions of sulfur and nitrogen oxides as well as fly ash. An important conclusion of the study is that using CWSPs based on filter cakes is worthwhile both as the main fuel for thermal power stations and boiler plants and as starting fuel. Copyright © 2017 Elsevier B.V. All rights reserved.

ECONOMICS AND FEASIBILITY OF RANKINE CYCLE IMPROVEMENTS FOR COAL FIRED POWER PLANTS

Energy Technology Data Exchange (ETDEWEB)

Richard E. Waryasz; Gregory N. Liljedahl

2004-09-08

ALSTOM Power Inc.'s Power Plant Laboratories (ALSTOM) has teamed with the U.S. Department of Energy National Energy Technology Laboratory (DOE NETL), American Electric Company (AEP) and Parsons Energy and Chemical Group to conduct a comprehensive study evaluating coal fired steam power plants, known as Rankine Cycles, equipped with three different combustion systems: Pulverized Coal (PC), Circulating Fluidized Bed (CFB), and Circulating Moving Bed (CMB{trademark}). Five steam cycles utilizing a wide range of steam conditions were used with these combustion systems. The motivation for this study was to establish through engineering analysis, the most cost-effective performance potential available through improvement in the Rankine Cycle steam conditions and combustion systems while at the same time ensuring that the most stringent emission performance based on CURC (Coal Utilization Research Council) 2010 targets are met: > 98% sulfur removal; < 0.05 lbm/MM-Btu NO{sub x}; < 0.01 lbm/MM-Btu Particulate Matter; and > 90% Hg removal. The final report discusses the results of a coal fired steam power plant project, which is comprised of two parts. The main part of the study is the analysis of ten (10) Greenfield steam power plants employing three different coal combustion technologies: Pulverized Coal (PC), Circulating Fluidized Bed (CFB), and Circulating Moving Bed (CMB{trademark}) integrated with five different steam cycles. The study explores the technical feasibility, thermal performance, environmental performance, and economic viability of ten power plants that could be deployed currently, in the near, intermediate, and long-term time frame. For the five steam cycles, main steam temperatures vary from 1,000 F to 1,292 F and pressures from 2,400 psi to 5,075 psi. Reheat steam temperatures vary from 1,000 F to 1,328 F. The number of feedwater heaters varies from 7 to 9 and the associated feedwater temperature varies from 500 F to 626 F. The main part of the

Staged fluidized-bed coal combustor for boiler retrofit

International Nuclear Information System (INIS)

Rehmat, A.; Dorfman, L.; Shibayama, G.; Waibel, R.

1991-01-01

The Advanced Staged Fluidized-Bed Coal Combustion System (ASC) is a novel clean coal technology for either coal-fired repowering of existing boilers or for incremental power generation using combined-cycle gas turbines. This new technology combines staged combustion for gaseous emission control, in-situ sulfur capture, and an ash agglomeration/vitrification process for the agglomeration/vitrification of ash and spent sorbent, thus rendering solid waste environmentally benign. The market for ASC is expected to be for clean coal-fired repowering of generating units up to 250 MW, especially for units where space is limited. The expected tightening of the environmental requirements on leachable solids residue by-products could considerably increase the marketability for ASC. ASC consists of modular low-pressure vessels in which coal is partially combusted and gasified using stacked fluidized-bed processes to produce low-to-medium-Btu, high-temperature gas. This relatively clean fuel gas is used to repower/refuel existing pulverized-coal, natural gas, or oil-fired boilers using bottom firing and reburning techniques. The benefits of ASC coal-fired repowering include the ability to repower boilers without obtaining additional space while meeting the more stringent environmental requirements of the future. Low NO x , SO x , and particulate levels are expected while a nonleachable solid residue with trace metal encapsulation is produced. ASC also minimizes boiler modification and life-extension expenditures. Repowered efficiencies can be restored to the initial operating plant efficiency, and the existing boiler capacity can be increased by 10%. Preliminary cost estimates indicate that ASC will have up to a $250/kW capital cost advantage over existing coal-fired repowering options. 4 figs., 4 tabs

Computational fluid dynamics (CFD) analysis of the coal combustion in a boiler of a thermal power plant using different kinds of the manufactured coals

Energy Technology Data Exchange (ETDEWEB)

Silva, Cristiano Vitorino da; Lazzari, Luis Carlos; Ziemniczak, Aline; Beskow, Arthur Bortolin [Universidade Regional Integrada do Alto Uruguai e das Missoes (URI), Erechim, RS (Brazil)], E-mails: cristiano@uricer.edu.br, arthur@uricer.edu.br

2010-07-01

The state of the art in computational fluid dynamics and the availability of commercial codes encourage numerical studies of combustion processes. In the present work the commercial software CFX Ansys Europe Ltd. has been used to study the combustion of pulverized coal into the boiler of a thermal power plant. The objective of this work is to obtain new information for process optimization. Different kinds of manufactured coals were numerically tested in a thermal power plant installed at the southeast region of Brazil. The simulations were made using the actual burning conditions of the boiler. Results include the residence time of the fuel into the combustion chamber, temperature fields, flow fluid mechanics, heat transfer and pollutant formation, as well as the CO and NOx concentrations, aiming to determinate the best conditions to burn the investigated coals. The numerical investigation of the phenomena involved on the coal combustion processes are used to complete the experimental information obtained in operational tests. Considering the characteristics of different kinds of manufactured coals used, with this study is possible to achieve the most efficient boiler operation parameters, with decreasing costs of electricity production and reduction of environmentally harmful emissions. It was verified that the different kinds of manufactured coals demand different operation conditions, and the kind of manufactured coal used on the combustion process has a significant effect on the pollutant formation, mainly in rel action with ash concentration. (author)

Effect of pulverization of the bulk powder on the hydration of creatine anhydrate tablets and their pharmaceutical properties.

Science.gov (United States)

Sakata, Yukoh; Shiraishi, Sumihiro; Otsuka, Makoto

2005-12-10

The hydration behavior and expansion properties of untreated and pulverized creatine anhydrate (CRA) tablets were studied under 60 and 75%RH at 25 degrees C by using differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD). The tablet hardness of untreated and pulverized CRA tablets was significantly decreased after hydration. There was a linear relationship between the degree of hydration and the tablet hardness of untreated CRA tablets compressed at 1000 kg/cm2. In contrast, the relationship between the degree of hydration and the tablet hardness of pulverized CRA tablets was nonlinear. These results suggest that the reduction in hardness of pulverized CRA tablets does not depend solely on the hydration level of crystal water. PXRD analysis indicated that the diffraction pattern of the pulverized CRA powder was similar to that of the untreated CRA powder. However, the diffraction intensity of the pulverized CRA powder was slightly lower than that of the untreated CRA powder at high angle. The micropore radius of both untreated and pulverized CRA tablets was significantly increased after hydration, but analysis of the relationship between micropore radius and fractional hydration of crystal water showed that untreated CRA tablets were more affected than pulverized CRA tablets. Therefore, the reduction in tablet hardness depends not only on the hydration behavior but also on the crystal orientation of the CRA powder.

HIGH PRESSURE COAL COMBUSTON KINETICS PROJECT

Energy Technology Data Exchange (ETDEWEB)

Stefano Orsino

2005-03-30

As part of the U.S. Department of Energy (DoE) initiative to improve the efficiency of coal-fired power plants and reduce the pollution generated by these facilities, DOE has funded the High-Pressure Coal Combustion Kinetics (HPCCK) Projects. A series of laboratory experiments were conducted on selected pulverized coals at elevated pressures with the specific goals to provide new data for pressurized coal combustion that will help extend to high pressure and validate models for burnout, pollutant formation, and generate samples of solid combustion products for analyses to fill crucial gaps in knowledge of char morphology and fly ash formation. Two series of high-pressure coal combustion experiments were performed using SRI's pressurized radiant coal flow reactor. The first series of tests characterized the near burner flame zone (NBFZ). Three coals were tested, two high volatile bituminous (Pittsburgh No.8 and Illinois No.6), and one sub-bituminous (Powder River Basin), at pressures of 1, 2, and 3 MPa (10, 20, and 30 atm). The second series of experiments, which covered high-pressure burnout (HPBO) conditions, utilized a range of substantially longer combustion residence times to produce char burnout levels from 50% to 100%. The same three coals were tested at 1, 2, and 3 MPa, as well as at 0.2 MPa. Tests were also conducted on Pittsburgh No.8 coal in CO2 entrainment gas at 0.2, 1, and 2 MPa to begin establishing a database of experiments relevant to carbon sequestration techniques. The HPBO test series included use of an impactor-type particle sampler to measure the particle size distribution of fly ash produced under complete burnout conditions. The collected data have been interpreted with the help of CFD and detailed kinetics simulation to extend and validate devolatilization, char combustion and pollutant model at elevated pressure. A global NOX production sub-model has been proposed. The submodel reproduces the performance of the detailed chemical

Computational fluid dynamic simulations of coal-fired utility boilers: An engineering tool

Energy Technology Data Exchange (ETDEWEB)

Efim Korytnyi; Roman Saveliev; Miron Perelman; Boris Chudnovsky; Ezra Bar-Ziv [Ben-Gurion University of the Negev, Beer-Sheva (Israel)

2009-01-15

The objective of this study was to develop an engineering tool by which the combustion behavior of coals in coal-fired utility boilers can be predicted. We presented in this paper that computational fluid dynamic (CFD) codes can successfully predict performance of - and emission from - full-scale pulverized-coal utility boilers of various types, provided that the model parameters required for the simulation are properly chosen and validated. For that purpose we developed a methodology combining measurements in a 50 kW pilot-scale test facility with CFD simulations using the same CFD code configured for both test and full-scale furnaces. In this method model parameters of the coal processes are extracted and validated. This paper presents the importance of the validation of the model parameters which are used in CFD codes. Our results show very good fit of CFD simulations with various parameters measured in a test furnace and several types of utility boilers. The results of this study demonstrate the viability of the present methodology as an effective tool for optimization coal burning in full-scale utility boilers. 41 refs., 9 figs., 3 tabs.

Some environmental aspects related to sulphur emissions during combustion of Bulgarian coals

International Nuclear Information System (INIS)

Vassileva, C.; Vassilev, S.

2004-01-01

The mechanism of S emissions and their capture during combustion of some Bulgarian coals (Maritza East, Maritza West, Sofia, Pernik, Bobov Dol, Balkan) was studied based on the phase-mineral transformations in the inorganic matter during gradual heating of these coals. It was found that: 1) the organic, elemental and sulphide S is released from coal at 200-700 0 C; 2) the volatile S is initially captured by intermediate Ca-, Mg-, K-, Na-, Fc-, and Ba-oxides (mainly from decomposed organic matter and carbonates) with formation of their sulphates at 200-1000 0 C; 3) the decomposition of original and newly-formed sulphates occurs at 800-1300 0 C and they are the major source of volatile SO 2 from stack emissions of thermoelectric power stations (TPSs). The described mechanism of S emissions and their capture indicates that the traditional pulverized combustion (1200-1600 0 C) of the high-sulphur Bulgarian coals in TPSs is inadequate from an environmental point of view and other alternatives should be applied. Some of them such as fluidized-bed combustion and selective blending of the coals are proposed

DESIGNING AND OPPORTUNITY FUEL WITH BIOMASS AND TIRE-DERIVED FUEL FOR COFIRING AT WILLOW ISLAND GENERATING STATION AND COFIRING SAWDUST WITH COAL AT ALBRIGHT GENERATING STATION

Energy Technology Data Exchange (ETDEWEB)

K. Payette; D. Tillman

2004-06-01

During the period July 1, 2000-March 31, 2004, Allegheny Energy Supply Co., LLC (Allegheny) conducted an extensive demonstration of woody biomass cofiring at its Willow Island and Albright Generating Stations. This demonstration, cofunded by USDOE and Allegheny, and supported by the Biomass Interest Group (BIG) of EPRI, evaluated the impacts of sawdust cofiring in both cyclone boilers and tangentially-fired pulverized coal boilers. The cofiring in the cyclone boiler--Willow Island Generating Station Unit No.2--evaluated the impacts of sawdust alone, and sawdust blended with tire-derived fuel. The biomass was blended with the coal on its way to the combustion system. The cofiring in the pulverized coal boiler--Albright Generating Station--evaluated the impact of cofiring on emissions of oxides of nitrogen (NO{sub x}) when the sawdust was injected separately into the furnace. The demonstration of woody biomass cofiring involved design, construction, and testing at each site. The results addressed impacts associated with operational issues--capacity, efficiency, and operability--as well as formation and control of airborne emissions such as NO{sub x}, sulfur dioxide (SO{sub 2}2), opacity, and mercury. The results of this extensive program are detailed in this report.

Engineering development of advanced coal-fired low-emissions boiler system. Phase II subsystem test design and plan - an addendum to the Phase II RD & T Plan

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-05-01

Shortly after the year 2000 it is expected that new generating plants will be needed to meet the growing demand for electricity and to replace the aging plants that are nearing the end of their useful service life. The plants of the future will need to be extremely clean, highly efficient and economical. Continuing concerns over acid rain, air toxics, global climate changes, ozone depletion and solid waste disposal are expected to further then regulations. In the late 1980`s it was commonly believed that coal-fired power plants of the future would incorporate either some form of Integrated Gasification Combined Cycle (IGCC) or first generation Pressurized Fluidized Bed Combustion (PFBS) technologies. However, recent advances In emission control techniques at reduced costs and auxiliary power requirements coupled with significant improvements In steam turbine and cycle design have clearly indicated that pulverized coal technology can continue to be competitive In both cost and performance. In recognition of the competitive potential for advanced pulverized coal-fired systems with other emerging advanced coal-fired technologies, DOE`s Pittsburgh Energy Technology Center (PETC) began a research and development initiative In late 1990 named, Combustion 2000, with the intention of preserving and expanding coal as a principal fuel In the Generation of electrical power. The project was designed for two stages of commercialization, the nearer-term Low Emission Boiler System (LEBS) program, and for the future, the High Performance Power System (HIPPS) program. B&W is participating In the LEBS program.

Raw mix designing for coal as a fuel in cement kiln as a major fuel and its impact on clinker parameters

International Nuclear Information System (INIS)

Noor-ul-Amin; Ali, K.

2011-01-01

In this paper the use of coal, found at Jabba Taar and Jabba Khushk Khyber Pakhtoon Khwa, in cement manufacturing as a major fuel and its impacts on the raw mix and clinker parameters has been discussed. The maximum amount of coal for pulverizing with raw mix was found to be 10% of the raw mix as calculated from the calorific value and the heat of clinkerization of coal. The coal residue left after burning was utilized in the cement raw material, for which a new raw mix was designed. The new raw mix was converted in to clinker. The resulting clinker was studied for all parameters as per British specification. It was found that the clinker obtained from the newly designed raw mix with coal ash, was in accordance to the British standard specifications. (author)

Influence of Environmentally Friendly and High-Efficiency Composite Additives on Pulverized Coal Combustion in Cement Industry

Directory of Open Access Journals (Sweden)

Zhiyong Wang

2016-01-01

Full Text Available 4 kinds of chemical reagents and 3 kinds of industrial wastes were selected as burning additives for 2 kinds of coals in cement industry. The work focused on the replacement of partial chemical reagents by industrial wastes, which not only reduced the cost and took full advantage of industrial wastes, but also guaranteed the high combustion efficiency and removed the NOX and SO2 simultaneously. The experiments were carried out in DTF. The combustion residues were analyzed by SEM and XRD. The results showed that the burnout rate was increased after adding the additives; meanwhile, the NOX and SO2 release concentration were reduced, but the degree of action varied for different additives and coals. The substitute of chemical reagents by industrial wastes was very effective; overall, the cold-rolled iron oxide worked better than others; the particles surface was tougher and the peaks of crystalline phase were lower than raw coal, which indicated that the additives played good roles in combustion process.

Coal utilization technologies in the production of electric energy; Technologie wykorzystania wegla do produkcji energii elektrycznej

Energy Technology Data Exchange (ETDEWEB)

Golec, T.; Rakowski, J. [Power Institute, Warsaw (Poland)

2004-07-01

The paper presents an assessment of the various technologies for power generation from coal and discusses the development prospects for each. The technologies are: pulverized fuel fired boilers for supercritical steam parameters; atmospheric fluidized bed boilers; pressurised fluidized-bed combustion boilers; gas and steam units integrated with gasification of solid fuels; and co-firing of solid fuels. It addresses, briefly, CO{sub 2} reduction technologies. 26 refs., 3 figs., 8 tabs.

POC-scale testing of a dry triboelectrostatic separator for fine coal cleaning

Energy Technology Data Exchange (ETDEWEB)

Yoon, R.H.; Luttrell, G.H.; Adel, G.T. [Virginia Polytechnic Institute and State Univ., Blacksburg, VA (United States)

1995-11-01

Numerous advanced coal cleaning processes have been developed in recent years that are capable of substantially reducing both the ash and sulfur contents of run-of-mine coals. The extent of cleaning depends on the liberation characteristics of the coal, which generally improve with reducing particle size. however, since most of the advanced technologies are wet processes, the clean coal product must be dewatered before it can be transported and burned in conventional boilers. This additional treatment step significantly increases the processing cost and makes the industrial applicability of these advanced technologies much less attractive. In order to avoid problems associated with fine coal dewatering, researchers at the Pittsburgh Energy Technology Center (PETC) developed a novel triboelectrostatic separation (TES) process that can remove mineral matter from dry coal. In this technique, finely pulverized coal is brought into contact with a material (such as copper) having a work function intermediate to that of the carbonaceous material and associated mineral matter. Carbonaceous particles having a relatively low work function become positively charged, while particles of mineral matter having significantly higher work functions become negatively charged. once the particles become selectively charged, a separation can be achieved by passing the particle stream through an electrically charged field. Details related to the triboelectrostatic charging phenomenon have been discussed elsewhere (Inculet, 1984).

Baseload coal investment decisions under uncertain carbon legislation.

Science.gov (United States)

Bergerson, Joule A; Lave, Lester B

2007-05-15

More than 50% of electricity in the U.S. is generated by coal. The U.S. has large coal resources, the cheapest fuel in most areas. Coal fired power plants are likely to continue to provide much of U.S. electricity. However, the type of power plant that should be built is unclear. Technology can reduce pollutant discharges and capture and sequester the CO2 from coal-fired generation. The U.S. Energy Policy Act of 2005 provides incentives for large scale commercial deployment of Integrated Coal Gasification Combined Cycle (IGCC) systems (e.g., loan guarantees and project tax credits). This analysis examines whether a new coal plant should be Pulverized Coal (PC) or IGCC. Do stricter emissions standards (PM, SO2, NOx, Hg) justify the higher costs of IGCC over PC? How does potential future carbon legislation affect the decision to add carbon capture and storage (CCS) technology? Finally, can the impact of uncertain carbon legislation be minimized? We find that SO2, NOx, PM, and Hg emission standards would have to be far more stringent than twice current standards to justify the increased costs of the IGCC system. A C02 tax less than $29/ton would lead companies to continuing to choose PC, paying the tax for emitted CO2. The earlier a decision-maker believes the carbon tax will be imposed and the higher the tax, the more likely companies will choose IGCC w/CCS. Having government announce the date and level of a carbon tax would promote more sensible decisions, but government would have to use a tax or subsidy to induce companies to choose the technology that is best for society.

Utilizing Philippine Calatrava coal-diesel oil mixture (CDOM) as alternative fuel for industrial steam generator

Energy Technology Data Exchange (ETDEWEB)

Archie B. Maglaya [De La Salle University, Manila (Philippines). Department of Mechanical Engineering

2005-01-01

The fast depletion of fuel oil and the continuous increase in the demand for power is a global issue. In the Philippines, the demand for diesel oil is expected to increase significantly in a 20-year period as projected by the Department of Energy. In line with the Philippine Government's thrust to lessen the dependence on imported energy, the agenda for the search for alternative fuel is highly prioritized. Thus, this paper presents the results of the study on performance analysis and efficiency test of a diesel oil fired industrial steam generator using Philippine Calatrava coal-diesel oil mixture (CDOM) as alternative fuel. A computer program was developed in HyperText Markup Language (HTML{copyright}) and JavaScript{copyright} to aid the computation of the adiabatic flame temperature from the governing system of equations based on the heat interaction between CDOM fuel, combustion air and products of combustion to determine the most desirable alternative fuel. Actual experimentation for the determination of CDOM fuel properties was also conducted to verify the alternative fuel selected through theoretical calculations. Results showed that the CDOM fuel with a particle size passing 75 {mu}m (-200 mesh) sieve having a proportion of 5% pulverized coal-95% diesel oil and 10% pulverized coal-90% diesel oil could be handled throughout the test with no degradation of the industrial steam generator. The steam generator efficiency using diesel oil is close to the steam generator efficiency using both CDOM fuels. 20 refs., 5 figs., 4 tabs.

Industry perspectives on increasing the efficiency of coal-fired power generation

Energy Technology Data Exchange (ETDEWEB)

Torrens, I.M. [Shell Coal International, London (United Kingdom); Stenzel, W.C.

1997-12-31

Independent power producers will build a substantial fraction of expected new coal-fired power generation in developing countries over the coming decades. To reduce perceived risk and obtain financing for their projects, they are currently building and plan to continue to build subcritical coal-fired plants with generating efficiency below 40%. Up-to-date engineering assessment leads to the conclusion that supercritical generating technology, capable of efficiencies of up to 45%, can produce electricity at a lower total cost than conventional plants. If such plants were built in Asia over the coming decades, the savings in carbon dioxide emissions over their lifetime would be measured in billions of tons. IPPs perceive supercritical technology as riskier and higher cost than conventional technology. The truth needs to be confirmed by discussions with additional experienced power engineering companies. Better communication among the interested parties could help to overcome the IPP perception issue. Governments working together with industry might be able to identify creative financing arrangements which can encourage the use of more efficient pulverized clean coal technologies, while awaiting the commercialization of advanced clean coal technologies like gasification combined cycle and pressurized fluidized bed combustion.

CO-FIRING COAL, FEEDLOT, AND LITTER BIOMASS (CFB AND LFB) FUELS IN PULVERIZED FUEL AND FIXED BED BURNERS

International Nuclear Information System (INIS)

Kalyan Annamalai; John Sweeten; Saqib Mukhtar; Ben Thien; Gengsheng Wei; Soyuz Priyadarsan

2002-01-01

Intensive animal feeding operations create large amounts of animal waste that must be safely disposed of in order to avoid environmental degradation. Cattle feedlots and chicken houses are two examples. In feedlots, cattle are confined to small pens and fed a high calorie grain diet in preparation for slaughter. In chicken houses, thousands of chickens are kept in close proximity. In both of these operations, millions of tons of manure are produced every year. In this project a co-firing technology is proposed which would use manure that cannot be used for fertilizer, for power generation. Since the animal manure has economic uses as both a fertilizer and as a fuel, it is properly referred to as feedlot biomass (FB) for cow manure, or litter biomass (LB) for chicken manure. The biomass will be used a as a fuel by mixing it with coal in a 90:10 blend and firing it in existing coal fired combustion devices. This technique is known as co-firing, and the high temperatures produced by the coal will allow the biomass to be completely combusted. Therefore, it is the goal of the current research to develop an animal biomass cofiring technology. A cofiring technology is being developed by performing: (1) studies on fundamental fuel characteristics, (2) small scale boiler burner experiments, (3) gasifier experiments, (4) computer simulations, and (5) an economic analysis. The fundamental fuel studies reveal that biomass is not as high a quality fuel as coal. The biomass fuels are higher in ash, higher in moisture, higher in nitrogen and sulfur (which can cause air pollution), and lower in heat content than coal. Additionally, experiments indicate that the biomass fuels have higher gas content, release gases more readily than coal, and less homogeneous. Small-scale boiler experiments revealed that the biomass blends can be successfully fired, and NO(sub x) pollutant emissions produced will be similar to or lower than pollutant emissions when firing coal. This is a surprising

CO-FIRING COAL, FEEDLOT, AND LITTER BIOMASS (CFB AND LFB) FUELS IN PULVERIZED FUEL AND FIXED BED BURNERS

Energy Technology Data Exchange (ETDEWEB)

Kalyan Annamalai; John Sweeten; Saqib Mukhtar; Ben Thien; Gengsheng Wei; Soyuz Priyadarsan

2002-01-15

Intensive animal feeding operations create large amounts of animal waste that must be safely disposed of in order to avoid environmental degradation. Cattle feedlots and chicken houses are two examples. In feedlots, cattle are confined to small pens and fed a high calorie grain diet in preparation for slaughter. In chicken houses, thousands of chickens are kept in close proximity. In both of these operations, millions of tons of manure are produced every year. In this project a co-firing technology is proposed which would use manure that cannot be used for fertilizer, for power generation. Since the animal manure has economic uses as both a fertilizer and as a fuel, it is properly referred to as feedlot biomass (FB) for cow manure, or litter biomass (LB) for chicken manure. The biomass will be used a as a fuel by mixing it with coal in a 90:10 blend and firing it in existing coal fired combustion devices. This technique is known as co-firing, and the high temperatures produced by the coal will allow the biomass to be completely combusted. Therefore, it is the goal of the current research to develop an animal biomass cofiring technology. A cofiring technology is being developed by performing: (1) studies on fundamental fuel characteristics, (2) small scale boiler burner experiments, (3) gasifier experiments, (4) computer simulations, and (5) an economic analysis. The fundamental fuel studies reveal that biomass is not as high a quality fuel as coal. The biomass fuels are higher in ash, higher in moisture, higher in nitrogen and sulfur (which can cause air pollution), and lower in heat content than coal. Additionally, experiments indicate that the biomass fuels have higher gas content, release gases more readily than coal, and less homogeneous. Small-scale boiler experiments revealed that the biomass blends can be successfully fired, and NO{sub x} pollutant emissions produced will be similar to or lower than pollutant emissions when firing coal. This is a surprising

Pulverized coal firing of aluminum melting furnaces. First annual technical progress report, May 1978-June 1979

Energy Technology Data Exchange (ETDEWEB)

West, C.E.; Hines, J.E.; Stewart, D.L. Jr.; Yu, H.

1979-10-01

The ultimate objective of this program is the commercial demonstration of an efficient, environmentally acceptable coal firing process suitable for implementation on melting furnaces throughout the aluminum industry. To achieve this goal, the program has been divided into two phases. Phase I has begun with the design and construction of a 350 lb/h (coal) staged slagging cyclone combustor (SSCC) attached to a 7-ft dia aluminum melting ladle furnace. Process development will culminate with a 1000 pph prototype SSCC firing a 40,000 lb capacity open hearth melting furnace at the Alcoa Laboratories. Phase II implementation is currently planned for Alcoa's Lafayette, IN, Works, where two of the ingot plant's five open hearth melting furnaces will be converted to utilize coal. In addition to confirmation of data gathered in Phase I, the effect of extended production schedule operation on equipment and efficiencies will be determined. This work would begin in 1982 pursuant to technical and economic evaluation of the process development at that time. A major design subcontract for assistance in the design of the SSCC is 80% completed.

Utilization of brown coal in FRG power plants

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.

1985-07-01

FRG methods are studied for utilizing brown coal in view of the development of Kansk-Achinsk brown coal deposits. The use of brown coal in FRG power plants has increased from 15% in 1950- 1960 to 85% (total output) in 1982, providing 79.4 TWh of electrical energy. The remainder was used for briquetting, pulverization and breeze coke. In 1982 nearly 100 million tons of brown coal were burned by six large power stations (rated capacity 11,400 MW) to produce nearly 80 billion kWh of energy. Measures are discussed taken to reduce slagging and to remove excessive moisture content. Problems are analyzed associated with increased contamination of the atmosphere in areas with high population density (412/km/sup 2/) and cost of suppression is reviewed. According to available data, the cost of preventive measures taken by FRG, USA, Japan and the Netherlands is equal to 30% of the total cost of the energy. The most critical problem is suppression of sulfur dioxide, either by dry or wet scrubbers or by the addition of dry dolomite or lime to the furnace (75% of all SO/sub 2/ emissions in FRG comes from power stations). A method is described developed by RWE based on a series of distribution headers in the upper part of combustion chambers. At best, 70-80% reduction can be achieved. 14 references.

Fiscal 1996 survey report on the environmentally friendly type coal utilization system feasibility study. Feasibility study of the environmentally friendly type coal utilization system in the Philippines; Kankyo chowagata sekitan riyo system kanosei chosa. Philippines ni okeru kankyo chowagata sekitan riyo system kanosei chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

Grasping the present situation of coal utilization technology in the Philippines, the paper proposed a feasibility study of introduction of the environmentally friendly type coal utilization system which seems to be needed in the future. (1) Introduction of the environmentally friendly type coal utilization system in the electric power generation sector: there are only four full-scale running coal thermal power plants in the Philippines. In the future, several coal thermal plants are planned to be constructed by 2005, but for the new installation, it is desirable to adopt fluidized bed boilers with wide application to coal kinds. In case of 0.3-1.0 million MW class plants, it is planned to adopt high grade import coals, and it will be natural to fire pulverized coal. For the processing of flue gas, it is a must to install desulfurization facilities and smoke/soot removal devices. (2) Utilization/development of domestic low grade coals: at the mine-mouth generating plant, it is necessary to investigate the economically minable amount of coal, confirm productivity, survey coal quality, etc., and select boiler. As to coal briquetting technology, it is necessary to examine coal quality for tests and make a thorough study of what technology is most suitable. 50 figs., 78 tabs.

Evaluation of radionuclide contamination of soil, coal ash and zeolitic materials from Figueira thermoelectric power plant

International Nuclear Information System (INIS)

Fungaro, Denise Alves; Silva, Paulo Sergio Cardoso da; Campello, Felipe Arrelaro; Miranda, Caio da Silva; Izidoro, Juliana de Carvalho

2017-01-01

Neutron activation analysis and gamma-ray spectrometry was used to determine 238 U, 226 Ra, 228 Ra, 210 Pb, 232 Th and 40 K contents in feed pulverized coal, bottom ash, fly ash from cyclone and baghouse filters, zeolites synthesized from the ashes and two different soil samples. All the samples used in the study was collected at Figueira thermoelectric power plant, located in the city of Figueira, Paraná State, which coal presents a significant amount of uranium concentration. The natural radionuclide concentrations in pulverized coal were 4216 Bq kg -1 for 238 U, 180 Bq kg -1 for 226 Ra, 27 Bq kg -1 for 228 Ra, 28 Bq kg -1 for 232 Th and 192 Bq kg -1 for 40 K. The ashes fraction presented concentrations ranging from 683.5 to 1479 Bq kg -1 for 238 U, from 484 to 1086 Bq kg -1 for 226 Ra, from 291 to 1891 Bq kg -1 for 210 Pb, from 67 to 111 Bq kg -1 for 228 Ra, from 80 to 87 Bq -1 for 232 Th and from 489 to 718 Bq kg -1 for 40 K. Similar ranges were observed for zeolites. The activity concentration of 238 U was higher than worldwide average concentration for all samples. The concentration of the uranium series found in the ashes were lower than the values observed in similar studies carried out 10 years ago and under the limit adopted by the Brazilian guideline (CNEN-NN-4.01). Nevertheless, the concentrations of this specific area are higher than others coal mines and thermoelectric power plants in and out of Brazil, so it is advisable to evaluate the environmental impact of the installation. (author).

Relation between the petrographic composition of coal and the morphology of pyrolysis char produced in fluidized bed

Energy Technology Data Exchange (ETDEWEB)

B. Valentim; M.J. Lemos de Sousa; P. Abelha; D. Boavida; I. Gulyurtlu [Centro de Geologia da Universidade do Porto, Porto (Portugal)

2004-06-01

Several previous studies have already established, for pulverized coal combustion conditions, global correlations between petrographic composition of the coal and those of char produced from the same coal. However, for fluidized bed combustion, there has not been much new work since the eighties. The results presented in this paper include the petrographic characterization of seven different coals from several origins and also of their respective chars produced at 700, 800, 900, and 1000{sup o}C in a laboratory fluidized bed reactor. The results show a marked predominance of tenuispheres as the trial temperatures increase. While vitrinite-rich coals essentially produced highly porous chars, the inertinite-rich coals produced large amounts of medium- and low-porous chars. Semi-anthracite vitrinite produced high-porous chars and thermal affected coal particles originated low-porous and angular char morphotypes. The analysis of the data obtained revealed that vitrinite + liptinite related well with the high-porous char (sum of cenospheres and tenuinetworks), classified as Group 1. The same trend, but with a weaker relation, was also observed between vitrinite and liptinite rich microlithotypes and Group 1. 32 refs., 17 refs., 3 tabs.

Geochemistry of ultra-fine and nano-compounds in coal gasification ashes: A synoptic view

Energy Technology Data Exchange (ETDEWEB)

Kronbauer, Marcio A. [Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS (Brazil); Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Gonçalves, 9500, Bairro Agronomia, CEP: 91501-970, Porto Alegre, RS (Brazil); Izquierdo, Maria [School of Applied Sciences, Cranfield University, Bedfordshire MK43 0AL (United Kingdom); Dai, Shifeng [State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing 100083 (China); Waanders, Frans B. [School of Chemical and Minerals Engineering, North West University (Potchefstroom campus), Potchefstroom 2531 (South Africa); Wagner, Nicola J. [School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg (South Africa); Mastalerz, Maria [Indiana Geological Survey, Indiana University, Bloomington, IN 47405-2208 (United States); Hower, James C. [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States); Oliveira, Marcos L.S. [Environmental Science and Nanotechnology Department, Catarinense Institute of Environmental Research and Human Development, IPADHC, Capivari de Baixo, Santa Catarina (Brazil); Taffarel, Silvio R.; Bizani, Delmar [Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS (Brazil); and others

2013-07-01

The nano-mineralogy, petrology, and chemistry of coal gasification products have not been studied as extensively as the products of the more widely used pulverized-coal combustion. The solid residues from the gasification of a low- to medium-sulfur, inertinite-rich, volatile A bituminous coal, and a high sulfur, vitrinite-rich, volatile C bituminous coal were investigated. Multifaceted chemical characterization by XRD, Raman spectroscopy, petrology, FE-SEM/EDS, and HR-TEM/SEAD/FFT/EDS provided an in-depth understanding of coal gasification ash-forming processes. The petrology of the residues generally reflected the rank and maceral composition of the feed coals, with the higher rank, high-inertinite coal having anisotropic carbons and inertinite in the residue, and the lower rank coal-derived residue containing isotropic carbons. The feed coal chemistry determines the mineralogy of the non-glass, non-carbon portions of the residues, with the proportions of CaCO{sub 3} versus Al{sub 2}O{sub 3} determining the tendency towards the neoformation of anorthite versus mullite, respectively. Electron beam studies showed the presence of a number of potentially hazardous elements in nanoparticles. Some of the neoformed ultra-fine/nano-minerals found in the coal ashes are the same as those commonly associated with oxidation/transformation of sulfides and sulfates. - Highlights: • Coal waste geochemisty can provide increased environmental information in coal-mining areas. • Oxidation is the major process for mineral transformation in coal ashes. • The electron bean methodology has been applied to investigate neoformed minerals.

Aluminium dissolution for spray pulverization with nitric acid

International Nuclear Information System (INIS)

Rodrigo Otero, A.; Rodrigo Vilaseca, F.; Morales Calvo, G.

1977-01-01

A comparative study of the nitric acid dissolution of aluminium, by immersion and spray pulverization has been carried out in laboratory scale. As a result, the optimum operation conditions to control reaction in the plant are fixed. Operation costs are also evaluated. (author) [es

Report on the achievements in the Sunshine Project in fiscal 1988. Development of a coal liquefaction technology (Liquefaction performance test on Chinese coals); 1988 nendo sekitan ekika gijutsu kaihatsu, Chugokutan ekika seino shiken seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-03-01

Development has been carried out on a Chinese coal liquefaction technology jointly by Japan and China. The Japanese side fabricated and built a small continuous testing equipment. Shenbei coal produced in Liaoning Province, Tienju coal produced in Gansu Province and Shenmu coal produced in Shaanxi Province were used as test sample coals. These coals were crushed, washed with water, sorted, dried, pulverized below 100 mesh, and used as the test samples. For catalysts, a reagent Fe{sub 2}O{sub 3} and S as an auxiliary catalyst made in China were used. Anthracene oil freed from crystal was used as a starting solvent when making one-through operation and recycling operation. Hydrogen used had purity of 99.5% or higher. The current fiscal year has performed smoothly to the end either of the one-through operation or the solvent circulating operation on RUN-2200, 2300 (Chenbei coal) and 2,400, 2500 (Tienju coal). Operation of 2600, 2700 (Shenmu coal) experienced noise in the stirrer of the reactor, and leakage of the circulating gas from the recycled gas compressor. In addition, the differential pressure during operating the last run has increased to 50 k, when the temperature and pressure were reduced, and substances clogging the reactor inlet line were removed. Three kinds of the liquefied oils were brought back to Japan for detailed analyses. (NEDO)

JV Task 126 - Mercury Control Technologies for Electric Utilities Burning Bituminous Coal

Energy Technology Data Exchange (ETDEWEB)

Jason Laumb; John Kay; Michael Jones; Brandon Pavlish; Nicholas Lentz; Donald McCollor; Kevin Galbreath

2009-03-29

The EERC developed an applied research consortium project to test cost-effective mercury (Hg) control technologies for utilities burning bituminous coals. The project goal was to test innovative Hg control technologies that have the potential to reduce Hg emissions from bituminous coal-fired power plants by {ge}90% at costs of one-half to three-quarters of current estimates for activated carbon injection (ACI). Hg control technology evaluations were performed using the EERC's combustion test facility (CTF). The CTF was fired on pulverized bituminous coals at 550,000 Btu/hr (580 MJ/hr). The CTF was configured with the following air pollution control devices (APCDs): selective catalytic reduction (SCR) unit, electrostatic precipitator (ESP), and wet flue gas desulfurization system (WFDS). The Hg control technologies investigated as part of this project included ACI (three Norit Americas, Inc., and eleven Envergex sorbents), elemental mercury (Hg{sup 0}) oxidation catalysts (i.e., the noble metals in Hitachi Zosen, Cormetech, and Hitachi SCR catalysts), sorbent enhancement additives (SEAs) (a proprietary EERC additive, trona, and limestone), and blending with a Powder River Basin (PRB) subbituminous coal. These Hg control technologies were evaluated separately, and many were also tested in combination.

Characteristic Study of Some Different Kinds of Coal Particles Combustion with Online TG-MS-FTIR

Science.gov (United States)

Pan, Guanfu

2018-01-01

Four kinds of pulverized coal samples from China and Indonesia were studied by thermogravimetry coupled with mass spectrometry and fourier transform infrared spectroscopy (TG-MS-FTIR). The thermal behaviors and gaseous emissions of these coals were analyzed in this work. The results indicate that the relative lower values of H/C ratios, which normally represent the degree of aromatization and ring condensation in coal samples, could lead to the relative more intense thermal reaction. The time-evolved profiles of some typical gas products (i.e., CO, SO2, CH4, NO, NO2, NH3 and etc.) were provided by TG-MS-FTIR, and their variations are different. For all the samples, the releases of SO2 and COS can be found at lower temperature than those of NO and CO. As the temperature increases, the possible conversion of NO2 and NH3 to NO is deduced in this work.

Differential pulmonary inflammation and in vitro cytotoxicity of size-fractionated fly ash particles from pulverized coal combustion

Energy Technology Data Exchange (ETDEWEB)

M. Ian Gilmour; Silvia O' Connor; Colin A.J. Dick; C. Andrew Miller; William P. Linak [U.S. Environmental Protection Agency, Research Triangle Park, NC (United States). National Health and Environmental Effects Research Laboratory

2004-03-01

Exposure to airborne particulate matter (PM) has been associated with adverse health effects in humans. Pulmonary inflammatory responses were examined in CD1 mice after intratracheal instillation of 25 or 100 {mu}g of ultrafine ({lt}0.2 {mu}m), fine ({lt}2.5 {mu}m), and coarse ({gt}2.5 {mu}m) coal fly ash from a combusted Montana subbituminous coal, and of fine and coarse fractions from a combusted western Kentucky bituminous coal. After 18 hr, the lungs were lavaged and the bronchoalveolar fluid was assessed for cellular influx, biochemical markers, and pro-inflammatory cytokines. The responses were compared with saline and endotoxin as negative and positive controls, respectively. On an equal mass basis, the ultrafine particles from combusted Montana coal induced a higher degree of neutrophil inflammation and cytokine levels than did the fine or coarse PM. The western Kentucky fine PM caused a moderate degree of inflammation and protein levels in bronchoalveolar fluid that were higher than the Montana fine PM. Coarse PM did not produce any significant effects. In vitro experiments with rat alveolar macrophages showed that of the particles tested, only the Montana ultrafine displayed significant cytotoxicity. It is concluded that fly ash toxicity is inversely related with particle size and is associated with increased sulfur and trace element content. 42 refs., 5 figs., 3 tabs.

Impact of coal fly ash addition on ash transformation and deposition in a full-scale wood suspension-firing boiler

DEFF Research Database (Denmark)

Wu, Hao; Bashir, Muhammad Shafique; Jensen, Peter Arendt

2013-01-01

Ash transformation and deposition during pulverized wood combustion in a full-scale power plant boiler of 800 MWth were studied with and without the addition of coal fly ash. The transient ash deposition behavior was characterized by using an advanced deposit probe system at two boiler locations...... constant after a few hours. The formed deposits, especially those at the location with low flue gas temperatures, contained a considerable amount of K2SO4, KCl, and KOH/K2CO3. With the addition of a large amount (about 4 times of the mass flow of wood ash) of coal fly ash to the boiler, these alkali...

Aspects chimiques de la combustion du charbon pulvérisé. Première partie Chemical Aspects of the Combustion of Pulverized Coal. Part One

Directory of Open Access Journals (Sweden)

De Soete G. G.

2006-11-01

deux mécanismes totalement différents, par exemple entre le mécanisme d'ignition homogène et le mécanisme d'ignition hétérogène du charbon, avec des conséquences pratiques pour la stabilisation de la flamme industrielle ; autre exemple : la compétition entre les divers mécanismes homogènes de formation d'oxydes d'azote et les mécanismes hétérogènes de leur réduction sur des particules solides de coke, de suie et de cendre. Avec ces idées présentes comme un leitmotiv implicite, on passe en revue les grandes étapes de la flamme industrielle de charbon pulvérisé : la dévolatilisation rapide avec la formation progressive de volatils gazeux, de goudrons et de coke ; la transformation partielle des produits gazeux et liquides de pyrolyse en suies ainsi que leur oxydation en phase gazeuse ; la combustion hétérogène du coke ; l'ignition du charbon et sa dépendance par rapport à des processus critiques homogènes et (ou hétérogènes. Comme exemple typique d'un épiphénomènechimique, on suit la transformation des espèces azotées en NO et en N2, qui se greffe en contrepoint et à chaque pas sur tes différents thèmes successifs de cette symphonie de l'oxydation du charbon. En de nombreux points de cette évolution du charbon à travers la flamme, les connaissances de la chimie de com-bustion en phase gazeuse constituent un instrument utile d'interprétation (par exemple : pour l'oxydation des volatils, pour la discussion des modalités d'ignition. II n'en reste pas moins vrai que la plupart des problèmes chimiques hétérogènes sont bien spécifiques de la flamme de charbon ; leur traitement est rendu ardu à cause de la complexité, évolutive au cours de la combustion, du combustible solide lui-même. It is not easy to obtain a full picture of the multiple chemical phenomena which occur inside a pulverized coal flame. This bibliographie review attempts to give more than just a juxtaposition of data from the recent literature and risks making

Radiation/turbulence interactions in pulverized-coal flames. Second year technical progress report, September 30, 1994--September 30, 1995

Energy Technology Data Exchange (ETDEWEB)

Menguec, M.P.; McDonough, J.M.; Manickavsagam, S.; Mukerji, S.; Wang, D.; Ghosal, S.; Swabb, S.

1995-12-31

Our goal in this project is to investigate the interaction of radiation and turbulence in coalfired laboratory scale flames and attempt to determine the boundaries of the ``uncertainty domain`` in Figure 3 more rigorously. We have three distinct objectives: (1) To determine from experiments the effect of turbulent fluctuations on the devolatilization/pyrolysis of coal particles and soot yield, and to measure the change in the ``effective`` radiative properties of particulates due to turbulence interactions; (2) To perform local small-scale simulations to investigate the radiation-turbulence interactions in coal-fired flames starting from first principles; and (3) To develop a thorough and rigorous, but computationally practical, turbulence model for coal flames, starting from the experimental observations and small scale simulations.

Technical, environmental, and economic assessment of deploying advanced coal power technologies in the Chinese context

International Nuclear Information System (INIS)

Zhao Lifeng; Xiao Yunhan; Gallagher, Kelly Sims; Wang Bo; Xu Xiang

2008-01-01

The goal of this study is to evaluate the technical, environmental, and economic dimensions of deploying advanced coal-fired power technologies in China. In particular, we estimate the differences in capital cost and overall cost of electricity (COE) for a variety of advanced coal-power technologies based on the technological and economic levels in 2006 in China. This paper explores the economic gaps between Integrated Gasification Combined Cycle (IGCC) and other advanced coal power technologies, and compares 12 different power plant configurations using advanced coal power technologies. Super critical (SC) and ultra super critical (USC) pulverized coal (PC) power generation technologies coupled with pollution control technologies can meet the emission requirements. These technologies are highly efficient, technically mature, and cost-effective. From the point of view of efficiency, SC and USC units are good choices for power industry. The net plant efficiency for IGCC has reached 45%, and it has the best environmental performance overall. The cost of IGCC is much higher, however, than that of other power generation technologies, so the development of IGCC is slow throughout the world. Incentive policies are needed if IGCC is to be deployed in China

Amphiphilic semi-interpenetrating polymer networks using pulverized rubber

Science.gov (United States)

Shahidi, Nima

Scrap rubber materials provide a significant challenge to either reuse or safe disposal. Every year, millions of tires are discarded to landfills in the United States, consuming a staggering amount of land space, creating a high risk for large fires, breeding mosquitoes that spread diseases, and wasting the planet's natural resources. This situation cannot be sustained. The challenge of reusing scrap rubber materials is mainly due to the crosslinked structure of vulcanized rubber that prevent them from melting and further processing for reuse. The most feasible recycling approach is believed to be a process in which the vulcanized rubber is first pulverized into a fine powder and then incorporated into new products. The production of fine rubber particles is generally accomplished through the use of a cryogenic process that is costly. Therefore, development of a cost effective technology that utilizes a large quantity of the scrap rubber materials to produce high value added materials is an essential element in maintaining a sustainable solution to rubber recycling. In this research, a cost effective pulverization process, solid state shear extrusion (SSSE), was modified and used for continuous pulverization of the rubber into fine particles. In the modified SSSE process, pulverization takes place at high compressive shear forces and a controlled temperature. Furthermore, an innovative particle modification process was developed to enhance the chemical structure and surface properties of the rubber particles for manufacturing of high value added products. Modification of rubber particles was accomplished through the polymerization of a hydrophilic monomer mixture within the intermolecular structure of the hydrophobic rubber particles. The resulting composite particles are considered as amphiphilic particulate phase semi-interpenetrating polymer networks (PPSIPNs). The modified rubber particles are water dispersible and suitable for use in a variety of aqueous media

Measurements of Gasification Characteristics of Coal and Char in CO2-Rich Gas Flow by TG-DTA

Directory of Open Access Journals (Sweden)

Zhigang Li

2013-01-01

Full Text Available Pyrolysis, combustion, and gasification properties of pulverized coal and char in CO2-rich gas flow were investigated by using gravimetric-differential thermal analysis (TG-DTA with changing O2%, heating temperature gradient, and flow rate of CO2-rich gases provided. Together with TG-DTA, flue gas generated from the heated coal, such as CO, CO2, and hydrocarbons (HCs, was analyzed simultaneously on the heating process. The optimum O2% in CO2-rich gas for combustion and gasification of coal or char was discussed by analyzing flue gas with changing O2 from 0 to 5%. The experimental results indicate that O2% has an especially large effect on carbon oxidation at temperature less than 1100°C, and lower O2 concentration promotes gasification reaction by producing CO gas over 1100°C in temperature. The TG-DTA results with gas analyses have presented basic reference data that show the effects of O2 concentration and heating rate on coal physical and chemical behaviors for the expected technologies on coal gasification in CO2-rich gas and oxygen combustion and underground coal gasification.

Utilization of HSC-ROSE residue as coking aid for the production of high quality coke from brown coal

Energy Technology Data Exchange (ETDEWEB)

Bohlmann, D.; Limmer, H.; Naundorf, W.; Hood, R.L.; Washimi, K. (VEB Petrolchemisches Kombinat, Schwedt (German Democratic Republic))

1989-04-01

Evaluates suitability of HSC-ROSE petroleum pitch as binder for production of brown coal coke. This pitch has been available in the GDR since installation in 1988 of a 750 kt/a HSC (high conversion soaker cracking) plant, which processes 360 C visbreaker residue from Soviet crude oil, and the building of a ROSE (residue oil supercritical reaction) plant. Laboratory as well as semi-industrial experiments were carried out at the Freiberg Academy, GDR on pulverizing, briquetting and coking various brown coal types with HSC-ROSE pitch. Briquetting and coking results are shown in tables. Experiments showed that the resulting coke has 124% higher compression strength and 100% higher abrasion strength than regular brown coal coke without HSC-ROSE binder. The high quality coke is adequate for use as metallurgical blast furnace coke. An economic assessment of modifying an existing brown coal coking plant to process 2 Mt/a brown coal with 10% pitch binder is made. Required investment amounts to 54 million US dollars, estimated annual profits based on 1987 prices are 19.5 million US dollars. 4 refs.

Mineral conversion and microstructure change in the melting process of Shenmu coal ash

Energy Technology Data Exchange (ETDEWEB)

Yang Jianguo; Deng Furong; Zhao Hong; Cen Kefa [Zhejiang University, Hangzhou (China). State Key Laboratory of Clean Energy Utilization

2007-05-15

China has rich reserves of Shenmu coal, which has the typical characteristic of low-melting-point ash. If used in the pulverized-coal boiler of a power plant, Shenmu coal would cause serious slagging. In order to solve the slagging problem of Shenmu coal, the melting mechanism of Shenmu coal ash was studied. One of the Shenmu coals - Wenjialiang coal - was selected for the study. Using thermogravimetry-differential scanning colorimetry (TG-DSC) methods, the change of the coal ash's physicochemistry with temperature was studied. The typical temperature points in the melting process were obtained. Ash samples of the different temperature points were prepared in a high-temperature furnace with parameters similar to those used in the TG-DSC test, and were then cooled quickly in water. Later, the ash samples were analyzed using X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) methods in detail. Wenjialiang coal ash started to melt at 980{sup o}C. The ash was found to melt to a great extent at 1200{sup o}C and formed a multiform microstructure. At 1260{sup o}C, it was found to melt into a dense body with many pores, and formed a piece of vitreous body at 1340{sup o}C. Anorthite and gehlenite are the intermediate products that exist between 980 and 1340{sup o}C. They may be the main cause of the ash having low melting points, so that they could convert into a eutectic at low temperatures.

Study on the influence of electromagnetic field on the property of coal combustion burnout in circulating fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Xiang, Y. [Ruiping Coal and Electric Power Ltd. Co., Ruzhou (China)

2008-08-15

To study the influences of electromagnetism field pretreatment of pulverized Coal (EFPPC) on the properties of its combustion, thermogravimetric analysis, a Muffle furnace experiment and an X-ray diffraction experiment were carried out for three Coal banks. It was shown that EFPPC will induce the molecular structure of Coal to change into amorphous carbon, which causes an increase in the rate of oxygen absorption during the initial stages of Coal burning and reaction activity. It is also shown that the residual carbon of bituminous Coal would be increased by about 0.33% - 0.41%, i.e, the loss of standard Coal is about 3,000 t/a for double 480 t/h boilers, when applying EFPPC for 1 min at a temperature of 800 - 1,000 {sup o}C. When the temperature increases 200 {sup o}C, the residual carbon increases by about 2.07% but the effect of EFPPC is less than 0.21% for bituminous Coal and residual carbon is about 1.47% and the effect of EFPPC is less than 0.05% for lean Coal. Therefore the effect of increasing the temperature of EFPPC on residual carbon is less than that of increasing the time of EFPPC. 9 refs., 4 figs., 2 tabs.

Fuel characterization requirements for cofiring biomass in coal-fired boilers

International Nuclear Information System (INIS)

Prinzing, D.E.; Tillman, D.A.; Harding, N.S.

1993-01-01

The cofiring of biofuels with coal in existing boilers, or the cofiring of biofuels in combined cycle combustion turbine (CCCT) systems presents significant potential benefits to utilities, including reductions in SO 2 and NO x emissions as a function of reducing the mass flow of sulfur and nitrogen to the boiler, reducing CO 2 emissions from the combustion of fossil fuels; potentially reducing fuel costs both by the availability of wood residues and by the fact that biofuels are exempt from the proposed BTU tax; and providing support to industrial customers from the forest products industry. At the same time, cofiring requires careful attention to the characterization of the wood and coal, both singly and in combination. This paper reviews characterization requirements associated with cofiring biofuels and fossil fuels in boilers and CCCT installations with particular attention not only to such concerns as sulfur, nitrogen, moisture, and Btu content, but also to such issues as total ash content, base/acid ratio of the wood ash and the coal ash, alkali metal content in the wood ash and wood fuel (including converted fuels such as low Btu gas or pyrolytic oil), slagging and fouling indices, ash fusion temperature, and trace metal contents in the wood and coal. The importance of each parameter is reviewed, along with potential consequences of a failure to adequately characterize these parameters. The consequences of these parameters are reviewed with attention to firing biofuels with coal in pulverized coal (PC) and cyclone boilers, and firing biofuels with natural gas in CCCT installations

Analysis of the market penetration of clean coal technologies and its impacts in China's electricity sector

International Nuclear Information System (INIS)

Wang, Hao; Nakata, Toshihiko

2009-01-01

This paper discusses policy instruments for promoting the market penetration of clean coal technologies (CCTs) into China's electricity sector and the evaluation of corresponding effects. Based on the reality that coal will remain the predominant fuel to generate electricity and conventional pulverized coal boiler power plants have serious impacts on environment degradation, development of clean coal technologies could be one alternative to meet China's fast growing demand of electricity as well as protect the already fragile environment. A multi-period market equilibrium model is applied and an electricity model of China is established to forecast changes in the electricity system up to 2030s. Three policy instruments: SO 2 emission charge, CO 2 emission charge and implementing subsidies are considered in this research. The results show that all instruments cause a significant shift in China's electricity structure, promote CCTs' competitiveness and lead China to gain great benefit in both resource saving and environment improvement. Since resource security and environment degradation are becoming primary concerns in China, policies that could help to gain generations' market share of advanced coal-based technologies such as CCTs' is suitable for the current situation of China's electricity sector. (author)

Numerical simulations of a large scale oxy-coal burner

Energy Technology Data Exchange (ETDEWEB)

Chae, Taeyoung [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Park, Sanghyun; Ryu, Changkook [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Yang, Won [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group

2013-07-01

Oxy-coal combustion is one of promising carbon dioxide capture and storage (CCS) technologies that uses oxygen and recirculated CO{sub 2} as an oxidizer instead of air. Due to difference in physical properties between CO{sub 2} and N{sub 2}, the oxy-coal combustion requires development of burner and boiler based on fundamental understanding of the flame shape, temperature, radiation and heat flux. For design of a new oxy-coal combustion system, computational fluid dynamics (CFD) is an essential tool to evaluate detailed combustion characteristics and supplement experimental results. In this study, CFD analysis was performed to understand the combustion characteristics inside a tangential vane swirl type 30 MW coal burner for air-mode and oxy-mode operations. In oxy-mode operations, various compositions of primary and secondary oxidizers were assessed which depended on the recirculation ratio of flue gas. For the simulations, devolatilization of coal and char burnout by O{sub 2}, CO{sub 2} and H{sub 2}O were predicted with a Lagrangian particle tracking method considering size distribution of pulverized coal and turbulent dispersion. The radiative heat transfer was solved by employing the discrete ordinate method with the weighted sum of gray gases model (WSGGM) optimized for oxy-coal combustion. In the simulation results for oxy-model operation, the reduced swirl strength of secondary oxidizer increased the flame length due to lower specific volume of CO{sub 2} than N{sub 2}. The flame length was also sensitive to the flow rate of primary oxidizer. The oxidizer without N{sub 2} that reduces thermal NO{sub x} formation makes the NO{sub x} lower in oxy-mode than air-mode. The predicted results showed similar trends with measured temperature profiles for various oxidizer compositions. Further numerical investigations are required to improve the burner design combined with more detailed experimental results.

Fouling deposition characteristic by variation of coal particle size and deposition temperature in DTF (Drop Tube Furnace)

Energy Technology Data Exchange (ETDEWEB)

Namkung, Hueon; Jeon, Youngshin; Kim, Hyungtaek [Ajou Univ., Suwon (Korea, Republic of). Div. of Energy Systems Research; Xu, Li-hua [IAE, Suwon (Korea, Republic of). Plant Engineering Center

2013-07-01

One of the major operation obstacles in gasification process is ash deposition phenomenon. In this investigation, experiment was carried out to examine coal fouling characteristics using a laminar DTF (Drop Tube Furnace) with variation of operating condition such as different coal size, and probe surface temperature. Four different samples of pulverized coal were injected into DTF under various conditions. The ash particles are deposited on probe by impacting and agglomerating action. Fouling grains are made of eutectic compound, which is made by reacting with acid minerals and alkali minerals, in EPMA (Electron Probe Micro-Analysis). And agglomeration area of fouling at top layer is wide more than it of middle and bottom layer. The major mineral factors of fouling phenomenon are Fe, Ca, and Mg. The deposition quantity of fouling increases with increasing particle size, high alkali mineral (Fe, Ca, and Mg) contents, and ash deposition temperature.

The effect of char structure on burnout during pulverized coal combustion at pressure

Energy Technology Data Exchange (ETDEWEB)

Liu, G.; Wu, H.; Benfell, K.E.; Lucas, J.A.; Wall, T.F.

1999-07-01

An Australian bituminous coal sample was burnt in a drop tube furnace (DTF) at 1 atm and a pressurized drop tube furnace (PDTF) at 15 atm. The char samples were collected at different burnout levels, and a scanning electron microscope was used to examine the structures of chars. A model was developed to predict the burnout of char particles with different structures. The model accounts for combustion of the thin-walled structure of cenospheric char and its fragmentation during burnout. The effect of pressure on reaction rate was also considered in the model. As a result, approximately 40% and 70% cenospheric char particles were observed in the char samples collected after coal pyrolysis in the DTF and PDTF respectively. A large number of fine particles (< 30 mm) were observed in the 1 atm char samples at burnout levels between 30% and 50%, which suggests that significant fragmentation occurred during early combustion. Ash particle size distributions show that a large number of small ash particles formed during burnout at high pressure. The time needed for 70% char burnout at 15 atm is approximately 1.6 times that at 1 atm under the same temperature and gas environment conditions, which is attributed to the different pressures as well as char structures. The overall reaction rate for cenospheric char was predicted to be approximately 2 times that of the dense chars, which is consistent with previous experimental results. The predicted char burnout including char structures agrees reasonably well with the experimental measurements that were obtained at 1 atm and 15 atm pressures.

Investigation on the ignition, thermal acceleration and characteristic temperatures of coal char combustion

International Nuclear Information System (INIS)

Zhang, Bin; Fu, Peifang; Liu, Yang; Yue, Fang; Chen, Jing; Zhou, Huaichun; Zheng, Chuguang

2017-01-01

Highlights: • A new thermal model and measuring method for the ignition temperature are proposed. • Ignition occurs in a region but not a point with ambient conditions changing. • Ignition region is measured from the minimum to maximum ignition temperature. • T_i_g_,_m_a_x of coal char in TG-DSC is in line with the ignition temperature of EFR. - Abstract: Through using a new thermal analysis model and a method of coal/char combustion, the minimum ignition temperature and minimum ignition heat of three different ranks of pulverized coal char were measured by simultaneous Thermogravimetry and Differential Scanning Calorimetry (TG-DSC) experiments. The results show that the ignition of coal char occurs in the range between the minimum ignition temperature and the inflection-point temperature. The thermal acceleration and its gradient G_T increase with increasing heating rate and decrease with increasing coal char rank. The higher the G_T of the coal char, the more easily the ignition occurs and more rapidly the burning and burnout occur. The data show that the G_T of coal char of SLH lignite is 1.6 times more than that of coal char of ZCY bituminous and JWY anthracite in ignition zone, and 3.4 times in burning zone. The characteristic temperatures increase with increasing temperature of prepared char, heating rate and char rank. Moreover, the T_i_g_,_m_a_x calculated in DSC experiment is approximately in line with the ignition temperature obtained in the entrained flow reactor, which demonstrates the feasibility of the proposed theory.

Characterization of bottom ashes from coal pulverized power plants to determine their potential use feasibility

International Nuclear Information System (INIS)

Menendez, E.; Alvaro, A. M.; Argiz, C.; Parra, J. L.; Moragues, A.

2013-01-01

The disposal of coal by products represents environmental and economical problems around the world. Therefore, the reuse and valorisation of this waste has become an important issue in the last decades. While high-value construction products containing fly ash were developed and its use is actually totally accepted as an addition to cement, the use of the bottom ash as supplementary cementitious material has not been allow. This paper examines the chemical and physical properties of fly ashes and bottom ashes from two different coal power plants in order to compare them and analyse the potential feasibility of bottom ash as cement replacement. The mechanical properties of cement mortars made with different percentages of both ashes were also study. The results obtained showed similar chemical composition of both kinds of ashes. The compressive strength values of mortars with 10 % and 25 % of cement replacement (at 28 days) were above the limits established in European standards and there were not significant differences between fly ash and bottom ash from both origins. (Author)

Technology of CCS coal utilization (outline of large-size demonstration test for CCS); CCS tan riyo gijutsu

Energy Technology Data Exchange (ETDEWEB)

Konno, K [Center for Coal Utilization, Japan, Tokyo (Japan); Hironaka, H [Idemitsu Kosan Co. Ltd., Tokyo (Japan)

1996-09-01

The coal cartridge system (CCS) is a series of the total system, in which coal is processed centrally at a supply base for each unit of consumer areas, supplied as pulverized coal in bulk units, and coal ash after combustion is recovered and treated. The system is expected of advantages resulted from the centralized production, elimination of handling troubles, and cleanliness. Following a small scale demonstration test, a large demonstration test for practically usable scale has begun in 1990, and completed in fiscal 1995. This paper introduces the CCS and reports the result of the test. In the large demonstration test, a supply station (with manufacturing capability of 200,000 tons a year) was installed in the Aichi refinery of Idemitsu Kosan Co., Ltd., and systematization on quality design and system technologies has been carried out. Long-term continuous operation for five years was achieved (operation time of the supply facilities was about 19,000 hours) without a failure and accident, to which every elemental technology was evaluated highly, and convenience and reliability of the system was verified. 13 figs., 3 tabs.

Process simulation of co-firing torrefied biomass in a 220 MWe coal-fired power plant

International Nuclear Information System (INIS)

Li, Jun; Zhang, Xiaolei; Pawlak-Kruczek, Halina; Yang, Weihong; Kruczek, Pawel; Blasiak, Wlodzimierz

2014-01-01

Highlights: • The performances of torrefaction based co-firing power plant are simulated by using Aspen Plus. • Mass loss properties and released gaseous components have been studied during biomass torrefaction processes. • Mole fractions of CO 2 and CO account for 69–91% and 4–27% in total torrefied gases. • The electrical efficiency reduced when increasing either torrefaction temperature or substitution ratio of biomass. - Abstract: Torrefaction based co-firing in a pulverized coal boiler has been proposed for large percentage of biomass co-firing. A 220 MWe pulverized coal-power plant is simulated using Aspen Plus for full understanding the impacts of an additional torrefaction unit on the efficiency of the whole power plant, the studied process includes biomass drying, biomass torrefaction, mill systems, biomass/coal devolatilization and combustion, heat exchanges and power generation. Palm kernel shells (PKS) were torrefied at same residence time but 4 different temperatures, to prepare 4 torrefied biomasses with different degrees of torrefaction. During biomass torrefaction processes, the mass loss properties and released gaseous components have been studied. In addition, process simulations at varying torrefaction degrees and biomass co-firing ratios have been carried out to understand the properties of CO 2 emission and electricity efficiency in the studied torrefaction based co-firing power plant. According to the experimental results, the mole fractions of CO 2 and CO account for 69–91% and 4–27% in torrefied gases. The predicted results also showed that the electrical efficiency reduced when increasing either torrefaction temperature or substitution ratio of biomass. A deep torrefaction may not be recommended, because the power saved from biomass grinding is less than the heat consumed by the extra torrefaction process, depending on the heat sources

pulver: an R package for parallel ultra-rapid p-value computation for linear regression interaction terms.

Science.gov (United States)

Molnos, Sophie; Baumbach, Clemens; Wahl, Simone; Müller-Nurasyid, Martina; Strauch, Konstantin; Wang-Sattler, Rui; Waldenberger, Melanie; Meitinger, Thomas; Adamski, Jerzy; Kastenmüller, Gabi; Suhre, Karsten; Peters, Annette; Grallert, Harald; Theis, Fabian J; Gieger, Christian

2017-09-29

Genome-wide association studies allow us to understand the genetics of complex diseases. Human metabolism provides information about the disease-causing mechanisms, so it is usual to investigate the associations between genetic variants and metabolite levels. However, only considering genetic variants and their effects on one trait ignores the possible interplay between different "omics" layers. Existing tools only consider single-nucleotide polymorphism (SNP)-SNP interactions, and no practical tool is available for large-scale investigations of the interactions between pairs of arbitrary quantitative variables. We developed an R package called pulver to compute p-values for the interaction term in a very large number of linear regression models. Comparisons based on simulated data showed that pulver is much faster than the existing tools. This is achieved by using the correlation coefficient to test the null-hypothesis, which avoids the costly computation of inversions. Additional tricks are a rearrangement of the order, when iterating through the different "omics" layers, and implementing this algorithm in the fast programming language C++. Furthermore, we applied our algorithm to data from the German KORA study to investigate a real-world problem involving the interplay among DNA methylation, genetic variants, and metabolite levels. The pulver package is a convenient and rapid tool for screening huge numbers of linear regression models for significant interaction terms in arbitrary pairs of quantitative variables. pulver is written in R and C++, and can be downloaded freely from CRAN at https://cran.r-project.org/web/packages/pulver/ .

Pilot plant development of a new catalytic process for improved electrostatic separation of fly ash in coal-fired power plants

Energy Technology Data Exchange (ETDEWEB)

Olivares del Valle, J.; Martinez, L.S.; Baum, B.M.; Galeano, V.C. [Universidad de Sevilla (Spain)

1995-12-31

The design and operation of pulverized-coal-fired power plants (PCFPP) are usually regarded as fuel range in terms of sulphur and ash contents. These units may give severe environmental problems of fly ash emissions as a result of lower SO{sub 3} contents in the flue gas (FG) because the electrical resistivity of the solid particles is correspondingly lower, with consequent adverse effects on electrostatic precipitator (ESP) efficiency. More stringent air pollution laws cause many power companies to burn lower sulphur coal under boilers in plants that formerly burned higher S coal or ran with abnormal operational conditions (only remediable by shutdown and repairs). This presentation of the GASOX process is a contribution to the improvement of existing technology for flue gas conditioning (FGC), which is defined as a control system for (ESP) efficiency in PCFPP.

Estimation for origin of coals on biomaker analysis; Jinko sekitan oyobi tennen sekitan no biomaker bunseki ni yoru sekitan kigen busshitsu no suitei

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Y. [Geological Survey of Japan, Tsukuba (Japan); Sugimoto, Y. [National Institute of Materials and Chemical Research, Tsukuba (Japan); Okada, K. [Coal Mining Research Center, Tokyo (Japan)

1996-10-28

In order to study coal production processes, an estimation study was carried out on coal originating materials by using biomaker analysis. Test samples are original coals collected directly from a mine in Hokkaido (not having been subjected cleaning). Mixing and solvent extraction were performed after pulverization, and then tests were given on saturated hydrocarbon components divided by using a silicagel column chromatograph for the present study. It can be known from n-alkane distribution in the coal that low molecular alkane increases with increasing degree of coalification. Artificial coal made by wet-heating Metasequoia leaves contains only little n-alkane. Diterpenoid compound exists in the Taiheiyo and Akabira coals. Tetra-cyclic diterpernoid is contained abundantly in subtropical coniferous trees, serving as a parameter for warm environment. The compound is contained also in the Fushun coal, but not in Indonesian coals. Hopanoid constitution shows very high similarity, but H/C atomic ratio may vary largely even if the coalification is at the same degree. This is likely to be caused from difference in originating materials. Hopanoids are bacteria attributed substances, whose activities are not affected by the originating materials. 2 figs., 1 tab.

Evaluation of radionuclide contamination of soil, coal ash and zeolitic materials from Figueira thermoelectric power plant

Energy Technology Data Exchange (ETDEWEB)

Fungaro, Denise Alves; Silva, Paulo Sergio Cardoso da; Campello, Felipe Arrelaro; Miranda, Caio da Silva; Izidoro, Juliana de Carvalho, E-mail: dfungaro@ipen.br, E-mail: pscsilva@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

Neutron activation analysis and gamma-ray spectrometry was used to determine {sup 238}U, {sup 226}Ra, {sup 228}Ra, {sup 210}Pb, {sup 232}Th and {sup 40}K contents in feed pulverized coal, bottom ash, fly ash from cyclone and baghouse filters, zeolites synthesized from the ashes and two different soil samples. All the samples used in the study was collected at Figueira thermoelectric power plant, located in the city of Figueira, Paraná State, which coal presents a significant amount of uranium concentration. The natural radionuclide concentrations in pulverized coal were 4216 Bq kg{sup -1} for {sup 238}U, 180 Bq kg{sup -1} for {sup 226}Ra, 27 Bq kg{sup -1} for {sup 228}Ra, 28 Bq kg{sup -1} for {sup 232}Th and 192 Bq kg{sup -1} for {sup 40}K. The ashes fraction presented concentrations ranging from 683.5 to 1479 Bq kg{sup -1} for {sup 238}U, from 484 to 1086 Bq kg{sup -1} for {sup 226}Ra, from 291 to 1891 Bq kg{sup -1} for {sup 210}Pb, from 67 to 111 Bq kg{sup -1} for {sup 228}Ra, from 80 to 87 Bq{sup -1} for {sup 232}Th and from 489 to 718 Bq kg{sup -1} for {sup 40}K. Similar ranges were observed for zeolites. The activity concentration of {sup 238}U was higher than worldwide average concentration for all samples. The concentration of the uranium series found in the ashes were lower than the values observed in similar studies carried out 10 years ago and under the limit adopted by the Brazilian guideline (CNEN-NN-4.01). Nevertheless, the concentrations of this specific area are higher than others coal mines and thermoelectric power plants in and out of Brazil, so it is advisable to evaluate the environmental impact of the installation. (author).

Scenario-Based Analysis on Water Resources Implication of Coal Power in Western China

Directory of Open Access Journals (Sweden)

Jiahai Yuan

2014-10-01

Full Text Available Currently, 58% of coal-fired power generation capacity is located in eastern China, where the demand for electricity is strong. Serious air pollution in China, in eastern regions in particular, has compelled the Chinese government to impose a ban on the new construction of pulverized coal power plants in eastern regions. Meanwhile, rapid economic growth is thirsty for electric power supply. As a response, China planned to build large-scale coal power bases in six western provinces, including Inner Mongolia, Shanxi, Shaanxi, Xinjiang, Ningxia and Gansu. In this paper, the water resource implication of the coal power base planning is addressed. We find that, in a business-as-usual (BAU scenario, water consumption for coal power generation in these six provinces will increase from 1130 million m3 in 2012 to 2085 million m3 in 2020, experiencing nearly a double growth. Such a surge will exert great pressure on water supply and lead to serious water crisis in these already water-starved regions. A strong implication is that the Chinese Government must add water resource constraint as a critical point in its overall sustainable development plan, in addition to energy supply and environment protection. An integrated energy-water resource plan with regionalized environmental carrying capacity as constraints should be developed to settle this puzzle. Several measures are proposed to cope with it, including downsizing coal power in western regions, raising the technical threshold of new coal power plants and implementing retrofitting to the inefficient cooling system, and reengineering the generation process to waterless or recycled means.

Cost and performance of coal-based energy in Brazil

International Nuclear Information System (INIS)

Temchin, J.; DeLallo, M.R.

1998-01-01

As part of the US Department of Energy's (DOE) efforts to establish the strategic benefits of Clean Coal Technologies (CCT), there is a need to evaluate the specific market potential where coal is a viable option. One such market is Brazil, where significant growth in economic development requires innovative and reliable technologies to support the use of domestic coal. While coal is Brazil's most abundant and economic fossil energy resource, it is presently under utilized in the production of electrical power. This report presents conceptual design for pulverized coal (PC) and circulating fluidized-bed combustion (CFBC) options with resulting capital, operating and financial parameters based on Brazil application conditions. Recent PC and CFBC plant capital costs have dropped with competition in the generation market and have established a competitive position in power generation. Key issues addressed in this study include: Application of market based design approach for FBC and PC, which is competitive within the current domestic, and international power generation markets. Design, fabrication, purchase, and construction methods which reduce capital investment while maintaining equipment quality and plant availability. Impact on coast and performance from application of Brazilian coals, foreign trade and tax policies, construction logistics, and labor requirements. Nominal production values of 200 MWe and 400 MWe were selected for the CFBC power plant and 400 MWe for the PC. The 400 MWe size was chosen to be consistent with the two largest Brazilian PC units. Fluidized bed technology, with limited experience in single units over 200 MW, would consist of two 200 MWe circulating fluidized bed boilers supplying steam to one steam turbine for the 400 MWe capacity. A 200 MWe capacity unit was also developed for CFBC option to support opportunities in re-powering and where specific site or other infrastructure constraints limit production

Combustion of pulverized coal in vortex structures. Final report, October 1, 1993--December 31, 1995

Energy Technology Data Exchange (ETDEWEB)

Gollahalli, S.R.; Butuk, N.

1996-03-01

The objectives of the project were: (i) to understand the effects of heating one of the streams on the characteristics of shear layers, (ii) to investigate the changes in the characteristics of large scale vortex structures in the shear layer caused by the introduction of inert solid particles in one of the feed streams; (iii) to understand the effects of pyrolyzing solids on the shear layer behavior; and (iv) to study the effects of combustion of particles and their pyrolysis products on the shear layer structure, heat release rate, and pollutant emission characteristics. An experimental facility for generating two-dimensional shear layers containing vortex structures has been designed and fabricated. The experimental facility is essentially a low speed wind tunnel designed to (i) provide two gas streams, initially with uniform velocity profiles and isotropic turbulence, mixing at the end of a splitter plate, (ii) introduce vorticity by passively perturbing one of the streams, (iii) allow heating of one of the streams to temperatures high enough to cause pyrolysis of coal particles, and (iv) provide a natural gas flame in one of the streams to result in ignition and burning of coal particles.

Studies on reactivity of coal surfaces at low temperature; Teion ni okeru sekitan hyomen no hannosei no kento

Energy Technology Data Exchange (ETDEWEB)

Yasuda, H.; Kaiho, M.; Yamada, O.; Soneda, Y.; Kobayashi, M.; Makino, M. [National Institute for Resources and Environment, Tsukuba (Japan)

1996-10-28

With an objective to learn reactivity of coal at its surface, surfaces of oxidized coal samples were investigated. Miike coal was oxidized by using {sup 18}O2 in a closed loop system. As the reaction progresses, proportion of CO2 including isotopes increased rapidly as a result of oxidation of CO sites existing in the coal and the newly generated C{sup 18}O sites. The oxidizing reaction progressed via oxygen adsorbing sites generated near the surface, and oxygen containing groups. An FT-IR analysis estimated the depth of the oxidized layer to be 10{mu}m or less from particle surface. The oxidized coal was pulverized to see its surface condition. Functional groups introduced by the oxidation enter into the vicinity of the surface in a form to desorb as CO. CO2 is trapped in inner pores. The coal surface was observed by using an atomic force microscope. No observable openings in the pore structure were discerned on the surface before the oxidation, and the structure agrees with a closed pore model. Surface image oxidized in-situ by oxygen for one hour had slight roundness, which led to a supposition of structural change, and changes in the functional group and adsorption species. 7 refs., 5 figs.

78 FR 7137 - National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial...

Science.gov (United States)

2013-01-31

...\\ oxygen) \\a\\ (ppm @3% of heat input) \\a\\ oxygen) \\b\\ Existing--Coal Stoker 0.040 (5.3E-05) 0.022 5.7E-06... Bed with FB 0.040 (5.3E-05) 0.022 5.7E-06 140 150 heat exchanger. Existing--Coal-Burning Pulverized... Fluidized Bed with FB Heat 0.0011 (2.3E-05) 0.022 8.0E-07 140 150 Exchanger. New--Coal-Burning Pulverized...

Levels and patterns of polycyclic aromatic hydrocarbons in fly ash generated in Coal-fired power plant

International Nuclear Information System (INIS)

Ajmal, P.Y.; Sahu, S.K.; Pandit, G.G.; Shukla, V.K.; Puranik, V.D.

2005-01-01

The burning of pulverized coal to produce energy for generation of electricity in thermal power plants results in huge quantity of coal ash of varying properties. Because of the increase in electricity production, the amount of ash produced will increase proportionally. A large percentage of coal fly ash is comprised of relatively inert materials, such as silica and other trace and toxic elements. The coal ash also contain organic constituents of potential environmental concern. So far, very few studies on characterization of organic constituents in fly ash have been reported in the literature. In the present study, the fly ashes generated from the power stations are investigated regarding the distribution of 14 PAHs. The total amount of PAHs in the fly ash samples varied between 45.8 ng/g and 257.7 ng/g. Lower molecular weight (MW) PAHs, were found to be predominant in the fly ash samples. The concentration of Benzo(a)pyrene, which is the most potent carcinogenic PAH was found to vary between 0.8 ng/g to 6.3 ng/g with a mean concentration of 2.5 ng/g. (author)

Duckweed Lemna minor as a tool for testing toxicity of coal residues and polluted sediments

Energy Technology Data Exchange (ETDEWEB)

Jenner, H.A.; Janssen-Mommen, J.P.M. (Kema Environmental Services, Arnhem (Netherlands))

1993-07-01

Duckweed, Lemna minor, was used for testing single elements and leachates of coal ashes and sediments by expressing growth as surface coverage. The EC50 for the elements Cd, Cu, Zn, As(III), As(V), Se(IV), Se(VI), SeO[sub 2] were 0.86, 2.2, 4.4, 8.4, 297, 21, 67, 37 [mu]M respectively. Leachates were tested of pulverized coal fuel ash (PFA), including 'low NO[sub x]' ashes, coal gasification slag (CGS), and, as a reference, the polluted sediments of a canal. The concentrations of elements in leachates of 'low NO[sub x]' PFA were higher than those in leachates of conventional PFA. The leaching of anions from PFA was quicker than the cations. CGS showed an absolutely minimal element leaching. Comparison of the effects of conventional PFA with sediments from Rotterdam harbor, River Rhine, and the canal shows PFA to be the far less toxic one. The sediment samples from the canal demonstrated strong growth inhibition, probably due to high zinc concentrations originating from industrial activity.

Duckweed Lemna minor as a tool for testing toxicity of coal residues and polluted sediments

Energy Technology Data Exchange (ETDEWEB)

Jenner, H A; Janssen-Mommen, J P.M. [Kema Environmental Services, Arnhem (Netherlands)

1993-07-01

Duckweed, Lemna minor, was used for testing single elements and leachates of coal ashes and sediments by expressing growth as surface coverage. The EC50 for the elements Cd, Cu, Zn, As(III), As(V), Se(IV), Se(VI), SeO[sub 2] were 0.86, 2.2, 4.4, 8.4, 297, 21, 67, 37 [mu]M respectively. Leachates were tested of pulverized coal fuel ash (PFA), including 'low NO[sub x]' ashes, coal gasification slag (CGS), and, as a reference, the polluted sediments of a canal. The concentrations of elements in leachates of 'low NO[sub x]' PFA were higher than those in leachates of conventional PFA. The leaching of anions from PFA was quicker than the cations. CGS showed an absolutely minimal element leaching. Comparison of the effects of conventional PFA with sediments from Rotterdam harbor, River Rhine, and the canal shows PFA to be the far less toxic one. The sediment samples from the canal demonstrated strong growth inhibition, probably due to high zinc concentrations originating from industrial activity.

Mercury emission and speciation of coal-fired power plants in China

Science.gov (United States)

Wang, S. X.; Zhang, L.; Li, G. H.; Wu, Y.; Hao, J. M.; Pirrone, N.; Sprovieri, F.; Ancora, M. P.

2010-02-01

Comprehensive field measurements are needed to understand the mercury emissions from Chinese power plants and to improve the accuracy of emission inventories. Characterization of mercury emissions and their behavior were measured in six typical coal-fired power plants in China. During the tests, the flue gas was sampled simultaneously at inlet and outlet of Selective Catalytic Reduction (SCR), electrostatic precipitators (ESP), and flue gas desulfurization (FGD) using the Ontario Hydro Method (OHM). The pulverized coal, bottom ash, fly ash and gypsum were also sampled in the field. Mercury concentrations in coal burned in the measured power plants ranged from 17 to 385 μg/kg. The mercury mass balances for the six power plants varied from 87 to 116% of the input coal mercury for the whole system. The total mercury concentrations in the flue gas from boilers were at the range of 1.92-27.15 μg/m3, which were significantly related to the mercury contents in burned coal. The mercury speciation in flue gas right after the boiler is influenced by the contents of halogen, mercury, and ash in the burned coal. The average mercury removal efficiencies of ESP, ESP plus wet FGD, and ESP plus dry FGD-FF systems were 24%, 73% and 66%, respectively, which were similar to the average removal efficiencies of pollution control device systems in other countries such as US, Japan and South Korea. The SCR system oxidized 16% elemental mercury and reduced about 32% of total mercury. Elemental mercury, accounting for 66-94% of total mercury, was the dominant species emitted to the atmosphere. The mercury emission factor was also calculated for each power plant.

Lab-scale investigation of Middle-Bosnia coals to achieve high-efficient and clean combustion technology

Directory of Open Access Journals (Sweden)

Smajevic Izet

2014-01-01

Full Text Available This paper describes full lab-scale investigation of Middle-Bosnia coals launched to support selection an appropriate combustion technology and to support optimization of the boiler design. Tested mix of Middle-Bosnia brown coals is projected coal for new co-generation power plant Kakanj Unit 8 (300-450 MWe, EP B&H electricity utility. The basic coal blend consisting of the coals Kakanj: Breza: Zenica at approximate mass ratio of 70:20:10 is low grade brown coal with very high percentage of ash - over 40%. Testing that coal in circulated fluidized bed combustion technique, performed at Ruhr-University Bohum and Doosan Lentjes GmbH, has shown its inconveniency for fluidized bed combustion technology, primarily due to the agglomeration problems. Tests of these coals in PFC (pulverized fuel combustion technology have been performed in referent laboratory at Faculty of Mechanical Engineering of Sarajevo University, on a lab-scale PFC furnace, to provide reliable data for further analysis. The PFC tests results are fitted well with previously obtained results of the burning similar Bosnian coal blends in the PFC dry bottom furnace technique. Combination of the coals shares, the process temperature and the air combustion distribution for the lowest NOx and SO2 emissions was found in this work, provided that combustion efficiency and CO emissions are within very strict criteria, considering specific settlement of lab-scale furnace. Sustainability assessment based on calculation economic and environmental indicators, in combination with Low Cost Planning method, is used for optimization the power plant design. The results of the full lab-scale investigation will help in selection optimal Boiler design, to achieve sustainable energy system with high-efficient and clean combustion technology applied for given coals.

The influence of selected parameters on the efficiency and economic charactersistics of the oxy-type coal unit with a membrane-cryogenic oxygen separator

Directory of Open Access Journals (Sweden)

Kotowicz Janusz

2016-03-01

Full Text Available In this paper a 600 MW oxy-type coal unit with a pulverized bed boiler and a membrane-cryogenic oxygen separator and carbon capture installation was analyzed. A membrane-cryogenic oxygen separation installation consists of a membrane module and two cryogenic distillation columns. In this system oxygen is produced with the purity equal to 95%. Installation of carbon capture was based on the physical separation method and allows to reduce the CO2 emission by 90%. In this work the influence of the main parameter of the membrane process – the selectivity coefficient, on the efficiency of the coal unit was presented. The economic analysis with the use of the break-even point method was carried out. The economic calculations were realized in view of the break-even price of electricity depending on a coal unit availability.

Chemical and Physical Characteristics of Pulverized Granitic Rock Adjacent to the San Andreas, Garlock and San Jacinto Faults: Implications for Earthquake Physics

Science.gov (United States)

Rockwell, T. K.; Sisk, M.; Stillings, M.; Girty, G.; Dor, O.; Wechsler, N.; Ben-Zion, Y.

2008-12-01

We present new detailed analyses of pulverized granitic rocks from sections adjacent to the San Andreas, Garlock and San Jacinto faults in southern California. Along the San Andreas and Garlock faults, the Tejon Lookout Granite is pulverized in all exposures within about 100 m of both faults. Along the Clark strand of the San Jacinto fault in Horse Canyon, the pulverization of granitic rocks is highly asymmetric, with a much broader zone of pulverization along the southwest side of the Clark fault. In areas where the granite is injected as dyke rock into schist, only the granitic rock shows pulverization, demonstrating the control of rock type on the pulverization process. Chemical analyses indicate little or no weathering in the bulk of the rock, although XRD analysis shows the presence of smectite, illite, and minor kaolinite in the clay-sized fraction. Weathering products may dominate in the less than 1 micron fraction. The average grain size in all samples of pulverized granitic rock range between about 20 and 200 microns (silt to fine sand), with the size distribution in part a function of proximity to the primary slip zone. The San Andreas fault samples are generally finer than those collected from along the Garlock or San Jacinto faults. The particle size distribution for all samples is non-fractal, with a distinct slope break in the 60-100 micron range, which suggests that pulverization is not a consequence of direct shear. This average particle size is quite coarser than previous reports, which we attribute to possible measurement errors in the prior work. Our data and observations suggest that dynamic fracturing in the wall rock of these three major faults only accounts for 1% or less of the earthquake energy budget.

Modeling of integrated environmental control systems for coal-fired power plants

Energy Technology Data Exchange (ETDEWEB)

Rubin, E.S.; Salmento, J.S.; Frey, H.C.; Abu-Baker, A.; Berkenpas, M.

1991-05-01

The Integrated Environmental Control Model (IECM) was designed to permit the systematic evaluation of environmental control options for pulverized coal-fired (PC) power plants. Of special interest was the ability to compare the performance and cost of advanced pollution control systems to conventional'' technologies for the control of particulate, SO{sub 2} and NO{sub x}. Of importance also was the ability to consider pre-combustion, combustion and post-combustion control methods employed alone or in combination to meet tough air pollution emission standards. Finally, the ability to conduct probabilistic analyses is a unique capability of the IECM. Key results are characterized as distribution functions rather than as single deterministic values. (VC)

POC-SCALE TESTING OF A DRY TRIBOELECTROSTATIC SEPARATOR FOR FINE COAL CLEANING

Energy Technology Data Exchange (ETDEWEB)

R.H. Yoon; G.H. Luttrell; E.S. Yan; A.D. Walters

2001-04-30

Numerous advanced coal cleaning processes have been developed in recent years that are capable of substantially reducing both ash- and sulfur-forming minerals from coal. However, most of the processes involve fine grinding and use water as the cleaning medium; therefore, the clean coal products must be dewatered before they can be transported and burned. Unfortunately, dewatering fine coal is costly, which makes it difficult to deploy advanced coal cleaning processes for commercial applications. As a means of avoiding problems associated with the fine coal dewatering, the National Energy Technology Laboratory (NETL) developed a dry coal cleaning process in which mineral matter is separated from coal without using water. In this process, pulverized coal is subjected to triboelectrification before being placed in an electric field for electrostatic separation. The triboelectrification is accomplished by passing a pulverized coal through an in-line mixer made of copper. Copper has a work function that lies between that of carbonaceous material (coal) and mineral matter. Thus, coal particles impinging on the copper wall lose electrons to the metal thereby acquiring positive charges, while mineral matter impinging on the wall gain electrons to acquire negative charges. The charged particles then pass through an electric field where they are separated according to their charges into two or more products depending on the configuration of the separator. The results obtained at NETL showed that it is capable of removing more than 90% of the pyritic sulfur and 70% of the ash-forming minerals from a number of eastern U.S. coals. However, the BTU recoveries were less than desirable. The laboratory-scale batch triboelectrostatic separator (TES) used by NETL relied on adhering charged particles on parallel electrode surfaces and scraping them off. Therefore, its throughput will be proportional to the electrode surface area. If this laboratory device is scaled-up as is, it would

Online Monitoring System of Air Distribution in Pulverized Coal-Fired Boiler Based on Numerical Modeling

Directory of Open Access Journals (Sweden)

Żymełka Piotr

2017-12-01

Full Text Available Balanced distribution of air in coal-fired boiler is one of the most important factors in the combustion process and is strongly connected to the overall system efficiency. Reliable and continuous information about combustion airflow and fuel rate is essential for achieving optimal stoichiometric ratio as well as efficient and safe operation of a boiler. Imbalances in air distribution result in reduced boiler efficiency, increased gas pollutant emission and operating problems, such as corrosion, slagging or fouling. Monitoring of air flow trends in boiler is an effective method for further analysis and can help to appoint important dependences and start optimization actions. Accurate real-time monitoring of the air distribution in boiler can bring economical, environmental and operational benefits. The paper presents a novel concept for online monitoring system of air distribution in coal-fired boiler based on real-time numerical calculations. The proposed mathematical model allows for identification of mass flow rates of secondary air to individual burners and to overfire air (OFA nozzles. Numerical models of air and flue gas system were developed using software for power plant simulation. The correctness of the developed model was verified and validated with the reference measurement values. The presented numerical model for real-time monitoring of air distribution is capable of giving continuous determination of the complete air flows based on available digital communication system (DCS data.

Online Monitoring System of Air Distribution in Pulverized Coal-Fired Boiler Based on Numerical Modeling

Science.gov (United States)

Żymełka, Piotr; Nabagło, Daniel; Janda, Tomasz; Madejski, Paweł

2017-12-01

Balanced distribution of air in coal-fired boiler is one of the most important factors in the combustion process and is strongly connected to the overall system efficiency. Reliable and continuous information about combustion airflow and fuel rate is essential for achieving optimal stoichiometric ratio as well as efficient and safe operation of a boiler. Imbalances in air distribution result in reduced boiler efficiency, increased gas pollutant emission and operating problems, such as corrosion, slagging or fouling. Monitoring of air flow trends in boiler is an effective method for further analysis and can help to appoint important dependences and start optimization actions. Accurate real-time monitoring of the air distribution in boiler can bring economical, environmental and operational benefits. The paper presents a novel concept for online monitoring system of air distribution in coal-fired boiler based on real-time numerical calculations. The proposed mathematical model allows for identification of mass flow rates of secondary air to individual burners and to overfire air (OFA) nozzles. Numerical models of air and flue gas system were developed using software for power plant simulation. The correctness of the developed model was verified and validated with the reference measurement values. The presented numerical model for real-time monitoring of air distribution is capable of giving continuous determination of the complete air flows based on available digital communication system (DCS) data.

Mitsubishi latest coal fired USC boiler technology (CFE Pacifico 700 MW)

Energy Technology Data Exchange (ETDEWEB)

Hashimoto, T.; Sakamoto, K. [Mitsubishi Heavy Industries, Ltd., Nagasaki (Japan). Power Systems; Fujitab, M. [Mitsubishi Heavy Industries, Ltd., Yokohama (Japan). Power Systems

2013-07-01

Mitsubishi Heavy Industries, Ltd. (MHI) has successfully completed commissioning work for CFE (Comision Federal de Electricidad) Pacifico 700 MW coal-fired unit in March 2010 which is the first supercritical unit in Latin America. This supercritical boiler was designed with state of the art technologies such as low NOx burners, high fineness pulverizers, advanced vertical furnace wall technology and so on. Especially the advanced vertical furnace wall technology with some improvements is a key technology to realize swift load changes such as 5% load per minute ramping rate with assuring dynamic characteristics. Recently the requirement of the high efficiency and the swift load changes for the power boilers has been increased so that even a coal-fired unit needs flexible operation characteristics for balancing variety of power sources. One of the challenges for the swift load change is to keep the furnace wall metal temperature low during the load change, which the advanced vertical furnace wall could realize. The report describes the features of the unit and commissioning result including load swing test results in details.

Mercury emission and speciation of coal-fired power plants in China

Directory of Open Access Journals (Sweden)

S. X. Wang

2010-02-01

Full Text Available Comprehensive field measurements are needed to understand the mercury emissions from Chinese power plants and to improve the accuracy of emission inventories. Characterization of mercury emissions and their behavior were measured in six typical coal-fired power plants in China. During the tests, the flue gas was sampled simultaneously at inlet and outlet of Selective Catalytic Reduction (SCR, electrostatic precipitators (ESP, and flue gas desulfurization (FGD using the Ontario Hydro Method (OHM. The pulverized coal, bottom ash, fly ash and gypsum were also sampled in the field. Mercury concentrations in coal burned in the measured power plants ranged from 17 to 385 μg/kg. The mercury mass balances for the six power plants varied from 87 to 116% of the input coal mercury for the whole system. The total mercury concentrations in the flue gas from boilers were at the range of 1.92–27.15 μg/m³, which were significantly related to the mercury contents in burned coal. The mercury speciation in flue gas right after the boiler is influenced by the contents of halogen, mercury, and ash in the burned coal. The average mercury removal efficiencies of ESP, ESP plus wet FGD, and ESP plus dry FGD-FF systems were 24%, 73% and 66%, respectively, which were similar to the average removal efficiencies of pollution control device systems in other countries such as US, Japan and South Korea. The SCR system oxidized 16% elemental mercury and reduced about 32% of total mercury. Elemental mercury, accounting for 66–94% of total mercury, was the dominant species emitted to the atmosphere. The mercury emission factor was also calculated for each power plant.

A LOW COST AND HIGH QUALITY SOLID FUEL FROM BIOMASS AND COAL FINES

Energy Technology Data Exchange (ETDEWEB)

John T. Kelly; George Miller; Mehdi Namazian

2001-07-01

Use of biomass wastes as fuels in existing boilers would reduce greenhouse gas emissions, SO2 and NOx emissions, while beneficially utilizing wastes. However, the use of biomass has been limited by its low energy content and density, high moisture content, inconsistent configuration and decay characteristics. If biomass is upgraded by conventional methods, the cost of the fuel becomes prohibitive. Altex has identified a process, called the Altex Fuel Pellet (AFP) process, that utilizes a mixture of biomass wastes, including municipal biosolids, and some coal fines, to produce a strong, high energy content, good burning and weather resistant fuel pellet, that is lower in cost than coal. This cost benefit is primarily derived from fees that are collected for accepting municipal biosolids. Besides low cost, the process is also flexible and can incorporate several biomass materials of interest The work reported on herein showed the technical and economic feasibility of the AFP process. Low-cost sawdust wood waste and light fractions of municipal wastes were selected as key biomass wastes to be combined with biosolids and coal fines to produce AFP pellets. The process combines steps of dewatering, pellet extrusion, drying and weatherizing. Prior to pilot-scale tests, bench-scale test equipment was used to produce limited quantities of pellets for characterization. These tests showed which pellet formulations had a high potential. Pilot-scale tests then showed that extremely robust pellets could be produced that have high energy content, good density and adequate weatherability. It was concluded that these pellets could be handled, stored and transported using equipment similar to that used for coal. Tests showed that AFP pellets have a high combustion rate when burned in a stoker type systems. While NOx emissions under stoker type firing conditions was high, a simple air staging approach reduced emissions to below that for coal. In pulverized-fuel-fired tests it was

Numerical simulation of coal gasification process using the modifying Watanabe - Otaka model.

Energy Technology Data Exchange (ETDEWEB)

T. Papadopoulos; M. Losurdo; H. Spliethoff

2009-07-01

High-pressure entrained flow coal gasification is becoming increasingly important particularly in the development of Integrated Coal Gasification Combined Cycle (IGCC) technology for the production of electricity. However, there is a lack of knowledge worldwide for the gasification process and more especially for the chemical reactions (reactions rates) that take place under high pressure and temperature. Therefore a gasifier has been designed and is being built at the Institute for Energy Systems (Lehrstuhl fuer Energisysteme - LES) at the Technische Universitaet Muenchen (TUM). This gasifier is an entrained flow gasifier and has the advantage that it can operate to very high conditions of pressure and temperature, up to 50 bar pressure and 1800{sup o}C temperature. In an ongoing project, a great variety of experiments are planned to determine chemical reactions rates at high pressure conditions. In addition to the experimental work, CFD numerical simulations of pulverized coal gasification are being performed. The aim is to use numerical investigations for preliminary assessment of the facility. The goal is to develop a gasification model suitable for high pressure and condition tailored on the experiments to be used in CFD computations to predict chemical reactions, the heat transfer and the turbulence inside the gasifier. 9 refs., 2 figs., 2 tabs.

Ash liberation from included minerals during combustion of pulverized coal: the relationship with char structure and burnout

Energy Technology Data Exchange (ETDEWEB)

Wu, H.; Wall, T.; Liu, G.; Bryant, G. [University of Newcastle, Callaghan, NSW (Australia). CRC for Black Coal Utilization and Dept. of Chemical Engineering

1999-12-01

In this study, the float fraction ({lt} specific gravity of 2.0) of a size cut (63-90 {mu}m) bituminous coal was combusted in a drop tube furnace (DTF) at a gas temperature of 1300{degree}C under an atmosphere of air, to investigate the ash liberation at five coal burnoff levels (35.5%, 54.3%, 70.1%, 87.1% and 95.6%). The data indicated that char structure determines the ash liberation at different burnoff levels. Fragmentation of porous char was found to be the determinative mechanism for formation of fine ash during the early and middle stages of char combustion, while coalescence of included mineral matter determines the coarse ash formed in the later stages of combustion. The investigation confirmed that the char morphology and structure play a key role in determining char fragmentation, char burnout history, and the ash liberation during combustion. 35 refs., 5 figs., 2 tabs.

Report for fiscal 1994 by gasification technology subcommittee, Coal Gasification Committee; 1994 nendo sekitan gas ka iinkai gas ka gijutsu bukai hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

As the result of a RUN-9 operation in the research on technologies for hydrogen production from coal and for pilot plants, it is found that the Muswellbrook, Datong, and Blair Athol coals are all suitable for gasification in pilot plants. Their handlability is considerably improved when the grain sizes after crushing are allowed to remain coarse (with the Blair Athol coal still retaining some disadvantage). A concept design is prepared for a HYCOL (hydrogen from coal) process demonstration plant. The reference coal is an imported coal similar to the Taiheiyo coal, and the hydrogen production target is set at 1-million m{sup 3}N/d (590t/d in terms of Taiheiyo coal) and hydrogen purity at 95% or higher. The whole process consists of coal gasification (with oxygen serving as gasification agent), dedusting, conversion to CO, desulfurization and decarboxylation (recovery of sulfur), and methanation. The gasification furnace is a 1-chamber entrained bed type with a 2-stage gyration flow. Dried and pulverized coal is conveyed aboard an air flow into the gasification furnace, where it is thrown into partial combustion reaction with the gasification agent for gasification in a high-temperature zone (1,500-1,600 degrees C), and the ash is taken out as slag. The generated gas is cooled in a heat recovery boiler, dedusted in a cyclone dust filter, and then forwarded to the washing unit. (NEDO)

A Machine for Pulverizing and Sifting Gari Mash | Odigboh | Nigerian ...

African Journals Online (AJOL)

A prototype machine for pulverizing and sifting gari mash, designed as a companion to the gari frying machine developed by the authors, was built and tested. Driven by an electric motor, the prototype accepts lump3 of dewatered gari mash cuts them up into small pieces by a cake breaker and delivers the pieces by a belt ...

A study on the compressive and tensile strength of foamed concrete containing pulverized bone as a partial replacement of cement

International Nuclear Information System (INIS)

Falade, F.

2013-01-01

In this study, structural properties of foamed aerated concrete with and without pulverized bone were investigated. These properties are workability, plastic and testing densities, compressive strength, and tensile strength at the design density of 1600kg/m/sub 3/. The tensile strength was evaluated by subjecting 150 x 150 x750mm unreinforced foamed concrete beams to flexural test and 150x300mm cylinder specimens were subjected to splitting test. 150mm cube specimens were used for the determination of both the compressive strength and the testing density of the foamed aerated concrete. The plastic density was investigated using a container of known volume, and its workability determined using the slump test. The pulverized bone content was varied from 0 to 20% at interval of 5%. The specimens without the pulverized bone served as the control. At the designed density of 1600 kg/m/sub 3/, the results for the control specimens at 28-day curing age are 15.43 and 13.89N/mm/sub 2/ for air-and water-cured specimens respectively. The modulus of rupture and splitting tensile strength are 2.53 and 1.63N/mm/sub 2/ respectively. The results for specimens with pulverized bone did not differ significantly from the specimens without pulverized bone. From the results of this investigation, it can be concluded that foamed aerated concrete used for this study has potential for structural applications. Also pulverized bone can be used to reduce (partially replace) the quantity of cement used in aerated concrete production; thus ridding our environment of potentially harmful wastes, as well as reduce the consumption of non-renewable resources. (author)

Properties and Developments of Combustion and Gasification of Coal and Char in a CO2-Rich and Recycled Flue Gases Atmosphere by Rapid Heating

Directory of Open Access Journals (Sweden)

Zhigang Li

2012-01-01

Full Text Available Combustion and gasification properties of pulverized coal and char have been investigated experimentally under the conditions of high temperature gradient of order 200°C·s−1 by a CO2 gas laser beam and CO2-rich atmospheres with 5% and 10% O2. The laser heating makes a more ideal experimental condition compared with previous studies with a TG-DTA, because it is able to minimize effects of coal oxidation and combustion by rapid heating process like radiative heat transfer condition. The experimental results indicated that coal weight reduction ratio to gases followed the Arrhenius equation with increasing coal temperature; further which were increased around 5% with adding H2O in CO2-rich atmosphere. In addition, coal-water mixtures with different water/coal mass ratio were used in order to investigate roles of water vapor in the process of coal gasification and combustion. Furthermore, char-water mixtures with different water/char mass ratio were also measured in order to discuss the generation ratio of CO/CO2, and specified that the source of Hydrocarbons is volatile matter from coal. Moreover, it was confirmed that generations of CO and Hydrocarbons gases are mainly dependent on coal temperature and O2 concentration, and they are stimulated at temperature over 1000°C in the CO2-rich atmosphere.

Assessing the Exergy Costs of a 332-MW Pulverized Coal-Fired Boiler

Directory of Open Access Journals (Sweden)

Victor H. Rangel-Hernandez

2016-08-01

Full Text Available In this paper, we analyze the exergy costs of a real large industrial boiler with the aim of improving efficiency. Specifically, the 350-MW front-fired, natural circulation, single reheat and balanced draft coal-fired boiler forms part of a 1050-MW conventional power plant located in Spain. We start with a diagram of the power plant, followed by a formulation of the exergy cost allocation problem to determine the exergy cost of the product of the boiler as a whole and the expenses of the individual components and energy streams. We also define a productive structure of the system. Furthermore, a proposal for including the exergy of radiation is provided in this study. Our results show that the unit exergy cost of the product of the boiler goes from 2.352 to 2.5, and that the maximum values are located in the ancillary electrical devices, such as induced-draft fans and coil heaters. Finally, radiation does not have an effect on the electricity cost, but affects at least 30% of the unit exergy cost of the boiler’s product.

Towards a better understanding of biomass suspension co-firing impacts via investigating a coal flame and a biomass flame in a swirl-stabilized burner flow reactor under same conditions

DEFF Research Database (Denmark)

Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

2012-01-01

increases the residence time of coal particles. Both the factors favor a complete burnout of the coal particles. The higher volatile yields of the straw produce more off-gas, requiring more O2 for the fast gas phase combustion and causing the off-gas to proceed to a much larger volume in the reactor prior...... to mixing with oxidizer. For the pulverized straw particles of a few hundred microns in diameters, the intra-particle conversion is found to be a secondary issue at most in their combustion. The simulations also show that a simple switch of the straw injection mode can not improve the burnout of the straw...

Numerical simulation of the gasification based biomass cofiring on a 600 MW pulverized coal boiler

Energy Technology Data Exchange (ETDEWEB)

Yang, R.; Dong, C.Q.; Yang, Y.P.; Zhang, J.J. [Key Laboratory of Condition Monitoring and Control for Power Plant Equipment, Ministry of Education, Beijing (China); North China Electric Power Univ., Beijing (China). Key Laboratory of Security and Clean Energy Technology

2008-07-01

Biomass cofiring is the practice of supplementing a base fuel with biomass fuels such as wood waste, short rotation woody crops, short rotation herbaceous crops, alfalfa stems, various types of manure, landfill gas and wastewater treatment gas. The practice began in the 1980s and is becoming commonplace in Europe and the United States. The benefits include reduced carbon dioxide emissions and other airborne emissions such as nitrous oxides (NOx), sulphur dioxide and trace metals; potential for reduced fuel cost; and supporting economic development among wood products and agricultural industries in a given service area. However, technical challenges remain when biomass is directly cofired with coal. These include limited percentage of biomass for cofiring; fuel preparation, storage, and delivery; ash deposition and corrosion associated with the high alkali metal and chlorine content in biomass; fly ash utilization; and impacts on the selective catalytic reduction (SCR) system. This study involved a numerical simulation of cofiring coal and biomass gas in a 600 MWe tangential PC boiler using Fluent software. Combustion behaviour and pollutant formation in the conventional combustion and cofiring cases were compared. The study revealed that reduced NOx emissions can be achieved when producer gas is injected from the lowest layer burner. The nitrogen monoxide (NO) removal rate was between 56.64 and 70.37 per cent. In addition, slagging can be reduced because of the lower temperature. It was concluded that the convection heat transfer area should be increased or the proportion of biomass gas should be decreased to achieve higher boiler efficiency. 8 refs., 4 tabs., 8 figs.

NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

Energy Technology Data Exchange (ETDEWEB)

Jost O.L. Wendt

2002-08-15

This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NOx concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NOx and low NOx combustion conditions will be investigated (unstaged and staged combustion). Tradeoffs between CO2 control, NOx control, and inorganic fine particle and toxic metal emissions will be determined. Previous research has yielded data on trace metal partitioning for MSS by itself, with natural gas assist, for coal plus MSS combustion together, and for coal alone. We have re-evaluated the inhalation health effects of ash aerosol from combustion of MSS both by itself and also together with coal. We have concluded that ash from the co-combustion of MSS and coal is very much worse from an inhalation health point of view, than ash from either MSS by itself or coal by itself. The reason is that ZnO is not the ''bad actor'' as had been suspected before, but the culprit is, rather, sulfated Zn. The MSS supplies the Zn and the coal supplies the sulfur, and so it is the combination of coal and MSS that makes that process environmentally bad. If MSS is to be burned, it should be burned without coal, in the absence of sulfur.

Modeling of integrated environmental control systems for coal-fired power plants. Final report

Energy Technology Data Exchange (ETDEWEB)

Rubin, E.S.; Salmento, J.S.; Frey, H.C.; Abu-Baker, A.; Berkenpas, M.

1991-05-01

The Integrated Environmental Control Model (IECM) was designed to permit the systematic evaluation of environmental control options for pulverized coal-fired (PC) power plants. Of special interest was the ability to compare the performance and cost of advanced pollution control systems to ``conventional`` technologies for the control of particulate, SO{sub 2} and NO{sub x}. Of importance also was the ability to consider pre-combustion, combustion and post-combustion control methods employed alone or in combination to meet tough air pollution emission standards. Finally, the ability to conduct probabilistic analyses is a unique capability of the IECM. Key results are characterized as distribution functions rather than as single deterministic values. (VC)

Properties of palm oil fuel ash cement sand brick containing pulverized cockle shell as partial sand replacement

Science.gov (United States)

Mat Aris, S.; Muthusamy, K.; Uzer, A.; Ahmad, S. Wan

2018-04-01

Environmental pollution caused by the disposal of solid wastes generated from both palm oil industry and cockle shell trade has motivated researches to explore the potential of these wastes. Integrating these wastes in production of construction material is one of the ways to reduce amount of waste thrown at dumping area. Thus, the present investigation investigates the performance of palm oil fuel ash (POFA) cement sand brick containing pulverized cockle shell as partial fine aggregate replacement. All mixes used contain 20% of POFA as partial cement replacement. Total of six mixes were prepared by adding a range of pulverized cockle shell that is 0%, 10%, 20%, 30%, 40% and 50% as partial sand replacement. The mixes were prepared in form of brick. All the water cured samples were tested for compressive strength and flexural strength until 28 days. Findings show that brick produced using 20% pulverized cockle shell exhibit the highest compressive strength and flexural strength also the lowest water absorption value.

Achievement report on developing coal liquefaction technologies in fiscal 1998 - edition B. Development of bituminous coal liquefaction technology (studies by using pilot plant) 2/2; 1998 nendo sekitan ekika gijutsu kaihatsu seika hokokusho B. 2/2. Rekiseitan ekika gijutsu no kaihatsu (pilot plant ni yoru kenkyu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

With an objective to improve the environment by substituting petroleum energy by coal, and by reducing emission of SOx and NOx, research and development has been performed on coal liquefaction technologies. This paper summarizes the achievements thereof in fiscal 1998. In the operation study, the coal charging operation has been carried out for 269 days (6,169 hours) in total since the operation has been launched, and the targets were achieved. In the facility repairs, periodical inspections were performed including daily maintenance during the operation, the legal inspection on the boiler and the pressure vessel of the category one after completing the RUN-5, and disassembling and opening inspections on other devices. After having completed the RUN-6 and 7, the final verification inspection and the facility rinsing were performed after the operation studies have been completed. The data acquired in the facility maintenance were summarized as part of the technological package after the assessment. The investigative researches have executed development of a liquefying reaction simulator, tests and investigations on pulverization of the liquefying catalyst, evaluation on the activity of the used hydrogenating catalyst, and investigation on the effect of the coal liquefaction facilities and products on the environment. The technologies were investigated on coal liquefaction, and the plans for disassembling studies were established. (NEDO)

Steam generators and fuel engineering utilizing solid, liquid, gaseous and special fuels

Energy Technology Data Exchange (ETDEWEB)

Thor, G

1983-01-01

Provided were technological specifications and details in the design of brown coal fired steam generators, produced in the German Democratic Republic. These steam generators range in their capacity between 1.6 and more than 1,000 t/h. The appropriate coal feeding systems, water supply and cleaning equipment, coal pulverizers and ash removal units are also manufactured. Various schemes show the design of a 25 to 64 t/h, a 320 t/h and an 815 t/h brown coal steam generator. Specifications are given for series of fuel pulverizers available, for the water circulation system and steam evaporators. The VEB Dampferzeugerbau Berlin also offers steam generators for saliniferous brown coal with a steam capacity up to 125 t/h, steam generators for pulverized black coal with a capacity up to 350 t/h and oil and gas fired generators up to 250 t/h. The company has experience in combustion of biomass (sugar cane waste) with oil in steam generators of more than 100 t/h capacity, and in projecting firing systems for other biofuels including rice, peanut and coconut hulls, wood and bark. Multi-biofuel firing in combination with coal for steam generation is also regarded as possible. (In English)

Release and sorption of alkali metals in coal fired combined cycle power systems; Freisetzung und Einbindung von Alkalimetallverbindungen in kohlebefeuerten Kombikraftwerken

Energy Technology Data Exchange (ETDEWEB)

Mueller, Michael

2009-07-01

Coal fired combined cycle power systems will be a sufficient way to increase the efficiency of coal combustion. However, combined cycle power systems require a reliable hot gas cleanup. Especially alkali metals, such as sodium and potassium, can lead to hot corrosion of the gas turbine blading if they condensate as sulphates. The actual work deals with the release and sorption of alkali metals in coal fired combined cycle power systems. The influence of coal composition, temperature and pressure on the release of alkali species in coal combustion was investigated and the relevant release mechanisms identified. Alumosilicate sorbents have been found that reduce the alkali concentration in the hot flue gas of the Circulating Pressurized Fluidized Bed Combustion 2{sup nd} Generation (CPFBC 2{sup nd} Gen.) at 750 C to values sufficient for use in a gas turbine. Accordingly, alumosilicate sorbents working at 1400 C have been found for the Pressurized Pulverized Coal Combustion (PPCC). The sorption mechanisms have been identified. Thermodynamic calculations were performed to upscale the results of the laboratory experiments to conditions prevailing in power systems. According to these calculations, there is no risk of hot corrosion in both processes. Furthermore, thermodynamic calculations were performed to investigate the behaviour of alkali metals in an IGCC with integrated hot gas cleanup and H{sub 2} membrane for CO{sub 2} sequestration. (orig.)

An investigation into fuel pulverization with specific reference to high burn-up LOCA

International Nuclear Information System (INIS)

Yagnik, Suresh; Turnbull, James; Noirot, Jean; Walker, Clive; Hallstadius, Lars; Waeckel, N.; Blanpain, P.

2014-01-01

To investigate the phenomenon of high burn-up fuel pellet material potentially disintegrating into powder under a rapid temperature transient, such as in a LOCA-type accident scenario, two independent scoping studies were commissioned. The first was to investigate the effect of hydrostatic restraint pressure on Fission Gas Release (FGR) from small samples of highly irradiated fuel (71 MWd/kgU) during a series of rapid temperature ramps. Experimentally, when the FGR increased rapidly during the temperature transients, the fuel was assumed to be 'pulverized', i.e., fragmented into powder. In the second series of experiments, laser heating of small samples was used to investigate the temperature at which fuel pulverization was initiated. Subsequent to fuel disintegration, there was always a spectrum of particle sizes present. The significance of this observation was recognized in the context of extended burn-up operation in commercial reactors. Based on the observation from these investigations, a fuel fragmentation threshold has been discussed and developed. We conclude that fuel disintegration could be of potential importance in limiting the performance and productive lifetime of nuclear fuel. However, since only fuel closely adjacent to ballooned or ruptured cladding would be released in a LOCA-type transient, expulsion of pulverized fuel from the ruptured fuel rod is not considered a safety issue; cooling of the defected assembly remains possible and there is no issue with respect to local criticality. (author)

Numerical study of aerodynamics and brown coal combustion in the vortex furnace with air excess variation

Directory of Open Access Journals (Sweden)

Krasinsky Denis

2017-01-01

Full Text Available The results of numerical modelling of 3D turbulent two-phase reacting flow with account for all the principal heat and mass transfer processes during the pulverized brown coal combustion in the vortex furnace of a power plant boiler unit have been presented. For two computational cases where air excess coefficient α was varied (set to 1.15 and 1.25, the detailed aerothermochemical 3D structure of reacting flow in the furnace volume has been revealed. The comparison of integral heat engineering parameters and NOx emissions obtained in the two cases has shown a slightly improved vortex furnace performance in the case α=1.25.

Development of a coal-fired combustion system for industrial process heating applications. Phase 3 final report, November 1992--December 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

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.

Cofiring of biofuels in coal fired boilers: Results of case study analysis

Energy Technology Data Exchange (ETDEWEB)

Tillman, D.A. [Ebasco Environmental, Sacramento, CA (United States); Hughes, E. [Electric Power Research Institute, Palo Alto, CA (United States); Gold, B.A. [TVA, Chattanooga, TN (United States)

1993-12-31

Ebasco Environmental and Reaction Engineering, under contract to EPRI, performed a case study analysis of cofiring biomass in coal-fired boilers of the Tennessee Valley Authority (TVA). The study was also sponsored by DOE. This analysis included evaluating wood fuel receiving, preparation, and combustion in pulverized coal (PC) boilers and cyclone furnaces and an assessment of converting wood into pyrolysis oil or low Btu gas for use in a new combined cycle combustion turbine (CCCT) installation. Cofiring wood in existing coal-fired boilers has the most immediate potential for increasing the utilization of biofuels in electricity generation. Cofiring biofuels with coal can potentially generate significant benefits for utilities including: (1) reducing emissions of SO{sub 2} and NO{sub x}; (2) reducing the net emissions of CO{sub 2}; (3) potentially reducing the fuel cost to the utility depending upon local conditions and considering biomass is potentially exempt from the proposed Btu tax and may get a 1.5 cent/kWh credit for energy generated by wood combustion; (4) supporting local industrial forest industry; and (5) providing a long term market for the development of a biofuel supply and delivery industry. Potential benefits are reviewed in the context of cofiring biofuel at a rate of 15% heat input to the boiler, and compares this cofiring strategy and others previously tested or developed by other utilities. Other issues discussed include: (1) wood fuel specifications as a function of firing method; (2) wood fuel receiving and preparation system requirements; (3) combustion system requirements for cofiring biofuels with coal; (4) combustion impacts of firing biofuels with coal; (5) system engineering issues; (6) the economics of cofiring biofuel with coal. The Allen, TN 330 MW(e) cyclone boiler and Kingston, TN 135 MW(e) Boiler {number_sign}1, a tangentially fired PC unit, case studies are then summarized in the paper, highlighting the cofiring opportunities.

Application of Coal Thermal Treatment Technology for Oil-Free Firing of Boilers

Science.gov (United States)

Aliyarov, B.; Mergalimova, A.; Zhalmagambetova, U.

2018-04-01

The theoretical and practical introduction of this kind of firing boiler units in coal thermal power plants is considered in the article. The results of an experimental study of three types of coals are presented in order to obtain the required gaseous fuel. The aim of the study is to develop a new, economically and ecologically more acceptable method for firing boilers at thermal power plants, which is able to exclude the use of expensive and inconvenient fuel oil. The tasks of the experiment are to develop a technological scheme of kindling of boilers at thermal power plants, using as a type of ignition fuel volatile combustible substances released during the heating of coal, and to investigate three types of coal for the suitability of obtaining gaseous fuels, in sufficient volume and with the required heat of combustion. The research methods include the analysis of technical and scientific-methodological literature on the problem of the present study, the study of the experience of scientists of other countries, the full-scale experiment on the production of volatile combustible substances. During the full-scale experiment, the coal of 3 fields of Kazakhstan has been studied: Shubarkul, Maikuben and Saryadyr. The analysis has been performed and the choice of the most convenient technology for boiler kindling and maintenance of steady burning of the torch has been made according to the proposed method, as well as the corresponding technological scheme has been developed. As a result of the experiment, it can be stated that from coal in the process of its heating (without access to oxygen), it is possible to obtain a sufficient amount of combustible volatile substances. The released gaseous fuel has the necessary parameters and is quite capable of replacing an expensive fuel oil. The resulting gaseous fuel is quite convenient to use and environmentally cleaner. The piloting scheme developed as a result of the experiment can be introduced in pulverized-coal

3-DIMENSIONAL SIMULATION AND FEASIBILITY STUDY OF BIOMASS/COAL CO-COMBUSTION BURNER

Directory of Open Access Journals (Sweden)

Nataliya DUNAYEVSKA

2017-06-01

Full Text Available Combustion of solid biomass mixed with coal in existing boilers not only reduces harmful emissions, but also allows diversifying the available fuel base. Such technology allows to implement the efficient use of food industry solid wastes, which otherwise would be dumped in piles, and thus produce harmful environmental impact. The geometrical models of research reactor and a burner thermal preprocessing of pulverized coal were developed and calculational meshes were generated. The geometrical model of the VGP-100Vpresents only fluid domain whereas the effect of cooled walls was substituted by the equivalent biudary conditions deruved on the basis of direct experimentation. The model of the VGP-100V allowed accounting for the specifics of radiative heat transfer by comparison of experimental thermo-couple measurements to the simulated by the model one. A model has been developed allowing the determination of actual temperatures of combustion gases flow based upon the reading of unsheathed thermo-couples by taking into account the reradiation of the thermo-couple beads to the channel walls. Based on the ANSYS 3-D process model in the burner of the Trypilska Thermal Power Plant (TPP for the combustion of low-reactive coal with the thermochemical preparation of the design of an actual burner has been developed. On the basis of the experimental studies of the actual burner and the above-mentioned CFD calculations, the burner draft of the 65 MW for TPP-210A boiler aimed at the implementation of biomass-coal co-combustion was designed.

Achievement report for fiscal 1984 on Sunshine Program. Basic research on coal type and gasification characteristics; 1984 nendo tanshu to gas ka tokusei no kiso kenkyu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1985-03-01

The study of pressurized fluidized gasification of coal chars started in fiscal 1975, and a 0.2t/d unit was in operation until fiscal 1979. Since fiscal 1980, a 1t/d unit has been in operation. In fiscal 1984, an entrained bed gasification furnace was constructed, capable of high-temperature gasification of various coals, and it is now undergoing a test operation. This report consists of pressurized gasification tests for coal char, the result of a study on the effect of coal type on the char gasification reaction rate, and the result of experiments on the treatment of coal liquefaction residue, all accomplished in the 1t/d gasification unit. For the investigation of the effect of coal type, chars of 13 types of coals are subjected to reaction tests in the carbon dioxide gas, and weight reduction rates and changes in residue surface areas are determined while reaction is under way. The results are analyzed and parameters are made clear that enable a quantitative assessment of the effect of coal type on gasification reaction rates. Pulverized grains and coal liquefaction residue are blended and gasified in the fluidized bed in the presence of oxygen and steam. As the result, a gas capable of 2,000kcal/Nm{sup 3} containing 30% hydrogen and 25% carbon monoxide is acquired, when catalyst grains in the residue are segregated. (NEDO)

Liquid carbon dioxide/pulverized limestone globulsion delivery system for deep ocean storage

Energy Technology Data Exchange (ETDEWEB)

Swett, P.; Golomb, D.; Barry, E.; Ryan, D.; Lawton, C. [Massachusetts Univ., Lowell, MA (United States)

2005-07-01

Ocean storage of carbon dioxide (CO{sub 2}) raises serious environmental, technical and economic problems because a massive point injection of pure liquid CO{sub 2} at depth would create a plume of carbonic acid with a pH lower than 7. Acidified seawater is considered to be harmful to aquatic organisms. Laboratory studies have shown that injecting a globulsion consisting of CO{sub 2}, water (H{sub 2}O) and calcium carbonate (CaCO{sub 3}) instead of pure liquid CO{sub 2} results in an alkaline reaction rather than an acidic reaction. Because calcium carbonate and bicarbonate are natural ingredients of seawater, there is no expected harm due to the additive limestone. This paper presented a practical delivery system for the underwater creation of globulsion. When liquid or supercritical CO{sub 2} is mixed with a slurry of finely pulverized limestone (CaCO{sub 3}) in pure or seawater, a macro-emulsion is formed consisting of CO{sub 2} droplets coated with CaCO{sub 3} particles dispersed in water. In this study, liquid CO{sub 2} was piped to approximately 500 m depth, which is below the flash point of liquid CO{sub 2} into vapor. A slurry of pulverized limestone in seawater was also separately piped to this depth. A static mixer was mounted at the end of the pipes. Liquid CO{sub 2}, along with a slurry of pulverized limestone and ambient seawater were pumped into the mixer by a turbine. The globulsion exited from the other end of the mixer and sank like a dense plume to greater depths while entraining ambient seawater. The CaCO{sub 3}-coated globules precipitated from the neutrally buoyant plume toward the ocean bottom following equilibration. As such, the ocean was not be acidified with this method of CO{sub 2} discharging. It was concluded that even inland seas, such as the Mediterranean and Black Seas, could be considered for sequestration of a CO{sub 2}/H{sub 2}O/CaCO{sub 3} globulsion. Although adding pulverized limestone to liquid CO{sub 2} and the mixing

FUNDAMENTAL INVESTIGATION OF FUEL TRANSFORMATIONS IN PULVERIZED COAL COMBUSTION AND GASIFICATION TECHNOLOGIES

Energy Technology Data Exchange (ETDEWEB)

Robert Hurt; Joseph Calo; Thomas H. Fletcher; Alan Sayre

2005-04-29

The goal of this project was to carry out the necessary experiments and analyses to extend current capabilities for modeling fuel transformations to the new conditions anticipated in next-generation coal-based, fuel-flexible combustion and gasification processes. This multi-organization, multi-investigator project has produced data, correlations, and submodels that extend present capabilities in pressure, temperature, and fuel type. The combined experimental and theoretical/computational results are documented in detail in Chapters 1-8 of this report, with Chapter 9 serving as a brief summary of the main conclusions. Chapters 1-3 deal with the effect of elevated pressure on devolatilization, char formation, and char properties. Chapters 4 and 5 deal with advanced combustion kinetic models needed to cover the extended ranges of pressure and temperature expected in next-generation furnaces. Chapter 6 deals with the extension of kinetic data to a variety of alternative solid fuels. Chapter 7 focuses on the kinetics of gasification (rather than combustion) at elevated pressure. Finally, Chapter 8 describes the integration, testing, and use of new fuel transformation submodels into a comprehensive CFD framework. Overall, the effects of elevated pressure, temperature, heating rate, and alternative fuel use are all complex and much more work could be further undertaken in this area. Nevertheless, the current project with its new data, correlations, and computer models provides a much improved basis for model-based design of next generation systems operating under these new conditions.

Staged combustion - main method for suppressing nitrogen oxides in pulverized-coal fired boilers

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R. (Vsesoyuznyi Teplotekhnicheskii Institut (USSR))

1989-08-01

Describes principles behind staged combustion, which is based on organizing furnace operations so that only part of the air from the fuel is taken into the furnace. The remaining air, which is needed for combustion, is fed as a tertiary blast jet into the intermediate flame zone. Following inflammation and combustion of the volatile matter, the oxygen concentration in the flame drops sharply causing a retardation of the oxidation reactions forming NO and an intensification of the reactions causing the nitrogen-containing radicals NH{sub i} and CN to be converted into N{sub 2}. When the reducing agents CO, H{sub 2} and CH{sub 4} are present in certain flame zones, even the nitrogen oxide is reduced to N{sub 2}. The NO concentrations in the flame are reduced until the jet of tertiary air is introduced. Discusses with reference to practice in the USA and Western Europe how to achieve maximum effect of this method for different types of boiler and presents the results of observations of the introduction of staged combustion to the BKZ-210-140 boiler burning Kuznetsk gassy coal. 5 refs.

The pulverization and handling of soft plastics for energy recovery; Soenderdelning och hantering av mjuka plaster foer energiutvinning

Energy Technology Data Exchange (ETDEWEB)

Wiklund, Sven-Erik

2000-10-01

The purpose of the project has primarily been to investigate suitable equipment (mills, crushers, shredders) for the pulverization of different types of soft plastics from the agricultural sector (large sacks and silage plastic) and the peat extraction industry (plastic covers) with the aim of being able to use the plastic material as fuel in conventional solid waste-fired plants. Many of the mills that are used for pulverizing different types of biofuel have proved not to be particularly suitable for soft plastics. The project has comprised the following: * Contact with a number of plant owners with different types of plants (grate, CFB and BFB boilers) for a review of existing fuel handling and fuel feed equipment as well as the demands they make on the fuel that is to be fired. * Contact with Trio Plast concerning previous tests carried out in connection with the collection, baling, handling, pulverization and combustion of plastics from the agricultural sector. * Contact with mill suppliers for participation in the tests and for feedback on experience gained in connection with the pulverization of soft plastics. * Choice of a suitable plant for practical trials based on contact with the above plant owners as a reference group. * Practical trials in 5 mills with the pulverization of soft plastics from agriculture (silage plastic and large sacks) as well as plastic from peat extraction (plastic covers) and * Evaluation of technical, economic, energy-related and environmental preconditions. Following contact with several owners of solid waste-fired combustion plants, and after hearing their opinions, it became clear that many of them were doubtful about the combustion of plastic. They are primarily afraid of tripping superheaters, etc. Consequently, two plants without superheaters, one in Oestersund and the other in Malmoe, were chosen for the tests. The mills that were tested were: * A SIM mill from WahIkvist, Oedeshoeg Plant - a mobile slow-action pulverizer for

Collaborative Studies for Mercury Characterization in Coal and Coal Combustion Products, Republic of South Africa

Science.gov (United States)

Kolker, Allan; Senior, Constance L.; van Alphen, Chris

2014-12-15

Mercury (Hg) analyses were obtained for 42 samples of feed coal provided by Eskom, the national electric utility of South Africa, representing all 13 coal-fired power stations operated by Eskom in South Africa. This sampling includes results for three older power stations returned to service starting in the late 2000s. These stations were not sampled in the most recent previous study. Mercury concentrations determined in the present study are similar to or slightly lower than those previously reported, and input Hg for the three stations returned to service is comparable to that for the other 10 power stations. Determination of halogen contents of the 42 feed coals confirms that chlorine contents are generally low, and as such, the extent of Hg self-capture by particulate control devices (PCDs) is rather limited. Eight density separates of a South African Highveld (#4) coal were also provided by Eskom, and these show a strong mineralogical association of Hg (and arsenic) with pyrite. The density separates were used to predict Hg and ash contents of coal products used in South Africa or exported. A suite of 48 paired samples of pulverization-mill feed coal and fly ash collected in a previous (2010) United Nations Environment Programme-sponsored study of emissions from the Duvha and Kendal power stations was obtained for further investigation in the present study. These samples show that in each station, Hg capture varies by boiler unit and confirms that units equipped with fabric filters for air pollution control are much more effective in capturing Hg than those equipped with electrostatic precipitators. Apart from tracking the performance of PCDs individually, changes resulting in improved mercury capture of the Eskom fleet are discussed. These include Hg reduction through coal selection and washing, as well as through optimization of equipment and operational parameters. Operational changes leading to increased mercury capture include increasing mercury

Performance assessment of CO2 capture with calcination carbonation reaction process driven by coal and concentrated solar power

International Nuclear Information System (INIS)

Zhang, Xuelei; Liu, Yingguang

2014-01-01

Calcination carbonation reaction (CCR) process is regarded as a promising option for pulverized coal power plant to mitigate CO 2 emission. In this paper, concentrated solar power (CSP) substitutes for coal to supply part of the calcination energy in order to reduce the fossil fuel consumption associated with the calciner. A CCR process driven by coal and CSP is examined from the perspective of energy efficiency. This paper focuses on the parameters of heat recovery efficiency, CSP capacity, compression energy, air separation energy and recycled energy to determine the contribution of each to the overall energy penalty. In addition, the effects of heat recovery efficiency, CSP capacity, purge percentage and CO 2 capture efficiency on the co-driven case are analyzed through a sensitivity analysis. The results indicate that the thermal efficiency of integrating CCR co-driven process into an ultra-supercritical 1019 MW power plant is 35.37%, which means that the overall efficiency penalty is 9.63 percentage points. Moreover, the co-driven case reduces the fossil fuel consumption and the mass flow rate of fresh sorbent and circulation solids compared with coal-driven case. Increasing heat recovery efficiency and CSP efficiency can improve the co-driven case performance. - Highlights: • We examine a CCR process driven by coal and concentrated solar power simultaneously. • The contributors to the overall energy penalty are quantitatively identified. • Obvious coal-saving effect has been found in the co-driven system. • A sensitivity analysis is conducted to find the impact of key parameters

Co-Firing Oil Shale with Coal and Other Fuels for Improved Efficiency and Multi-Pollutant Control

Energy Technology Data Exchange (ETDEWEB)

Robert A. Carrington; William C. Hecker; Reed Clayson

2008-06-01

Oil shale is an abundant, undeveloped natural resource which has natural sorbent properties, and its ash has natural cementitious properties. Oil shale may be blended with coal, biomass, municipal wastes, waste tires, or other waste feedstock materials to provide the joint benefit of adding energy content while adsorbing and removing sulfur, halides, and volatile metal pollutants, and while also reducing nitrogen oxide pollutants. Oil shale depolymerization-pyrolysis-devolatilization and sorption scoping studies indicate oil shale particle sorption rates and sorption capacity can be comparable to limestone sorbents for capture of SO2 and SO3. Additionally, kerogen released from the shale was shown to have the potential to reduce NOx emissions through the well established “reburning” chemistry similar to natural gas, fuel oil, and micronized coal. Productive mercury adsorption is also possible by the oil shale particles as a result of residual fixed-carbon and other observed mercury capture sorbent properties. Sorption properties were found to be a function particle heating rate, peak particle temperature, residence time, and gas-phase stoichmetry. High surface area sorbents with high calcium reactivity and with some adsorbent fixed/activated carbon can be produced in the corresponding reaction zones that exist in a standard pulverized-coal or in a fluidized-bed combustor.

Characterization of a new Hencken burner with a transition from a reducing-to-oxidizing environment for fundamental coal studies

Science.gov (United States)

Adeosun, Adewale; Huang, Qian; Li, Tianxiang; Gopan, Akshay; Wang, Xuebin; Li, Shuiqing; Axelbaum, Richard L.

2018-02-01

In pulverized coal burners, coal particles usually transition from a locally reducing environment to an oxidizing environment. The locally reducing environment in the near-burner region is due to a dense region of coal particles undergoing devolatilization. Following this region, the particles move into an oxidizing environment. This "reducing-to-oxidizing" transition can influence combustion processes such as ignition, particulate formation, and char burnout. To understand these processes at a fundamental level, a system is required that mimics such a transition. Hence, we have developed and characterized a two-stage Hencken burner to evaluate the effect of the reducing-to-oxidizing transition and particle-to-particle interaction (which characterizes dense region of coal particles) on ignition and ultrafine aerosol formation. The two-stage Hencken burner allows coal particles to experience a reducing environment followed by a transition to an oxidizing environment. This work presents the results of the design and characterization of the new two-stage Hencken burner and its new coal feeder. In a unique approach to the operation of the flat-flame of the Hencken burner, the flame configurations are operated as either a normal flame or inverse flame. Gas temperatures and oxygen concentrations for the Hencken burner are measured in reducing-to-oxidizing and oxidizing environments. The results show that stable flames with well-controlled conditions, relatively uniform temperatures, and species concentrations can be achieved in both flame configurations. This new Hencken burner provides an effective system for evaluating the effect of the reducing-to-oxidizing transition and particle-to-particle interaction on early-stage processes of coal combustion such as ignition and ultrafine particle formation.

COAL-FIRED UTILITY BOILERS: SOLVING ASH DEPOSITION PROBLEMS; TOPICAL

International Nuclear Information System (INIS)

Christopher J. Zygarlicke; Donald P. McCollor; Steven A. Benson; Jay R. Gunderson

2001-01-01

The accumulation of slagging and fouling ash deposits in utility boilers has been a source of aggravation for coal-fired boiler operators for over a century. Many new developments in analytical, modeling, and combustion testing methods in the past 20 years have made it possible to identify root causes of ash deposition. A concise and comprehensive guidelines document has been assembled for solving ash deposition as related to coal-fired utility boilers. While this report accurately captures the current state of knowledge in ash deposition, note that substantial research and development is under way to more completely understand and mitigate slagging and fouling. Thus, while comprehensive, this document carries the title ''interim,'' with the idea that future work will provide additional insight. Primary target audiences include utility operators and engineers who face plant inefficiencies and significant operational and maintenance costs that are associated with ash deposition problems. Pulverized and cyclone-fired coal boilers are addressed specifically, although many of the diagnostics and solutions apply to other boiler types. Logic diagrams, ash deposit types, and boiler symptoms of ash deposition are used to aid the user in identifying an ash deposition problem, diagnosing and verifying root causes, determining remedial measures to alleviate or eliminate the problem, and then monitoring the situation to verify that the problem has been solved. In addition to a step-by-step method for identifying and remediating ash deposition problems, this guideline document (Appendix A) provides descriptions of analytical techniques for diagnostic testing and gives extensive fundamental and practical literature references and addresses of organizations that can provide help in alleviating ash deposition problems

FINE PARTICAL AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

Energy Technology Data Exchange (ETDEWEB)

Jost O.L. Wendt; Wayne S. Seames; Art Fernandez

2003-09-21

This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and pulverized coal. The objective was to determine potential tradeoffs between CO{sub 2} mitigation through using a CO{sub 2} neutral fuel, such as municipal sewage sludge, and the emergence of other potential problems such as the emission of toxic fly ash particles. The work led to new insight into mechanisms governing the partitioning of major and trace metals from the combustion of sewage sludge, and mixtures of coal and sewage sludge. The research also showed that the co-combustion of coal and sewage sludge emitted fine particulate matter that might potentially cause greater lung injury than that from the combustion of either coal alone or municipal sewage sludge alone. The reason appeared to be that the toxicity measured required the presence of large amounts of both zinc and sulfur in particles that were inhaled. MSS provided the zinc while coal provided the sulfur. Additional research showed that the toxic effects could most likely be engineered out of the process, through the introduction of kaolinite sorbent downstream of the combustion zone, or removing the sulfur from the fuel. These results are consequences of applying ''Health Effects Engineering'' to this issue. Health Effects Engineering is a new discipline arising out of this work, and is derived from using a collaboration of combustion engineers and toxicologists to mitigate the potentially bad health effects from combustion of this biomass fuel.

Thermal Integration of CO{sub 2} Compression Processes with Coal-Fired Power Plants Equipped with Carbon Capture

Energy Technology Data Exchange (ETDEWEB)

Edward Levy

2012-06-29

Coal-fired power plants, equipped either with oxycombustion or post-combustion CO{sub 2} capture, will require a CO{sub 2} compression system to increase the pressure of the CO{sub 2} to the level needed for sequestration. Most analyses show that CO{sub 2} compression will have a significant effect on parasitic load, will be a major capital cost, and will contribute significantly to reduced unit efficiency. This project used first principle engineering analyses and computer simulations to determine the effects of utilizing compressor waste heat to improve power plant efficiency and increase net power output of coal-fired power plants with carbon capture. This was done for units with post combustion solvent-based CO{sub 2} capture systems and for oxyfired power plants, firing bituminous, PRB and lignite coals. The thermal integration opportunities analyzed for oxycombustion capture are use of compressor waste heat to reheat recirculated flue gas, preheat boiler feedwater and predry high-moisture coals prior to pulverizing the coal. Among the thermal integration opportunities analyzed for post combustion capture systems are use of compressor waste heat and heat recovered from the stripper condenser to regenerate post-combustion CO{sub 2} capture solvent, preheat boiler feedwater and predry high-moisture coals. The overall conclusion from the oxyfuel simulations is that thermal integration of compressor heat has the potential to improve net unit heat rate by up to 8.4 percent, but the actual magnitude of the improvement will depend on the type of heat sink used and to a lesser extent, compressor design and coal rank. The simulations of a unit with a MEA post combustion capture system showed that thermal integration of either compressor heat or stripper condenser heat to preheat boiler feedwater would result in heat rate improvements from 1.20 percent to 4.19 percent. The MEA capture simulations further showed that partial drying of low rank coals, done in combination

Not every ecotax is good for the environment

International Nuclear Information System (INIS)

Brinkman, L.; Huppes, G.

1999-01-01

Although coal gasification is the cleanest form of coal-fired electric power generation it's advantage is not reflected in the environmental taxes in the Netherlands ('ecotax'). Recommendations are given to improve the ecotax in order to better reflect the advantages of a coal gasifier over e.g. a pulverized coal plant. 9 refs

Tribocharging in electrostatic beneficiation of coal: Effects of surface composition on work function as measured by x-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy in air

International Nuclear Information System (INIS)

Trigwell, S.; Mazumder, M.K.; Pellissier, R.

2001-01-01

The cleaning of coal by electrostatic beneficiation is based on tribocharging characteristics of pulverized coal particles with diameter smaller than 120 μm. The tribocharging process should be such that the organic coal particles must charge with a polarity opposite to that of the sulfur and the mineral containing particles so that coal can be separated from minerals by using a charge separator. However, the charge distribution of electrostatically separated coal particles indicates that coal exhibits bipolar charging. A significant fraction of the coal particles charges negatively which appears to be in conflict with expectations in that the organic coal particles should charge positively, and the mineral particles, present as impurities such as pyrite, charge negatively when tribocharged against copper. The relative work functions of the particles (coal and mineral) and that of the metal surface (copper or stainless steel) used for tribocharging predict these expected results. However, ultraviolet photoelectron spectroscopy (UPS) measurements in air on specimens of three different coal species, showed the work function to be approximately 5.4 eV, which is higher than a reported measured work function of 3.93 eV. Studies by UPS and x-ray photoelectron spectroscopy on copper, stainless steel, aluminum, and other commonly used tribocharging materials such as nylon and polytetrafluorethylene, as well as pure pyrite, showed that the work function varied considerably as a function of surface composition. Therefore, the reason for the bipolar charging of the coal particles may be the too small differences in work functions between coal powder and copper used as the charging material. The choice of a material for impaction triboelectric charging for coal or mineral separation should therefore depend upon the actual work function as modified by the ambient conditions such as moisture content and the oxidation of the surface

Coal background paper. Coal demand

International Nuclear Information System (INIS)

1997-01-01

Statistical data are presented on coal demands in IEA and OECD member countries and in other countries. Coal coaking and coaking coal consumption data are tabulated, and IEA secretariat's coal demand projections are summarized. Coal supply and production data by countries are given. Finally, coal trade data are presented, broken down for hard coal, steam coal, coking coal (imports and export). (R.P.)

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

KAUST Repository

Andersen, Myrrha E.

2016-10-19

Pulverized bituminous coal was burned in a 10. W externally heated entrained flow furnace under air-combustion and three oxy-combustion inlet oxygen conditions (28, 32, and 36%). Experiments were designed to produce flames with practically relevant stoichiometric ratios (SR. =1.2-1.4) and constant residence times (2.3. s). Size-classified fly ash samples were collected, and measurements focused on the soot, elemental carbon (EC), and organic carbon (OC) composition of the total and ultrafine (<0.6. μm) fly ash. Results indicate that although the total fly ash carbon, as measured by loss on ignition, was always acceptably low (<2%) with all three oxy-combustion conditions lower than air-combustion, the ultrafine fly ash for both air-fired and oxy-fired combustion conditions consists primarily of carbonaceous material (50-95%). Carbonaceous components on particles <0.6. μm measured by a thermal optical method showed that large fractions (52-93%) consisted of OC rather than EC, as expected. This observation was supported by thermogravimetric analysis indicating that for the air, 28% oxy, and 32% oxy conditions, 14-71% of this material may be OC volatilizing between 100. C and 550. C with the remaining 29-86% being EC/soot. However, for the 36% oxy condition, OC may comprise over 90% of the ultrafine carbon with a much smaller EC/soot contribution. These data were interpreted by considering the effects of oxy-combustion on flame attachment, ignition delay, and soot oxidation of a bituminous coal, and the effects of these processes on OC and EC emissions. Flame aerodynamics and inlet oxidant composition may influence emissions of organic hazardous air pollutants (HAPs) from a bituminous coal. During oxy-coal combustion, judicious control of inlet oxygen concentration and placement may be used to minimize organic HAP and soot emissions.

FY 1990 report on the results of the development of the entrained bed coal gasification power plant. Part 1. Element study; 1990 nendo seika hokokusho. Funryusho sekitan gaska hatsuden plant kaihatsu - Sono 1. Yoso kenkyu hen

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-03-01

For the purpose of establishing the technology of the integrated coal gasification combined cycle power generation, element study was made for a pilot plant of 200t/d entrained bed coal gasification power generation, and the FY 1990 results were summarized. In the study by the gasification test on 2t/d furnace, gasification test was conducted for the OM coal newly selected as a coal proposed for the expansion of coal kind. As a result, the pulverized coal/char of OM coal have almost good handling property and showed favorable gasification performance. In the study of large gas turbine combustor for demonstrative machine, with the aim of developing a combustor that makes stable combustion also in the low load region possible, fabrication of the accessory equipment of combustor (choke mechanism, measuring use duct and heat insulating plate) was made for the actual-pressure/actual-size combustion test. In the study by simulation of the total system of combined cycle power generation, etc., the following were conducted: verification of characteristics of the integrated control (state of the ordinary operation, state of the mock load control, etc.), load dump simulation (state of the bleed cooperation, state of the bleed separation (state of the air booster operation, etc.)), etc. (NEDO)

The future development of the British coal topping cycles

International Nuclear Information System (INIS)

Harrison, J.S.; Dawes, S.G.; Minchener, A.J.

1992-01-01

In the United Kingdom (UK), at present most of the electricity produced from coal is generated using large pulverized fuel boilers with a conventional steam cycle. This technology has been developed over many years and has culminated in a 6 x 660 MWe station at Drax. The design cycle efficiency of such a station is some 40%, lower heating value basis, this limit being due to the nature of the Rankin cycle appropriate for steam turbines without utilization of the lower grade heat as in a combined heat and power (CHP) system. This paper reports that there is an increasing concern regarding the potential environmental impact of fossil-fuel fired systems. In particular, emissions limits are being tightened for particulates, NO x SO 2 . There is also concern over the greenhouse gases such as CO 2 . For existing conventional plant, this has resulted in the retrofitting of low NO x burners coupled in some instances with the introduction of flue gas desulphurization (FGD) equipment. Such modifications lead to significant increases in the capital and operating costs, with loss in cycle efficiency when FGD is fitted. Thus at Drax the efficiency will fall by some 1% to below 39%. These adverse effects have increased the need for alternative coal-fired generation systems which will have higher efficiencies while at the same time improving the environmental impact of the power stations. The environmental debate over the use of fossil fuels for power generation will continue, with continuing public uncertainty especially over the extent and causes of enhanced global warming. The debate will continue against a background of rising power generation demand worldwide, particularly in developing countries. What is clear is that in the absence of long-term, cost effective and technologically proven alternatives to fossil fuels, coal will remain the prime fuel for power generation

Measurements and simulation for design optimization for low NOx coal-firing system

Energy Technology Data Exchange (ETDEWEB)

E. Bar-Ziv; Y. Yasur; B. Chudnovsky; L. Levin; A. Talanker [Ben-Gurion University of Negev, Beer-Sheva (Israel)

2003-07-01

The information required to design a utility steam generator is the heat balance, fuel analysis and emission. These establish the furnace wall configuration, the heat release rates, and the firing technology. The furnace must be sized for (1) residence time for complete combustion with low NOx, and (2) reduction of flue gas temperature to minimize ash deposition. To meet these, computational fluid dynamics (CFD) of the combustion process in the furnace were performed and proven to be a powerful tool for this purpose. Still, reliable numerical simulations require careful interpretation and comparison with measurements. We report numerical results and measurements for a 575 MW pulverized coal tangential firing boiler of the Hadera power plant of Israel Electric Corporation (IEC). Measured and calculated values were found to be in reasonable agreement. We used the simulations for optimization and investigated temperature distribution, heat fluxes and concentration of chemical species. We optimized both the furnace flue gas temperature entering the convective path and the staged residence time for low NOx. We tested mass flow rates through close-coupled and separate overfire air ports and its arrangement and the coal powder fineness. These parameters can control the mixing rate between the fuel and the oxidizer streams and can affect the most important characteristics of the boiler such as temperature regimes, coal burning rate and nitrogen oxidation/reduction. From this effort, IEC started to improve the boiler performance by replacing the existing typical tangential burners to low NOx firing system to ensure the current regulation requirements of emission pollutions.

Experience with vertical down-fired, coal-fuelled, low emissions air heaters incorporating automatic ash removal

Energy Technology Data Exchange (ETDEWEB)

Keller, M.; Noble, R.K.; Keller, J. [Tulsa Combustion LLC, Tulsa, OK (United States)

2009-07-01

This paper discussed the conversion of a horizontally-oriented air heater system with a vertically-oriented pulverized coal-fuelled air heater system. The vertically-oriented heater was used for automatic de-ashing and avoiding the ash accumulation often seen in horizontally-oriented systems. The study showed that the use of the vertical system significantly reduced emissions of nitrous oxides (NO{sub x}), carbon monoxide (CO) and volatile organic compounds (VOCs). Slag and salt attacks on the refractory were also reduced. The vertical systems provided automatic ash removal and eliminated hot spots on the refractory. The potential for variations in composition was also reduced. It was concluded that the system's smaller footprint means that it can be used in retrofits and can be installed in small spaces. 12 figs.

PETROBRAS green petroleum coke used as partial replacement for coal injected mixtures in blast furnaces; Utilizacao do coque verde de petroleo da PETROBRAS em substituicao parcial ao carvao mineral das misturas injetadas em altos fornos

Energy Technology Data Exchange (ETDEWEB)

Silva, Agenor Medrado da; Medrado, Swami Botelho; Noblat, Sebastiao Jorge Xavier [Companhia Siderurgia Nacional. CSN. Gerencia Geral de Processos Siderurgicos. RJ (Brazil)], e-mails: ams@csn.com.br, swami@csn.com.br, s.noblat@csn.com.br; Carvalho Junior, Joao Andrade de [Universidade Estadual Paulista Julio de Mesquita Filho. Faculdade de Engenharia de Guaratingueta. Departamento de Energia, SP (Brazil)], e-mail: joao@feg.unesp.br

2010-04-15

The PETROBRAS produced green petroleum coke (GPC) is a carbon rich fuel, virtually ash-free, with low sulfur content and is a fuel suitable to replace metallurgical coke in blast furnaces. The GPC was tested in a pulverized coal injection simulator built in the Volta Redonda research center. It presented a low burning efficiency due to low volatile material content and high substitution rate by the carbon content. The industrial-scale tests were carried out in blast furnaces with up to 50% PETROBRAS GPC in the coal blends, which has never been done before in the steel industry. The injected coal/CVP mixtures produced no negative side effects in the blast furnace grinding systems, pneumatic conveying or operating process. The mixture burning process inside the blast furnace, showed a decrease in fuel consumption, with a significant reduction in metallurgical coke consumption. The industrial-scale tests of the GPC mixtures did not reach the 70% maximum for lack of the GPC feedstock, it being necessary to continue with standard coal mixtures. (author)

Development and numerical/experimental characterization of a lab-scale flat flame reactor allowing the analysis of pulverized solid fuel devolatilization and oxidation at high heating rates

Energy Technology Data Exchange (ETDEWEB)

Lemaire, R., E-mail: romain.lemaire@mines-douai.fr; Menanteau, S. [Mines Douai, EI, F-59508 Douai (France)

2016-01-15

This paper deals with the thorough characterization of a new experimental test bench designed to study the devolatilization and oxidation of pulverized fuel particles in a wide range of operating conditions. This lab-scale facility is composed of a fuel feeding system, the functioning of which has been optimized by computational fluid dynamics. It allows delivering a constant and time-independent mass flow rate of fuel particles which are pneumatically transported to the central injector of a hybrid McKenna burner using a carrier gas stream that can be inert or oxidant depending on the targeted application. A premixed propane/air laminar flat flame stabilized on the porous part of the burner is used to generate the hot gases insuring the heating of the central coal/carrier-gas jet with a thermal gradient similar to those found in industrial combustors (>10{sup 5} K/s). In the present work, results issued from numerical simulations performed a priori to characterize the velocity and temperature fields in the reaction chamber have been analyzed and confronted with experimental measurements carried out by coupling particle image velocimetry, thermocouple and two-color pyrometry measurements so as to validate the order of magnitude of the heating rate delivered by such a new test bench. Finally, the main features of the flat flame reactor we developed have been discussed with respect to those of another laboratory-scale system designed to study coal devolatilization at a high heating rate.

Development and numerical/experimental characterization of a lab-scale flat flame reactor allowing the analysis of pulverized solid fuel devolatilization and oxidation at high heating rates.

Science.gov (United States)

Lemaire, R; Menanteau, S

2016-01-01

This paper deals with the thorough characterization of a new experimental test bench designed to study the devolatilization and oxidation of pulverized fuel particles in a wide range of operating conditions. This lab-scale facility is composed of a fuel feeding system, the functioning of which has been optimized by computational fluid dynamics. It allows delivering a constant and time-independent mass flow rate of fuel particles which are pneumatically transported to the central injector of a hybrid McKenna burner using a carrier gas stream that can be inert or oxidant depending on the targeted application. A premixed propane/air laminar flat flame stabilized on the porous part of the burner is used to generate the hot gases insuring the heating of the central coal/carrier-gas jet with a thermal gradient similar to those found in industrial combustors (>10(5) K/s). In the present work, results issued from numerical simulations performed a priori to characterize the velocity and temperature fields in the reaction chamber have been analyzed and confronted with experimental measurements carried out by coupling particle image velocimetry, thermocouple and two-color pyrometry measurements so as to validate the order of magnitude of the heating rate delivered by such a new test bench. Finally, the main features of the flat flame reactor we developed have been discussed with respect to those of another laboratory-scale system designed to study coal devolatilization at a high heating rate.

Co-combustion of gasified contaminated waste wood in a coal fired power plant

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This project demonstrates the technical and economical feasibility of the producing and cofiring of product gas from demolition waste wood. For this purpose LCV product gas is generated in an atmospheric circulating fluidized bed (CFB) gasification plant, cooled and cleaned and transported to the boiler of a 600 MWe pulverized coal fired power plant. Gas cooling and cleaning takes place in a waste heat boiler and a multi stage wet gas cleaning train. Steam raised in the waste heat boiler is exported to the power plant. On an annual basis 70,000 tons of steam coal are substituted by 150,000 tons of contaminated demolition waste wood (50,000 tons oil equivalent), resulting in a net CO2 emission reduction of 170,000 tons per year, while concurrently generating 205 GWh of electrical power. The wood gasification plant was built by NV EPZ (now incorporated in Essent Energi BV) for Amergas BV, now a 100% subsidiary of Essent Energie BV. The gasification plant is located at the Amer Power Station of NV EPZ Production (now Essent Generation) at Geertruidenberg, The Netherlands. Demonstrating several important design features in wood gasification, the plant started hot service in the Spring of 2000, with first gasification accomplished in the Summer of 2000 and is currently being optimized. (au)

Measurement of O2 in the Combustion Chamber of Apulverized Coal Boiler

Directory of Open Access Journals (Sweden)

Břetislav Janeba

2012-01-01

Full Text Available Operational measurements of the O2 concentration in the combustion chamber of a pulverized coal boiler are not yet common practice. Operators are generally satisfied with measuring the O2 concentration in the second pass of the boiler, usually behind the economizer, where a flue gas sample is extracted for analysis in a classical analyzer. A disadvantage of this approach is that there is a very weak relation between the measured value and the condition in specific locations in the fireplace, e.g. the function of the individual burners and the combustion process as a whole. A new extractionline was developed for measuring the O2 concentration in the combustion chamber. A planar lambda probe is used in this approach. The extraction line is designed to get outputs that can be used directly for diagnosis or management of the combustion in the boiler.

The rates of production of CO and CO2 from the combustion of pulverized coal particles in a shock tube

NARCIS (Netherlands)

Commissaris, F.A.C.M.; Banine, V.Y.; Roekaerts, D.J.E.M.; Veefkind, A.

1998-01-01

This work presents some results of experiments on coal combustion in a shock tube, as well as a time-dependent model of the boundary layer of a single, burning char particle under similar conditions. The partial pressure of O2 in a shock tube was varied between 0 and 10 bar, with gas temperatures

Stochastic model of flow and dispersion of fine particles in a packed bed; Kakuritsu katei wo mochiita juten sonai deno funtai no ryudo to bunsan model

Energy Technology Data Exchange (ETDEWEB)

Takeda, K [Kawasaki Steel Corp., Tokyo (Japan); Lockwood, F

1996-06-01

For the calculation of pulverized coal combustion in a blast furnace blow pipe and tuyere, a model was built for the evaluation of the movement and dispersion of particles in a packed bed by use of a stochastic approach. In the stochastic particle trajectory calculation taking into consideration the impact of fluctuations in gas turbulence, interaction distance between particles and eddies and interaction time have to be determined, in addition to fluctuations in gas flow velocity (to be determined by measuring the instantaneous flow velocity in a normal distribution generated according to random numbers). The eddy life was determined using Shuen`s formula on the premise that the particle-eddy interaction occurs within the calculated life or the transit time, whichever is shorter. As for the turbulence energy {kappa}, it was determined by the {kappa}-{epsilon} model for the free space and by the {kappa}-Lm(mixing length) model for the packed bed. From the average of a multiplicity of particles in the experiment, such time average specific values as the average density and flow velocity vectors of particles in the space, and particle trajectories, were calculated, which proved to agree with values from experiments. Once in the packed bed, the pulverized coal underwent a sudden deceleration due to its interaction with particles in the packed bed, and the pulverized coal flow near the central axis was rapidly diffused in the packed bed. This model is expected to find its use in the study of pulverized coal combustion in the blast furnace. 18 refs., 12 figs., 2 tabs.

The long-term life cycle private and external costs of high coal usage in the US

International Nuclear Information System (INIS)

Bergerson, Joule; Lave, Lester

2007-01-01

Using four times as much coal in 2050 for electricity production need not degrade air quality or increase greenhouse gas emissions. Current SO x and NO x emissions from the power sector could be reduced from 12 to less than 1 and from 5 to 2 million tons annually, respectively, using advanced technology. While direct CO 2 emissions from new power plants could be reduced by over 87%, life cycle emissions could increase by over 25% due to the additional coal that is required to be mined and transported to compensate for the energy penalty of the carbon capture and storage technology. Strict environmental controls push capital costs of pulverized coal (PC) and integrated coal gasification combined cycle (IGCC) plants to $1500-1700/kW and $1600-2000/kW, respectively. Adding carbon capture and storage (CCS) increases costs to $2400-2700/kW and $2100-3000/kW (2005 dollars), respectively. Adding CCS reduces the 40-43% efficiency of the ultra-supercritical PC plant to 31-34%; adding CCS reduces the 32-38% efficiency of the GE IGCC plant to 27-33%. For IGCC, PC, and natural gas combined cycle (NGCC) plants, the carbon dioxide tax would have to be $53, $74, and $61, respectively, to make electricity from a plant with CCS cheaper. Capturing and storing 90% of the CO 2 emissions increases life cycle costs from 5.4 to 11.6 cents/kWh. This analysis shows that 90% CCS removal efficiency, although being a large improvement over current electricity generation emissions, results in life cycle emissions that are large enough that additional effort is required to achieve significant economy-wide reductions in the US for this large increase in electricity generation using either coal or natural gas

Gas manufacture, materials for

Energy Technology Data Exchange (ETDEWEB)

Evans, F J

1867-01-11

Cannel coal, parrot coal, shale, or the like is reduced to a fine powder and mixed with finely-divided bituminous coal, or the two coals are reduced to powder together, or pulverized bituminous coal is mixed with resin, resin oil, or coal tar. The mixture is charged into the retorts. The mixture containing resin and etc. may be first heated to cause the ingredients to cohere, and then compressed into blocks for transport.

Development of a high-performance, coal-fired power generating system with a pyrolysis gas and char-fired high-temperature furnace

Energy Technology Data Exchange (ETDEWEB)

Shenker, J.

1995-11-01

A high-performance power system (HIPPS) is being developed. This system is a coal-fired, combined-cycle plant that will have an efficiency of at least 47 percent, based on the higher heating value of the fuel. The original emissions goal of the project was for NOx and SOx to each be below 0.15 lb/MMBtu. In the Phase 2 RFP this emissions goal was reduced to 0.06 lb/MMBtu. The ultimate goal of HIPPS is to have an all-coal-fueled system, but initial versions of the system are allowed up to 35 percent heat input from natural gas. Foster Wheeler Development Corporation is currently leading a team effort with AlliedSignal, Bechtel, Foster Wheeler Energy Corporation, Research-Cottrell, TRW and Westinghouse. Previous work on the project was also done by General Electric. The HIPPS plant will use a high-Temperature Advanced Furnace (HITAF) to achieve combined-cycle operation with coal as the primary fuel. The HITAF is an atmospheric-pressure, pulverized-fuel-fired boiler/air heater. The HITAF is used to heat air for the gas turbine and also to transfer heat to the steam cycle. its design and functions are very similar to conventional PC boilers. Some important differences, however, arise from the requirements of the combined cycle operation.

Development of a high-performance, coal-fired power generating system with a pyrolysis gas and char-fired high-temperature furnace

International Nuclear Information System (INIS)

Shenker, J.

1995-01-01

A high-performance power system (HIPPS) is being developed. This system is a coal-fired, combined-cycle plant that will have an efficiency of at least 47 percent, based on the higher heating value of the fuel. The original emissions goal of the project was for NOx and SOx to each be below 0.15 lb/MMBtu. In the Phase 2 RFP this emissions goal was reduced to 0.06 lb/MMBtu. The ultimate goal of HIPPS is to have an all-coal-fueled system, but initial versions of the system are allowed up to 35 percent heat input from natural gas. Foster Wheeler Development Corporation is currently leading a team effort with AlliedSignal, Bechtel, Foster Wheeler Energy Corporation, Research-Cottrell, TRW and Westinghouse. Previous work on the project was also done by General Electric. The HIPPS plant will use a high-Temperature Advanced Furnace (HITAF) to achieve combined-cycle operation with coal as the primary fuel. The HITAF is an atmospheric-pressure, pulverized-fuel-fired boiler/air heater. The HITAF is used to heat air for the gas turbine and also to transfer heat to the steam cycle. its design and functions are very similar to conventional PC boilers. Some important differences, however, arise from the requirements of the combined cycle operation

Source profiles of particulate matter emissions from a pilot-scale boiler burning North American coal blends.

Science.gov (United States)

Lee, S W

2001-11-01

Recent awareness of suspected adverse health effects from ambient particulate matter (PM) emission has prompted publication of new standards for fine PM with aerodynamic diameter less than 2.5 microm (PM2.5). However, scientific data on fine PM emissions from various point sources and their characteristics are very limited. Source apportionment methods are applied to identify contributions of individual regional sources to tropospheric particulate concentrations. The existing industrial database developed using traditional source measurement techniques provides total emission rates only, with no details on chemical nature or size characteristics of particulates. This database is inadequate, in current form, to address source-receptor relationships. A source dilution system was developed for sampling and characterization of total PM, PM2.5, and PM10 (i.e., PM with aerodynamic diameter less than 10 pm) from residual oil and coal combustion. This new system has automatic control capabilities for key parameters, such as relative humidity (RH), temperature, and sample dilution. During optimization of the prototype equipment, three North American coal blends were burned using a 0.7-megawatt thermal (MWt) pulverized coal-fired, pilot-scale boiler. Characteristic emission profiles, including PM2.5 and total PM soluble acids, and elemental and carbon concentrations for three coal blends are presented. Preliminary results indicate that volatile trace elements such as Pb, Zn, Ti, and Se are preferentially enriched in PM2.5. PM2.5 is also more concentrated in soluble sulfates relative to total PM. Coal fly ash collected at the outlet of the electrostatic precipitator (ESP) contains about 85-90% PM10 and 30-50% PM2.5. Particles contain the highest elemental concentrations of Si and Al while Ca, Fe, Na, Ba, and K also exist as major elements. Approximately 4-12% of the materials exists as soluble sulfates in fly ash generated by coal blends containing 0.2-0.8% sulfur by mass

International Coal Report's coal year 1991

Energy Technology Data Exchange (ETDEWEB)

McCloskey, G [ed.

1991-05-31

Following introductory articles on factors affecting trade in coal and developments in the freight market, tables are given for coal exports and coal imports for major countries worldwide for 1989 and 1990. Figures are also included for coal consumption in Canada and the Eastern bloc,, power station consumption in Japan, coal supply and demand in the UK, electric utility coal consumption and stocks in the USA, coal production in Australia, Canada and USA by state, and world hard coal production. A final section gives electricity production and hard coal deliveries in the EEC, sales of imported and local coal and world production of pig iron and steel.

Use of Green Mussel Shell as a Desulfurizer in the Blending of Low Rank Coal-Biomass Briquette Combustion

Directory of Open Access Journals (Sweden)

Mahidin Mahidin

2016-08-01

Full Text Available Calcium oxide-based material is available abundantly and naturally. A potential resource of that material comes from marine mollusk shell such as clams, scallops, mussels, oysters, winkles and nerites. The CaO-based material has exhibited a good performance as the desulfurizer oradsorbent in coal combustion in order to reduce SO2 emission. In this study, pulverized green mussel shell, without calcination, was utilized as the desulfurizer in the briquette produced from a mixture of low rank coal and palm kernel shell (PKS, also known as bio-briquette. The ratio ofcoal to PKS in the briquette was 90:10 (wt/wt. The influence of green mussel shell contents and combustion temperature were examined to prove the possible use of that materialas a desulfurizer. The ratio of Ca to S (Ca = calcium content in desulfurizer; S = sulfur content in briquette werefixed at 1:1, 1.25:1, 1.5:1, 1.75:1, and 2:1 (mole/mole. The burning (or desulfurization temperature range was 300-500 °C; the reaction time was 720 seconds and the air flow rate was 1.2 L/min. The results showed that green mussel shell can be introduced as a desulfurizer in coal briquette or bio-briquette combustions. The desulfurization process using that desulfurizer exhibited the first order reaction and the highest average efficiency of 84.5%.

NEW SOLID FUELS FROM COAL AND BIOMASS WASTE; FINAL

International Nuclear Information System (INIS)

Hamid Farzan

2001-01-01

Under DOE sponsorship, McDermott Technology, Inc. (MTI), Babcock and Wilcox Company (B and W), and Minergy Corporation developed and evaluated a sludge derived fuel (SDF) made from sewage sludge. Our approach is to dry and agglomerate the sludge, combine it with a fluxing agent, if necessary, and co-fire the resulting fuel with coal in a cyclone boiler to recover the energy and to vitrify mineral matter into a non-leachable product. This product can then be used in the construction industry. A literature search showed that there is significant variability of the sludge fuel properties from a given wastewater plant (seasonal and/or day-to-day changes) or from different wastewater plants. A large sewage sludge sample (30 tons) from a municipal wastewater treatment facility was collected, dried, pelletized and successfully co-fired with coal in a cyclone-equipped pilot. Several sludge particle size distributions were tested. Finer sludge particle size distributions, similar to the standard B and W size distribution for sub-bituminous coal, showed the best combustion and slagging performance. Up to 74.6% and 78.9% sludge was successfully co-fired with pulverized coal and with natural gas, respectively. An economic evaluation on a 25-MW power plant showed the viability of co-firing the optimum SDF in a power generation application. The return on equity was 22 to 31%, adequate to attract investors and allow a full-scale project to proceed. Additional market research and engineering will be required to verify the economic assumptions. Areas to focus on are: plant detail design and detail capital cost estimates, market research into possible project locations, sludge availability at the proposed project locations, market research into electric energy sales and renewable energy sales opportunities at the proposed project location. As a result of this program, wastes that are currently not being used and considered an environmental problem will be processed into a renewable

NITROUS OXIDE EMISSIONS FROM FOSSIL FUEL COMBUSTION

Science.gov (United States)

The role of coal combustion as a significant global source of nitrous oxide (N2O) emissions was reexamined through on-line emission measurements from six pulverized-coal-fired utility boilers and from laboratory and pilot-scale combustors. The full-scale utility boilers yielded d...

Co-firing Bosnian coals with woody biomass: Experimental studies on a laboratory-scale furnace and 110 MWe power unit

Directory of Open Access Journals (Sweden)

Smajevic Izet

2012-01-01

Full Text Available This paper presents the findings of research into cofiring two Bosnian cola types, brown coal and lignite, with woody biomass, in this case spruce sawdust. The aim of the research was to find the optimal blend of coal and sawdust that may be substituted for 100% coal in large coal-fired power stations in Bosnia and Herzegovina. Two groups of experimental tests were performed in this study: laboratory testing of co-firing and trial runs on a large-scale plant based on the laboratory research results. A laboratory experiment was carried out in an electrically heated and entrained pulverized-fuel flow furnace. Coal-sawdust blends of 93:7% by weight and 80:20% by weight were tested. Co-firing trials were conducted over a range of the following process variables: process temperature, excess air ratio and air distribution. Neither of the two coal-sawdust blends used produced any significant ash-related problems provided the blend volume was 7% by weight sawdust and the process temperature did not exceed 1250ºC. It was observed that in addition to the nitrogen content in the co-fired blend, the volatile content and particle size distribution of the mixture also influenced the level of NOx emissions. The brown coal-sawdust blend generated a further reduction of SO2 due to the higher sulphur capture rate than for coal alone. Based on and following the laboratory research findings, a trial run was carried out in a large-scale utility - the Kakanj power station, Unit 5 (110 MWe, using two mixtures; one in which 5%/wt and one in which 7%/wt of brown coal was replaced with sawdust. Compared to a reference firing process with 100% coal, these co-firing trials produced a more intensive redistribution of the alkaline components in the slag in the melting chamber, with a consequential beneficial effect on the deposition of ash on the superheater surfaces of the boiler. The outcome of the tests confirms the feasibility of using 7%wt of sawdust in combination

Chemical forms of the fluorine, chlorine, oxygen and carbon in coal fly ash and their correlations with mercury retention

Energy Technology Data Exchange (ETDEWEB)

Deng, Shuang [State Key Laboratory of Environmental Criteria and Risk Assessment (China); Research Academy of Environmental Sciences, Beijing 100012 (China); Shu, Yun [Research Academy of Environmental Sciences, Beijing 100012 (China); Li, Songgeng, E-mail: sgli@ipe.ac.cn [State Key Laboratory of Multi-phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Tian, Gang; Huang, Jiayu [Research Academy of Environmental Sciences, Beijing 100012 (China); Zhang, Fan, E-mail: zhangfan5188@vip.sina.com [Research Academy of Environmental Sciences, Beijing 100012 (China)

2016-01-15

Highlights: • Chlorine and fluorine are present mainly in an inorganic form on ash. • Correlations of carbon–oxygen complexes with mercury retention are established. • Concentrations of carbon–oxygen complexes on ash are related to coal type. • No effect of fluorine on mercury retention is observed. • Chlorine, fluorine and carbon in ash are enriched on surface. - Abstract: Fly ashes recovered from the particulate control devices at six pulverized coal boiler unites of China, are studied using an X-ray photoelectron spectroscopy (XPS) with a particular focus on the functionalities of fluorine (F), chlorine (Cl), carbon and oxygen on fly ash. It is found that the inorganic forms of F and Cl are predominant on the ash surface in comparison with their organics, and the proportion of organic Cl is relatively higher than that of organic F. Similar results are also obtained in the bulk by correlating the F and Cl contents with those of the unburnt carbon and other compositions in ash. Strong correlations of mercury retention with surface carbon–oxygen functional groups indicate that the C=O, OH/C−O and (O−C=O)−O on surface are of significant importance for mercury retention in fly ash. Their surface concentrations are related to coal type. The presence of Cl in fly ash helps with mercury retention. No obvious effect of F is observed.

Report on the research achievements in the Sunshine Project in fiscal 1992. Studies on liquefying reaction in coal, and reforming and utilization of the products; 1992 nendo sekitan no ekika hanno to seiseibutsu no kaishitsu riyo no kenkyu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1983-03-01

This paper describes the achievements in the Sunshine Project in fiscal 1992 in studies on liquefying reaction in coal, and reforming of the products. High conversion rate was attained in the co-treatment of bitumen and Taiheiyo coals by using highly dispersing oil soluble solvent without performing coking, even if the asphaltene concentration is high. When a very highly acidic trifluoromethane sulfonic acid catalyst is used, hydrogenation and conversion to solubilized low molecules is possible even with a solvent having low affinity with coal. Swelling effect by tetralin is remarkable in pulverized coal, and the conversion rate was improved greatly under high-pressure hydrogen. When naphtha of the Wandoan coal liquefied oil is given extraction treatment with base and acid/base, the gas production decreases noticeably when hydrogenating and refining the extracts, resulting in reduced hydrogen consumption and improved oil recovery rate. Furthermore, when the extraction treated naphtha is hydrogenated, denitrification can be achieved completely. Kerosene and light oil liquefied from the Wandoan coal were cracked by fluidity contact, whereas the light gravity product yield due to the decomposition was found low because of containing a great amount of two-ring aromatics. The pressure crystal deposition method using solvent is effective in separation of high-melting point compounds including anthracene from heavy gravity oil. (NEDO)

Nanometre-sized pores in coal: Variations between coal basins and coal origin

Science.gov (United States)

Sakurovs, Richard; Koval, Lukas; Grigore, Mihaela; Sokolava, Anna; Ruppert, Leslie F.; Melnichenko, Yuri B.

2018-01-01

We have used small angle neutron scattering (SANS) to investigate the differences in methane and hexane penetration in pores in bituminous coal samples from the U.S., Canada, South Africa, and China, and maceral concentrates from Australian coals. This work is an extension of previous work that showed consistent differences between the extent of penetration by methane into 10–20 nm size pores in inertinite in bituminous coals from Australia, North America and Poland.In this study we have confirmed that there are differences in the response of inertinite to methane and hexane penetration in coals sourced from different coal basins. Inertinite in Permian Australian coals generally has relatively high numbers of pores in the 2.5–250 nm size range and the pores are highly penetrable by methane and hexane; coals sourced from Western Canada had similar penetrability to these Australian coals. However, the penetrability of methane and hexane into inertinite from the Australian Illawarra Coal Measures (also Permian) is substantially less than that of the other Australian coals; there are about 80% fewer 12 nm pores in Illawarra inertinite compared to the other Australian coals examined. The inertinite in coals sourced from South Africa and China had accessibility intermediate between the Illawarra coals and the other Australian coals.The extent of hexane penetration was 10–20% less than CD4 penetration into the same coal and this difference was most pronounced in the 5–50 nm pore size range. Hexane and methane penetrability into the coals showed similar trends with inertinite content.The observed variations in inertinite porosity between coals from different coal regions and coal basins may explain why previous studies differ in their observations of the relationships between gas sorption behavior, permeability, porosity, and maceral composition. These variations are not simply a demarcation between Northern and Southern Hemisphere coals.

Separation of unburned carbon from coal fly ash through froth flotation; Sekitanbai no shisshiki datsutanso gijutsu kaihatsu shiken

Energy Technology Data Exchange (ETDEWEB)

Miwa, T [Center for Coal Utilization, Japan, Tokyo (Japan); Murakami, T [The Coal Mining Research Center, Japan, Tokyo (Japan)

1996-09-01

Coal ash tends to become containing more unburned carbon and porous substances depending on conditions of combustion, whose adverse effects to products due to water adsorbability, absorbability and color tones create obstacles in its utilization. Therefore, research and development works have been progressed on wet type carbon removing technology which is characterized in that coal is pulverized to preferable degrees and subjected to flotation. This paper reports the results obtained during fiscal 1995. The results may be summarized as follows: as a result of the comparison test on a column flotation machine and an FW type flotation machine of machine stirring type, the former machine showed better flotation efficiency; several methods were investigated on crushing as a treatment prior to flotation, whereas a mixer with greater circumferential speed and a homo mixer showed the highest efficiency; strength of the impact to the flotation efficiency was found to decrease in the order of pulp concentration > pretreatment time > collector addition ratio; and as a result of the evaluation on refined ash as a cement admixture and carbons as fuel, possibilities were found in them for practical application. 16 figs., 2 tabs.

Integrating Waste Heat from CO₂ Removal and Coal-Fired Flue Gas to Increase Plant Efficiency

Energy Technology Data Exchange (ETDEWEB)

Irvin, Nick [Southern Company Services, Inc., Birmingham, AL (United States); Kowalczyk, Joseph [Southern Company Services, Inc., Birmingham, AL (United States)

2017-04-01

In project DE-FE0007525, Southern Company Services demonstrated heat integration methods for the capture and sequestration of carbon dioxide produced from pulverized coal combustion. A waste heat recovery technology (termed High Efficiency System) from Mitsubishi Heavy Industries America was integrated into an existing 25-MW amine-based CO₂ capture process (Kansai Mitsubishi Carbon Dioxide Recovery Process®1) at Southern Company’s Plant Barry to evaluate improvements in the energy performance of the pulverized coal plant and CO₂ capture process. The heat integration system consists of two primary pieces of equipment: (1) the CO₂ Cooler which uses product CO₂ gas from the capture process to heat boiler condensate, and (2) the Flue Gas Cooler which uses air heater outlet flue gas to further heat boiler condensate. Both pieces of equipment were included in the pilot system. The pilot CO₂ Cooler used waste heat from the 25-MW CO₂ capture plant (but not always from product CO₂ gas, as intended). The pilot Flue Gas Cooler used heat from a slipstream of flue gas taken from downstream of Plant Barry’s air heater. The pilot also included a 0.25-MW electrostatic precipitator. The 25-MW High Efficiency System operated for approximately six weeks over a four month time period in conjunction with the 25-MW CO₂ capture facility at Plant Barry. Results from the program were used to evaluate the technical and economic feasibility of full-scale implementation of this technology. The test program quantified energy efficiency improvements to a host power plant that could be realized due to the High Efficiency System. Through the execution of this project, the team verified the integrated operation of the High Efficiency System and Kansai Mitsubishi Carbon Dioxide Recovery Process®. The ancillary benefits of the High Efficiency System were also quantified, including reduced water consumption

NONEQUILIBRIUM SULFUR CAPTURE AND RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

International Nuclear Information System (INIS)

Dr. Bert Zauderer

1999-01-01

Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. They are deposited on the liquid slag layer on the combustor wall. Due to the low solubility of sulfur in slag, slag must be rapidly drained from the combustor to limit sulfur gas re-evolution. Analysis indicated that slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to perform a series of tests to determine the factors that control the retention of the sulfur in the slag. 36 days of testing on the combustor were completed prior to the end of this reporting period, 12/31/98. This compares with 16 tests required in the original project plan. Combustor tests in early 1997 with high (37%) ash, Indian coal confirmed that high slag mass flow rates of about 500 lb/hr resulted in retention in the slag of up to 20% of the injected sulfur content mineral matter. To further increase the slag flow rate, rice husks, which contain 20% ash, and rice husk char, which contain 70% ash, were co-fired with coal in the combustor. A series of 13 combustor tests were performed in fourth quarter of 1997 and a further 6 tests were performed in January 1998 and in the summer of 1998. The test objective was to achieve slag flow rates between 500 and 1,000 lb/hr. Due to the very low bulk density of rice husk, compared to pulverized coal, almost the entire test effort focused on developing methods for feeding the rice husks into combustor. In the last test of December 1997, a peak mineral matter, injection rate of 592 lb/hr was briefly achieved by injection of coal, rice husk char, gypsum, and limestone into the combustor. However, no significant sulfur concentration was measured in the slag removed from the combustor. The peak injection rate reached with biomass in the 1997 tests was 310 lb/hr with rice husk, and 584 lb/hr with rice husk char

SAMPLING, ANALYSIS, AND PROPERTIES OF PRIMARY PM-2.5: APPLICATION TO COAL-FIRED UTILITY BOILERS

Energy Technology Data Exchange (ETDEWEB)

Allen L. Robinson; Spyros N. Pandis; Eric Lipsky; Charles Stainer; Natalie Anderson; Satoshi Takahama; Sarah Rees

2003-02-01

A dilution sampler was used to examine the effects of dilution ratio and residence time on the particulate emissions from a pilot-scale pulverized coal combustor. Measurements include the particle size distribution from 0.003 to 2.5 {micro}m, PM{sub 2.5} mass emission rate and PM2.5 composition (OC/EC, major ions, and elemental). Hot filter samples were also collected simultaneously in order to compare the dilution sampler measurement with standard stack sampling methodologies such as EPA Method 5. Measurements were made both before and after the bag-house, the particle control device used on the coal combustor. Measurements were made with three different coal types and a coal-biomass blend. The residence time and dilution ratio do not influence the PM{sub 2.5} mass emission rate, but have a significant effect on the size distribution and total number emissions. Measurements made before the bag-house showed increasing the residence time dramatically decreases the total particle number concentration, and shifts the particle mass to larger sizes. The effects of residence time can be explained quantitatively by the coagulation of the emitted particles. Measurements made after the bag-house were not affected by coagulation due to the lower concentration of particles. Nucleation of sulfuric acid vapor within the dilution was an important source of ultrafine particles. This nucleation is strongly a function of dilution ratio because of the competition between condensation and nucleation. At low dilution ratios condensation dominates and little nucleation is observed; increasing the dilution ratio promotes nucleation because of the corresponding decrease in available surface area per unit volume for condensation. No nucleation was observed after the bag house where conditions greatly favor nucleation over condensation; we suspect that the bag house removed the SO{sub 3} in the flue gas. Exhaust SO{sub 3} levels were not measured during these experiments. Dilution caused

PSO Project 10085

DEFF Research Database (Denmark)

Jappe Frandsen, Flemming; Wu, Hao; Glarborg, Peter

Co-combustion of refuse derived fuels (RDF) with coal in pulverized coal-fired power plants can potentially increase the electrical efficiency of utilizing RDF and reduce the formation of some harmful pollutants such as dioxins. The objective of this project was to provide a general assessment of...

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

Energy Technology Data Exchange (ETDEWEB)

Smith, P.V. [Global Environmental Solutions, Inc., Morton Grove, IL (United States)

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.

Analysis of industrial flame characteristics and constancy study using image processing technique

Directory of Open Access Journals (Sweden)

Bibhuti Bhusan Samantaray

2015-12-01

Full Text Available The study of characterizing and featuring different kinds of flames has become more important than ever in order to increase combustion efficiency and decrease particulate emissions, especially since the study of industrial flames requires more attention. In the present work, different kinds of combustion flames have been characterized by means of digital image processing (DIP in a 500 kW PF pilot swirl burner. A natural gas flame and a set of pulverized fuel flames of coal and biomass have been comparatively analyzed under co-firing conditions. Through DIP, statistical and spectral features of the flame have been extracted and graphically represented as two-dimensional distributions covering the root flame area. Their study and comparison leads to different conclusions about the flame behavior and the effect of co-firing coal and biomass in pulverized fuel flames. Higher oscillation levels in co-firing flames versus coal flames and variations in radiation regimen were noticed when different biomasses are blended with coal and brought under attention.

ENGINEERING FEASIBILITY AND ECONOMICS OF CO2 SEQUESTRATION/USE ON AN EXISTING COAL-FIRED POWER PLANT: A LITERATURE REVIEW

Energy Technology Data Exchange (ETDEWEB)

Carl R. Bozzuto; Nsakala ya Nsakala

2000-01-31

The overall objective of this study is to evaluate the technical feasibility and the economics of alternate CO{sub 2} capture and sequestration/use technologies for retrofitting an existing pulverized coal-fired power plant. To accomplish this objective three alternative CO{sub 2} capture and sequestration systems will be evaluated to identify their impact on an existing boiler, associated boiler auxiliary components, overall plant operation and performance and power plant cost, including the cost of electricity. The three retrofit technologies that will be evaluated are as follows: (1) Coal combustion in air, followed by CO{sub 2} separation from flue gas with Kerr-McGee/ABB Lummus Global's commercial MEA-based absorption/stripping process. (2) Coal combustion in an O{sub 2}/CO{sub 2} environment with CO{sub 2} recycle. (3) Coal combustion in air with oxygen removal and CO{sub 2} captured by tertiary amines In support of this objective and execution of the evaluation of the three retrofit technologies a literature survey was conducted. It is presented in an ''annotated'' form, consistent with the following five sections: (1) Coal Combustion in O{sub 2}/CO{sub 2} Media; (2) Oxygen Separation Technologies; (3) Post Combustion CO{sub 2} Separation Technologies; (4) Potential Utilization of CO{sub 2}; and (5) CO{sub 2} Sequestration. The objective of the literature search was to determine if the three retrofit technologies proposed for this project continue to be sound choices. Additionally, a review of the literature would afford the opportunity to determine if other researchers have made significant progress in developing similar process technologies and, in that context, to revisit the current state-of-the-art. Results from this literature survey are summarized in the report.

Effect of large aspect ratio of biomass particles on carbon burnout in a utility boiler

Energy Technology Data Exchange (ETDEWEB)

D. Gera; M.P. Mathur; M.C. Freeman; Allen Robinson [Fluent, Inc./NETL, Morgantown, WV (United States)

2002-12-01

This paper reports on the development and validation of comprehensive combustion sub models that include the effect of large aspect ratio of biomass (switchgrass) particles on carbon burnout and temperature distribution inside the particles. Temperature and carbon burnout data are compared from two different models that are formulated by assuming (i) the particles are cylindrical and conduct heat internally, and (ii) the particles are spherical without internal heat conduction, i.e., no temperature gradient exists inside the particle. It was inferred that the latter model significantly underpredicted the temperature of the particle and, consequently, the burnout. Additionally, some results from cofiring biomass (10% heat input) with pulverized coal (90% heat input) are compared with the pulverized coal (100% heat input) simulations and coal experiments in a tangentially fired 150 MW{sub e} utility boiler. 26 refs., 7 figs., 4 tabs.

Near-Zero Emissions Oxy-Combustion Flue Gas Purification Task 2: SOx/Nox/Hg Removal for High Sulfur Coal

Energy Technology Data Exchange (ETDEWEB)

Nick Degenstein; Minish Shah; Doughlas Louie

2012-05-01

The goal of this project is to develop a near-zero emissions flue gas purification technology for existing PC (pulverized coal) power plants that are retrofitted with oxy-combustion technology. The objective of Task 2 of this project was to evaluate an alternative method of SOx, NOx and Hg removal from flue gas produced by burning high sulfur coal in oxy-combustion power plants. The goal of the program was not only to investigate a new method of flue gas purification but also to produce useful acid byproduct streams as an alternative to using a traditional FGD and SCR for flue gas processing. During the project two main constraints were identified that limit the ability of the process to achieve project goals. 1) Due to boiler island corrosion issues >60% of the sulfur must be removed in the boiler island with the use of an FGD. 2) A suitable method could not be found to remove NOx from the concentrated sulfuric acid product, which limits sale-ability of the acid, as well as the NOx removal efficiency of the process. Given the complexity and safety issues inherent in the cycle it is concluded that the acid product would not be directly saleable and, in this case, other flue gas purification schemes are better suited for SOx/NOx/Hg control when burning high sulfur coal, e.g. this project's Task 3 process or a traditional FGD and SCR.

Fundamental study of the pulverized coal char combustion in oxyfuel mode with drop tube furnace

Energy Technology Data Exchange (ETDEWEB)

Ito, Takamasa; Takafuji, Makoto; Suda, Toshiyuki; Fujimori, Toshiro [Heat and Fluid Dynamics Department, Yokohama (Japan)

2013-07-01

The combustion characteristics of coal char particles in either O{sub 2}/N{sub 2} or O{sub 2}/CO{sub 2} conditions were experimentally investigated. Especially, the char burnout, the char particle temperature and the shrinkage of the char particles were discussed. A Drop Tube Furnace (DTF: whose wall temperature was set at 873, 923 and 973 K) was used as the experimental apparatus. The experimental results revealed that, in equivalent oxygen concentration, the char burnout and the char particle temperature were higher in O{sub 2}/N{sub 2} conditions than those in O{sub 2}/CO{sub 2} conditions. The shrinkage of the char particle did not show the large difference in either O{sub 2}/N{sub 2} or O{sub 2}/CO{sub 2} conditions. Up to 15% of char burnout, the char particle diameters were reduced gradually. Up to 80% of char burnout, the char particle diameters were not changed. This is supposed that the chemical reaction is mainly occurred not on the external surface but on the internal surface of the char particle. Over 80% of char burnout, sudden shrinkage could be seen. Finally, an empirical equation for the prediction of the char particle shrinkage was introduced. Further investigation is required in high operating temperature, where CO{sub 2} gasification may have a large influence on the char burnout.

Fluidized bed boiler feed system

Science.gov (United States)

Jones, Brian C.

1981-01-01

A fluidized bed boiler feed system for the combustion of pulverized coal. Coal is first screened to separate large from small particles. Large particles of coal are fed directly to the top of the fluidized bed while fine particles are first mixed with recycled char, preheated, and then fed into the interior of the fluidized bed to promote char burnout and to avoid elutriation and carryover.

Coal geopolitics

International Nuclear Information System (INIS)

Giraud, P.N.; Suissa, A.; Coiffard, J.; Cretin, D.

1991-01-01

This book divided into seven chapters, describes coal economic cycle. Chapter one: coals definition; the principle characteristics and properties (origin, calorific power, international classification...) Chapter two: the international coal cycle: coal mining, exploration, coal reserves estimation, coal handling coal industry and environmental impacts. Chapter three: the world coal reserves. Chapter four: the consumptions, productions and trade. Chapter five: the international coal market (exporting mining companies; importing companies; distributors and spot market operators) chapter six: the international coal trade chapter seven: the coal price formation. 234 refs.; 94 figs. and tabs [fr

DRUCKFLAMM - Investigation on combustion and hot gas cleanup in pulverized coal combustion systems. Final report; DRUCKFLAMM - Untersuchungen zur Verbrennung und Heissgasreinigung bei der Druckkohlenstaubfeuerung. Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Hein, K.R.G.; Benoehr, A.; Schuermann, H.; Stroehle, J.; Klaiber, C.; Kuhn, R.; Maier, J.; Schnell, U.; Unterberger, S.

2001-07-01

The ambitions of making energy supply more efficient and less polluting brought forth the development of coal based combined cycle power plants allowing considerable increases in net efficiencies. One of the regarded firing concepts for a coal based combined cycle power plant is represented by the pressurised pulverised coal combustion process which has the highest efficiency potential compared with the other coal based concepts. The fundamental purpose of the project was to gain firm knowledge concerning firing behaviour of coal in a pressurised pulverised coal combustion system. Detailed investigations were carried out in a pressurised entrained flow reactor taking into account fuel conversion and particle behaviour, pollutant formation and material behaviour under conditions of a pressurised pulverised coal firing. During the project's investigations several different measurement techniques were tested and partially also acquired (e.g. a two-colour-pyrometry system to measure simultaneous particle surface temperature and particle diameter of burning fuel particles). Calculation models under pressurised conditions for pressure vessel simulation and better scale-up were developed synchronously with the experimental investigations. The results gained using the pressurised entrained flow reactor show that many combustion mechanisms are influenced by increased pressure, for instance the fuel conversion is intensified and at the same time pollutant emissions decreased. The material investigations show that the ceramic materials used due to the very high combustion temperatures are very sensitive versus slagging and fast temperature changes, therefore further development requirements are needed to fully realise the high durability of ceramics in the pressurised furnace. Concerning the improvement of existing models for furnace simulation under pressurised conditions, a good resemblance can be observed when considering the actual measurement results from the test

TOXIC SUBSTANCES FROM COAL COMBUSTION-A COMPREHENSIVE ASSESSMENT

Energy Technology Data Exchange (ETDEWEB)

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

UU focused on the behavior of trace metals in the combustion zone by studying vaporization from single coal particles. The coals were burned at 1700 K under a series of fuel-rich and oxygen-rich conditions. The data collected in this study will be applied to a model that accounts for the full equilibrium between carbon monoxide and carbon dioxide. The model also considers many other reactions taking place in the combustion zone, and involves the diffusion of gases into the particle and combustion products away from the particle. A comprehensive study has been conducted at UA to investigate the post-combustion partitioning of trace elements during large-scale combustion of pulverized coal combustion. For many coals, there are three distinct particle regions developed by three separate mechanisms: (1) a submicron fume, (2) a micron-sized fragmentation region, and (3) a bulk (>3 {micro}m) fly ash region. The controlling partitioning mechanisms for trace elements may be different in each of the three particle regions. A substantial majority of semi-volatile trace elements (e.g., As, Se, Sb, Cd, Zn, Pb) volatilize during combustion. The most common partitioning mechanism for semi-volatile elements is reaction with active fly ash surface sites. Experiments conducted under this program at UC focused on measuring mercury oxidation under cooling rates representative of the convective section of a coal-fired boiler to determine the extent of homogeneous mercury oxidation under these conditions. In fixed bed studies at EERC, five different test series were planned to evaluate the effects of temperature, mercury concentration, mercury species, stoichiometric ratio of combustion air, and ash source. Ash samples generated at UA and collected from full-scale power plants were evaluated. Extensive work was carried out at UK during this program to develop new methods for identification of mercury species in fly ash and sorbents. We demonstrated the usefulness of XAFS spectroscopy for

Co-combustion of pulverized coal and solid recovered fuel in an entrained flow reactor- General combustion and ash behavior

DEFF Research Database (Denmark)

Wu, Hao; Glarborg, Peter; Frandsen, Flemming

2011-01-01

.9 wt.%, 14.8 wt.% and 25 wt.%, respectively. The effect of additives was evaluated by maintaining the share of secondary fuel (mixture of SRF and additive) at 14.8 wt.%. The experimental results showed that the fuel burnout, NO and SO2 emission in co-combustion of coal and SRF were decreased...... with increasing share of SRF. The majority of the additives inhibited the burnout, except for NaCl which seemed to have a promoting effect. The impact of additives on NO emission was mostly insignificant, except for ammonium sulphate which greatly reduced the NO emission. For SO2 emission, it was found that all...

Emissions from carpet combustion in a pilot-scale rotary kiln: comparison with coal and particle-board combustion

Energy Technology Data Exchange (ETDEWEB)

Stephanie Lucero Konopa; James A. Mulholland; Matthew J. Realff; Paul M. Lemieux [Georgia Institute of Technology, Atlanta, GA (United States). School of Civil and Environmental Engineering

2008-08-15

The use of post-consumer carpet as a potential fuel substitute in cement kilns and other high-temperature processes is being considered to address the problem of huge volumes of carpet waste and the opportunity of waste-to-energy recovery. Carpet represents a high volume waste stream, provides high energy value, and contains other recoverable materials for the production of cement. This research studied the emission characteristics of burning 0.46-kg charges of chopped nylon carpet squares, pulverized coal, and particle-board pellets in a pilot-scale natural gas-fired rotary kiln. Carpet was tested with different amounts of water added. Emissions of oxygen, carbon dioxide, nitric oxide (NO), sulfur dioxide (SO{sub 2}), carbon monoxide (CO), and total hydrocarbons and temperatures were continuously monitored. It was found that carpet burned faster and more completely than coal and particle board, with a rapid volatile release that resulted in large and variable transient emission peaks. NO emissions from carpet combustion ranged from 0.06 to 0.15 g/MJ and were inversely related to CO emissions. Carpet combustion yielded higher NO emissions than coal and particleboard combustion, consistent with its higher nitrogen content. S{sub 2} emissions were highest for coal combustion, consistent with its higher sulfur content than carpet or particle board. Adding water to carpet slowed its burn time and reduced variability in the emission transients, reducing the CO peak but increasing NO emissions. Results of this study indicate that carpet waste can be used as an effective alternative fuel, with the caveats that it might be necessary to wet carpet or chop it finely to avoid excessive transient puff emissions due to its high volatility compared with other solid fuels, and that controlled mixing of combustion air might be used to control NO emissions from nylon carpet. 13 refs., 5 figs., 1 tab.

Effect of phosphorous transformation on the reduction of PM{sub 10} formation during Co-combustion of coal and sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Zhuo, J.K.; Dong, M.; Li, G.D.; Li, S.Q.; Song, Q.; Yao, Q. [Tsinghua Univ., Beijing (China). Key Lab. of Thermal Science and Power Engineering; Duan, L. [Tsinghua Univ., Beijing (China). Dept. of Environmental Science and Engineering

2013-07-01

Co-combustion of Municipal Sewage Sludge with coal will become increasingly widely used, regarded as an important incineration method with the high thermal efficiency, low emissions, low investment and operating costs. However, the presence of phosphorus in fine particle has gained increased attention due to its environmental adverse affection and deactivation of SCR DeNOx catalysts. Therefore, the behavior of phosphorus in fine particles during co-combustion of coal and sewage sludge was investigated in a 25 kW quasi one-dimensional down-fired pulverized coal combustor, where PM{sub 10} was collected from the furnace centerline in the outlet of flue gas cooler by using a two-stage nitrogen-aspirated, water-cooling isokinetic sampling probe followed a 13-stage electric low pressure impactor. Then the formation mechanism of PM{sub 10} was investigated by observing the different fractions of sewage sludge in the coal. Similar to the coal combustion, the particle-size-distributions (PSD) of PM{sub 10} mass concentration by co-combustion of sewage sludge with coal exhibit two distinct modes separated by a fraction of 0.157-0.263 {mu}m, ultrafine mode and intermediate mode. With the sewage sludge blended sludge up to 15% (thermal ratio), the mass concentration of the total fly ash and PM{sub 10+} (Dp > 10 {mu}m) vastly increased from 1,088 and 547 mg/Nm{sup 3} (during coal combustion) to 5,059 and 4,403 mg/Nm{sup 3}. However, the mass concentration of fine particulates, such as PM{sub 1}, PM{sub 2.5} and PM{sub 10} was maintained at the emission level of coal combustion. When the fraction of sewage sludge less than 15%, the mass concentration of fine particle is higher than the emission during coal combustion, while the growth rate is only by the 3.6, 7.9 and 4.8% of the total concentration of fly ash (5% thermal). The change of the PSD of mass concentration during co- combustion of sewage sludge and coal, mainly was caused by the interaction between Si, Al and Ca, Fe

Characterization of open-cycle coal-fired MHD generators. Quarterly technical summary report No. 6, October 1--December 31, 1977. [PACKAGE code

Energy Technology Data Exchange (ETDEWEB)

Kolb, C.E.; Yousefian, V.; Wormhoudt, J.; Haimes, R.; Martinez-Sanchez, M.; Kerrebrock, J.L.

1978-01-30

Research has included theoretical modeling of important plasma chemical effects such as: conductivity reductions due to condensed slag/electron interactions; conductivity and generator efficiency reductions due to the formation of slag-related negative ion species; and the loss of alkali seed due to chemical combination with condensed slag. A summary of the major conclusions in each of these areas is presented. A major output of the modeling effort has been the development of an MHD plasma chemistry core flow model. This model has been formulated into a computer program designated the PACKAGE code (Plasma Analysis, Chemical Kinetics, And Generator Efficiency). The PACKAGE code is designed to calculate the effect of coal rank, ash percentage, ash composition, air preheat temperatures, equivalence ratio, and various generator channel parameters on the overall efficiency of open-cycle, coal-fired MHD generators. A complete description of the PACKAGE code and a preliminary version of the PACKAGE user's manual are included. A laboratory measurements program involving direct, mass spectrometric sampling of the positive and negative ions formed in a one atmosphere coal combustion plasma was also completed during the contract's initial phase. The relative ion concentrations formed in a plasma due to the methane augmented combustion of pulverized Montana Rosebud coal with potassium carbonate seed and preheated air are summarized. Positive ions measured include K/sup +/, KO/sup +/, Na/sup +/, Rb/sup +/, Cs/sup +/, and CsO/sup +/, while negative ions identified include PO/sub 3//sup -/, PO/sub 2//sup -/, BO/sub 2//sup -/, OH/sup -/, SH/sup -/, and probably HCrO/sub 3/, HMoO/sub 4//sup -/, and HWO/sub 3//sup -/. Comparison of the measurements with PACKAGE code predictions are presented. Preliminary design considerations for a mass spectrometric sampling probe capable of characterizing coal combustion plasmas from full scale combustors and flow trains are presented

Future carbon regulations and current investments in alternative coal-fired power plant technologies

International Nuclear Information System (INIS)

Sekar, Ram C.; Parsons, John E.; Herzog, Howard J.; Jacoby, Henry D.

2007-01-01

We analyze how uncertain future US carbon regulations shape the current choice of the type of power plant to build. Our focus is on two coal-fired technologies, pulverized coal (PC) and integrated coal gasification combined cycle technology (IGCC). The PC technology is cheapest-assuming there is no need to control carbon emissions. The IGCC technology may be cheaper if carbon must be captured. Since power plants last many years and future regulations are uncertain, a US electric utility faces a standard decision under uncertainty. A company will confront the range of possible outcomes, assigning its best estimate of the probability of each scenario, averaging the results and determining the power plant technology with the lowest possible cost inclusive of expected future carbon related costs, whether those costs be in the form of emissions charges paid or capital expenditures for retrofitting to capture carbon. If the company assigns high probability to no regulation or to less stringent regulation of carbon, then it makes sense for it to build the PC plant. But if it assigns sufficient probability to scenarios with more stringent regulation, then the IGCC technology is warranted. We provide some useful benchmarks for possible future regulation and show how these relate back to the relative costs of the two technologies and the optimal technology choice. Few of the policy proposals widely referenced in the public discussion warrant the choice of the IGCC technology. Instead, the PC technology remains the least costly. However, recent carbon prices in the European Emissions Trading System are higher than these benchmarks. If it is any guide to possible future penalties for emissions in the US, then current investment in the IGCC technology is warranted. Of course, other factors need to be factored into the decision as well

Coal 1992

Energy Technology Data Exchange (ETDEWEB)

1992-01-01

ACR's Coal 1992, the successor to the ACR Coal Marketing Manual, contains a comprehensive set of data on many aspects of the Australian coal industry for several years leading up to 1992. Tables and text give details of coal production and consumption in New South Wales, Queensland and other states. Statistics of the Australian export industry are complemented by those of South Africa, USA, New Zealand, Canada, Indonesia, China, Colombia, Poland and ex-USSR. Also listed are prices of Australian coking and non-coking coal, Australian coal stocks (and those of other major countries), loading port capacities, freight rates and coal quality requirements (analysis of coals by brand and supplier). A listing of Australian coal exporting companies is provided. A description of the spot Coal Screen Dealing System is given. World hard coal imports are listed by country and coal imports by major Asian countries tabulated. A forecast of demand by coal type and country up to the year 2000 is included.

Characterization of Coal Porosity for Naturally Tectonically Stressed Coals in Huaibei Coal Field, China

Science.gov (United States)

Li, Xiaoshi; Hou, Quanlin; Li, Zhuo; Wei, Mingming

2014-01-01

The enrichment of coalbed methane (CBM) and the outburst of gas in a coal mine are closely related to the nanopore structure of coal. The evolutionary characteristics of 12 coal nanopore structures under different natural deformational mechanisms (brittle and ductile deformation) are studied using a scanning electron microscope (SEM) and low-temperature nitrogen adsorption. The results indicate that there are mainly submicropores (2~5 nm) and supermicropores (coal and mesopores (10~100 nm) and micropores (5~10 nm) in brittle deformed coal. The cumulative pore volume (V) and surface area (S) in brittle deformed coal are smaller than those in ductile deformed coal which indicates more adsorption space for gas. The coal with the smaller pores exhibits a large surface area, and coal with the larger pores exhibits a large volume for a given pore volume. We also found that the relationship between S and V turns from a positive correlation to a negative correlation when S > 4 m2/g, with pore sizes coal. The nanopore structure (coal. PMID:25126601

Increase of Ecological Safety, Reliability and Efficiency of Coal-Fired Boilers

Directory of Open Access Journals (Sweden)

Volkov E.P.

2017-04-01

Full Text Available The changes of environmental legislation of the Russian Federation will lead to a drastic increase of the ecological payments for environmental pollution in excess of technological standards. Significant excess in relative emissions of nitrogen oxides take place in burning solid fuel with liquid slag-tap removal. The purpose of this article was to develop technical solutions for low-cost reconstruction of the boilers to ensure efficient combustion of the fuel and technological standards of emissions of nitrogen oxides. As shown the use of straight-flow burners with compulsory optimization of the aerodynamics of the furnace and the organization of staged combustion of fuel will provide low nitrogen oxide emissions and efficient fuel combustion. Research on physical models has demonstrated the feasibility of increasing the angle of the pulverized coal burners down to 65-70o, and also achieved a more uniform distribution and increase the speed of the jets coming from upper and lower tertiary air vertical compartments of nozzles through the installation of the vertical extra sheets, which guide the flow in a space between jets. The results obtained allow the transfer of existing boilers with slag-tag removal to a solid with the installation of direct-flow burners and optimization of the aerodynamics of the furnace, which provides regulations for energy efficiency and ecological safety corresponding to the best, achieved technologies, and dramatically reduces environmental payments. The proposed technology in boiler BKZ-210-140F allowed reducing emissions of nitrogen oxides by more than 2 times when burning highly reactive Kuznetsk coal, as shown as an example.

The behavior of ash species in suspension fired biomass boilers

DEFF Research Database (Denmark)

Jensen, Peter Arendt

While fluid bed and grate fired boilers initially was the choice of boilers used for power production from both wood and herbaceous biomass, in recent years suspension fired boilers have been increasingly used for biomass based power production. In Denmark several large pulverized fuel boilers have...... been converted from coal to biomass combustion in the last 15 years. This have included co-firing of coal and straw, up to 100% firing of wood or straw andthe use of coal ash as an additive to remedy problems with wood firing. In parallel to the commercialization of the pulverized biomass firing...... technology a long range of research studies have been conducted, to improve our understanding of the influence and behavior of biomass ash species in suspension fired boilers. The fuel ash plays a key role with respect tooptimal boiler operation and influences phenomena’s as boiler chamber deposit formation...

Coal upgrading

Energy Technology Data Exchange (ETDEWEB)

Nunes, S. [IEA Clean Coal Centre, London (United Kingdom)

2009-10-15

This report examines current technologies and those likely to be used to produce cleaner coal and coal products, principally for use in power generation and metallurgical applications. Consideration is also given to coal production in the leading coal producing countries, both with developed and developing industries. A range of technologies are considered. These include the coal-based liquid fuel called coal water mixture (CWM) that may compete with diesel, the production of ultra-clean coal (UCC) and coal liquefaction which competes with oil and its products. Technologies for upgrading coal are considered, especially for low rank coals (LRC), since these have the potential to fill the gap generated by the increasing demand for coal that cannot be met by higher quality coals. Potential advantages and downsides of coal upgrading are outlined. Taking into account the environmental benefits of reduced pollution achieved through cleaner coal and reduced transport costs, as well as other positive aspects such as a predictable product leading to better boiler design, the advantages appear to be significant. The drying of low rank coals improves the energy productively released during combustion and may also be used as an adjunct or as part of other coal processing procedures. Coal washing technologies vary in different countries and the implications of this are outlined. Dry separation technologies, such as dry jigging and electrostatic separation, are also described. The demonstration of new technologies is key to their further development and demonstrations of various clean coal technologies are considered. A number of approaches to briquetting and pelletising are available and their use varies from country to country. Finally, developments in upgrading low rank coals are described in the leading coal producing countries. This is an area that is developing rapidly and in which there are significant corporate and state players. 81 refs., 32 figs., 3 tabs.

SYSTEM OF PRECISE DOSING OF COAGULANT IN THE PULVERIZING AERATOR POWERED BY WIND USING FUZZY LOGIC

Directory of Open Access Journals (Sweden)

Andrzej Osuch

2017-06-01

Full Text Available One of the methods used to support land restoration lakes is the method of pulverizing aeration. Use of aerators powered exclusively by wind improves the condition of reservoirs, while not compromising the environment. The pulverizing aeration process drive is windy on the water aeration zone near bottom, while removing harmful gases anaerobic metabolism. Aerators of this type due to the unique method of operation also enable dosing of inactivation coagulants with oxygenated water to the depths of the lake. Mileage coagulant dosing can be made dependent on the speed of the wind, which has an impact on the performance of his work, because with the increase of wind speed dispensing valve coagulants should be stronger open. One of the methods for assessing the state of lakes is to measure water transparency. The softer visibility, the most likely state of the water is better. Dosage of coagulant so you can make the transparency of the water. Similarly, with increasing transparency water dispensing valve should be more covered up. Control of the drain valve dispenser coagulant can be simultaneously dependent on two factors. The study was designed method of control drain valve dispenser coagulant using fuzzy inference.

Advanced design nuclear power plants: Competitive, economical electricity. An analysis of the cost of electricity from coal, gas and nuclear power plants

International Nuclear Information System (INIS)

1992-06-01

This report presents an updated analysis of the projected cost of electricity from new baseload power plants beginning operation around the year 2000. Included in the study are: (1) advanced-design, standardized nuclear power plants; (2) low emissions coal-fired power plants; (3) gasified coal-fired power plants; and (4) natural gas-fired power plants. This analysis shows that electricity from advanced-design, standardized nuclear power plants will be economically competitive with all other baseload electric generating system alternatives. This does not mean that any one source of electric power is always preferable to another. Rather, what this analysis indicates is that, as utilities and others begin planning for future baseload power plants, advanced-design nuclear plants should be considered an economically viable option to be included in their detailed studies of alternatives. Even with aggressive and successful conservation, efficiency and demand-side management programs, some new baseload electric supply will be needed during the 1990s and into the future. The baseload generating plants required in the 1990s are currently being designed and constructed. For those required shortly after 2000, the planning and alternatives assessment process must start now. It takes up to ten years to plan, design, license and construct a new coal-fired or nuclear fueled baseload electric generating plant and about six years for a natural gas-fired plant. This study indicates that for 600-megawatt blocks of capacity, advanced-design nuclear plants could supply electricity at an average of 4.5 cents per kilowatt-hour versus 4.8 cents per kilowatt-hour for an advanced pulverized-coal plant, 5.0 cents per kilowatt-hour for a gasified-coal combined cycle plant, and 4.3 cents per kilowatt-hour for a gas-fired combined cycle combustion turbine plant

MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

Energy Technology Data Exchange (ETDEWEB)

E.G. Eddings; A. Molina; D.W. Pershing; A.F. Sarofim; K.A. Davis; M.P. Heap; T.H. Fletcher; H. Zhang

2000-04-01

Reduction of NO{sub x} emission is an important environmental issue in pulverized coal combustion. The most cost-effective approach to NO{sub x} reduction is air-staging which can also operate with additional down-stream techniques such as reburning [1]. Air staging promotes the conversion of NO{sub x} precursors (HCN, NH{sub 3}, etc.) to N{sub 2} by delaying the oxygen supply to the greatest extent when those nitrogen species are released during devolatilization. Such a delay gives the primary volatiles a chance to undergo secondary reactions, including tar cracking and soot formation. Secondary reactions of volatiles largely determine the fate of the ultimate NO{sub x} production from pyrolysis, therefore a detailed investigation into the transformation of nitrogen species during secondary reactions and effects of soot on nitrogen release is critical for design and implementation of new pollution control strategies. Current nitrogen models (including the CPD model at BYU) only simulate the nitrogen release during primary pyrolysis, which happens at low temperatures. This project helps to build a nitrogen release model that accounts for secondary reactions and the effects of soot at temperatures relevant to industrial burners.

Bio-coal briquettes using low-grade coal

Science.gov (United States)

Estiaty, L. M.; Fatimah, D.; Widodo

2018-02-01

The technology in using briquettes for fuel has been widely used in many countries for both domestic and industrial purposes. Common types of briquette used are coal, peat, charcoal, and biomass. Several researches have been carried out in regards to the production and the use of briquettes. Recently, researches show that mixing coal and biomass will result in an environmentally friendly briquette with better combustion and physical characteristics. This type of briquette is known as bio-coal briquettes. Bio-coal briquettes are made from agriculture waste and coal, which are readily available, cheap and affordable. Researchers make these bio-coal briquettes with different aims and objectives, depending on the issues to address, e.g. utilizing agricultural waste as an alternative energy to replace fossil fuels that are depleting its reserves, adding coal to biomass in order to add calorific value to bio-coal briquette, and adding biomass to coal to improve its chemical and physical properties. In our research, biocoal briquettes are made to utilize low grade coal. The biomass we use, however, is different from the ones used in past researches because it has undergone fermentation. The benefits of using such biomass are 1. Fermentation turns the hemi cellulose into a simpler form, so that the burning activation energy decreases while the calorific value increases. 2. Enzym produced will bind to heavy metals from coal as co-factors, forming metals that are environmentally friendly.

Coal

International Nuclear Information System (INIS)

Teissie, J.; Bourgogne, D. de; Bautin, F.

2001-12-01

Coal world production represents 3.5 billions of tons, plus 900 millions of tons of lignite. 50% of coal is used for power generation, 16% by steel making industry, 5% by cement plants, and 29% for space heating and by other industries like carbo-chemistry. Coal reserves are enormous, about 1000 billions of tons (i.e. 250 years of consumption with the present day rate) but their exploitation will be in competition with less costly and less polluting energy sources. This documents treats of all aspects of coal: origin, composition, calorific value, classification, resources, reserves, production, international trade, sectoral consumption, cost, retail price, safety aspects of coal mining, environmental impacts (solid and gaseous effluents), different technologies of coal-fired power plants and their relative efficiency, alternative solutions for the recovery of coal energy (fuel cells, liquefaction). (J.S.)

CoalVal-A coal resource valuation program

Science.gov (United States)

Rohrbacher, Timothy J.; McIntosh, Gary E.

2010-01-01

CoalVal is a menu-driven Windows program that produces cost-of-mining analyses of mine-modeled coal resources. Geological modeling of the coal beds and some degree of mine planning, from basic prefeasibility to advanced, must already have been performed before this program can be used. United States Geological Survey mine planning is done from a very basic, prefeasibility standpoint, but the accuracy of CoalVal's output is a reflection of the accuracy of the data entered, both for mine costs and mine planning. The mining cost analysis is done by using mine cost models designed for the commonly employed, surface and underground mining methods utilized in the United States. CoalVal requires a Microsoft Windows? 98 or Windows? XP operating system and a minimum of 1 gigabyte of random access memory to perform operations. It will not operate on Microsoft Vista?, Windows? 7, or Macintosh? operating systems. The program will summarize the evaluation of an unlimited number of coal seams, haulage zones, tax entities, or other area delineations for a given coal property, coalfield, or basin. When the reader opens the CoalVal publication from the USGS website, options are provided to download the CoalVal publication manual and the CoalVal Program. The CoalVal report is divided into five specific areas relevant to the development and use of the CoalVal program: 1. Introduction to CoalVal Assumptions and Concepts. 2. Mine Model Assumption Details (appendix A). 3. CoalVal Project Tutorial (appendix B). 4. Program Description (appendix C). 5. Mine Model and Discounted Cash Flow Formulas (appendix D). The tutorial explains how to enter coal resource and quality data by mining method; program default values for production, operating, and cost variables; and ones own operating and cost variables into the program. Generated summary reports list the volume of resource in short tons available for mining, recoverable short tons by mining method; the seam or property being mined

Development of melting system using oxy-coal combustion; Sekitan chokusetsu riyo kinzoku yoyu system gijutsu (NSR) (pilot setsubi unten jokyo ni tsuite)

Energy Technology Data Exchange (ETDEWEB)

Sugiyama, T [Center for Coal Utilization, Japan, Tokyo (Japan); Suwa, T; Kobayashi, N; Iino, K; Yamamoto, Y; Igarashi, H [Nippon Sanso K.K., Tokyo (Japan)

1996-09-01

This metal melting system is a process to efficiently melt and regenerate scraps of aluminum, copper and iron by utilizing high-temperature energy obtained from pulverized coal-oxygen combustion. The process is intended to utilize coal in place of petroleum for reduced fuel cost. Joint studies have been carried out as a subsidy operation of the Agency of Natural Resources and Energy with a schedule of six years starting fiscal 1992. Development tests are being performed using a 5-ton/ch pilot plant facility since fiscal 1995 after having gone through experiments using a 1-ton/ch bench scale furnace. This paper reports the results obtained to date. Using the pilot plant facility, fiscal 1995 has achieved the initial target values, such as thermal efficiency of 55% or higher, and yield of 96% or higher for non-ferrous metals and 94% or higher for iron. The melting behavior in the furnace has improved the thermal efficiency as a whole by retaining the conditions in the preheating step for an extended period of time. The thermal efficiency has been improved better than with the bench furnace as a result of upscaling effect. 9 figs., 3 tabs.

Coking coal outlook from a coal producer's perspective

International Nuclear Information System (INIS)

Thrasher, E.

2008-01-01

Australian mine production is recovering from massive flooding while Canadian coal shipments are limited by mine and rail capacity. Polish, Czech, and Russian coking coal shipments have been reduced and United States coking coal shipments are reaching their maximum capacity. On the demand side, the Chinese government has increased export taxes on metallurgical coal, coking coal, and thermal coal. Customers seem to be purchasing in waves and steel prices are declining. This presentation addressed the global outlook for coal as well as the challenges ahead in terms of supply and demand. Supply challenges include regulatory uncertainty; environmental permitting; labor; and geology of remaining reserves. Demand challenges include global economic uncertainty; foreign exchange values; the effect of customers making direct investments in mining operations; and freight rates. Consolidation of the coal industry continued and several examples were provided. The presentation also discussed other topics such as coking coal production issues; delayed mining permits and environmental issues; coking coal contract negotiations; and stock values of coking coal producers in the United States. It was concluded that consolidation will continue throughout the natural resource sector. tabs., figs

A theoretical study using the multiphase numerical simulation technique for effective use of H2 as blast furnaces fuel

Directory of Open Access Journals (Sweden)

Jose Adilson de Castro

2017-07-01

Full Text Available We present a numerical simulation procedure for analyzing hydrogen, oxygen and carbon dioxide gases injections mixed with pulverized coals within the tuyeres of blast furnaces. Effective use of H2 rich gas is highly attractive into the steelmaking blast furnace, considering the possibility of increasing the productivity and decreasing the specific emissions of carbon dioxide becoming the process less intensive in carbon utilization. However, the mixed gas and coal injection is a complex technology since significant changes on the inner temperature and gas flow patterns are expected, beyond to their effects on the chemical reactions and heat exchanges. Focusing on the evaluation of inner furnace status under such complex operation a comprehensive mathematical model has been developed using the multi interaction multiple phase theory. The BF, considered as a multiphase reactor, treats the lump solids (sinter, small coke, pellets, granular coke and iron ores, gas, liquids metal and slag and pulverized coal phases. The governing conservation equations are formulated for momentum, mass, chemical species and energy and simultaneously discretized using the numerical method of finite volumes. We verified the model with a reference operational condition using pulverized coal of 215 kg per ton of hot metal (kg thm−1. Thus, combined injections of varying concentrations of gaseous fuels with H2, O2 and CO2 are simulated with 220 kg thm−1 and 250 kg thm−1 coals injection. Theoretical analysis showed that stable operations conditions could be achieved with productivity increase of 60%. Finally, we demonstrated that the net carbon utilization per ton of hot metal decreased 12%.

Coal contract cost reduction through resale of coal

International Nuclear Information System (INIS)

Simon, R.

1990-01-01

The weak coal market of the 1980's has enabled utilities and other users of coal to enjoy stable or falling prices for coal supplies. Falling prices for coal stimulated the renegotiation of numerous coal contracts in recent years, as buyers look to take advantage of lower fuel prices available in the marketplace. This paper examines the use of coal resale transactions as a means of reducing fuel costs, and analyzes the benefits and risks associated with such transactions

Optimization of pulverised coal combustion by means of CFD/CTA modeling

Directory of Open Access Journals (Sweden)

Filkoski Risto V.

2006-01-01

Full Text Available The objective of the work presented in this paper was to apply a method for handling two-phase reacting flow for prediction of pulverized coal combustion in large-scale boiler furnace and to assess the ability of the model to predict existing power plant data. The paper presents the principal steps and results of the numerical modeling of power boiler furnace with tangential disposition of the burners. The computational fluid dynamics/computational thermal analysis (CFD/CTA approach is utilized for creation of a three-dimensional model of the boiler furnace, including the platen superheater in the upper part of the furnace. Standard k-e model is employed for description of the turbulent flow. Coal combustion is modeled by the mixture fraction/probability density function approach for the reaction chemistry, with equilibrium assumption applied for description of the system chemistry. Radiation heat transfer is computed by means of the simplified P-N model, based on the expansion of the radiation intensity into an orthogonal series of spherical harmonics. Some distinctive results regarding the examined boiler performance in capacity range between 65 and 95% are presented graphically. Comparing the simulation predictions and available site measurements concerning temperature, heat flux and combustion efficiency, a conclusion can be drawn that the model produces realistic insight into the furnace processes. Qualitative agreement indicates reasonability of the calculations and validates the employed sub-models. After the validation and verification of the model it was used to check the combustion efficiency as a function of coal dust sieve characteristics, as well as the impact of burners modification with introduction of over fire air ports to the appearance of incomplete combustion, including CO concentration, as well as to the NOx concentration. The described case and other experiences with CFD/CTA stress the advantages of numerical modeling and

Australian Coal Company Risk Factors: Coal and Oil Prices

OpenAIRE

M. Zahid Hasan; Ronald A. Ratti

2014-01-01

Examination of panel data on listed coal companies on the Australian exchange over January 1999 to February 2010 suggests that market return, interest rate premium, foreign exchange rate risk, and coal price returns are statistically significant in determining the excess return on coal companies’ stock. Coal price return and oil price return increases have statistically significant positive effects on coal company stock returns. A one per cent rise in coal price raises coal company returns ...

Coal Tar and Coal-Tar Pitch

Science.gov (United States)

Learn about coal-tar products, which can raise your risk of skin cancer, lung cancer, and other types of cancer. Examples of coal-tar products include creosote, coal-tar pitch, and certain preparations used to treat skin conditions such as eczema, psoriasis, and dandruff.

An experimental and mathematical modeling study comparing the reactivity and burnout of pulverized coal in air (O{sub 2}/N{sub 2}) and oxyfuel (O{sub 2}/CO{sub 2}) environments

Energy Technology Data Exchange (ETDEWEB)

Liza Elliott; Yinghui Liu; Bart Buhre; Jennifer Martin; Raj Gupta; Terry Wall [University of Newcastle, Callaghan, NSW (Australia). Cooperative Research Centre for Coal in Sustainable Development, Chemical Engineering

2005-07-01

Carbon dioxide in flue gas from conventional combustion processes is present as a dilute gas. CO{sub 2} capture is more easily achieved from a concentrated CO{sub 2} stream, which can be achieved by firing fuels with oxygen to obtain a sequestration ready gas stream, called oxy-fuel combustion. In this technology, the oxygen stream is usually diluted by recycled flue gas (RFG), so that the coal burns in an environment which is primarily O{sub 2}/CO{sub 2}. A size cut of a number of pulverised coals were devolatalised in N{sub 2} and CO{sub 2}. These sized coals were also combusted in a drop-tube furnace in an O{sub 2}/N{sub 2} environment simulating air combustion, and O{sub 2}/CO{sub 2} simulating oxyfuel combustion, with varying O{sub 2} levels from 3 to 30% v/v. Measurements of the extent of devolatilisation and coal burnout were completed. The detailed data provided for one coal indicated that the devolatilisation process in the O{sub 2}/CO{sub 2} environments is influenced by char gasification, and the char reaction rates are fitted better by a fractional order rate than first order in oxygen. Combustion rates in the oxyfuel environment were slightly higher. Estimates of the burnout for furnaces retrofitted from air to oxyfuel indicate that a better burnout can be expected. These trends were common for all coals. 14 refs., 4 figs., 5 tabs.

Coal summit II

Energy Technology Data Exchange (ETDEWEB)

1983-01-01

Various papers were presented on world coal trade. Papers include: Poland as a producer and exporter of coal; the dynamics of world coal trade; Cerrejon coal production perspectives; present state of the Australian coal industry; present state of the EC coal market and future prospects; prospects of US coal exports to Europe; forecast of Italian coal supply and demand through 1990; statistics from coal transportation outlook; status of world coal ports.

Particle-size distribution (PSD) of pulverized hair: A quantitative approach of milling efficiency and its correlation with drug extraction efficiency.

Science.gov (United States)

Chagas, Aline Garcia da Rosa; Spinelli, Eliani; Fiaux, Sorele Batista; Barreto, Adriana da Silva; Rodrigues, Silvana Vianna

2017-08-01

Different types of hair were submitted to different milling procedures and their resulting powders were analyzed by scanning electron microscopy (SEM) and laser diffraction (LD). SEM results were qualitative whereas LD results were quantitative and accurately characterized the hair powders through their particle size distribution (PSD). Different types of hair were submitted to an optimized milling conditions and their PSD was quite similar. A good correlation was obtained between PSD results and ketamine concentration in a hair sample analyzed by LC-MS/MS. Hair samples were frozen in liquid nitrogen for 5min and pulverized at 25Hz for 10min, resulting in 61% of particles sample extracted after pulverization comparing with the same sample cut in 1mm fragments. When milling time was extended to 25min, >90% of particles were sample retesting and quality control procedures. Copyright © 2017 Elsevier B.V. All rights reserved.

Pulverizing processes affect the chemical quality and thermal property of black, white, and green pepper (Piper nigrum L.).

Science.gov (United States)

Liu, Hong; Zheng, Jie; Liu, Pengzhan; Zeng, Fankui

2018-06-01

In this study, the effects of different pulverizing methods on the chemical attributes and thermal properties of black, white and green pepper were evaluated. Cryogenic grinding minimally damaged the lipid, moisture, crude protein, starch, non-volatile ether extract, piperine, essential oil and the typical pepper essential oil compounds of the spices. The pulverizing methods and storage significantly affected the compositions of the fatty acid in the peppers, except for palmitic acid and lignoceric acid. The amino acid contents and the thermo-gravimetric analysis curve were hardly influenced by the grinding techniques. The use of cryogenic grinding to prepare pepper ensured the highest quality of pepper products. Regardless of grinding technique, the values of moisture, piperine, unsaturated fatty acids, essential oil, monoterpenes, and the absolute concentrations of typical pepper essential oil constituents (except caryophyllene oxide) decreased, whereas the amino acid, lipid, protein, starch, and non-volatile ether extract content as well as the thermal properties were insignificantly changed after storage at 4 °C for 6 months.

Measurement of gas species, temperatures, coal burnout, and wall heat fluxes in a 200 MWe lignite-fired boiler with different overfire air damper openings

Energy Technology Data Exchange (ETDEWEB)

Jianping Jing; Zhengqi Li; Guangkui Liu; Zhichao Chen; Chunlong Liu [Harbin Institute of Technology, Harbin (China). School of Energy Science and Engineering

2009-07-15

Measurements were performed on a 200 MWe, wall-fired, lignite utility boiler. For different overfire air (OFA) damper openings, the gas temperature, gas species concentration, coal burnout, release rates of components (C, H, and N), furnace temperature, and heat flux and boiler efficiency were measured. Cold air experiments for a single burner were conducted in the laboratory. The double-swirl flow pulverized-coal burner has two ring recirculation zones starting in the secondary air region in the burner. As the secondary air flow increases, the axial velocity of air flow increases, the maxima of radial velocity, tangential velocity and turbulence intensity all increase, and the swirl intensity of air flow and the size of recirculation zones increase slightly. In the central region of the burner, as the OFA damper opening widens, the gas temperature and CO concentration increase, while the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and coal particles ignite earlier. In the secondary air region of the burner, the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and the gas temperature and CO concentration vary slightly. In the sidewall region, the gas temperature, O{sub 2} concentration, and NOx concentration decrease, while the CO concentration increases and the gas temperature varies slightly. The furnace temperature and heat flux in the main burning region decrease appreciably, but increase slightly in the burnout region. The NOx emission decreases from 1203.6 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 0% to 511.7 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 80% and the boiler efficiency decreases from 92.59 to 91.9%. 15 refs., 17 figs., 3 tabs.

Low-Pressure and Low-Temperature Hydriding-Pulverization-Dehydriding Method for Producing Shape Memory Alloy Powders

Science.gov (United States)

Murguia, Silvia Briseño; Clauser, Arielle; Dunn, Heather; Fisher, Wendy; Snir, Yoav; Brennan, Raymond E.; Young, Marcus L.

2018-04-01

Shape memory alloys (SMAs) are of high interest as active, adaptive "smart" materials for applications such as sensors and actuators due to their unique properties, including the shape memory effect and pseudoelasticity. Binary NiTi SMAs have shown the most desirable properties, and consequently have generated the most commercial success. A major challenge for SMAs, in particular, is their well-known compositional sensitivity. Therefore, it is critical to control the powder composition and morphology. In this study, a low-pressure, low-temperature hydriding-pulverization-dehydriding method for preparing well-controlled compositions, size, and size distributions of SMA powders from wires is presented. Starting with three different diameters of as-drawn martensitic NiTi SMA wires, pre-alloyed NiTi powders of various well-controlled sizes are produced by hydrogen charging the wires in a heated H3PO4 solution. After hydrogen charging for different charging times, the wires are pulverized and subsequently dehydrided. The wires and the resulting powders are characterized using scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction. The relationship between the wire diameter and powder size is investigated as a function of hydrogen charging time. The rate of diameter reduction after hydrogen charging of wire is also examined. Finally, the recovery behavior due to the shape memory effect is investigated after dehydriding.

Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas

International Nuclear Information System (INIS)

Zhang, F.M.; Liu, B.S.; Zhang, Y.; Guo, Y.H.; Wan, Z.Y.; Subhan, Fazle

2012-01-01

Highlights: ► A series of mesoporous Cu x Mn y O z /SBA-15 sorbents were fabricated for hot coal gas desulfurization. ► 1Cu9Mn/SBA-15 sorbent with high breakthrough sulfur capacity is high stable and regenerable. ► Utilization of SBA-15 constrained the sintering and pulverization of sorbents. - Abstract: A series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700–850 °C. The successive nine desulfurization–regeneration cycles at 800 °C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn 2 O 3 particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800 °C is 13.8 g S/100 g sorbents, which is remarkably higher than these of 40 wt%LaFeO 3 /SBA-15 (4.8 g S/100 g sorbents) and 50 wt%LaFe 2 O x /MCM-41 (5.58 g S/100 g sorbents) used only at 500–550 °C. This suggested that the loading of Mn 2 O 3 active species with high thermal stability to SBA-15 support significantly increased sulfur capacity at relatively higher sulfidation temperature. The fresh and used xCuyMn/SBA-15 sorbents were characterized by means of BET, XRD, XPS, XAES, TG/DSC and HRTEM techniques, confirmed that the structure of the sorbents remained intact before and after hot coal gas desulfurization.

Coal-92

International Nuclear Information System (INIS)

Hillring, B.; Sparre, C.

1992-11-01

Swedish consumption of coal and coke during 1991 and trends in technology, environment and market aspects of coal use are reported. Steam coal use in the heating sector was unchanged from 1991, 1.2 Mtons. Reduced consumption in smaller district heating units (due to conversion to biofuels and gas) was compensated by increased use for power generation in cogeneration plants. Coal consumption in industry fell 0.10 Mton to 0.84 Mton due to lower production in one industry branch. Import of steam coal was 1.1 Mton (down 0.5 Mton from 1990) since new rules for strategic reserves allowed a reduction of stocks. During the last five years stocks have been reduced by 2 Mtons. Import of metallurgical coal was 1.6 Mton, unchanged from 1990. The report also gives statistics for the coal using plants in Sweden, on coal R and D, and on emission laws for coal firing. (9 tabs., 2 figs.)

Environmental and economic gains of the conversion of the Zvolen (Slovakia) district CHP plant from low quality brown coal combustion to co-firing of biomass and low-sulphur brown coal

International Nuclear Information System (INIS)

Ilavsky, Jan; Jankovsky, Julius

2006-01-01

Zvolen CHP plant was originally commissioned in 1954. Overall installed output is 311 MW in heat production and 44,3 MW in power. Annual supply to the consumers was 788,910 GJ of heat and 102,459 GJ of electricity in 2004. Some 60 % of the heat production was used for heat and hot water supply to more than 9,000 houses and apartments and 40 % to industrial consumers. It uses pulverized lignite with up to 1 % of sulphur content as fuel. The content of sulphur in emitted flue gas is as high as 3,500-4,000 mg SO 2 /m 3 . It causes serious environmental problems in the region. New national limits for greenhouse gases emissions are 1.700 mg SO 2 /m 3 and 600 mg NO x /m 3 with effect from 1 January 2007. CHP is not able to achieve them without substantial improvement of technology with very high investment costs. Several alternatives of technical changes have been analysed in a study. Shift from lignite to low-sulphur content brown coal with co-firing of biomass has been identified economically most feasible and environmentally acceptable solution. The paper presents results of the study analysing the whole chain from biomass resources in the region up to the technical solutions for boilers reconstruction. The first part of the study was focused at identification of biomass resources for energy use from forestry, wood processing industry and agriculture. Ecological, economic and operational factors limiting utilization of potential biomass resources were identified and factored into calculations. Two boilers, each of them with the output of 108 MW t , will be reconstructed for co-firing of pulverized low sulphur content brown coal and biomass. Biomass will share up to 30% of the combusted fuel. After the reconstruction one boiler will remain with the same output of 108 MW t and the other will be with the output of 65 MW t . Power will be produced by the back pressure 25 MW e turbine. Chips will be stored in 9.000 m 3 open depot and in 3.000 m 3 silo. Chips will be fed

Efficiency of using direct-flow burners and nozzles in implementation of dry-bottom ash removal at the TPP-210A boiler furnace

Science.gov (United States)

Arkhipov, A. M.; Kanunnikov, A. A.; Kirichkov, V. S.; Prokhorov, V. B.; Fomenko, M. V.; Chernov, S. L.

2017-02-01

In reconstruction of operating pulverized coal-fired boilers, one of the main factors is the choice of a method for slag removal: dry bottom ash removal (DBAR) or slag-tap removal (STR). In this case, ecological and economic aspects should be taken into account, and also the early ignition of pulverized coal fuel, the reliability of operation of the furnace walls in the mode without slagging, and the stability of slag removal should be provided. In this work, issues of changeover of the pulverized coal-fired boilers of the TPP-210A type from the STR mode to the DBAR mode are considered. As of today, the main problems during the operation of these boilers are the high emissions of nitrogen oxides together with flue gases into the atmosphere and the appropriated payoffs, a small range of loads available, the necessity of stabilization of the pulverizedcoal flame sustainability by using the highly reactive fuel, large mechanical fuel underburning, etc. Results of studying aerodynamics of a furnace with DBAR obtained in the process of physical simulation are given; technical solutions and preliminary design (configuration of burners and nozzles in the boiler furnace, conceptual design of the pulverized coal burner, configuration of TPP-210A boiler with the low heat liberation of furnace cross-section and volumetric heat release) are set forth, which are associated with the optimization of aerodynamics of furnace volume, when the direct-flow burners and nozzles are used, and with organization of the efficient staged combustion of solid fuel. Two versions of possible modernization of a boiler unit are considered. Under conditions of the planned increase in the steam production capacity, the most promising measures are as follows: the DBAR implementation with reducing heat releases of the cross-section and volume of the furnace approximately by half, the installation of the direct-flow burners and nozzles with injection of recirculation gases into the active combustion

Predicted coal production trends in Kentucky: The results of available coal resources, coal quality demands, and regulatory factors

International Nuclear Information System (INIS)

Watson, W.D.

1993-01-01

Many factors affect the viability of regional coal production markets including (1) coal quality and recoverable tonnage, (2) coal mining cost, (3) the regional and time varying patterns of coal demand growth, (4) regulations and other institutional constraints that affect coal demand and utilization, and (5) the regional array of coal transport modes and rates. This analysis integrates these factors into an assessment of coal production prospects (separately) for eastern and western Kentucky coal producing counties for the decade of the 90's. The integration indicates that eastern Kentucky coal production will peak and begin to decline by the end of the decade whereas western Kentucky coal production will continue to grow. No single factor explains these trends. There is plenty of available minable coal. The combination of changes in environmental regulations, some increase in coal mining costs, and the mining-out of low sulfur reserves are the main factors that account for the production trends

Variability of Mercury Content in Coal Matter From Coal Seams of The Upper Silesia Coal Basin

Science.gov (United States)

Wierzchowski, Krzysztof; Chećko, Jarosław; Pyka, Ireneusz

2017-12-01

The process of identifying and documenting the quality parameters of coal, as well as the conditions of coal deposition in the seam, is multi-stage and extremely expensive. The taking and analyzing of seam samples is the method of assessment of the quality and quantity parameters of coals in deep mines. Depending on the method of sampling, it offers quite precise assessment of the quality parameters of potential commercial coals. The main kind of seam samples under consideration are so-called "documentary seam samples", which exclude dirt bands and other seam contaminants. Mercury content in coal matter from the currently accessible and exploited coal seams of the Upper Silesian Coal Basin (USCB) was assessed. It was noted that the mercury content in coal seams decreases with the age of the seam and, to a lesser extent, seam deposition depth. Maps of the variation of mercury content in selected lithostratigraphic units (layers) of the Upper Silesian Coal Basin have been created.

Cocombustion of secondary fuels with Rhenish brown coal; Mitverbrennung von Sekundaerbrennstoffen mit rheinischer Braunkohle

Energy Technology Data Exchange (ETDEWEB)

Gerhardt, Alexander; Kull, Rene; Zepf, Eva; Fuller, Aaron; Maier, Joerg; Scheffknecht, Guenter [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen; Jong, Martin de [KEMA Nederland B.V. (Netherlands); Glorius, Thomas [REMONDIS Trade and Sales GmbH (Germany)

2008-07-01

The Institute of Combustion and Power Plant of Technology of the University of Stuttgart (Stuttgart, Federal Republic of Germany) performs scientific research within the range of solid firings. The cocombustion of secondary fuels in coal-fired power stations as well as the production of secondary fuels are examined in the project RECOFUEL. The production of secondary fuels is performed from harmless house wastes and commercial wastes as well as from biological residues from forestry and agriculture. Secondary fuels offer an alternative to fossil fuels for the power production in different branches of industry and reduce the emission of carbon dioxide from fossil sources. For the attempts in two power stations of RWE Power AG (Essen, Federal Republic of Germany) the quality-certified secondary fuel SBS1 registered of the company Remondis GmbH (Luenen, Federal Republic of Germany) was used. This secondary fuel was developed and subjected to an intensive analysis. Experiments in a pulverized fuel furnace and in a fluidised bed were performed at the power stations Weisweiler and Berrenrath in order to examine different aspects of the cocombustion.

Coal blending preparation for non-carbonized coal briquettes

Science.gov (United States)

Widodo; Fatimah, D.; Estiaty, L. M.

2018-02-01

Referring to the national energy policy targets for the years 2025, the government has launched the use of coal briquettes as an alternative energy replacement for kerosene and firewood. Non-carbonized briquettes in the form of coal briquettes as well as bio-coal briquettes are used in many small-medium industries and households, and are rarely used by large industries. The standard quality of coal briquettes used as raw material for non-carbonized briquettes is a minimum calorific value of 4,400 kcal/kg (adb); total sulfur at a maximum of 1% (adb), and water content at plants), the environment of deposition, and the geological conditions of the surrounding area, so that the coal deposits in each region will be different as well as the amount and also the quality. Therefore, the quantity and the quality of coal in each area are different to be eligible in the making of briquettes to do blending. In addition to the coal blending, it is also necessary to select the right materials in the making of coal briquettes and bio-coal briquettes. The formulation of the right mixture of material in the making of briquettes, can be produced of good quality and environmental friendly.

Demonstrating a New Census of Infrared Galaxies with ALMA (DANCING-ALMA). I. FIR Size and Luminosity Relation at z = 0-6 Revealed with 1034 ALMA Sources

Science.gov (United States)

Fujimoto, Seiji; Ouchi, Masami; Shibuya, Takatoshi; Nagai, Hiroshi

2017-11-01

We present the large statistics of the galaxy effective radius R e in the rest-frame far-infrared (FIR) wavelength {R}{{e}({FIR})} obtained from 1627 Atacama Large Millimeter/submillimeter Array (ALMA) 1 mm band maps that become public by 2017 July. Our ALMA sample consists of 1034 sources with the star formation rate ˜ 100{--}1000 {M}⊙ {{yr}}-1 and the stellar mass ˜ {10}10{--}{10}11.5 {M}⊙ at z = 0-6. We homogeneously derive {R}{{e}({FIR})} and FIR luminosity L FIR of our ALMA sources via the uv-visibility method with the exponential disk model, carefully evaluating selection and measurement incompletenesses by realistic Monte-Carlo simulations. We find that there is a positive correlation between {R}{{e}({FIR})} and L FIR at the >99% significance level. The best-fit power-law function, {R}{{e}({FIR})}\\propto {L}{FIR}α , provides α =0.28+/- 0.07, and shows that {R}{{e}({FIR})} at a fixed L FIR decreases toward high redshifts. The best-fit α and the redshift evolution of {R}{{e}({FIR})} are similar to those of R e in the rest-frame UV (optical) wavelength {R}{{e}({UV})} ({R}{{e}({Opt}.)}) revealed by Hubble Space Telescope (HST) studies. We identify that our ALMA sources have significant trends of {R}{{e}({FIR})}≲ {R}{{e}({UV})} and {R}{{e}({Opt}.)}, which suggests that the dusty starbursts take place in compact regions. Moreover, {R}{{e}({FIR})} of our ALMA sources is comparable to {R}{{e}({Opt}.)} of quiescent galaxies at z ˜ 1-3 as a function of stellar mass, supporting the evolutionary connection between these two galaxy populations. We also investigate rest-frame UV and optical morphologies of our ALMA sources with deep HST images, and find that ˜30%-40% of our ALMA sources are classified as major mergers. This indicates that dusty starbursts are triggered by not only the major mergers but also the other mechanism(s).

Feasibility study on energy conservation and environmental improvement at Pakistan Steel

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Feasibility study on energy conservation and environmental improvement was carried out with the aim of considering the realization of the CDM (clean development mechanism) project for reduction of global warming gas emissions and contributing to the environmental improvement and economic growth in Pakistan. In the study, projects on the following were studied: coke oven coal moisture control (CMC), sinter cooler waste heat recovery, blast furnace hot stove waste heat recovery, blast furnace pulverized coal injection (PCI), blast furnace top pressure recovery turbine (TRT), hot strip mill reheating furnace regenerative type burner, coke oven environmental improvement, and blast furnace cast house dust collection. As a result of the study, the implementation of the following three projects was regarded as promising in terms of energy conservation and economical effects: blast furnace pulverized coal injection, blast furnace top pressure recovery turbine and hot strip mill reheating furnace regenerative type burner. Further, the reduction in poisonous gas by the coke oven environmental improvement project was made a top priority. In Pakistan, the price of energy is kept low, and therefore, effects of energy conservation projects are not very much expected. However, the PCI project has an effect of substitution of low-priced domestic coal for imported coal. (NEDO)

Geochemistry of coals, coal ashes and combustion wastes from coal-fired power stations

International Nuclear Information System (INIS)

Vassilev, S.V.; Vassileva, C.G.

1997-01-01

Contents, concentration trends, and modes of occurrence of 67 elements in coals, coal ashes, and combustion wastes at eleven Bulgarian thermoelectric power stations (TPS) were studied. A number of trace elements in coal and coal ash have concentrations greater than their respective worldwide average contents (Clarke values). Trace elements are concentrated mainly in the heavy accessory minerals and organic matter in coal. In decreasing order of significance, the trace elements in coal may occur as: element-organic compounds; impurities in the mineral matter; major components in the mineral matter; major and impurity components in the inorganic amorphous matter; and elements in the fluid constituent. A number of trace elements in the waste products, similar to coal ashes, exceed known Clarke contents. Trace elements are mainly enriched in non-magnetic, heavy and fine-grained fractions of fly ash. They are commonly present as impurities in the glass phases, and are included in the crystalline components. Their accessory crystalline phases, element-organic compounds, liquid and gas forms, are of subordinate importance. Some elements from the chalcophile, lithophile and siderophile groups may release into the atmosphere during coal burning. For others, the combustion process appears to be a powerful factor causing their relative enrichment in the fly ash and rarely in the bottom ash and slag. 65 refs., 1 fig., 11 tabs

New coal

Energy Technology Data Exchange (ETDEWEB)

1979-07-01

Specially dedicated to coal, this edition comprises a series of articles of general interest dealing with the position of the French coalmining industry (interview with M.P. Gardent), the coal market in France, the work of CERCHAR, etc. New techniques, in-situ gasification of deep coal, gasification of coal by nuclear methods, the conversion of coal into petrol, the Emile Huchet power plant of Houilleres du Bassin de Lorraine, etc., are dealt with.

Report on 1979 result of R and D under Sunshine Project. Development of coal liquefaction technology (development of solvent treatment and liquefaction plant); 1979 nendo sekitan ekika gijutsu no kaihatsu seika hokokusho. Yozai shori ekika plant no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1980-03-01

A report was made on the result for fiscal 1979 of the development of a coal solvent treatment and liquefaction plant. With the purpose of establishing a technology of making equipment for a coal liquefaction plant by a solvent treatment method, R and D were conducted on a solid liquid separation method and on the construction and operation of an experimental equipment having a scale of the maximum 1 t/day coal processing, providing technical data for the construction of an efficient coal liquefaction equipment. In studying the operation of a centrifugal separator, it was run using heating solvent, dummy slurry and coal extraction slurry, with no abnormality found in each equipment and with knowledge obtained of the separation state of the solid. The machine is capable of obtaining SRC of 0.2-0.3% low ash contents. Water operation was performed for the extraction processing device (agitation tank, heating furnace, compression pump, circulation pump, etc.) of the 1 t/day experimental plant and, as a result, a relation was confirmed between a water flow rate and pressure loss of the piping part. The detailed design, manufacture and installation were completed for a part (pulverizer, solvent tank, feeding pump, etc.) of the equipment for the coal pre-processing slurry making process and the extraction process, with a trial run implemented for adjustment and confirmation of the operation. The cold/hot continuous trial run by a solvent smoothly proceeded, proving the performance to be the same as the specifications. (NEDO)

Industrial use of coal and clean coal technology

Energy Technology Data Exchange (ETDEWEB)

Leibson, I; Plante, J J.M.

1990-06-01

This report builds upon two reports published in 1988, namely {ital The use of Coal in the Industrial, Commercial, Residential and Transportation Sectors} and {ital Innovative Clean Coal Technology Deployment}, and provides more specific recommendations pertaining to coal use in the US industrial sector. The first chapter addresses industrial boilers which are common to many industrial users. The subsequent nine chapters cover the following: coke, iron and steel industries; aluminium and other metals; glass, brick, ceramic, and gypsum industries; cement and lime industries; pulp and paper industry; food and kindred products; durable goods industry; textile industry; refining and chemical industry. In addition, appendices supporting the contents of the study are provided. Each chapter covers the following topics as applicable: energy overview of the industry sector being discussed; basic processes; foreign experience; impediments to coal use; incentives that could make coal a fuel of choice; current and projected use of clean coal technology; identification of coal technology needs; conclusions; recommendations.

Effect of secondary fuels and combustor temperature on mercury speciation in pulverized fuel co-combustion: part 1

Energy Technology Data Exchange (ETDEWEB)

Shishir P. Sable; Wiebren de Jong; Ruud Meij; Hartmut Spliethoff [Delft University Technology, Delft (Netherlands). Section Energy Technology, Department of Process and Energy

2007-08-15

The present work mainly involves bench scale studies to investigate partitioning of mercury in pulverized fuel co-combustion at 1000 and 1300{sup o}C. High volatile bituminous coal is used as a reference case and chicken manure, olive residue, and B quality (demolition) wood are used as secondary fuels with 10 and 20% thermal shares. The combustion experiments are carried out in an entrained flow reactor with a fuel input of 7-8 kWth. Elemental and total gaseous mercury concentrations in the flue gas of the reactor are measured on-line, and ash is analyzed for particulate mercury along with other elemental and surface properties. Animal waste like chicken manure behaves very differently from plant waste. The higher chlorine contents of chicken manure cause higher ionic mercury concentrations whereas even with high unburnt carbon, particulate mercury reduces with increase in the chicken manure share. This might be a problem due to coarse fuel particles, low surface area, and iron contents. B-wood and olive residue cofiring reduces the emission of total gaseous mercury and increases particulate mercury capture due to unburnt carbon formed, fine particles, and iron contents of the ash. Calcium in chicken manure does not show any effect on particulate or gaseous mercury. It is probably due to a higher calcium sulfation rate in the presence of high sulfur and chlorine contents. However, in plant waste cofiring, calcium may have reacted with chlorine to reduce ionic mercury to its elemental form. According to thermodynamic predictions, almost 50% of the total ash is melted to form slag at 1300{sup o}C in cofiring because of high calcium, iron, and potassium and hence mercury and other remaining metals are concentrated in small amounts of ash and show an increase at higher temperatures. No slag formation was predicted at 1000{sup o}C. 24 refs., 8 figs., 4 tabs.