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Sample records for bed combustion technical

  1. Technical evaluation: pressurized fluidized-bed combustion technology

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S A; Vogel, G J; Gehl, S M; Hanway, Jr, J E; Henry, R F; Parker, K M; Smyk, E B; Swift, W M; Podolski, W F

    1982-04-01

    The technology of pressurized fluidized-bed combustion, particularly in its application to a coal-burning combined-cycle plant, is evaluated by examining the technical status of advanced-concept plant components - boiler system (combustor, air-handling and air-injection equipment, and heat exchangers); solids handling, injection, and ejection system; hot-gas cleanup equipment; instrumentation/control system; and the gas turbine - along with materials of plant construction. Environmental performance as well as energy efficiency are examined, and economic considerations are reviewed briefly. The evaluation concludes with a broad survey of the principal related research and development programs in the United States and other countries, a foreview of the most likely technological developments, and a summary of unresolved technical issues and problems.

  2. Bed material agglomeration during fluidized bed combustion. Technical progress report, January 1, 1995--March 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Dawson, M.R.; Smeenk, J.L.

    1995-04-01

    Experiments performed support the hypothesis that a reducing atmosphere during fluidized bed coal combustion contributes to the formation of agglomerates. Reducing conditions are imposed by controlling the amount of combustion air supplied to the combustor, 50% of theoretical in these experiments. These localized reducing conditions may arise from either poor lateral bed mixing or oxygen-starved conditions due to the coal feed locations. Deviations from steady-state operating conditions in bed pressure drop may be used to detect agglomerate formation. Interpretation of the bed pressure drop was made more straightforward by employing a moving average difference method. During steady-state operation, the difference between the moving point averages should be close to zero, within {plus_minus}0.03 inches of water. Instability within the combustor, experienced once agglomerates begin to form, can be recognized as larger deviations from zero, on the magnitude of {plus_minus}0.15 inches of water.

  3. Proceedings of the sixth international conference on fluidized bed combustion. Volume II. Technical sessions

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-08-01

    The Sixth International Conference on Fluidized Bed Combustion was held April 9-11, 1980, at the Atlanta Hilton, Atlanta, Georgia. It was sponsored by the US Department of Energy, the Electric Power Research Institute, the US Environmental Protection Agency, and the Tennessee Valley Authority. The papers covered recent developments in atmospheric and pressurized fluidized-bed combustion, especially the design, operation and control of pilot and demonstration plants. The cleanup of combustion products and the erosion, corrosion and fouling of gas turbines was emphasized also. Fifty-five papers from Volume 2 of the proceedings have been entered individually into EDB and ERA; five papers had been entered previously from other sources. (LTN)

  4. Proceedings of the sixth international conference on fluidized bed combustion. Volume III. Technical sessions

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-08-01

    The Sixth International Conference on Fluidized Bed Combustion was held April 9-11, 1980, at the Atlanta Hilton, Atlanta, Georgia. It was sponsored by the US Department of Energy, the Electric Power Research Institute, the US Environmental Protection Agency, and the Tennessee Valley Authority. Forty-five papers from Vol. III of the proceedings have been entered individually into EDB and ERA. Two papers had been entered previously from other sources. (LTN)

  5. Fluidized bed combustion in praxis

    International Nuclear Information System (INIS)

    Operation at deregulated energy markets emphasize utilities competitiveness in power generation. This means power plant investment cost as well as operation and maintenance costs must be competitive to ensure economical performance. Improvements in competitiveness can also be achieved investing to modem combustion technology and this way improve power generation efficiency (lower fuel consumption). Other means to improve cost effectiveness are optimisation of daily operation and process control system but also improving fuel flexibility if feasible (fuel price). The other need for utilities in the future is of course environmental issues like reduction of CO2 emissions in particular. As known fluidized bed combustion offers many advantages that might be needed at future energy markets. These are superior fuel and operation flexibility, multi-fuel capability, environmental performance with inherently low NOx emissions due favourable combustion conditions and cost effective sulphur reduction applying in-furnace SO2 capture. These advantages makes fluidized bed combustion attractive alternative power generation in the future. The current trends for development of the technology are discussed in this paper. (authors)

  6. SEWAGE SLUDGE COMBUSTION IN A SPOUTED BED CASCADE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Mirko Barz

    2003-01-01

    @@ In modern society, sewage is disposed of in a two-step process: it is first made into granules and the sewage sludge granules are then burned in an appropriate combustor. The present paper describes a spouted bed cascade system for sewage sludge combustion developed at the Technical University of Berlin at the turn of the present century. Combustion results in the recovery of the combustible matters of the sewage in the form of thermal energy.

  7. Fluidized bed combustion of pesticide-manufacture liquid wastes

    Directory of Open Access Journals (Sweden)

    SAŠA MILETIĆ

    2010-04-01

    Full Text Available Industrial liquid wastes can be in the form of solutions, suspensions, sludges, scums or waste oil and have organic properties. The objective of this work was to demonstrate the technical feasibility of a fluidized bed as a clean technology for burning liquid waste from a pesticide production plant. The combustion of liquid waste mixtures, obtained from realistic samples, was investigated in a pilot scale fluidized bed with quartz sand particles of 0.63–1.25 mm in diameter and 2610 kg/m3 in density at 800–950 °C. To ensure complete combustion of liquid waste and additional fuel, the combustion chamber was supplied with excess air and the U/UmF (at ambient temperature was in between 1.1 and 2.3. In the fluidized bed chamber, liquid waste, additional liquid fuel and air can be brought into intense contact sufficient to permit combustion in bed without backfire problems. The experimental results show that the fluidized bed furnace offers excellent thermal uniformity and temperature control. The results of the combustion tests showed that degradation of liquid wastes can be successfully realized in a fluidized bed with no harmful gaseous emissions by ensuring that the temperatures of both the bed and the freeboard are not lower than 900 °C.

  8. CIRCULATING MOVING BED COMBUSTION PROOF OF CONCEPT

    Energy Technology Data Exchange (ETDEWEB)

    Jukkola, Glen

    2010-06-30

    Circulating Moving Bed (CMB) combustion technology has its roots in traditional circulating fluidized bed technology and involves a novel method of solid fuel combustion and heat transfer. CMB technology represents a step change in improved performance and cost relative to conventional PC and FBC boilers. The CMB heat exchanger preheats the energy cycle working fluid, steam or air, to the high temperature levels required in systems for advanced power generation. Unique features of the CMB are the reduction of the heat transfer surfaces by about 60% as a result of the enhanced heat transfer rates, flexibility of operation, and about 30% lower cost over existing technology. The CMB Phase I project ran from July 2001 through March 2003. Its objective was to continue development of the CMB technology with a series of proof of concept tests. The tests were conducted at a scale that provided design data for scale up to a demonstration plant. These objectives were met by conducting a series of experiments in ALSTOM Power’s Multi-use Test Facility (MTF). The MTF was modified to operate under CMB conditions of commercial interest. The objective of the tests were to evaluate gas-to-solids heat transfer in the upper furnace, assess agglomeration in the high temperature CMB bubbling bed, and evaluate solids-to-tube heat transfer in the moving bed heat exchanger. The Phase I program results showed that there are still some significant technical uncertainties that needed to be resolved before the technology can be confidently scaled up for a successful demonstration plant design. Work remained in three primary areas: • scale up of gas to solid heat transfer • high temperature finned surface design • the overall requirements of mechanical and process design. The CMB Phase II workscope built upon the results of Phase I and specifically addressed the remaining technical uncertainties. It included a scaled MTF heat transfer test to provide the necessary data to scale up gas

  9. Technical notes for the conceptual design for an atmospheric fluidized-bed direct combustion power generating plant. [570 MWe plant

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-04-01

    The design, arrangement, thermodynamics, and economics of a 578 MW(e) (nominal gross) electric power generating plant equipped with a Foster Wheeler Energy Corporation (FWEC) atmospheric fluidized bed (AFB) boiler are described. Information is included on capital and operating costs, process systems, electrical systems, control and instrumentation, and environmental systems. This document represents a portion of an overall report describing the conceptual designs of two atmospheric fluidized bed boilers and balance of plants for the generation of electric power and the analysis and comparison of these conceptual designs to a conventional pulverized coal-fired electric power generation plant equipped with a wet limestone flue gas desulfurization system.

  10. Technical notes for the conceptual design for an atmospheric fluidized-bed direct combustion power generating plant. [570 MWe plant

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-04-01

    The design, arrangement, thermodynamics, and economics of a 592 MW(e) (nominal gross) electric power generating plant equipped with a Babcock and Wilcox Company (B and W) atmospheric fluidized bed (AFB) boiler are described. Information is included on capital and operating costs, process systems, electrical systems, control and instrumentation, and environmental systems. This document represents a portion of an overall report describing the conceptual designs of two atmospheric fluidized bed boilers and balance of plants for the generation of electric power and the analysis and comparison of these conceptual designs to a conventional pulverized coal-fired electric power generation plant equipped with a wet limestone flue gas desulfurization system.

  11. Finial Scientific/Technical Report: Application of a Circulating Fluidized Bed Process for the Chemical Looping Combustion of Solid Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Wei-Ping Pan; Dr. John T. Riley

    2005-10-10

    Chemical Looping Combustion is a novel combustion technology for the inherent separation of the greenhouse gas, CO{sub 2}. In 1983, Richter and Knoche proposed reversible combustion, which utilized both the oxidation and reduction of metal. Metal associated with its oxidized form as an oxygen carrier was circulated between two reactors--oxidizer and reducer. In the reducer, the solid oxygen carrier reacts with the fuel to produce CO{sub 2}, H{sub 2}O and elemental metal only. Pure CO{sub 2} will be obtained in the exit gas stream from the reducer after H{sub 2}O is condensed. The pure CO{sub 2} is ready for subsequent sequestration. In the oxidizer, the elemental metal reacts with air to form metal oxide and separate oxygen from nitrogen. Only nitrogen and some unused oxygen are emitted from the oxidizer. The advantage of CLC compared to normal combustion is that CO{sub 2} is not diluted with nitrogen but obtained in a relatively pure form without any energy needed for separation. In addition to the energy-free purification of CO{sub 2}, the CLC process also provides two other benefits. First, NO{sub x} formation can be largely eliminated. Secondly, the thermal efficiency of a CLC system is very high. Presently, the CLC process has only been used with natural gas. An oxygen carrier based on an energy balance analysis and thermodynamics analysis was selected. Copper (Cu) seems to be the best choice for the CLC system for solid fuels. From this project, the mechanisms of CuO reduction by solid fuels may be as follows: (1) If pyrolysis products of solid fuels are available, reduction of CuO could start at about 400 C or less. (2) If pyrolysis products of solid fuels are unavailable and the reduction temperature is lower, reduction of CuO could occur at an onset temperature of about 500 C, char gasification reactivity in CO{sub 2} was lower at lower temperatures. (3) If pyrolysis products of solid fuels are unavailable and the reduction temperature is higher than 750 C

  12. Fluidised-bed combustion of gasification residue

    Energy Technology Data Exchange (ETDEWEB)

    Korpela, T.; Kudjoi, A.; Hippinen, I.; Heinolainen, A.; Suominen, M.; Lu Yong [Helsinki Univ. of Technology (Finland). Lab of Energy Economics and Power Plant Engineering

    1996-12-01

    Partial gasification processes have been presented as possibilities for future power production. In the processes, the solid materials removed from a gasifier (i.e. fly ash and bed material) contain unburnt fuel and the fuel conversion is increased by burning this gasification residue either in an atmospheric or a pressurised fluidised-bed. In this project, which is a part of European JOULE 2 EXTENSION research programme, the main research objectives are the behaviour of calcium and sulphur compounds in solids and the emissions of sulphur dioxide and nitrogen oxides (NO{sub x} and N{sub 2}O) in pressurised fluidised-bed combustion of gasification residues. (author)

  13. Improvement of Combustion Characteristics in Fluidized Bed

    International Nuclear Information System (INIS)

    The present investigation is directed towards the experimental study of the effect of a new design of the bed temperature on the overall thermal efficiency and heat transfer by conduction, convection and radiation in gaseous fuel-fluidized bed combustion system. The experiments are performed on a water-cooled fluidized bed model furnace with cylindrical cross-section of 0.25 m diameter and its height is 0.60 m. the fluidising medium used is sand particles with average diameter 1.5 mm. The bed temperature is varied between 700 degree C and 1100 degree C. Measurements f carbon dioxide, carbon monoxide and oxygen concentrations are carried out by using water-cooled sampling probe, and infrared and paramagnetic analyzers. The results obtained show that the bed temperature, the total heat transfer to the wall and the bed combustion efficiency increase with the decrease of the air-fuel ratio. It is also found that 91% of the total heat transfer is in the fluidising part of the bed and most of this heat is transferred by convection from hot sand particles to the wall. Two empirical formulae for the calculation of the wall heat transfer coefficient and the particle convective heat transfer coefficient are proposed. A verification of the proposed empirical formulae is made by comparing the calculated values with the experimental results.

  14. Fluidized bed combustion of pesticide-manufacture liquid wastes

    OpenAIRE

    SAŠA MILETIĆ; GORDAN SAVČIĆ; RADMILA GARIĆ-GRULOVIĆ; NENAD RADIĆ; BOŠKO GRBIĆ; ŽELJKO GRBAVČIĆ; ZORANA ARSENIJEVIĆ; BOJANA ĐORĐEVIĆ

    2010-01-01

    Industrial liquid wastes can be in the form of solutions, suspensions, sludges, scums or waste oil and have organic properties. The objective of this work was to demonstrate the technical feasibility of a fluidized bed as a clean technology for burning liquid waste from a pesticide production plant. The combustion of liquid waste mixtures, obtained from realistic samples, was investigated in a pilot scale fluidized bed with quartz sand particles of 0.63–1.25 mm in diameter and 2610 kg/m3 in d...

  15. Fluidized bed combustion: mixing and pollutant limitation

    Energy Technology Data Exchange (ETDEWEB)

    Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion

    1997-10-01

    Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

  16. Fluidized bed combustion research in Turkey

    International Nuclear Information System (INIS)

    At present 20% of the total energy consumption in Turkey is met by combustion of lignites. The amount of lignite utilization in the total energy consumption in the year 2000 is expected to double compared to the present. The prevalent characteristics of Turkish lignites are high volatile matter, moisture, ash, and sulfur contents and low calorific value. Also, there are combustion difficulties in conventional combustors associated with the low ash sintering temperatures. For these reasons, there is a major air pollution problem in the main cities of Turkey during winter months. In this paper, the authors review the fluidized bed combustion research work undertaken in Turkey in the last decade and discuss the relevant problem of volatile matter combustion, stability and design

  17. Continuing development of regenerable sorbents for fluidized-bed combustion. Semiannual technical progress report No. 2, April 1-September 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Kalfadelis, C D

    1980-01-01

    Our efforts were directed primarily to preparation for and/the initial operation of the laboratory-scale hot fluidized bed test system (LSHFB). The initial test sequence in the LSHFB system was performed with a fixed-bed of 100 grams of barium titanate synthetic sorbent. The sorbent bed was alternately sulfated and regenerated five times. Sulfation was accomplished at 900/sup 0/C, with a synthetic flue gas mixture comprising 10.1% CO/sub 2/, 4.95% O/sub 2/, 0.2435% SO/sub 2/ and 84.7% N/sub 2/. Regeneration was performed at 1025/sup 0/C with a gas containing 8.0% CO and 92.0% N/sub 2/. After an initial drop in sulfation performance after the first sulfation/regeneration cycle, performance held steady, or was shown to be improving, during the succeeding four cycles. Although the initial operation of this system proceeded relatively smoothly, the reactor was found to have been irreparably damaged by the end of the initial test sequence. A new reactor was subsequently designed, fabricated, and installed in the unit. Concurrently, sorbent pellet preparation by extrusion was investigated in the Catalyst Preparation Facility at the Baton Rouge Laboratory of Exxon Research and Engineering Company. Preparation of sorbent pellets for use in the LSHFB operation was continued on a laboratory-scale at Linden throughout the reporting period. Cost and time estimates were prepared for operation of the bench-scale fluidized bed coal combustion and regeneration facilities, including preparation of the requisite volumes of synthetic sorbent pellets needed for that program.

  18. Experimental comparison of two different ilmenites in fluidized bed and fixed bed chemical-looping combustion

    International Nuclear Information System (INIS)

    Highlights: • Two ilmenite oxygen carriers were tested in fluidized and fixed bed mode. • Activation effects were higher for coarse particles than for small particles. • The final fuel conversion found was higher in the fixed bed for CO and H2 – CH4 was not influenced. • Sintering due to temperature increase during oxidation occurred in the fixed bed. - Abstract: Carbon capture for storage or reuse is seen as one possibility to lower the emissions of anthropogenic CO2. Chemical-looping combustion (CLC) is a promising second generation technique to capture CO2 from thermochemical fuel conversion processes, such as combustion for power generation. The technical implementation of CLC can be conducted using different arrangement approaches based on fluidized or fixed bed reactor designs. When it comes to conversion of solid fuels, the lifetime of an oxygen carrier in a CLC system may be limited by side reactions with fuel ash, or by carryover losses. Therefore, low cost oxygen carriers are preferred. In that context, ilmenite, an iron titanium oxide has been the subject of a number of studies. Here, two ilmenite samples from the Lac Tio mine, Quebec, Canada, extracted from different preparation states were evaluated during activation at 900 °C using a CO–CH4–H2 gas mixture diluted in N2. The experiments were carried out both under fluidized bed and fixed bed conditions to point out qualitative differences. Generally fixed bed reduction indicated higher gas conversion although coarser particles were used. However, if oxidation is carried out in a fixed bed, particle sintering may be a substantial problem

  19. Numerical modeling of straw combustion in a fixed bed

    DEFF Research Database (Denmark)

    Zhou, Haosheng; Jensen, Anker; Glarborg, Peter;

    2005-01-01

    straw combustion processes include moisture evaporation, straw pyrolysis, gas combustion, and char combustion. The model provides detailed information of the structure of the ignition flame front. Simulated gas species concentrations at the bed surface, ignition flame front rate, and bed temperature are...... in good agreement with measurements at different operating conditions such as primary air-flow rate, pre-heating of the primary air, oxygen concentration, moisture content in straw, and bulk density of the straw in the fixed bed. A parametric study indicates that the effective heat conductivity......, straw packing condition, and heat capacity of the straw have considerable effects on the model predictions of straw combustion in the fixed bed....

  20. Combined gas-steam power stations with pressurized fluidized bed combustion (PFBC) of coal

    Energy Technology Data Exchange (ETDEWEB)

    Grzegorczyk, W. (Energoprojekt, Warsaw (Poland))

    1990-11-01

    Presents pressurized fluidized bed combustion (PFBC) of coal that combines fluidized bed combustion with two-agent gas-steam circulation. PFBC permits clean combustion of coal with low calorific value and high ash and sulfur content. The ABB company offered a block for the Pruszkow power plant in Poland. Specifications of the block are given as: thermal power in fuel 430 MW and electrical power 175 MW. The boiler, gas turbine and turbine set are described. Technical and economic indices are given. The supplier attests that the emission values of 70 mg sulfur dioxide per MJ and 120 mg of nitrogen dioxide will not be exceeded under normal conditions.

  1. Fluidized-bed calciner with combustion nozzle and shroud

    International Nuclear Information System (INIS)

    A nozzle employed as a burner within a fluidized bed is coaxially enclosed within a tubular shroud that extends beyond the nozzle length into the fluidized bed. The open-ended shroud portion beyond the nozzle end provides an antechamber for mixture and combustion of atomized fuel with an oxygen-containing gas. The arrangement provides improved combustion efficiency and excludes bed particles from the high-velocity, high-temperature portions of the flame to reduce particle attrition. 4 claims, 2 figures

  2. The characteristics of bed agglomeration during fluidized bed combustion of eucalyptus bark

    International Nuclear Information System (INIS)

    The bed agglomeration behaviors were investigated experimentally when eucalyptus bark was burning tested in a laboratory scale fluidized bed reactor. The focuses of this work were the influences of operating conditions and bed materials on the bed agglomeration tendency and the elucidation in the behaviors of fuel inorganic elements and the governing mode of the agglomeration. It was found that the defluidization caused by the bed agglomeration was clearly detectable from the decrease in measured bed pressure. The growth of bed particle and accumulation of agglomerates during combustion provided the partial to complete defluidization. The defluidization was promoted by the increase of bed temperature and bed particle size, and the decrease of fluidizing air velocity. The SEM-EDS analyses revealed that the bed agglomeration was mainly attributed to the formation of potassium silicate compounds as liquid phase during the combustion. This was initiated by the chemical reaction between the bed particle and the released ash constituents. In this study, the inorganic migration from fuel particle to bed particle was likely dominated by the condensation/reaction. The thermodynamic examination by ternary phase diagram analysis corroborated that the liquid phase formation of the ash derived materials controlled the agglomeration. The alumina sand prevented the bed agglomeration since it was inactive in the formation of viscous molten substances during combustion at the observed temperatures. - Highlights: • The behaviors of bed agglomeration were studied during the fluidized bed combustion of eucalyptus bark. • The increase in bed temperature and sand size, and the decrease of air velocity promoted bed defluidization. • The formation of molten potassium silicate compounds conduced to the bed agglomeration. • Condensation/reaction was the dominant inorganic migration mechanism from fuel particle to bed particle. • The alumina sand prevented effectively the bed

  3. Sandia Combustion Research: Technical review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

  4. Carbon Shale Combustion in the Fluidized Bed Reactor

    OpenAIRE

    Olek Małgorzata; Kandefer Stanisław; Kaniowski Wiesław; Żukowski Witold; Baron Jerzy

    2014-01-01

    The purpose of this article is to present the possibilities of coal shale combustion in furnaces with bubbling fluidized bed. Coal shale can be autothermally combusted in the fluidized bed, despite the low calorie value and high ash content of fuel. Established concentrations of CO (500 ppm) and VOC (30 mg/m3) have indicated a high conversion degree of combustible material during combustion process. Average concentrations of SO2 and NOx in the flue gas were higher than this received from the ...

  5. Combustion of Jordanian oil shale using circulating fluidized bed

    International Nuclear Information System (INIS)

    this study re[resents design and manufacturing of a lab-scale circulating fluidized bed (C.F.B) to burn low grade fuel such as Jordanian oil shale. Hydrodynamic properties of C.F.B. were studied like minimum fluidization velocity, circulation flux and carryover rate. a hot run was firstly conducted by the combustion of L.P.G. to start up the combustion process. It proceeds until reaching the minimum burning temperature of oil shale particles, at which time the LPG supply was gradually reduced and oil shale feeding started. soon after reaching a self sustainable condition of oil shale particles, the LPG supply was cut off. The main combustion variables were investigated such as air to fuel ratios, temperature profiles across the bed, exhaust gas analysis and combustion efficiency. a combustion intensity of 859 kg/hr.m2 and combustion efficiency of 96% were achieved. (authors). 19 refs., 9 tab., 18 fig

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-02-01

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

  7. Utilization of ventilation air methane as a supplementary fuel at a circulating fluidized bed combustion boiler.

    Science.gov (United States)

    You, Changfu; Xu, Xuchang

    2008-04-01

    Ventilation air methane (VAM) accounts for 60-80% of the total emissions from coal mining activities in China, which is of serious greenhouse gas concerns as well as a waste of valuable fuel sources. This contribution evaluates the use of the VAM utilization methods as a supplementary fuel at a circulating fluidized bed combustion boiler. The paper describes the system design and discusses some potential technical challenges such as methane oxidation rate, corrosion, and efficiency. Laboratory experimentation has shown that the VAM can be burnt completely in circulated fluidized bed furnaces, and the VAM oxidation does not obviously affect the boiler operation when the methane concentration is less than 0.6%. The VAM decreased the incomplete combustion loss for the circulating fluidized bed combustion furnace. The economic benefit from the coal saving insures that the proposed system is more economically feasible. PMID:18505001

  8. Flow and combustion characteristics of a 2-dimensional spouted bed

    Science.gov (United States)

    Sawyer, R. F.; Hart, J. R.; Ohtake, K.

    1982-03-01

    A two dimensional spouted bed laboratory combustor was designed and constructed with the objective of studying the interaction among the gas flow, particle flow, and combustion. The facility, designed for a maximum thermal power of 20 kW, has a quartz front wall providing full optical access to particle flows and combustion processes. The combustor was characterized in terms of pressure, temperature, gas velocity, and particle velocity profiles and operating limits. Initial studies employed premixed propane and air and a fixed bed height, bed material, injector slot width, and combustor geometry. As in previous investigations of axisymmetric spouted beds, the ratio of particle mass circulation rate to jet mass flow rate was observed to be about ten. Combustion increased this ratio by about 10%. A pulsating mode of operation was noted with a characteristic frequency of about 10 Hz, controlled by the interaction of the particle and gas flows.

  9. Carbon Shale Combustion in the Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)

    Olek Małgorzata

    2014-06-01

    Full Text Available The purpose of this article is to present the possibilities of coal shale combustion in furnaces with bubbling fluidized bed. Coal shale can be autothermally combusted in the fluidized bed, despite the low calorie value and high ash content of fuel. Established concentrations of CO (500 ppm and VOC (30 mg/m3 have indicated a high conversion degree of combustible material during combustion process. Average concentrations of SO2 and NOx in the flue gas were higher than this received from the combustion of high quality hard coal, 600 ppm and 500 ppm, respectively. Optional reduction of SO2 and NOx emission may require the installation of flue gas desulphurization and de-NOx systems.

  10. Circulating fluidized bed combustion in the turbulent regime: Modeling of carbon combustion efficiency and sulfur retention

    Energy Technology Data Exchange (ETDEWEB)

    Adanez, J.; Gayan, P.; Grasa, G.; Diego, L.F. de; Armesto, L.; Cabanillas, A.

    1999-07-01

    In this work carbon combustion efficiencies and sulfur retentions in CFBC under the turbulent regime were studied. Experimental results were obtained from the combustion of a lignite and an anthracite with a limestone in a CBF pilot plant with 20 cm internal diameter and 6.5 m height. The effect of operating conditions such as coal and limestone particle size distributions, temperature, excess air, air velocity and Ca/S molar ratio on carbon combustion efficiency and sulfur retention was studied. On the other hand, a mathematical model for the carbon combustion efficiencies and sulfur retentions in circulating fluidized bed combustors operating under the turbulent regime was developed. The model has been developed considering the hydrodynamics behavior of a turbulent bed, the kinetics of carbon combustion and sulfur retention in the riser. The hydrodynamics characteristics of the turbulent regime were previously studied in a cold pilot plant and equations to determine the axial and radial voidage in the bed were proposed. A core-annulus structure in the dilute region of the bed was found in this regime. Carbon combustion and sulfur retention were modeled by modifying a model developed for fast beds and taking into account turbulent regime characteristics. The experimental results of carbon combustion efficiencies and sulfur retentions were compared with those predicted by the model and a good correlation was found for all the conditions used.

  11. Co-combustion of waste materials using fluidized bed technology

    Energy Technology Data Exchange (ETDEWEB)

    M. Lopes; I. Gulyurtlu; P. Abelha; T. Crujeira; D. Boavida; I. Cabrita [INETI-DEECA, Lisbon (Portugal)

    2004-07-01

    There is growing interest in using renewable fuels in order to sustain the CO{sub 2} accumulation. Several waste materials can be used as coal substitutes as long as they contain significant combustible matter, as for example MSW and sewage sludge. Besides the outcome of the energetic valorization of such materials, combustion must be regarded as a pre-treatment process, contributing to the safe management of wastes. Landfilling is an expensive management option and requires a previous destruction of the organic matter present in residues, since its degradation generates greenhouse gases and produces acidic organic leachates. Fluidized bed combustion is a promising technology for the use of mixtures of coal and combustible wastes. This paper presents INETI's experience in the co-combustion of coal with this kind of residues performed in a pilot fluidized bed. Both the RDF (from MSW and sewage sludge) and sewage sludge combustion problems were addressed, relating the gaseous emissions, the behaviour of metals and the leachability of ashes and a comparison was made between co-combustion and mono-combustion in order to verify the influence of the utilization of coal. 9 refs., 1 fig., 3 tabs.

  12. Atmospheric fluidized bed coal combustion research, development and application

    CERN Document Server

    Valk, M

    1994-01-01

    The use of fluidized bed coal combustion technology has been developed in the past decade in The Netherlands with a view to expanding the industrial use of coal as an energy supply. Various research groups from universities, institutes for applied science and from boiler industries participated and contributed to this research area. Comprehensive results of such recent experimentation and development work on atmospheric fluidized bed combustion of coal are covered in this volume. Each chapter, written by an expert, treats one specific subject and gives both the theoretical background as well a

  13. N2O emission under fluidized bed combustion condition

    International Nuclear Information System (INIS)

    In this paper, many rules about N2O and NOx emission under fluidized bed combustion conditions were found by experiments. The research results indicate that CaO, CaSO4, Fe2O3 and char have important influence on decomposition of N2O; co-combustion of coal and biomass are effective measures to low N2O and NOx emission

  14. Natural gas combustion in a catalytic turbulent fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Foka, M.; Chaouki, J.; Guy, C.; Klvana, D. [Ecole Polytechnique de Montreal, Quebec (Canada). Dept. of Chemical Engineering

    1994-12-01

    Catalytic fluidized bed combustion of natural gas is shown to be an emerging technology capable of meeting all environmental constraints as far as nitrogen oxides and carbon monoxide are concerned. This technology uses powder catalysts in the turbulent flow regime where the gas-solid contact is optimal so as to maintain a high combustion efficiency. In fact, the catalytic combustion carried out in both the bubbling and the turbulent regimes at 450-500{sup o}C shows that the turbulent regime is more favorable. A single phase plug flow model with axial dispersion is shown to fit satisfactorily the data obtained at 500{sup o}C where the combustion efficiency is very good. A self-sustained combustion was achieved with a mixture of 4% methane at around 500{sup o}C with a complete conversion of methane and a zero emission of NO{sub x} and CO. (author)

  15. Modelling of Devolatilization in Fluidized Bed Combustion

    DEFF Research Database (Denmark)

    Stenseng, Mette; Lin, Weigang; Johnsson, Jan Erik;

    1997-01-01

    A mathematical model is developed to describe the devolatilization process in a circulating fluidized bed combustor. The model is a combination of two submodels: single particle devolatilization and fluid dynamics. The single particle model includes the influence of both chemical kinetics and hea...

  16. Combustion of Corn Straw in a Fluidized-Bed Reactor

    Czech Academy of Sciences Publication Activity Database

    Durda, Tomáš

    Prague : Institute of Chemical Process Fundamental of the CAS, v. v. i, 2015 - (Bendová, M.; Wagner, Z.), s. 22-23 ISBN 978-80-86186-70-2. [Bažant Postgraduate Conference 2015. Prague (CZ)] Institutional support: RVO:67985858 Keywords : fluidized-bed reactor * combustion processes * corn straw Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  17. Combustion of oil palm solid wastes in fluidized bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuddin, A.H. [Univ. Kebangsaan Malaysia, Bangi (Malaysia). Faculty of Engineering; Sopian, K. [Univ. of Miami, Coral Gables, FL (United States). College of Engineering

    1995-12-31

    The palm oil industry of Malaysia is the largest in the world producing about 55% of the world production. The industry has approximately 270 mills throughout the country with processing sizes ranging from 10 tonnes/hour to 120 tonnes/hour. All mills produce solid wastes, about 50% of the fresh fruit bunches in terms of weight. The solid wastes produced are in the form of empty fruit bunches, fibers and shells. These wastes have high energy value, ranging from 14 to 18 MJ/kg. The industry is currently self-sufficient in terms of energy. Fibers and shell wastes are being used as boiler fuel to raise steam for electrical power production and process steam. However, the combustion technology currently being employed is obsolete with low efficiency and polluting. A fluidized bed combustor pilot plant is designed and constructed at Combustion Research Laboratory, Universiti Kebangsaan Malaysia. The combustor is made up of 600 mm {times} 900 mm rectangular bed filled with sand up to 400 mm height, static. A bank of heat transfer tubes is imbedded in the bed, designed to absorb 50% of heat released by the fuel in the bed. The remaining heat is transferred in tubes placed on the wall of the freeboard area. Experimental studies were carried out in the pilot plant using palm oil solid wastes. The combustion temperatures were maintained in the range 800--900 C. The performance of the combustor was evaluated in terms of combustion and boiler efficiencies and flue gas emissions monitored.

  18. The combustion of low calorific value fuels (oil shale) by using fluidized bed combustor

    International Nuclear Information System (INIS)

    The present work reports an experimental data for combustion of oil-shale in a fluidized bed combustor. The experimental set up was designed for the combustion of low calorific value fuel such as oil-shale to facilitate the variation of many parameters over a wide operating range. A cold run was firstly conducted to study the fluidization parameters. Fluidization experiment were made with different sized quartiz particles. Minimum fluidization velocities and other fluidization characteristics were determined at room temperature. Secondary a hot run was started, first studying the combustion of 'LPG' in a fluidized bed as a starting process, then studying the combustion if oil-shale with different flow rates. The experimetal results are promising and give rise to hopes that this valuable deposit can be used as a fuel source and can be burned sucessfully in a fluidized bed combustor. This study had prooved that utilization of oil-shale a fuel source is no more a complicated technical problem, this opens the way for power generation using fluidized bed combustors. (author). 17 refs., 32 figs., 3 tabs

  19. Combustion of palm oil solid waste in fluidized bed combustor

    International Nuclear Information System (INIS)

    Results of experimental investigations of fluidized bed combustion of palm oil wastes consisting of shell, fibre and empty fruit bunches high heating value of 17450 kJ/kg and low heating value of 14500 kJ/kg. The fluidized bed combuster used has a vessel size of 486 x 106 mm3, surface area of evaporation tubes and distribution air pipes of 500 mm2 and 320 mm2 respectively. It was found that a fuel feeding rate 160 kg/h is required to achieve a steam flow rate of 600 kg/h, with the combustion efficiency 96% and boiler efficiency of 72%, emission level of flue gas NOx at less than 180 ppm, SO2 at less than 20 ppm are measured in the flue gas. (Author)

  20. Effect of bed particles to combustion of gases in fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Raiko, R.; Wallen, V.; Etelaeaho, R.; Correia, S. [Tampere Univ. of Technology (Finland). Energy and Process Engineering

    1997-10-01

    The objective of this project was to obtain experimental data on effects of sand particles to the combustion of gases. The effect of the surface area of the particles was tested using different sized particles. The fluidized bed reactor used in these experiments was a stainless-steel tube with an internal diameter of 42 mm surrounded by an electric heater. The test rig was built in the Laboratory of Energy and Process Engineering at Tampere University of Technology. In order to elucidate the possible changes of particle surface, microscopic and porosimetric studies were conducted with both fresh bed particles and used bed particles. These measurements indicate that carbon monoxide significantly reacts with oxygen in the particulate or emulsion phase of a fluidized bed, if the residence time is long enough. The reaction rate depends mainly on temperature, air coefficient, residence time and particle size of the solids. It seems that the combustion enhances if the average particle size increases. Whether this is caused by increased free path length or reduced specific surface area of the bed is yet unknown. The first might be more probable cause because the majority of reactions often took place in the freeboard right above the bed. It was clear that the bed hindered proper combustion in several cases. (orig.)

  1. Standard technical specifications combustion engineering plants

    International Nuclear Information System (INIS)

    This report documents the results of the combined effort of the NRC and the industry to produce improved Standard Technical Specifications (STS) for Combustion Engineering Plants. The improved STS wee developed based on the criteria in the interim Commission Policy Statement on Technical Specification Improvements for Nuclear Power Reactors, dated February 6, 1987. The improved STS will be used as the basis for individual nuclear power plant licensees to develop improved plant-specific technical specifications. This report contains three volumes. This document, Volume 1, contains the Specifications for all chapters and sections of the improved STS. Volume 2 contains the Bases for Sections 3.4--3.9 of the improved STS

  2. Chemical looping combustion of coal in interconnected fluidized beds

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chemical looping combustion is the indirect combustion by use of oxygen carrier. It can be used for CO2 capture in power generating processes. In this paper, chemical looping combustion of coal in interconnected fluidized beds with inherent separation of CO2 is proposed. It consists of a high velocity fluidized bed as an air reactor in which oxygen carrier is oxidized, a cyclone, and a bubbling fluidized bed as a fuel reactor in which oxygen carrier is reduced by direct and indirect reactions with coal. The air reactor is connected to the fuel reactor through the cyclone. To raise the high carbon conversion efficiency and separate oxygen carrier particle from ash, coal slurry instead of coal particle is introduced into the bottom of the bubbling fluidized bed. Coal gasification and the reduction of oxygen carrier with the water gas take place simultaneously in the fuel reactor. The flue gas from the fuel reactor is CO2 and water. Almost pure CO2 could be obtained after the con- densation of water. The reduced oxygen carrier is then returned back to the air reactor, where it is oxidized with air. Thermodyanmics analysis indicates that NiO/Ni oxygen carrier is the optimal one for chemical looping combustion of coal. Simulation of the processes for chemical looping combustion of coal, including coal gasification and reduction of oxygen carrier, is carried out with Aspen Plus software. The effects of air reactor temperature, fuel reactor temperature, and ratio of water to coal on the composition of fuel gas, recirculation of oxygen carrier par- ticles, etc., are discussed. Some useful results are achieved. The suitable tem- perature of air reactor should be between 1050―1150℃and the optimal temperature of the fuel reactor be between 900―950℃.

  3. Chemical looping combustion of coal in interconnected fluidized beds

    Institute of Scientific and Technical Information of China (English)

    SHEN LaiHong; ZHENG Min; XIAO Jun; ZHANG Hui; XIAO Rui

    2007-01-01

    Chemical looping combustion is the indirect combustion by use of oxygen carrier.It can be used for CO2 capture in power generating processes. In this paper,chemical looping combustion of coal in interconnected fluidized beds with inherent separation of CO2 is proposed. It consists of a high velocity fluidized bed as an air reactor in which oxygen carrier is oxidized, a cyclone, and a bubbling fluidized bed as a fuel reactor in which oxygen carrier is reduced by direct and indirect reactions with coal. The air reactor is connected to the fuel reactor through the cyclone. To raise the high carbon conversion efficiency and separate oxygen carrier particle from ash, coal slurry instead of coal particle is introduced into the bottom of the bubbling fluidized bed. Coal gasification and the reduction of oxygen carrier with the water gas take place simultaneously in the fuel reactor. The flue gas from the fuel reactor is CO2 and water. Almost pure CO2 could be obtained after the condensation of water. The reduced oxygen carrier is then returned back to the air reactor, where it is oxidized with air. Thermodyanmics analysis indicates that NiO/Ni oxygen carrier is the optimal one for chemical looping combustion of coal.Simulation of the processes for chemical looping combustion of coal, including coal gasification and reduction of oxygen carrier, is carried out with Aspen Plus software. The effects of air reactor temperature, fuel reactor temperature, and ratio of water to coal on the composition of fuel gas, recirculation of oxygen carrier particles, etc., are discussed. Some useful results are achieved. The suitable temperature of air reactor should be between 1050-1150Cand the optimal temperature of the fuel reactor be between 900-950℃.

  4. Sludge combustion in fluidized bed reactors at laboratory scale

    International Nuclear Information System (INIS)

    The combustion of a dried sewage sludge in laboratory scale fluidized bed has been studied in Naples by the Istituto di ricerche sulla combustione (Irc) in the framework of a National project named Thermal Process with Energy Recovery to be used in laboratory and pre-pilot scale apparatus. The attention has been focused on emissions of unreacted carbon as elutriated fines, on the emissions of pollutant gases and on the assessment of the inventory of fly- and bottom ashes. The combustion behaviour of sewage sludge has been compared with those of a market available Tyre Derived Fuel (TDF) and a biomass from Mediterranean area (Robinia Pseudoacacia) and with that of a South African bituminous coal. Stationary combustion tests were carried out at 8500 C by feeding particles in the size range 0-1 mm into a bed of silica sand without any sorbent addition. The fluidized bed combustor has been operated, at a superficial gas velocity of 0.4 m/s and different excesses of air ranging between 14 and 98%. Relatively high combustion efficiency, larger than 98.9% has been obtained in experiments carried out with sewage sludge and excess of air larger than 20%. These values, are comparable with those obtained in previously experimental activity carried out under similar operative conditions with a South Africa Bituminous coal (97-98%). It is larger than those obtained by using a Tyre Derived Fuel (89-90%) and the Robinia Pseudoacacia Biomass (93-93%). The relative importance of carbon fines elutriation, CO emissions and volatile bypassing the bed in determining the loss of combustion efficiency has been evaluated for the different fuels tested

  5. The suitability of horse manure and bedding materials for combustion

    Energy Technology Data Exchange (ETDEWEB)

    Tyni, S.; Tiainen, M. S.; Laitinen, R. S. (Univ. of Oulu, Dept. of Chemistry (Finland)). email: sanna.tyni@oulu.fi

    2009-07-01

    The number of horses has increased in Finland since 1994 approximately by 2000 horse/ year and 2008 there was almost 70000 registered horses and ponies in Finland. This has derived to a considerable number of new stables at city area where the waste management, particularly of the mixture of manure and bedding material, is a challenge. These stables have disposed their residues often by land filling. The present legislation prohibits the dispose of organic material by land filling since the anaerobic decomposition emits for example methane that is a greenhouse gas. The legislation also regulates using of manure as fertilizer in fields. This leads to the situation where stable owners have urge for new ways to dispose of residues. In Finland peat, sawdust, and straw are commonly used as a bedding material for horses in stable boxes. The more important function of the bedding material is to keep the boxes dry and clean by absorbing urine. The selection of bedding material depends on the properties of the materials such as availability, price, absorption capacity, and hygiene properties. Composting of sawdust is slower than peat, therefore mixture of manure and sawdust is not preferred for utilization as fertilizer. Additionally use of the manure residues as fertilizers is limited by impurities such as plant seeds in manure. Combustion would be attractive way to solve disposal problems of the mixture of manure and bedding materials. At the moment legislation in Finland defines manure residues as a waste. Therefore the combustion is only allowed in waste combustion units. If the combustion of the manure residues would be allowed at farms or at small local boilers, it enables farms to have better degree of self-sufficiency of energy. The utilization of these new materials as a fuel demands study of combustion properties of these biomasses. It is also essential to have knowledge of chemical composition and behaviour of ashes, when the final disposing is considered e.g. as

  6. Fluid bed solids heater. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Preuit, L. C.

    1980-01-01

    A solids heater which operates at up to 2000 F was designed, fabricated, installed and operated through checkout at the Morgantown Energy Technology Center at Morgantown, West Virginia. The system, designated the 2000 F Fluid Bed Solids Heater (FBSH) uses a fluidized bed to heat limestone to 600 F and aluminium oxide or silicon carbide to 2000 F and discharges heated solids upon demand. The FBSH with added valve handling and pressurization equipment is known as the Valve Hot Solids Test Unit and is intended for use by the US Department of Energy for testing of valves for severe service applications in coal conversion and utilization processes. The FBSH as designed and supplied by Combustion Power Company includes process equipment, controls, the enclosing building and other associated equipment. In the 600 F range of operation it can circulate limestone through two valve test trains simultaneously on a continuous basis. Only one valve test train is used for 2000 F solids and operation in that range is also continuous. Limestone, crushed to minus 5/16 size, is heated, discharged, and recycled at a maximum average rate of 250 lb/min while aluminum oxide or silicon carbide, No. 8 grit, is circulated at rates up to 167 lb/min. The FBSH control system is designed for automatic operation, and capability is included for external computerized data acquisition and/or supervisory control. An operating and maintenance manual and as-built drawings have been submitted. This report describes the FBSH equipment, its design basis, and its operation. It has been prepared and submitted in fulfillment of Contract Number DIAC05-77ET10499.

  7. Peach and apricot stone combustion in a bubbling fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Kaynak, B.; Atimtay, Aysel T. [Department of Environmental Engineering, Middle East Technical University, Ankara 06531 (Turkey); Topal, H. [Department of Mechanical Engineering, Engineering and Architecture Faculty, Gazi University, Ankara 06570 (Turkey)

    2005-07-25

    In this study, a bubbling fluidized bed combustor (BFBC) of 102 mm inside diameter and 900 mm height was used to investigate the combustion characteristics of peach and apricot stones produced as a waste from the fruit juice industry. A lignite coal was also burned in the same combustor. The combustion characteristics of the wastes were compared with that of a lignite coal that is most widely used in Turkey. On-line concentrations of O{sub 2}, CO, CO{sub 2}, SO{sub 2}, NO{sub X} and total hydrocarbons (C{sub m}H{sub n}) were measured in the flue gas during combustion experiments. By changing the operating parameters (excess air ratio, fluidization velocity, and fuel feed rate), the variation of emissions of various pollutants was studied. Temperature distribution along the bed was measured with thermocouples. During the combustion tests, it was observed that the volatile matter from peach and apricot stones quickly volatilizes and mostly burn in the freeboard. The temperature profiles along the bed and the freeboard also confirmed this phenomenon. It was found that as the volatile matter of fruit stones increases, the combustion takes place more in the freeboard region. The results of this study have shown that the combustion efficiencies ranged between 98.8% and 99.1% for coal, 96.0% and 97.5% for peach stone and 93.4% and 96.3% for apricot stones. The coal has zero CO emission, but biomass fuels have very high CO emission which indicates that a secondary air addition is required for the system. SO{sub 2} emission of the coal is around 2400-2800 mg/Nm{sup 3}, whereas the biomass fuels have zero SO{sub 2} emission. NO{sub x} emissions are all below the limits set by the Turkish Air Quality Control Regulation of 1986 (TAQCR) for all tests. As the results of combustion of two biomass fuels are compared with each other, peach stones gave lower CO and NO{sub x} emissions but the SO{sub 2} emissions are a little higher than for apricot stones. These results suggest that

  8. Fluidized bed combustion (citations from Engineering Index). Report for 1970--Mar 1976

    International Nuclear Information System (INIS)

    These worldwide citations cover the fluidized bed processes and processors for the combustion of oil, coal, and industrial as well as municipal wastes. It also includes sludge incineration, fluidized bed boilers, and air pollution abatement by fluidized bed combustion. (Contains 136 abstracts)

  9. Circulating fluidized bed combustion in the turbulent regime: modelling of carbon combustion efficiency and sulphur retention

    Energy Technology Data Exchange (ETDEWEB)

    Adanez, J.; Gayan, P.; Grasa, G.; de Diego, L.F.; Armesto, L.; Cabanillas, A. [Instituto de Carboquimica (CSIC), Zaragoza (Spain). Dept. of Energy and Environment

    2001-08-10

    A model has been developed considering the hydrodynamic behaviour of a turbulent circulating fluidized bed, the kinetics of coal combustion and sulphur retention in the riser. The hydrodynamic characteristics of the turbulent fluidization regime were integrated together with the kinetic submodels of char combustion and sulphur retention by limestone. From the combustion of a lignite and an anthracite with limestone addition in a hot CBF pilot plant of 20 cm internal diameter and 6.5 m high, the effect of operating conditions such as temperature, excess air, air velocity, Ca/S molar ratio, coal and limestone particle size distributions on carbon combustion efficiency and sulphur retention were studied. The experimental results were compared with those predicted by the model and a good correlation was found for all the conditions used. 56 refs., 10 figs., 1 tab.

  10. Nitrogen Chemistry in Fluidized Bed Combustion of Coal

    DEFF Research Database (Denmark)

    Jensen, Anker Degn

    , was proposed and compared to experimental data. The agreement between model and experimental data was fair. Experiments were also conducted with simultaneous oxidation of HCN and sulphation of seven different types of limestone. The catalytic activity of the limestones decreases to a non-zero level......The present Ph.D thesis describes an experimental and theoretical investigation of the formation and destruction of nitrogen oxides (NOx and N2O) in fluidized bed combustion (FBC) of coal. A review of the current knowledge of nitrogen chemistry in FBC is presented. The review covers both laboratory...... studies and pilot and full-scale observations. In the experimental part of the work, the heterogeneous oxidation of HCN catalyzed by two Danish limestones was investigated in a fixed bed laboratory reactor to establish how the reduction of the SO2 emission by addition of limestone to FBC influences...

  11. Standard Technical Specifications, Combustion Engineering plants

    International Nuclear Information System (INIS)

    This NUREG contains improved Standard Technical Specifications (STS) for Combustion Engineering (CE) Plants and documents the positions of the Nuclear Regulatory Commission based on the CE Owners Group's proposed STS. This document is the result of extensive technical meetings and discussions among the NRC staff, the Nuclear Steam Supply System (NSSS) Owners Groups, the NSSS vendors, and the Nuclear Management and Resources Council (NUMARC). The improved STS were developed based on the criteria in the interim Commission Policy Statement on Technical Specification Improvements for Nuclear Power Reactors, dated February 6, 1987. The improved STS will be used as the basis for individual nuclear power plant licensees to develop improved plant-specific technical specifications. This report contains three volumes. Volume 1 contains the Specifications for all chapters and sections of the improved SM. Volume 2 contains the Bases for Chapters 2.0 and 3.0, and Sections 3.1--3.3 of the improved STS. This document Volume 3 contains the Bases for Sections 3.4--3.9 of the improved M

  12. Fluidized bed combustion (citations from the American Petroleum Institute data base). Report for 1964-Jan 79

    Energy Technology Data Exchange (ETDEWEB)

    Cavagnaro, D.M.

    1980-04-01

    These citations from the American Petroleum Institute pertain to fluidized bed processes and processors for the combustion of oil, coal, natural gas, and industrial and municipal wastes. They also discuss air pollution control by fluidized bed combustion, sludge incineration, fluidized bed boilers and furnaces, and design of the fluidized bed combustors. (This updated bibliography contain 108 abstracts, 9 of which are new entries to the previous edition.)

  13. Combustion of rice husk in a multiple-spouted fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Albina, D.O. [Asian Institute of Technology, Pathumthani (Thailand). Energy Program

    2003-09-01

    The performance of the multiple-spouted fluidized bed was evaluated by investigating the effects of different parameters on combustion efficiency and emission for different methods of feeding. The parameters considered were the different levels of combustion air and the different primary-to-secondary air ratios at each level, while the methods of feeding were under-bed and over-bed feeding. It was found that the method of feeding influenced the combustion efficiency of the multiple-spouted bed. The combustion efficiency appeared to be higher with under-bed feeding as compared to over-bed feeding; and emission of CO was less in the case of under-bed feeding than with over-bed feeding. The changes in excess air levels influenced the combustion efficiency of the spouted bed. It was found that combustion efficiency with over-bed feeding was best at 10% excess air; in general, combustion efficiency with under-bed feeding was favorable at 20% excess air level. (author)

  14. Conceptual design of a Ni-based chemical looping combustion process using fixed-beds

    International Nuclear Information System (INIS)

    Highlights: • The feasibility of fixed-bed CLC with methane and Ni-based carriers is assessed. • A conceptual design has determined operating windows for each stage of the system. • Low O2 content and low inlet gas temperature limit temperature in oxidation front. • Results show technical viability of fixed-bed CLC and its potential for further development. - Abstract: This work presents a comprehensive conceptual design of a Ni-based chemical looping combustion process (CLC) carried out in fixed bed reactors. The process is intended to exploit the well-known advantages of the Ni/NiO redox system for CLC applications in terms of high reactivity, O2 carrying capacity and chemical and thermal stability. Solutions to the problem of heat management in fixed bed reactors at high temperature and high pressure are described, while a continuous flow of nitrogen for driving a gas turbine is produced. Each reactor involved in the process goes through a cyclic sequence of five reaction and heat transfer stages. Cool product gas recirculations are incorporated into the Ni oxidation and NiO reduction stages in order to moderate the maximum temperatures in the beds and control the displacement of the reaction and heat transfer fronts. A preliminary conceptual design of the process has been carried out to determine the minimum number of reactors needed for continuous operation in typical large-scale CO2 capture systems. Basic reactor models and assumptions based on an ideal plug flow pattern have been used in all the reactors during the chemical reactions and the heat transfer operations. This has made it possible to identify reasonable operating windows for the eight fixed-bed reactors that make up the CO2 capture system, and has demonstrated not only its technical viability but also its great potential for further development

  15. Advanced Combustion and Emission Control Technical Team Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-06-01

    The Advanced Combustion and Emission Control (ACEC) Technical Team is focused on removing technical barriers to the commercialization of advanced, high-efficiency, emission-compliant internal combustion (IC) engines for light-duty vehicle powertrains (i.e., passenger car, minivan, SUV, and pickup trucks).

  16. Effect of ash content on the combustion process of simulated MSW in the fixed bed.

    Science.gov (United States)

    Sun, Rui; Ismail, Tamer M; Ren, Xiaohan; Abd El-Salam, M

    2016-02-01

    This paper experimentally and numerically investigates the effects of ash content on the combustion process of simulated Municipal Solid Waste (MSW). A fixed-bed experimental reactor was utilized to reveal the combustion characteristics. Temperature distributions, ignition front velocity, and the characteristics of gas species' release were measured and simulated during the combustion process. In the present work, the two-dimensional unsteady mathematical heterogeneous model was developed to simulate the combustion process in the bed, including the process rate model as well as NOx production model. The simulation results in the bed are accordant with the experimental results. The results show that as ash content increases, the lower burning rate of fuel results in char particles leaving the grate without being fully burned, causing a loss of combustible material in the MSW in a fixed bed and therefore reducing the combustion efficiency and increasing the burning time of the MSW. PMID:26476592

  17. METAL FILTERS FOR PRESSURIZED FLUID BED COMBUSTION (PFBC) APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Alvin

    2004-01-02

    Advanced coal and biomass-based gas turbine power generation technologies (IGCC, PFBC, PCFBC, and Hipps) are currently under development and demonstration. Efforts at the Siemens Westinghouse Power Corporation (SWPC) have been focused on the development and demonstration of hot gas filter systems as an enabling technology for power generation. As part of the demonstration effort, SWPC has been actively involved in the development of advanced filter materials and component configuration, has participated in numerous surveillance programs characterizing the material properties and microstructure of field-tested filter elements, and has undertaken extended, accelerated filter life testing programs. This report reviews SWPC's material and component assessment efforts, identifying the performance, stability, and life of porous commercial metal, advanced alloy, and intermetallic filters under simulated, pressurized fluidized-bed combustion (PFBC) conditions.

  18. Development of second-generation pressurized fluidized bed combustion process

    Energy Technology Data Exchange (ETDEWEB)

    Wolowodiuk, W.; Robertson, A. [Foster Wheeler Development Corp., Livingston, NJ (United States); Bonk, D. [Dept. of Energy, Morgantown, WV (United States)

    1995-12-01

    Under the sponsorship of the United States Department of Energy, Foster Wheeler Development Corporation, and its team members, Westinghouse, Gilbert/Commonwealth, and the Institute of Gas Technology are developing second-generation pressurized fluidized bed combustion technology capable of achieving net plant efficiency in excess of 45 percent based on the higher heating value of the coal. A three-phase program entails design and costing of a 500 MWe power plant and identification of developments needed to commercialize this technology (Phase 1), testing of individual components (Phase 2), and finally testing these components in an integrated mode (Phase 3). This paper briefly describes the results of the first two phases as well as the progress on the third phase. Since other projects which use the same technology are in construction or in negotiation stages-namely, the Power System Development Facility and the Four Rivers Energy Modernization Projects-brief descriptions of these are also included.

  19. Effect of secondary air injection on the combustion efficiency of sawdust in a fluidized bed combustor

    OpenAIRE

    K. V. N. Srinivasa Rao; G. Venkat Reddy

    2008-01-01

    Agricultural wastes like bagasse, paddy husks, sawdust and groundnut shells can be effectively used as fuels for fluidized bed combustion; otherwise these biomass fuels are difficult to handle due to high moisture and fines content. In the present work the possibility of using sawdust in the fluidized bed combustor, related combustion efficiencies and problems encountered in the combustion process are discussed. The temperature profiles for sawdust with an increase in fluidizing velocity alon...

  20. Modern fluidized bed combustion in Ostrava-Karvina cogeneration plants

    Energy Technology Data Exchange (ETDEWEB)

    Mazac, V. [Energoprojekt Praha, Ostrava (Czechoslovakia); Novacek, A. [Moravskoslezske teplamy, Ostrava (Czechoslovakia); Volny, J. [Templamy Karvina (Czechoslovakia)

    1995-12-01

    The contemporary situation of our environment claims the sensitive approach to solving effective conversion of energy. Limited supplies of noble fuels and their prices evoke the need to use new combustion technologies of accessible fuels in given region without negative ecological influences. Energoproject participates in the preparation of the two projects in Ostrava-Karvin{acute a} black coal field in Czech Republic. The most effective usage of fuel energy is the combined of electricity and heat. If this physical principle is supported by a pressurized fluidized bed combustion (PFBC) one obtains a high electricity/heat ratio integrated steam-gas cycle on the basis of solid fuel. Cogeneration plant Toebovice is the dominant source (600 MW{sub th}) of Ostrava district heating system (1100 MW{sub th}). The high utilization of the installed output and utilization of the clean, compact and efficient of the PFBC technology is the principal but not the single reason for the selection of the Toebovice power plant as the first cogeneration plant for installation of the PFBC in Czech Republic. The boiler will burn black coal from the neighboring coal basin.

  1. The influence of fine char particles burnout on bed agglomeration during the fluidized bed combustion of a biomass fuel

    Energy Technology Data Exchange (ETDEWEB)

    Scala, Fabrizio; Chirone, Riccardo [Istituto di Ricerche sulla Combustione, CNR, P.le V. Tecchio, 80-80125 Naples (Italy); Salatino, Piero [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II, P.le V. Tecchio, 80-80125 Naples (Italy)

    2003-11-15

    The combustion of biomass char in a bubbling fluidized bed is hereby addressed, with specific reference to the influence that the combustion of fine char particles may exert on ash deposition and bed agglomeration phenomena. Experiments of steady fluidized bed combustion (FBC) of powdered biomass were carried out with the aim of mimicking the postcombustion of attrited char fines generated in the fluidized bed combustion of coarse char. Experimental results showed that the char elutriation rate is much smaller than expected on the basis of the average size of the biomass powder and of the carbon loading in the combustor. Samples of bed material collected after prolonged operation of the combustor were characterized by scanning electron microscopy (SEM)-EDX analysis and revealed the formation of relatively coarse sand-ash-carbon aggregates. The phenomenology is consistent with the establishment of a char phase attached to the bed material as a consequence of adhesion of char fines onto the sand particles. Combustion under sound-assisted fluidization conditions was also tested. As expected, enhancement of fines adhesion on bed material and further reduction of the elutriation rate were observed. Experimental results are interpreted in the light of a simple model which accounts for elutriation of free fines, adhesion of free fines onto bed material and detachment of attached fines by attrition of char-sand aggregates. Combustion of both free and attached char fines is considered. The parameters of the model are assessed on the basis of the measured carbon loadings and elutriation rates. Model computations are directed to estimate the effective size and the peak temperature of char-sand aggregates. The theoretical estimates of the effective aggregate size match fairly well those observed in the experiments.

  2. A CFD model for biomass combustion in a packed bed furnace

    Science.gov (United States)

    Karim, Md. Rezwanul; Ovi, Ifat Rabbil Qudrat; Naser, Jamal

    2016-07-01

    Climate change has now become an important issue which is affecting environment and people around the world. Global warming is the main reason of climate change which is increasing day by day due to the growing demand of energy in developed countries. Use of renewable energy is now an established technique to decrease the adverse effect of global warming. Biomass is a widely accessible renewable energy source which reduces CO2 emissions for producing thermal energy or electricity. But the combustion of biomass is complex due its large variations and physical structures. Packed bed or fixed bed combustion is the most common method for the energy conversion of biomass. Experimental investigation of packed bed biomass combustion is difficult as the data collection inside the bed is challenging. CFD simulation of these combustion systems can be helpful to investigate different operational conditions and to evaluate the local values inside the investigation area. Available CFD codes can model the gas phase combustion but it can't model the solid phase of biomass conversion. In this work, a complete three-dimensional CFD model is presented for numerical investigation of packed bed biomass combustion. The model describes the solid phase along with the interface between solid and gas phase. It also includes the bed shrinkage due to the continuous movement of the bed during solid fuel combustion. Several variables are employed to represent different parameters of solid mass. Packed bed is considered as a porous bed and User Defined Functions (UDFs) platform is used to introduce solid phase user defined variables in the CFD. Modified standard discrete transfer radiation method (DTRM) is applied to model the radiation heat transfer. Preliminary results of gas phase velocity and pressure drop over packed bed have been shown. The model can be useful for investigation of movement of the packed bed during solid fuel combustion.

  3. Fluidized bed combustion and its application to refused fuels. Combustion en leche fluido y su aplicacion a combustibles residuales

    Energy Technology Data Exchange (ETDEWEB)

    Euba, J.

    1994-01-01

    As a consequence of the energetic crisis produced in th 70's it was proposed to find new power supplies and it also was the start of the use of traditional energy, which up to that date had not been profitable. At the same time, the worry about the pollutant emissions to the environment was increasing and finally it was approved a new legislation on atmosphere pollution, which is the Directive of the European community Council of 24th November 1988. Under these circumstances there are very important the new technologies for the supply of residual combustion with low values of pollution, where it is very important the combustion in fluidized bed. (Author)

  4. Thermal valorization of footwear leather wastes in bubbling fluidized bed combustion.

    Science.gov (United States)

    Bahillo, A; Armesto, L; Cabanillas, A; Otero, J

    2004-01-01

    Transformation of hide (animal skins) into leather is a complicated process during which significant amounts of wastes are generated. Footwear is the sector that consumes the major part of leather (60%). Logically, this industry is producing the largest quantity of leather wastes. The objective of this work was to demonstrate the technical feasibility of fluidized bed technology to recover the energy from burning footwear leather wastes. Considering the characteristics of leather waste, especially the heating value (12.5-21 MJ/kg), it can be considered a fairly good fuel. Moreover, leather waste has suitable characteristics for combustion, e.g., high volatile matter (76.5%) and low ash content (5.2%). Two factors deserve special attention: N3O and NOx emissions as a consequence of its unusual high nitrogen content (14.1%) and the chromium speciation because chromium is the main element of ash (3.2%) due to its use in leather tanning. A series of experiments has been carried out in a 0.1 MWt bubbling fluidized bed pilot plant. The combustion efficiency, flue gas composition and chromium speciation were investigated. Despite having high nitrogen content, a low conversion rate of fuel-N to NOx and N2O was attained. Chromium was concentrated in the solid streams and it was consistently found as Cr(III+); no presence of Cr(VI+) was detected. PMID:15504671

  5. Importance of fragmentation on the steady state combustion of wood char in a bubbling fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Pinho, Carlos [Universidade do Porto (CEFT/FEUP), Porto (Portugal). Faculdade de Engenharia. Centro de Estudos de Fenomenos de Transporte], E-mail: ctp@fe.up.pt

    2010-07-01

    A simple mathematical model for the analysis of the steady state behavior of a bubbling fluidized bed burner is presented, with the main intention of evaluating the importance of the primary fragmentation of fuel particles on the performance of this type of burners. This model has pedagogical advantages because of its simplicity and easiness of application to the analysis of realistic situations. The model is based upon the classical models used for the study of batch combustion processes in fluidized bed reactors. Experimental data from studies of fluidized bed combustion of portuguese vegetable chars are used to support the analysis of the performance of a 1 m diameter fluidized bed combustor. (author)

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

    Science.gov (United States)

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

    2009-02-01

    Power generation from biomass is an attractive technology that utilizes agricultural residual waste. In order to explain the behavior of biomass-fired fluidized bed incinerator, biomass sources from agricultural residues (rice husk and palm kernel) were co-fired with coal in a 0.15m diameter and 2.3m high fluidized bed combustor. The combustion efficiency and carbon monoxide emissions were studied and compared with those for pure coal combustion. Co-combustion of a mixture of biomass with coal in a fluidized bed combustor designed for coal combustion increased combustion efficiency up to 20% depending upon excess air levels. Observed carbon monoxide levels fluctuated between 200 and 900 ppm with the addition of coal. It is evident from this research that efficient co-firing of biomass with coal can be achieved with minimal modifications to existing coal-fired boilers. PMID:18614348

  7. Combustion characteristics of particles of hazardous solid waste mixtures in a fixed bed

    International Nuclear Information System (INIS)

    Hazardous waste disposal is vitally important as industrial production increases. Grate furnaces are a common means to incinerate hazardous waste. In this present work, a fixed bed assembly is used to experimentally model combustion within grate furnaces. Combustion characteristics are examined and the effects of primary air rate, moisture, bed height and particle size on burning rate, ignition-front speed and temperatures in the bed are also investigated. The results indicate that a rising temperature front descends through the bed while weight loss remains constant during the main combustion stage. Primary air rates and moisture content are shown to have significant effects on burning rates and average ignition-front speeds. Bed height has no effect on burning rates but does have an effect on average ignition-front speeds. Particle size is found to have slight effects on burning rates while having no effect on average ignition-front speeds.

  8. Residues characterisation from the fluidised bed combustion of East London's solid recovered fuel

    OpenAIRE

    Balampanis, Dimitris E.; Pollard, Simon J. T.; Simms, N; Longhurst, Philip J.; Coulon, Frederic; Villa, Raffaella

    2010-01-01

    Waste thermal treatment in Europe is moving towards the utilisation of the combustible output of mechanical, biological treatment (MBT) plants. The standardisation of solid recovered fuels (SRF) is expected to support this trend and increase the amount of the generated combustion residues. In this work, the residues and especially the fly ashes from the fluidised bed combustion (FBC) of East London’s NCV 3, Cl 2, and Hg 1 class SRF, are characterised. The following toxicity ...

  9. Fluidized bed combustion. volume 3. 1978-March, 1980 (citations from the NTIS data base). Report for 1978-Mar 80

    Energy Technology Data Exchange (ETDEWEB)

    Cavagnaro, D.M.

    1980-03-01

    The bibliography cites studies on fluidized bed processes and processors for the combustion of coal, oil, and industrial and municipal wastes. It also covers sludge incineration, fluidized bed boilers, and air pollution control by fluidized bed combustion. (This updated bibliography contains 240 abstracts, 91 of which are new entries to the previous edition.)

  10. Fluidized bed combustion. volume 2. 1977-March, 1980 (citations from the Engineering Index data base). Report for 1977-mar 80

    Energy Technology Data Exchange (ETDEWEB)

    Cavagnaro, D.M.

    1980-03-01

    The cited reports from a worldwide literature survey cover the fluidized bed processes and processors for the combustion of oil, coal, and industrial as well as municipal wastes. It also includes sludge incineration, fluidized bed boilers, and air pollution abatement by fluidized bed combustion. (This updated bibliography contains 390 abstracts, 165 of which are new entries to the previous edition.)

  11. Technical Report: Rayleigh Scattering Combustion Diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Wyatt [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hecht, Ethan [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-07-29

    A laser Rayleigh scattering (LRS) temperature diagnostic was developed over 8 weeks with the goal of studying oxy-combustion of pulverized coal char in high temperature reaction environments with high concentrations of carbon dioxide. Algorithms were developed to analyze data collected from the optical diagnostic system and convert the information to temperature measurements. When completed, the diagnostic will allow for the kinetic gasification rates of the oxy-combustion reaction to be obtained, which was previously not possible since the high concentrations of high temperature CO2 consumed thermocouples that were used to measure flame temperatures inside the flow reactor where the combustion and gasification reactions occur. These kinetic rates are important for studying oxycombustion processes suitable for application as sustainable energy solutions.

  12. Fluidized combustion of beds of large, dense particles in reprocessing HTGR fuel

    International Nuclear Information System (INIS)

    Fluidized bed combustion of graphite fuel elements and carbon external to fuel particles is required in reprocessing high-temperature gas-cooled reactor (HTGR) cores for recovery of uranium. This burning process requires combustion of beds containing both large particles and very dense particles as well as combustion of fine graphite particles which elutriate from the bed. Equipment must be designed for optimum simplicity and reliability as ultimate operation will occur in a limited access ''hot cell'' environment. Results reported in this paper indicate that successful long-term operation of fuel element burning with complete combustion of all graphite fines leading to a fuel particle product containing <1% external carbon can be performed on equipment developed in this program

  13. Experimental findings on thermal use of residues and biofuels in circulating fluidized bed combustion systems; Experimentelle Ergebnisse zur thermischen Nutzung von Rest- und Biobrennstoffen in zirkulierenden Wirbelschichtfeuerungen

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, W.; Brunne, T.; Girndt, H. [Technische Univ. Dresden (Germany); Albrecht, J. [Lurgi Lentjes Babcock, Frankfurt am Main (Germany); Youssef, M. [Minia Univ. (Egypt)

    1996-12-31

    The energy Engineering Institute of Dresden Technical University investigated the combustion and emission characteristics of a number of combustion systems, including a circulating fluidized bed system with a capacity of 0.3 MW{sub th}. Egypt`s sugar cane industry produces large volumes of bagasse. The conbustion and emission characteristics of this biofuel in a circulating fludized bed combustion systems were investigated in a joint research project of the University of Minia and Dresden Technical University. (orig.) [Deutsch] Am Institut fuer Energietechnik der TU Dresden wird das Verbrennungs- und Emissionsverhalten verschiedenster Brennstoffe in unterschiedlichen Feuerungssystemen untersucht. Neben anderen Pilotanlagen steht eine zirkulierende Wirbelschichtfeuerung (ZWFS) mit einer Leistung von 0.3 MW{sub th} zur Verfuegung. In der Zuckerrohrindustrie Aegyptens fallen grosse Mengen von Bagasse an. In einer gemeinsamen Forschungsarbeit zwischen der Universitaet Minia und der TU Dresden sollte das Verbrennungs- und Emissionsverhalten dieses Biobrennstoffes in einer ZWSF untersucht werden. (orig)

  14. Numerical simulation of gas concentration and dioxin formation for MSW combustion in a fixed bed.

    Science.gov (United States)

    Sun, Rui; Ismail, Tamer M; Ren, Xiaohan; Abd El-Salam, M

    2015-07-01

    A numerical model was employed to simulate the combustion process in a fixed porous bed of municipal solid waste (MSW). Mass, momentum, energy and species conservation equations of the waste bed were set up to describe the incineration process. The rate of moisture evaporation, volatile matter devolatilization, char combustion, NOx production, and reduction and dioxin formation were calculated and established according to the local thermal conditions and waste property characteristics. Changes in the bed volume during incineration were calculated according to the reaction rate of the process. The simulation results were compared with experimental data, which shows that the incineration process of waste in the fixed bed was reasonably simulated. The simulation results of weight loss and solid temperature in the bed agree with the experimental data, which shows that the waste combustion rate is nearly constant in the middle of the incineration process, and that moisture evaporation takes up most of the time for the overall incineration experiment. The emission of gas species from the bed surface is also agreeably simulated, with O2, CO2, and CO concentrations in flue gas agreeing with the experimental data. The simulation results benefit the understanding of the combustion process in the waste bed as well as the design of incinerator grates. PMID:25897505

  15. Co-combustion of tannery sludge in a commercial circulating fluidized bed boiler.

    Science.gov (United States)

    Dong, Hao; Jiang, Xuguang; Lv, Guojun; Chi, Yong; Yan, Jianhua

    2015-12-01

    Co-combusting hazardous wastes in existing fluidized bed combustors is an alternative to hazardous waste treatment facilities, in shortage in China. Tannery sludge is a kind of hazardous waste, considered fit for co-combusting with coal in fluidized bedboilers. In this work, co-combustion tests of tannery sludge and bituminous coal were conducted in a power plant in Jiaxing, Zhejiang province. Before that, the combustion behavior of tannery sludge and bituminous were studied by thermogravimetric analysis. Tannery sludge presented higher reactivity than bituminous coal. During the co-combustion tests, the emissions of harmful gases were monitored. The results showed that the pollutant emissions met the Chinese standard except for NOx. The Concentrations of seven trace elements (As, Cr, Cd, Ni, Cu, Pb, Mn) in three exit ash flows (bottom ash in bed, fly ash in filter, and submicrometer aerosol in flue gas) were analyzed. The results of mono-combustion of bituminous coal were compared with those of co-combustion with tannery sludge. It was found that chromium enriched in fly ash. At last, the leachability of fly ash and bottom ash was analyzed. The results showed that most species were almost equal to or below the limits except for As in bottom ashes and Cr in the fly ash of co-combustion test. The concentrations of Cr in leachates of co-combustion ashes are markedly higher than that of coal mono-combustion ashes. PMID:26278370

  16. Experimental Investigations of Extracted Rapeseed Combustion Emissions in a Small Scale Stationary Fluidized Bed Combustor

    OpenAIRE

    Dieter Steinbrecht; Tristan Vincent; Nguyen Dinh Tung

    2009-01-01

    The objective of this study was to observe the combustion process of extracted rapeseed (ER) grist in a stationary fluidized bed combustor (SFBC) and evaluate the chemical compositions of the flue gas emissions. The experimental tests of ER combustion in the 90 to 200 kW (Kilowatt) SFB combustion test facility show that the optimal ER combustion temperature is within the range from 850 to 880° C. Temperature and the concentration of exhausted emissions (e.g. O 2 , CO, CO 2 , NO, NO 2 , SO 2 ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-08-15

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

  18. Properties of Concrete Incorporating Bed Ash from Circulating Fluidized Bed Combustion and Ground Granulates Blast-furnace Slag

    Institute of Scientific and Technical Information of China (English)

    CHENG An; HSU Hui-Mi; CHAO Sao-Jeng

    2011-01-01

    The properties of concrete incorporating circulating fluidized bed combustion (CFBC) bed ash and ground granulates blast-furnace slag (GGBS) were studied. Compressive strength,drying shrinkage, mercury intrusion porosimetry (MIP), scanning electronic microscopy (SEM), and X-ray diffraction (XRD) of concrete samples containing CFBC bed ash and GGBS were used. This work used initial surface absorption test (ISAT) and rapid chloride penetration test (RCPT) on concrete to measure the absorption and the ability of concrete to resist chloride ion characteristics for different concrete samples containing CFBC bed ash and GGBS. Open circuit potential (OCP), direct current polarization resistance were obtained to evaluate rebar corrosion. The CFBC bed ash was X-ray amorphous and consist of SiO2, A12O3 and CaO compounds. As the replacement of CFBC for sand increases, the rate of initial surface absorption (ISA) increases but compressive strength decreases.When the content of CFBC bed ash replacement for sand maintains constant, the replacement of GGBS for cement increases, compressive strength increases but the rate of ISA decreases. Chloride and corrosion resistance of rebar significantly improve by utilizing a proper amount of CFBC bed ash and GGBS in concrete.

  19. Analysis of the fluidized bed combustion behavior of Quercus ilex char

    International Nuclear Information System (INIS)

    Because of the high content of alkaline metals, biomass has very reactive ashes and these have a strong impact upon pyrolysis and combustion phenomena. From the study of the evolution with the combustion temperature, of the kinetic and diffusive data of several wood chars, it was found that the Quercus ilex (holm oak) char had an unexpected evolution of the heterogeneous phase reaction rate constant. Scanning electronic microscopy analysis of the ashes and thermogravimetric analysis of the char where performed, and the results shown that close to 750 °C there is a loss of mass associated with the release of inorganic matter, especially potassium and phosphorus, which have a known influence on the combustion process and the subsequent kinetic data collection. - Highlights: • Fluidized bed combustion of biomass. • Combustion behavior of holm oak char. • Influence of alkaline components on char combustion kinetic data

  20. CO-COMBUSTION OF REFUSE DERIVED FUEL WITH COAL IN A FLUIDISED BED COMBUSTOR

    OpenAIRE

    W. A. Wan Ab Karim Ghani; Alias, A. B.; K.R.CLIFFE

    2009-01-01

    Power generation from biomass is an attractive technology which utilizes municipal solid waste-based refused derived fuel. In order to explain the behavior of biomass-fired fluidized bed incinerator, biomass sources from refuse derived fuel was co-fired with coal in a 0.15 m diameter and 2.3 m high fluidized bed combustor. The combustion efficiency and carbon monoxide emissions were studied and compared with those from pure coal combustion. This study proved that the blending effect had incre...

  1. Effect of secondary air injection on the combustion efficiency of sawdust in a fluidized bed combustor

    Directory of Open Access Journals (Sweden)

    K. V. N. Srinivasa Rao

    2008-03-01

    Full Text Available Agricultural wastes like bagasse, paddy husks, sawdust and groundnut shells can be effectively used as fuels for fluidized bed combustion; otherwise these biomass fuels are difficult to handle due to high moisture and fines content. In the present work the possibility of using sawdust in the fluidized bed combustor, related combustion efficiencies and problems encountered in the combustion process are discussed. The temperature profiles for sawdust with an increase in fluidizing velocity along the vertical height above the distributor plate indicate that considerable burning of fuel particles is taking place in the freeboard zone rather than complete burning within the bed. Therefore, an enlarged disengagement section is provided to improve the combustion of fines. The temperature profiles along the bed height are observed at different feed rates. The feed rate of sawdust corresponding to the maximum possible temperature was observed to be 10.2 kg/h. It is observed that 50-60% excess air is optimal for reducing carbon loss during the burning of sawdust. The maximum possible combustion efficiency with sawdust is 99.2% and is observed with 65% excess air.

  2. Forest biomass waste combustion in a pilot-scale bubbling fluidised bed combustor

    International Nuclear Information System (INIS)

    Combustion experiments of forest biomass waste in a pilot-scale bubbling fluidised bed combustor were performed under the following conditions: i) bed temperature in the range 750-800 oC, ii) excess air in the range 10-100%, and iii) air staging (80% primary air and 20% secondary air). Longitudinal pressure, temperature and gas composition profiles along the reactor were obtained. The combustion progress along the reactor, here defined as the biomass carbon conversion to CO2, was calculated based on the measured CO2 concentration at several locations. It was found that 75-80% of the biomass carbon was converted to CO2 in the region located below the freeboard first centimetres, that is, the region that includes the bed and the splash zone. Based on the CO2 and NO concentrations in the exit flue gas, it was found that the overall biomass carbon conversion to CO2 was in the range 97.2-99.3%, indicating high combustion efficiency, whereas the biomass nitrogen conversion to NO was lower than 8%. Concerning the Portuguese regulation about gaseous emissions from industrial biomass combustion, namely, the accomplishment of CO, NO and volatile organic compounds (VOC) (expressed as carbon) emission limits, the set of adequate operating conditions includes bed temperatures in the range 750oC-800 oC, excess air levels in the range 20%-60%, and air staging with secondary air accounting for 20% of total combustion air.

  3. Partitioning behavior of trace elements during pilot-scale fluidized bed combustion of high ash content lignite

    International Nuclear Information System (INIS)

    This study describes the partitioning of 20 trace elements (As, B, Ba, Cd, Co, Cr, Cu, Hg, Li, Mn, Mo, Ni, P, Pb, Sb, Se, Sn, Tl, V, Zn) and eight major and minor elements (Al, Ca, Fe, K, Mg, Na, Si, Ti) during the combustion of high ash content lignite. The experiments were carried out in the 0.3 MWt Middle East Technical University (METU) atmospheric bubbling fluidized bed combustor (ABFBC) test rig with and without limestone addition. Inert bed material utilized in the experiments was bed ash obtained previously from the combustion of the same lignite without limestone addition in the same test rig. Concentrations of trace elements in coal, limestone, bottom ash, cyclone ash and filter ash were determined by inductively coupled plasma optical emission spectroscopy (ICP-OES). Partitioning of major and minor elements are influenced by the ash split between the bottom ash and fly ash and that the major proportion of most of the trace elements (As, Ba, Cr, Hg, Li, Mo, Ni, Sn, V, Zn) are recovered in fly ash. Limestone addition shifts the partitioning of Ba, Cr, Mo, Ni, Sn, V, Zn from bottom ash to fly ash

  4. A fixed granular-bed sorber for measurement and control of alkali vapors in PFBC (pressurized fluidized-bed combustion)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Swift, W.M.

    1990-01-01

    Alkali vapors (Na and K) in the hot flue gas from the pressurized fluidized-bed combustion (PFBC) of coal could cause corrosion problems with the gas turbine blades. In a laboratory-scale PFBC test with Beulah lignite, a fixed granular bed of activated bauxite sorbent was used to demonstrate its capability for measuring and controlling alkali vapors in the PFBC flue gas. The Beulah lignite was combusted in a bed of Tymochtee dolomite at bed temperatures ranging from 850 to 875{degrees}C and a system pressure of 9.2 atm absolute. The time-averaged concentration of sodium vapor in the PFBC flue gas was determined from the analysis of two identical beds of activated bauxite and found to be 1.42 and 1.50 ppmW. The potassium vapor concentration was determined to be 0.10 ppmW. The sodium material balance showed that only 0.24% of the total sodium in the lignite was released as vapor species in the PFBC flue gas. This results in an average of 1.56 ppmW alkali vapors in the PFBC flue gas. This average is more than 1.5 orders of magnitude greater than the currently suggested alkali specification limit of 0.024 ppm for an industrial gas turbine. The adsorption data obtained with the activated bauxite beds were also analyzed mathematically by use of a LUB (length of unused bed)/equilibrium section concept. Analytical results showed that the length of the bed, L{sub o} in centimeters, relates to the break through time, {theta}{sub b} in hours, for the alkali vapor to break through the bed as follows: L{sub o} = 33.02 + 1.99 {theta}{sub b}. This formula provides useful information for the engineering design of fixed-bed activated bauxite sorbers for the measurement and control of alkali vapors in PFBC flue gas. 26 refs., 4 figs., 4 tabs.

  5. Concepts of Emission Reduction in Fluidized Bed Combustion of Biomass

    Directory of Open Access Journals (Sweden)

    Amon Purgar

    2012-01-01

    Full Text Available A status report on fluidized bed technology in Austria is under preparation, in response to the Fluidized Bed Conversion multi-lateral technology initiative of the International Energy Agency. This status report focuses on the current operation of fluidized bed combustors. Combustors have been installed in the following industrial sectors: pulp and paper, biomass heat and power plants, waste-to-energy plants, and communal sewage sludge treatment plants. There are also some small demonstration plants. These plants all have in common that they treat renewable fuel types. In many cases, only bio-fuels are treated. Besides the ability to burn a wide range of low-grade and difficult fuels, fluidized bed combustors have the advantages of low NOX emissions and the possibility of in-process capture of SO2. Various emission reduction concepts for fluidized bed combustors that are typical for their industrial sector are discussed. The discussion of these concepts focuses on NOX, SO2 and dust.

  6. Experimental determination of bed agglomeration tendencies of some common agricultural residues in fluidized bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Natarajan, E.; Rao, A.N. [Anna University, Madras (India). Centre for New and Renewable Sources of Energy; Ohman, M.; Nordin, A. [Umea University (Sweden). Energy Technology Centre; Gabra, M. [Lulea University of Technology (Sweden). Div. of Energy Engineering; Liliedahl, T. [Royal Institute of Technology, Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    1998-12-31

    Ever increasing energy demand and the polluting nature of existing fossil fuel energy sources demonstrate the need for other non-polluting and renewable sources of energy. The agricultural residues available in abundance in many countries can be used for power generation. The fluidized bed technology seems to be suitable for converting a wide range of agricultural residues into energy, due to its inherent advantages of fuel flexibility, low operating temperature and isothermal operating condition. The major ash-related problem encountered in fluidized beds is agglomeration which, in the worst case, may result in total defluidization and unscheduled downtime. The initial agglomeration temperature for some common tropical agricultural residues were experimentally determined by using a newly developed method based on the controlled fluidized bed agglomeration test. The agricultural residues chosen for the study were rice husk, bagasse, cane trash and olive flesh. The results showed that the initial agglomeration temperatures were less than the initial deformation temperature predicted by the ASTM standard ash fusion tests for all fuels considered. The initial agglomeration temperatures of rice husk and bagasse were more than 1000{sup o}C. The agglomeration of cane trash and olive flesh was encountered at relatively low temperatures and their initial agglomeration temperatures in gasification were lower than those in combustion with both bed materials. The use of lime as bed material instead of quartz improved the agglomeration temperature of cane trash and olive flesh in combustion and decreased the same in gasification. The results indicate that rice husk and bagasse can be used in the fluidized bed for energy generation since their agglomeration temperatures are sufficiently high. (author)

  7. Standard Technical Specifications for Combustion Engineering Pressurized Water Reactors

    International Nuclear Information System (INIS)

    The Standard Technical Specifications for Combustion Engineering Pressurized Water Reactors (CE-STS) is a generic document prepared by the US NRC for use in the licensing process of current Combustion Engineering Pressurized Water Reactors. The CE-STS sets forth the limits, operating conditions, and other requirements applicable to nuclear reactor facility operation as set forth by Section 50.36 of 10 CFR 50 for the protection of the health and safety of the public. The document is revised periodically to reflect current licensing requirements

  8. Realisation of a combustion pilot using a circulating fluidised bed of coal

    Energy Technology Data Exchange (ETDEWEB)

    Baussand, P.; Lassagne, L.; Jacob, V.R.; Azay, P.; Kaluzny, P.; Foster, P. [Greca, Grenoble (France)

    2000-07-01

    The authors present the processes which led to the realization of a combustion pilot using a Circulating Fluidized bed that can burn various fuels. To meet this aim, a pilot functional analysis of the needs was conducted in order to determine the schedule of conditions as close as possible to the expectations of the laboratory. This pilot had to be modular to carry out various combustions such as coal and household refuse. The first results concerning the combustion of coal are also presented, which show that this pilot is functional.

  9. Feasibility of Combustion of Petroleum Coke in 230t/h Circulating Fluidized Bed Boiler

    Institute of Scientific and Technical Information of China (English)

    HAN Dong-tai; SONG Zheng-chang; XU Tao

    2003-01-01

    In order to reuse the high sulfur petroleum coke, the waste in chemical industry, as fuel of power plant for energy recovery, the combustion property of petroleum coke was researched experimentally in circulating fluidized bed (CFB) boiler. The performance of the boiler in burning mixed fuel with different ratios of coal to petroleum coke is obtained. Based on the experimental data, Factors influencing the stability of combustion,thermal efficiency of boiler, and emissions and desulphurisation are discussed. This study demonstrates that the combustion of petroleum coke in CFB boiler is applicable, and has great significance on the design and operation of CFB boiler to burn petroleum coke.

  10. Modelling of NOx emissions from pressurized fluidized bed combustion - A parameter study

    DEFF Research Database (Denmark)

    Jensen, Anker; Johnsson, Jan Erik

    1997-01-01

    Simulations with a mathematical model of a pressurized bubbling fluidized-bed combustor (PFBC) combined with a kinetic model for NO formation and reduction are reported. The kinetic model for NO formation and reduction considers NO and NH3 as the fixed nitrogen species, and includes homogeneous r...... velocity, the bubble size, the bubble rise velocity and the gas interchange coefficient between bubble and dense phase. The most important combustion parameters are the rates of CO and CH4 combustion and the CO/(CO + CO2) ratio from char combustion. (C) 1997 Elsevier Science Ltd....

  11. Thermal decomposition of selected chlorinated hydrocarbons during gas combustion in fluidized bed

    OpenAIRE

    Olek Malgorzata; Baron Jerzy; Zukowski Witold

    2013-01-01

    Abstract Background The process of thermal decomposition of dichloromethane (DCM) and chlorobenzene (MCB) during the combustion in an inert, bubbling fluidized bed, supported by LPG as auxiliary fuel, have been studied. The concentration profiles of C6H5CI, CH2Cl2, CO2, CO, NOx, COCl2, CHCl3, CH3Cl, C2H2, C6H6, CH4 in the flue gases were specified versus mean bed temperature. Results The role of preheating of gaseous mixture in fluidized bed prior to its ignition inside bubbles was identified...

  12. Combustion of agro-waste with coal in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Atimtay, Aysel T. [Middle East Technical University, Department of Environmental Engineering, Ankara (Turkey)

    2010-02-15

    In this study, a review of the studies done on the co-combustion of some agro-waste in a bubbling fluidized bed combustor (BFBC) having an inside diameter of 102 mm and a height of 900 mm is given. The agro-waste used to investigate the co-combustion characteristics were peach and apricot stones produced as a waste from the fruit juice industry, and olive cake produced as a waste from the olive oil industry. These are typical wastes for a Mediterranean country. A lignite coal was used for co-combustion. On-line concentrations of O{sub 2}, CO, CO{sub 2}, SO{sub 2}, NO{sub x} and total hydrocarbons (C{sub m} H{sub n}) were measured in the flue gas during combustion experiments. Variations of emissions of various pollutants were studied by changing the operating parameters (excess air ratio, fluidization velocity and fuel feed rate). Temperature distribution along the bed was measured with thermocouples. Emissions were also monitored from the exhaust. Various combinations of coal and biomass mixtures were tested. During the combustion tests, it was observed that the volatile matter from the biomass quickly volatilizes and mostly burns in the freeboard. The temperature profiles along the bed and the freeboard also confirmed this phenomenon. It was found that as the volatile matter of the biomass increases, combustion takes place more in the freeboard region. Better combustion conditions occur at higher excess air ratios. The results showed that co-combustion with these three proposed biomasses lowers the SO{sub 2} and NO{sub x} emissions considerably. CO and hydrocarbon emissions are lower at the higher excess air ratios. (orig.)

  13. Contribution to the combustion and emission of nitrogen oxides of Kosovo and Kolubara coals in fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Radovanovic, M.; Savic, R.

    1996-12-31

    In this paper, the results of combustion of different sizes of domestic lignites Kosovo and Kolubara are presented. Investigation has been carried on a laboratory experimental facility for combustion in fluidized bed, power 1 kW. Specified amount of fuel is put into fluidized bed and temperature and concentration of combustion products (O{sub 2}, CO{sub 2}, CO, NO, NO{sub s} and SO{sub 2}) are recorded and produced. The emission of nitrogen oxides is specially treated in this paper. Also, the ignition delay of volatile matter, combustion of volatiles and total time of combustion are found. 25 refs., 9 figs., 4 tabs.

  14. CO-COMBUSTION OF REFUSE DERIVED FUEL WITH COAL IN A FLUIDISED BED COMBUSTOR

    Directory of Open Access Journals (Sweden)

    W. A. WAN AB KARIM GHANI

    2009-03-01

    Full Text Available Power generation from biomass is an attractive technology which utilizes municipal solid waste-based refused derived fuel. In order to explain the behavior of biomass-fired fluidized bed incinerator, biomass sources from refuse derived fuel was co-fired with coal in a 0.15 m diameter and 2.3 m high fluidized bed combustor. The combustion efficiency and carbon monoxide emissions were studied and compared with those from pure coal combustion. This study proved that the blending effect had increased the carbon combustion efficiency up to 12% as compared to single MSW-based RDF. Carbon monoxide levels fluctuated between 200-1600 ppm were observed when coal is added. It is evident from this research that efficient co-firing of biomass with coal can be achieved with minimum modification of existing coal-fired boilers.

  15. Simultaneous determination of devolatilization and char burnout times during fluidized bed combustion of coal

    International Nuclear Information System (INIS)

    In this paper, the authors investigate a method for simultaneous determination of devolatilization and char burnout times based on the analysis of CO2 emissions from a fluidized bed combustor. The technique is not-intrusive and can be performed under realistic combustion conditions. The authors' method involves batching single-sized coal sample sin a fluidized bed combustor that is heated with propane gas or other fuel. Carbon dioxide profiles versus time for the batch tests are analyzed with a linear model to obtain characteristic time constants for coal devolatilization and char combustion which can be related to total devolatilization time and burnout time for a coal sample. The authors' approach does not require special sample preparation, can be performed in actual combustion equipment, and employs standard boiler instrumentation

  16. Simultaneous determination of devolatilization and char burnout times during fluidized bed combustion of coal

    International Nuclear Information System (INIS)

    In this paper, the authors investigate a method for simultaneous determination of devolatilization and char burnout times based on the analysis of CO2 emissions from a fluidized bed combustor. The technique is non-intrusive and can be performed under realistic combustion conditions. The authors' method involves batching single-size coal samples in a fluidized bed combustor that is heated with propane gas or other fuel. Carbon dioxide profiles versus time for the batch tests are analyzed with a linear model to obtain characteristic time constants for coal devolatilization and char combustion which can be related to total devolatilization time and burnout time for a coal sample. The authors' approach does not require special sample preparation, can be performed in actual combustion equipment and employs standard boiler instrumentation

  17. Combustion characteristics of Athabasca froth treatment tailings in a simulated fluidilized bed

    Energy Technology Data Exchange (ETDEWEB)

    Esmaeili, P.; Ghosh, M.; Speirs, B. C. [Imperial Oil Resources (Canada); Leon, M. A.; Rao, S.; Dutta, A.; Basu, P. [Greenfield Research Inc. (Canada)

    2011-07-01

    In surface-mined oil sands, a stream of water, asphaltenes, solids and residual bitumen/solvent, known as PFT tailings, is created during the bitumen production process. The aim of this study was to investigate the use of this PFT tailings stream as a fuel source for combustion in a fluidized bed for energy recovery. To do so, physical and fluidization characteristics of the fuel as well as combustion kinetics were assessed through laboratory analysis. In addition, the fuel's combustion characteristics were investigated through experiments in a quartz wool matrix tubular reactor and theoretical calculations at various moisture contents. Results showed that this fuel can be burned in a fluidized bed with a reactivity comparable to that of coal samples. This research found that PFT tailings could be used to generate energy during disposal but further work will have to be undertaken in a hot CFB combustor to confirm this.

  18. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume V. Appendix: stability and instability in fluidized-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Louis, J.F.; Tung, S.E.

    1980-10-01

    This document is the fifth of the seven volumes series of our Phase II Final Report. The material developed in this volume has not been incorporated into the system model. It will be used as a precursor of a transient model to be developed in the next phase of our model work. There have been various fluidized combustor models of differing complexity and scope published in the literature. Most of these models have identified and predicted - often in satisfactory agreement with results from pilot units - the key steady state combustor characteristics such as the mass of carbon in the bed (carbon loading), the combustion efficiency, the sulfur retention by the solid sorbent and the pollutant (mainly NO/sub x/) emissions. These models, however, cannot be in most instances successfully used to study the extinction and ignition characteristics of the combustor because they are isothermal in structure in the sense that the bed temperature is not an output variable but rather an input one and must be a priori specified. In order to remedy these inadequacies of the previous models, we here present a comprehensive account of the formulation and some typical results of a new nonisothermal model which has been developed in order to study, among other things, the ignition and extinction characteristics of the AFBC units. This model is able to predict the temperature patterns in the bed, the carbon loading, the combustion efficiency and the O/sub 2/ and CO concentration profiles in the combustor for the different design or operational characteristics.

  19. Co-combustion of agricultural wastes in a circulating fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Huseyin Topal; Aysel T. Atimtay [Gazi University, Ankara (Turkey). Dept. of Mechanical Engineering

    2005-07-01

    In this study a circulating fluidized bed combustion (CFBC) of 125 mm inside diameter and 1800 mm height was used to investigate the co-combustion characteristics of peach and apricot stones produced as a waste from the fruit juice industry, and sunflower stems produced as a waste from the edible oil industry with a lignite coal. Lignite coal is a coal most widely used in Turkey. On-line concentrations of O{sub 2}, CO, CO{sub 2}, SO{sub 2}, NOx and total hydrocarbons (C{sub m}H{sub n}) were measured in the flue gas during combustion experiments. By changing the operating parameters the variation of emissions of various pollutants were studied. During combustion tests, it was observed that the volatile matter from agro-wastes quickly volatilizes and mostly burn in the riser. The temperature profiles along the bed and the rise also confirmed this phenomenon. It was found that as the volatile matter content of agro-waste increases, the combustion efficiency increases and the combustion takes place more in the upper region of the riser. These results suggest that agro-wastes are potential fuels that can be utilized for clean energy production by using CFBC in countries where agricultural activities are heavy. 3 refs., 4 figs., 5 tabs.

  20. Chemical Processes Related to Combustion in Fluidised Bed

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Lindqvist, Oliver [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Environmental Inorganic Chemistry

    2002-12-01

    This report covers work that has been carried out in the combustion chemistry group at the Dept. of Environmental Inorganic Chemistry, Chalmers, within the STEM project 12859-1, during the period 2000-07-01 to 2002-06-30. The work was comprised of the following parts: Sulphur chemistry under pressurised and atmospheric conditions; Gas/solid reactions related to sintering and fouling; Chemistry of volatile metals in combustion; Ash leaching properties; Theoretical modelling of the interactions between ions in a solution and mineral surfaces; Some related issues and co-operations with other departments. The work on sulphur chemistry has been a central issue in our group and it has now been finalised with a PhD thesis discussing some aspects of the sulphation of limestone under pressurised conditions. The influence of a number of parameters on the sulphation efficiency was investigated and compared with similar studies under atmospheric conditions. In a special study it was shown that the influence of alternating calcining - non-calcining conditions on the conversion was substantial. In addition, the oxidation of CaS and sulphided limestone was studied and a regeneration method for the sulphide sorbent was proposed. In the project part concerning gas - solid reactions that are relevant to sintering and fouling, the application of an on-line measurement technique for the study of alkali metal capture by kaolin or other sorbents is described. A new reactor set-up has been constructed and the initial results from this set up are promising. The chemistry of cadmium in combustion of MSW and biomass is the object of a PhD project. This work has been concentrated on the task of identifying Cd-compounds in fly ash samples. It has now come to a point where enough data has been collected to make it possible to give an indication about the Cd speciation in some ash types. In MSW ash particles, cadmium seem to occur mainly as chloride, oxide and sulphate. The work will continue

  1. An SEM/EDX study of bed agglomerates formed during fluidized bed combustion of three biomass fuels

    International Nuclear Information System (INIS)

    The agglomeration behaviour of three biomass fuels (exhausted and virgin olive husk and pine seed shells) during fluidized bed combustion in a lab-scale reactor was studied by means of SEM/EDX analysis of bed agglomerate samples. The effect of the fuel ash composition, bed temperature and sand particle size on agglomeration was investigated. The study was focused on the main fuel ash components and on their interaction with the bed sand particles. Agglomeration was favoured by high temperature, small sand size, a high fraction of K and Na and a low fraction of Ca and Mg in the fuel ash. An initial fuel ash composition close to the low-melting point eutectic composition appears to enhance agglomeration. The agglomerates examined by SEM showed a hollow structure, with an internal region enriched in K and Na where extensive melting is evident and an external one where sand particles are only attached by a limited number of fused necks. Non-molten or partially molten ash structures deposited on the sand surface and enriched in Ca and Mg were also observed. These results support an ash deposition-melting mechanism: the ash released by burning char particles inside the agglomerates is quantitatively deposited on the sand surface and then gradually embedded in the melt. The low-melting point compounds in the ash migrate towards the sand surface enriching the outermost layer, while the ash structure is progressively depleted of these compounds

  2. Beneficiation of pulverized coal combustion fly ash in fluidised bed reactors

    Energy Technology Data Exchange (ETDEWEB)

    Cammarota, A.; Chirone, R.; Solimene, R.; Urciuolo, M. [Istituto di Ricerche sulla Combustione - C.N.R., P.le V. Tecchio 80, 80125 Napoli (Italy)

    2008-07-15

    The paper addresses the thermal treatment of pulverized coal combustion fly ash belonging to the group C of Geldart powder classification in unconventional configurations of fluidised bed reactors. A sound-assisted fluidised bed combustor operated at 850 and 750 C, and a fluidised bed combustor characterized by a conical geometry, operated at 850 C, are the two lab-scale reactors tested. Combustion experiments have been carried out at different air excesses, ranging between 10% and 170%, and in the case of the conical fluidization column with different bed inventory. Both tested configurations have been proved to be efficient to reduce the carbon content initially present in the fly ash of 11%{sub w}, to a very low level, generally smaller than 1%{sub w}. Both the fly ash residence time in the reactor and the air excess strongly influenced the reactor performance. Residence times of 3-4 min and 10-60 min have been estimated for experiments carried out with the sound-assisted fluidised bed combustor and with the conical fluidised bed combustor, respectively. Regarding the possibility of a concurrent reduction of unburned carbon in the ash and of a particle size separation of the beneficiated material, on the basis of the obtained experimental data, the sound-assisted fluidised bed combustor is not able to separate the broad particle size distribution of the fly ash in different outlet solid streams. The use of a conical fluidised bed combustor is promising to realize an efficient separation of the inlet broad particle size distribution of the fly ash fed to the reactor into narrower outlet solid streams extracted from different locations: combustor exit, top and bottom of the bed. In this framework a hydrodynamic characterization of binary mixtures in a conical fluidised bed column carried out at ambient and high temperature (850 C) has demonstrated that the operating conditions of the conical fluidised bed combustor can be chosen on the basis of a compromise

  3. Development program on pressurized fluidized-bed combustion. Annual report, July 1, 1974--June 30, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, G.J.; Cunningham, P.; Fischer, J.

    1975-07-01

    The feasibility of using fluidized-bed combustors in power and steam plants is being evaluated. The concept involves burning fuels such as coal in a fluidized bed of either a naturally occurring, calcium-containing limestone or dolomite or in a synthetically prepared calcium-containing stone. The calcium oxide in the stone reacts with the sulfur released during combustion to form calcium sulfate, which remains in the bed, thus decreasing the level of SO/sub 2/ in the flue gas. Levels of NO/sub x/ in the flue gas are also low. The effect of operating variables and type of stone on the levels of SO/sub 2/ and NO/sub x/ is being determined. Behavior of trace elements during combustion has been preliminarily evaluated. The properties of a fluidized bed at minimum fluidization at different temperatures and pressures have been determined. The CaSO/sub 4/ produced in the combustion process is regenerated to CaO for reuse in the combustor by reductive decomposition at 1095/sup 0/C (2000/sup 0/F). The effects of operating variables on sulfur release during regeneration are being evaluated. Another regeneration process, solid-solid reaction of CaSO/sub 4/ with CaS, is also being investigated. Fundamental investigations of the kinetics of sulfation and regeneration reactions for the natural and synthetic stones are continuing. A model for the sulfation reaction is presented. The status of the new combustor andancillary regenerator equipment is discussed. (auth)

  4. Some specific features of organic waste combustion in fluidized bed facility

    International Nuclear Information System (INIS)

    Discussion is given to the specific features of reprocessing nuclear fuel cycle liquid organic waste in a fluidized bed apparatus at moderate temperatures. Issues are considered relevant to efficiency and safety of the process and effects of nitrogen oxides on temperature regime. Conditions of thermal decomposition of TBP, paraffin and aromatic hydrocarbons (Dowtherm) are revealed. Relations are established of interactions between phosphorus oxides resulting from TBP combustion and a packing material (Al, Ca). Cs and Ru trapping efficiency is evaluated for organic phase combustion on bed granules. The recent studies have shown that hydrocarbon compounds available in waste to be disposed of can promote transuranium nuclide migration and subsequent escape to the environment. This is the reason why reprocessing this type of nuclear fuel cycle waste is one of the most important directions in waste localization. Investigations carried out in the course of the liquid nitric acid waste calcination in a fluidized bed apparatus indicated the high efficiency of kerosene thermal oxidation within 400--500 C. In this connection the authors have performed experiments in a laboratory scale to more accurately determine combustion regime for some organic compounds that found use in technologies of spent fuel radiochemical reprocessing. The studies were conducted in a fluidized bed facility. Its major component is a packed apparatus in the form cylinders with a cone shaped joint in the middle

  5. Possible ways of suppression of agglomeration of particles in fluidized bed combustion of selected waste biomass fuels

    International Nuclear Information System (INIS)

    Fluidized bed combustion (FBC) of biomass is often complicated by agglomeration of particles within the bed. The alkali compounds from biomass ash have tendency to accumulate esp. in a bed with sand particles. For typical cases of FBC of straw, wood and sewage sludge from a paper mill the experimental results on fluidized bed particle agglomeration are presented and possible ways for agglomeration abatement are critically assessed (author)

  6. A comparison of circulating fluidised bed combustion and gasification power plant technologies for processing mixtures of coal, biomass and plastic waste

    Energy Technology Data Exchange (ETDEWEB)

    McIlveen-Wright, D.R.; Huang, Y.; McMullan, J.T. [NICERT, University of Ulster at Jordanstown, Newtownabbey BT37 0QB, Northern Ireland (United Kingdom); Pinto, F.; Franco, C.; Gulyurtlu, I. [INETI-DEECA, Estrada do Paco do Lumiar, 22, 1649-038 Lisboa (Portugal); Armesto, L.; Cabanillas, A. [CIEMAT, Avda Complutense, 22, 28040 Madrid (Spain); Caballero, M.A.; Aznar, M.P. [Chemical and Environmental Engineering Department, Centro Politecnico Superior, Maria de Luna, University of Saragossa, 50018 Saragossa (Spain)

    2006-09-15

    Environmental regulations concerning emission limitations from the use of fossil fuels in large combustion plants have stimulated interest in biomass for electricity generation. The main objective of the present study was to examine the technical and economic viability of using combustion and gasification of coal mixed with biomass and plastic wastes, with the aim of developing an environmentally acceptable process to decrease their amounts in the waste stream through energy recovery. Mixtures of a high ash coal with biomass and/or plastic using fluidised bed technologies (combustion and gasification) were considered. Experiments were carried out in laboratory and pilot plant fluidised bed systems on the combustion and air/catalyst and air/steam gasification of these feedstocks and the data obtained were used in the techno-economic analyses. The experimental results were used in simulations of medium to large-scale circulating fluidised bed (CFB) power generation plants. Techno-economic analysis of the modelled CFB combustion systems showed efficiencies of around 40.5% (and around 46.5% for the modelled CFB gasification systems) when fuelled solely by coal, which were only minimally affected by co-firing with up to 20% biomass and/or wastes. Specific investments were found to be around $2150/kWe to $2400/kWe ($1350/kWe to $1450/kWe) and break-even electricity selling prices to be around $68/MWh to $78/MWh ($49/MWh to $54/MWh). Their emissions were found to be within the emission limit values of the large combustion plant directive. Fluidised bed technologies were found to be very suitable for co-firing coal and biomass and/or plastic waste and to offer good options for the replacement of obsolete or polluting power plants. (author)

  7. A comparison of circulating fluidised bed combustion and gasification power plant technologies for processing mixtures of coal, biomass and plastic waste

    International Nuclear Information System (INIS)

    Environmental regulations concerning emission limitations from the use of fossil fuels in large combustion plants have stimulated interest in biomass for electricity generation. The main objective of the present study was to examine the technical and economic viability of using combustion and gasification of coal mixed with biomass and plastic wastes, with the aim of developing an environmentally acceptable process to decrease their amounts in the waste stream through energy recovery. Mixtures of a high ash coal with biomass and/or plastic using fluidised bed technologies (combustion and gasification) were considered. Experiments were carried out in laboratory and pilot plant fluidised bed systems on the combustion and air/catalyst and air/steam gasification of these feedstocks and the data obtained were used in the techno-economic analyses. The experimental results were used in simulations of medium to large-scale circulating fluidised bed (CFB) power generation plants. Techno-economic analysis of the modelled CFB combustion systems showed efficiencies of around 40.5% (and around 46.5% for the modelled CFB gasification systems) when fuelled solely by coal, which were only minimally affected by co-firing with up to 20% biomass and/or wastes. Specific investments were found to be around $2150/kWe to $2400/kWe ($1350/kWe to $1450/kWe) and break-even electricity selling prices to be around $68/MWh to $78/MWh ($49/MWh to $54/MWh). Their emissions were found to be within the emission limit values of the large combustion plant directive. Fluidised bed technologies were found to be very suitable for co-firing coal and biomass and/or plastic waste and to offer good options for the replacement of obsolete or polluting power plants. (author)

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

    Science.gov (United States)

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

    2016-06-01

    The temporal release of selenium from coal during combustion and gasification in a fluidized bed was measured in situ by an on-line analysis system of trace elements in flue gas. The on-line analysis system is based on an inductively coupled plasma optical emission spectroscopy (ICP-OES), and can measure concentrations of trace elements in flue gas quantitatively and continuously. The results of on-line analysis suggest that the concentration of selenium in flue gas during coal gasification is higher than that during coal combustion. Based on the results of on-line analysis, a second-order kinetic law r(x)=0.94e(-26.58/RT)(-0.56 x(2) -0.51 x+1.05) was determined for selenium release during coal combustion, and r(x)=11.96e(-45.03/RT)(-0.53 x(2) -0.56 x+1.09) for selenium release during coal gasification. These two kinetic laws can predict respectively the temporal release of selenium during coal combustion and gasification with an acceptable accuracy. Thermodynamic calculations were conducted to predict selenium species during coal combustion and gasification. The speciation of selenium in flue gas during coal combustion differs from that during coal gasification, indicating that selenium volatilization is different. The gaseous selenium species can react with CaO during coal combustion, but it is not likely to interact with mineral during coal gasification. PMID:26897573

  9. Simulation of emission performance and combustion efficiency in biomass fired circulating fluidized bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Gungor, Afsin [Nigde University, Faculty of Engineering and Architecture, Department of Mechanical Engineering, 51100 Nigde (Turkey)

    2010-04-15

    In this study, the combustion efficiency and the emission performance of biomass fired CFBs are tested via a previously published 2D model [Gungor A. Two-dimensional biomass combustion modeling of CFB. Fuel 2008; 87: 1453-1468.] against two published comprehensive data sets. The model efficiently simulates the outcome with respect to the excess air values, which is the main parameter that is verified. The combustion efficiency of OC changes between 82.25 and 98.66% as the excess air increases from 10 to 116% with the maximum error of about 8.59%. The rice husk combustion efficiency changes between 98.05 and 97.56% as the bed operational velocity increases from 1.2 to 1.5 m s{sup -1} with the maximum error of about 7.60%. CO and NO{sub x} emissions increase with increasing bed operational velocity. Increasing excess air results in slightly higher levels of NO{sub x} emission. A significant amount of combustion occurs in the upper zone due to the high volatile content of the biomass fuels. (author)

  10. Ash and heavy metals in fluidized-bed combustion of wood wastes; Tuhka ja raskasmetallit puuperaeisen jaetteen kerrosleijupoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Kaessi, T.; Aittoniemi, P. [IVO Power Engineering, Vantaa (Finland); Kauppinen, E.; Latva-Somppi, J.; Kurkela, J. [VTT Chemical Technology, Espoo (Finland); Partanen, J. [IVO Technology Centre, Vantaa (Finland)

    1997-10-01

    Ash formation and deposition mechanisms during co-combustion of pulp mill sludge and bark in industrial bubbling fluidized bed (BFB) combustor have been studied. Similar fuels were used in a bench-scale BFB for co-combustion of sludge and bark pellets and comparative studies with separate combustion of these fuels. Results indicated that in industrial scale unit significant fraction of ash had vaporization. About 14 mass-% of the total fly ash was found in the particle size below 0.2 {mu}m. The vaporized species consisted of potassium (K), sulfur (S), chlorine (Cl) and also of minor quantities of sodium (Na). In the benchscale similar vaporization fractions during co-combustion were measured, about 11 mass-%. During the combustion of bark this ratio, about 20 mass-%, was higher than during sludge combustion. The vaporized ash fraction was in the case of dried sludge combustion about 7 mass-%, but with wet sludge the vaporization rate was remarkably lower, about 1-2 mass-%. An increase in the bed temperature increased also ash vaporization. Test run period without combustion at elevated temperatures produced very low quantities of vaporized ash. The vaporized species in bench-scale test during bark pellet combustion were K, S and Cl, for sludge combustion also Na was clearly detected. No condensation of the vaporized species in bed area or furnace walls was observed. Bed defluidization was studied in the bench-scale unit. During bark pellet combustion the bed-agglomeration proceeded via small ash particle, below 2 {mu}m, coating on sand particle surface and consequent bonding between the ash layers. In the case of sludge combustion the accumulation of large ash particles and sintering of these porous agglomerates was observed to cause bed coarsening and defluidization. (orig.)

  11. Development of fluidized bed combustion of biomass; Leijupolttoprosessin kehittaeminen vaikeille biopolttoaineille soveltuvaksi

    Energy Technology Data Exchange (ETDEWEB)

    Hiltunen, M.; Vaehaenen-Koivuluoma, T. [Foster Wheeler Energia Oy, Karhula (Finland)

    1997-10-01

    Some commercial BFB boilers burning biofuels, or biofuels and industrial wood wastes have suffered serious problems in bed material sintering. In worst cases the cumulation of reactive alkali compounds has caused total sintering of bed material even during a few days` operation. This presentation reports the results obtained from three separate cases, where sintering problems occurred. Boiler A burned biofuel with quartz sand and limestone addition. Boiler B burned softwood bark and industrial wood waste with sand addition. Boiler C burned softwood bark and sludge with sand addition. Due to the fuel used, bed sintering occurred in all boilers. Obviously, sintering was also influenced by some technical problems. Bed material samples have been analyzed with XRF and SEM-EDS techniques. According to these analyses, the main reason for sintering in boiler A is the cumulation of reactive potassium in bed material. In boiler B, the main reason is the fuel change from a mixture of softwood bark and industrial wood waste to pure industrial wood waste. The extra load of reactive sodium exceeded the critical concentration of alkali compounds in bed material. Also in boiler C, the fuel change from a mixture of softwood bark and sludge to pure softwood bark seems to be one of the reasons for bed sintering. After the fuel change the bed saturated with reactive potassium and the bed sintered. (orig.)

  12. Characterization of residues from waste combustion in fluidized bed boilers. Evaluation report

    International Nuclear Information System (INIS)

    In this report a thorough characterization of the solid residues from municipal solid waste combustion in a Kvaerner EnviroPower bubbling fluidized bed boiler in Lidkoeping, is presented. Three different end products are generated, namely bottom ash, cyclone ash, and filter ash. The bottom ash, consisting of bed ash and hopper ash, is screened and useful bed material recycled. In the characterization, also the primary constituents bed ash and hopper ash have been included. A chemical characterization have been performed including total inorganic contents, content of unburnt matter, leaching behaviour (availability tests, column tests, pH-static tests) and leaching tests according to certain standards for classification (AFX31-210, DIN38414, TCLP). Physical characterization have included grain size distribution, grain density, compaction properties and stabilization of cyclone ash with subsequent testing of comprehensive strength and saturated hydraulic conductivity. From an environmental point of view, the quality of the bottom ash and probably the cyclone ash from fluidized bed combustion as determined in this study, indicate a potential for utilization. Utilization of the bottom ash could be accepted in certain countries, e.g. France, according to their current limit values. In other countries, e.g. Sweden, no general limit values are given and utilization have to be applied for in each case. The judgement is then based, not only on total contents in the residue and its leaching behaviour, but also on the specific environmental conditions at the site. 7 refs, 17 figs, 12 tabs

  13. Phase composition of solid residue of fluidized bed coal combustion, quality tests, and application possibilities

    International Nuclear Information System (INIS)

    The scope of this paper is to focus the attention on the newly produced ashes - residues after fluidized bed coal combustion. The favorite phase composition of this material due to low combustion temperature of 850 grad C exhibits very good cementitious properties. Fluidized ashes may be preferably used in the production of some types of Portland cements as a gypsum replacement and in cement-free concretes. The quality tests of this sulfo-calcareous material are proposed as well as some application possibilities. (authors)

  14. Calcium-based sorbents behaviour during sulphation at oxy-fuel fluidised bed combustion conditions

    OpenAIRE

    García Labiano, Francisco; Rufas, Aránzazu; Diego Poza, Luis F. de; Obras-Loscertales, Margarita de las; Gayán Sanz, Pilar; Abad Secades, Alberto; Adánez Elorza, Juan

    2011-01-01

    Sulphur capture by calcium-based sorbents is a process highly dependent on the temperature and CO2 concentration. In oxy-fuel combustion in fluidised beds (FB), CO2 concentration in the flue gas may be enriched up to 95%. Under so high CO2 concentration, different from that in conventional coal combustion with air, the calcination and sulphation behaviour of the sorbent must be defined to determine the optimum operating temperature in the FB combustors. In this work, the SO2 retention capacit...

  15. Interactions between SO2 and NOx emissions in fluidised bed combustion of coal. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W.

    1994-01-01

    ;Contents: Introduction; The emissions of SO2 and NOx and their interactions in fluidized-bed combustion (FBC) of coal; SO2 and NOx emissions in FBC of coal: a literature survey; Oxidation of NH3 in a fixed bed; Oxidation of NH3: influence of SO2, CO and CO2; Modeling SO2 and NOx emissions in AFBC: a simple approach; Modeling SO2 and NOx emissions in CFBC; Modeling SO2 and NOx emissions in FBC: a fundamental approach; Optimization and Conclusions.

  16. Numerical simulations of the industrial circulating fluidized bed boiler under air- and oxy-fuel combustion

    International Nuclear Information System (INIS)

    Measured and numerical results of air-fuel combustion process within large scale industrial circulating fluidized bed (CFB) boiler is presented in this paper. For numerical simulations the industrial compact CFB boiler was selected. Numerical simulations were carried out using three-dimensional model where the dense particulate transport phenomenon was simultaneously modelled with combustion process. The fluidization process was modelled using the hybrid Euler-Lagrange approach. The impact of the geometrical model simplification on predicted mass distribution and temperature profiles over CFB boiler combustion chamber two kinds of geometrical models were used, namely the complete model which consist of combustion chamber, solid separators, external solid super-heaters and simplified boiler geometry which was reduced to the combustion chamber. The evaluated temperature and pressure profiles during numerical simulations were compared against measured data collected during boiler air-fuel operation. Collected data was also used for validating numerical model of the oxy-fuel combustion model. Stability of the model and its sensitivity on changes of several input parameters were studied. The comparison of the pressure and temperature profiles for all considered cases gave comparable trends in contrary to measured data. Moreover, some additional test was carried out the check the influence of radiative heat transfer on predicted temperature profile within the CFB boiler. - Highlights: • Hybrid Euler-Lagrange approach was used for modelling particle transport, air- and oxy-fuel combustion process. • Numerical results were validated against measured data. • The influence of different boiler operating conditions on calculated temperature profile was investigated. • New strategy for resolving particle transport in circulating fluidized bed was shown

  17. Co-combustion of peach and apricot stone with coal in a bubbling fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Atimtay, Aysel T.; Kaynak, Burcak [Department of Environmental Engineering, Middle East Technical University, Ankara 06531 (Turkey)

    2008-02-15

    In this study a bubbling fluidized bed combustor (BFBC) having an inside diameter of 102 mm and a height of 900 mm was used to investigate the co-combustion characteristics of peach and apricot stones produced as a waste from the fruit juice industry with coal. A lignite coal was used for co-combustion. On-line concentrations of O{sub 2}, CO, CO{sub 2}, SO{sub 2}, NO{sub X} and total hydrocarbons (C{sub m}H{sub n}) were measured in the flue gas during combustion experiments. Variations of emissions of various pollutants were studied by changing the operating parameters (excess air ratio, fluidization velocity, and fuel feed rate). Temperature distribution along the bed was measured with thermocouples. For co-combustion of apricot and peach fruit stones with a lignite coal, various ratios of biomass to coal ranging from 0 to 100 wt.% were tested. For the peach stone co-combustion tests, efficiencies are about 98% and for the apricot stone co-combustion tests, efficiencies ranged between 94.7% and 96.9% for 25%, 50% and 75% of apricot stone in the fuel mixture. The results of this study have shown that as the biomass ratio in the fuel mixture increases, the combustion takes place at the upper regions of the main column. This causes higher temperatures in the freeboard than the bed. Also the CO and hydrocarbon (C{sub m}H{sub n}) emissions increase as the biomass percentage increases in the fuel mixture. This causes decrease in the combustion efficiency. These results suggest that peach and apricot stones are potential fuels that can be utilized for clean energy production in small-scale fruit juice industries by using BFBC. The percentage of peach stones or apricot stones in the fuel mixture is suggested to be below 50 wt.% in order to obtain the emission limits of EU. During the design of the BFBC, one has to be careful about the volatile matter (VM) content of the biomass. For the complete combustion of the VM, longer freeboard or secondary air addition should be

  18. Fundamental Combustion Characteristics of Sewage Sludge in Fluidized Bed Incinerator with Turbocharger

    Science.gov (United States)

    Murakami, Takahiro; Suzuki, Yoshizo; Nagasawa, Hidekazu; Yamamoto, Takafumi; Koseki, Takami; Hirose, Hitoshi; Ochi, Shuichi

    An epoch-making incineration plant, which is equipped with a pressurized fluidized-bed combustor coupled to a turbocharger, for the recovery of the energy contained in sewage sludge is proposed. This plant has three main advantages. (1) A pressure vessel is unnecessary because the maximum operating pressure is 0.3 MPa (absolute pressure). The material cost for plant construction can be reduced. (2) CO2 emissions originating from power generation can be decreased because the FDF (Forced Draft Fan) and the IDF (Induced Draft Fan) are omitted. (3) Steam in the flue gas becomes a working fluid of the turbocharger, so that in addition to the combustion air, the surplus air is also generable. Therefore, this proposed plant will not only save energy but also the generate energy. The objective of this study is to elucidate the fundamental combustion characteristics of the sewage sludge using a lab-scale pressurized fluidized bed combustor (PFBC). The tested fuels are de-watered sludge and sawdust. The temperature distribution in the furnace and N2O emissions in the flue gas are experimentally clarified. As the results, for sludge only combustion, the temperature in the sand bed decreases by drying and pyrolysis, and the pyrolysis gas burns in the freeboard so that the temperature rises. On the other hand, the residual char of sawdust after pyrolysis burns stably in the sand bed for the co-firing of sludge and sawdust. Thus the temperature of the co-firing is considerably higher than that of the sludge only combustion. N2O emissions decreases with increasing freeboard temperature, and are controlled by the temperature for all experimental conditions. These data can be utilize to operation the demonstration plant.

  19. Proceedings of the Sixth International Conference on Fluidized Bed Combustion. Volume 1. Plenary sessions

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-08-01

    The Sixth International Conference on Fluidized Bed Combustion was held at the Atlanta Hilton, Atlanta, Georgia, April 9-11, 1980. The papers in this volume involved presentation of the research and development programs of the US (US DOE, TVA, EPRI and US EPA), United Kingdom, Federal Republic of Germany and the People's Republic of China. Eight papers from Vol. 1 (Plenary Sessions) of the proceedings have been entered individually into EDB and ERA. (LTN)

  20. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Ping Pan; Andy Wu; John T. Riley

    2005-07-30

    This purpose of this report is to present the progress made on the project ''Establishment of an Environmental Control Technology Laboratory (ECTL) with a Circulating Fluidized-Bed Combustion (CFBC) System'' during the period April 1, 2005 through June 30, 2005. The following tasks have been completed. First, the new Combustion Laboratory was occupied on June 15, 2005, and the construction of the Circulating Fluidized-Bed (CFB) Combustor Building is in the final painting stage. Second, the fabrication and manufacturing contract for the CFBC Facility was awarded to Sterling Boiler & Mechanical, Inc. of Evansville, Indiana. Sterling is manufacturing the assembly and component parts of the CFBC system. The erection of the CFBC system is expected to start September 1, 2005. Third, mercury emissions from the cofiring of coal and chicken waste was studied experimentally in the laboratory-scale simulated fluidized-bed combustion facility. The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter is described.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Teats, F.G.; Swift, W.M. (Argonne National Lab., IL (United States)); Banerjee, D.D. (Illinois Clean Coal Inst., Carterville, IL (United States))

    1993-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Teats, F.G.; Swift, W.M. [Argonne National Lab., IL (United States); Banerjee, D.D. [Illinois Clean Coal Inst., Carterville, IL (United States)

    1993-04-01

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

  3. International evaluation of the programme on fluid bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H. [Ruhr Univ., Bochum (Germany); Magnusson, B.F. [Norwegian Univ. of Science and Technology, Trondheim (Norway); Reed, T. [Colorado School of Mines (United States)

    1996-12-31

    This report on the Swedish National Program on Fluid Bed Combustion and Gasification is part of the on-going evaluation process adopted by the funding organization NUTEK. This agency has invited the undersigned to act as members of an international panel responsible for evaluating the progress made in 9 projects initiated between 1993-1996. The output of this evaluation procedure is given in this report. The main aim of the Fluid Bed Combustion and Gasification Program is to develop industrially relevant knowledge and competence in experimental and computational techniques capable of characterizing the flow, heat transfer, combustion, gasification, ash formation and deposition and emissions in fluid bed gasifiers and combustors. To achieve this aim NUTEK is sponsoring research in a number of universities and encourages close cooperation between universities and industry. In the evaluation of the various sponsored research programs, the evaluation committee has considered the following key points: relevance of research to industrial needs; originality of research; program management; adequacy of resources; degree of collaboration between industry and academia; international standing of research. In this report comments and recommendations are made on individual projects as well as on the programme in general and they express the unanimous view of the panel members

  4. Thermal decomposition of selected chlorinated hydrocarbons during gas combustion in fluidized bed

    Directory of Open Access Journals (Sweden)

    Olek Malgorzata

    2013-01-01

    Full Text Available Abstract Background The process of thermal decomposition of dichloromethane (DCM and chlorobenzene (MCB during the combustion in an inert, bubbling fluidized bed, supported by LPG as auxiliary fuel, have been studied. The concentration profiles of C6H5CI, CH2Cl2, CO2, CO, NOx, COCl2, CHCl3, CH3Cl, C2H2, C6H6, CH4 in the flue gases were specified versus mean bed temperature. Results The role of preheating of gaseous mixture in fluidized bed prior to its ignition inside bubbles was identified as important factor for increase the degree of conversion of DCM and MCB in low bed temperature, in comparison to similar process in the tubular reactor. Conclusions Taking into account possible combustion mechanisms, it was identified that autoignition in bubbles rather than flame propagation between bubbles is needed to achieve complete destruction of DCM and MCB. These condition occurs above 900°C causing the degree of conversion of chlorine compounds of 92-100%.

  5. Combustion studies of high moisture content waste in a fluidised bed.

    Science.gov (United States)

    Suksankraisorn, K; Patumsawad, S; Fungtammasan, B

    2003-01-01

    The combustion of three high moisture content waste materials in a fluidised bed combustor has been investigated and a comparison with co-firing of these materials with coal in the same combustor has been made. Waste materials burnt were olive oil waste, municipal solid waste and potato, which is representative of vegetable waste. Mixtures of up to 20% mass concentration water in the waste were fed to the combustor. Above that value the moisture content was too high to sustain combustion without addition of coal. Measurements of CO, NOx, SO2 temperatures were made and the carbon combustion efficiency evaluated. Co-firing with coal resulted in markedly higher combustion efficiencies with an increase of approximately 10-80% when burning the simulated MSW. However, this was much lower than the value of 93% when coal was burnt on its own. It was also much lower than the value obtained, average 90%, when co-firing potato and olive oil waste with coal and there was little difference in the combustion efficiency between the two types of waste and with increasing moisture content. It was concluded that the high ash content of the simulated MSW 26%, compared with 5% in the other two waste materials resulted in slower burning and consequently the char particles were elutriated from the bed without being fully burnt. In term of gaseous emissions during co-combustion, CO emission is relatively insensitive to change in waste fraction. While emission of SO2 can be reduced as the waste fraction increases as a result of fuel-S dilution. But in terms of percent fuel-S converted, it is actually increased by increasing waste fraction. Emissions of NO and N2O increase slightly with MSW fraction. PMID:12893016

  6. State of the art and the future fuel portfolio of fluidized bed combustion systems; Status und kuenftiges Brennstoffportfolio bei Wirbelschichtfeuerungen

    Energy Technology Data Exchange (ETDEWEB)

    Szentannai, Pal; Friebert, Arpad; Winter, Franz [Technische Univ. Wien (Austria). Inst. fuer Verfahrens-, Umwelttechnik und technische Biowissenschaften

    2008-07-01

    Coal, biomass and substitute fuels energetically can be used efficiently and with low pollution in fluidized bed plants. In comparison to biomass there are significant differences between the circulating and stationary fluidized bed technology. The stationary fluidised bed is fed predominantly with biomasses and residual substances. Coal usually is the basis fuel in the circulating fluidised bed. Biomass and residual substances frequently are course-fired. The state of the art is the employment of a broad fuel mixture in small and large fluidized-bed combustion systems. Future developments present an increased use of sewage sludge, fluidized bed combustion systems with wood as a basis fuel, utilization of household waste and the gas production.

  7. Co-combustion of biomass and gaseous fuel in a novel configuration of fluidized bed: Thermal characteristics

    International Nuclear Information System (INIS)

    Highlights: • Jetting-fountain fluidized bed enables smooth co-firing of biomass and gaseous fuel. • Applying jetting-fountain configuration dampens greatly freeboard overheating. • Heat gain by bed greatly increases with jetting-fountain configuration. • Increasing gaseous fuel ratio causes more reduction in freeboard overheating. • Heat gain by bed considerably increases with increasing gaseous fuel ratio. - Abstract: Experimental study on co-combustion of rice straw and natural gas has been performed in a fluidized bed. The used combustor allows the novel, jetting-fountain configuration and the conventional operation as well. In the jetting-fountain configuration, natural gas premixed with the air sufficient for combustion proceeds through the jet pipe to create a jetting-fountain zone. Whereas only the air required for rice straw combustion passes through the gas distributor. The experiments show that smooth combustion of natural gas with rice straw can be performed in the jetting-fountain fluidized bed avoiding acoustic effects and explosions of burning bubbles that occurs in conventional operation. The jetting-fountain fluidized bed is shown to dampen greatly the freeboard overheating at particularly lower bed temperatures. This is because the fountain-particles absorb a great part of heat released in the freeboard and recover it back to the bed. It is confirmed by measuring the in-bed cooling load that was found to increase considerably at lower bed temperatures. The natural gas contribution is found to play a major role when applying the jetting-fountain configuration. Increasing the natural gas contribution enlarges the fountain zone that causes greater reduction in the freeboard overheating and recovers more heat back to the bed. Measuring the in-bed cooling also approves the later conclusion

  8. Fluidized-bed and fixed-bed reactor testing of methane chemical looping combustion with MgO-promoted hematite

    International Nuclear Information System (INIS)

    Highlights: • Mg-promoted hematite showed better performance than hematite for methane CLC. • Stable reaction performance was observed during cyclic CH4 CLC fluidized bed tests. • Attrition resistance was better than that with standard FCC catalysts. • 5 wt% MgO increased both the oxygen capacity and reaction rates for CH4 CLC. • Possible mechanisms for the CH4 CLC OC performance enhancement are presented. - Abstract: In this study MgO-promoted Fe2O3 hematite oxygen carriers were synthesized from various Mg sources and evaluated for methane chemical looping combustion. Particles suitable for fluidized bed flow reactor studies were prepared in the lab. Cyclic CLC tests conducted in the fluidized bed with MgO promoted hematite showed better performance than that with hematite. Attrition resistance of laboratory prepared MgO promoted hematite was excellent. Reactivity and stability of the oxygen carrier materials were also tested in the thermogravimetric analyzer and bench-scale reactors. Scanning electron microscopy and energy-dispersive X-ray spectroscopy, and X-ray diffraction were used to study the morphology and elemental compositions present in the hematite and promoted hematite oxygen carriers prior to and following the multi-cycle chemical looping reaction. The incorporation of 5 wt% MgO led to an increased reaction rate and an increase in oxygen utilized as compared to the pure hematite oxygen carrier. Possible reasons for the promotion effect by MgO were evaluated. These studies reveal that the best performing oxygen carrier was the 5 wt% MgO/Fe2O3 which exhibited no observed degradation in the kinetics and conversion performance in the methane step over 15 reduction and oxidation cycles. The Mg promoted oxygen carrier also showed reduced coke formation as compared to the pure hematite carrier

  9. Pressurized Fluidized Bed Combustion Second-Generation System Research and Development

    Energy Technology Data Exchange (ETDEWEB)

    A. Robertson; D. Horazak; R. Newby; H. Goldstein

    2002-11-01

    Research is being conducted under United States Department of Energy (DOE) Contract DE-AC21-86MC21023 to develop a new type of coal-fired plant for electric power generation. This new type of plant--called a Second-Generation or Advanced Pressurized Circulating Fluidized Bed Combustion (APCFB) plant--offers the promise of efficiencies greater than 45% (HHV), with both emissions and a cost of electricity that are significantly lower than conventional pulverized-coal-fired plants with scrubbers. The APCFB plant incorporates the partial gasification of coal in a carbonizer, the combustion of carbonizer char in a pressurized circulating fluidized bed boiler (PCFB), and the combustion of carbonizer syngas in a topping combustor to achieve gas turbine inlet temperatures of 2300 F and higher. A conceptual design was previously prepared for this new type of plant and an economic analysis presented, all based on the use of a Siemens Westinghouse W501F gas turbine with projected carbonizer, PCFB, and topping combustor performance data. Having tested these components at the pilot plant stage, the referenced conceptual design is being updated to reflect more accurate performance predictions together with the use of the more advanced Siemens Westinghouse W501G gas turbine and a conventional 2400 psig/1050 F/1050 F/2-1/2 in. steam turbine. This report describes the updated plant which is projected to have an HHV efficiency of 48% and identifies work completed for the October 2001 through September 2002 time period.

  10. Standard technical specifications for combustion engineering pressurized water reactors

    International Nuclear Information System (INIS)

    This Standard Technical Specification (STS) has been structured for the broadest possible use on Combustion Engineering plants currently being reviewed for an Operating License. Two separate and discrete containment specification sections are provided for each of the following containment types: Atmospheric and Dual. Optional specifications are provided for those features and systems which may be included in individual plant designs but are not generic in their scope of application. Alternate specifications are provided in a limited number of cases to cover situations where alternate specification requirements are necessary on a generic basis because of design differences. This revision of STS does not typically include requirements which may be added or revised as a result of the NRC staff's further review of the Three Mile Island incident

  11. Development program on pressurized fluidized-bed combustion. Annual report, July 1975--June 1976

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, G.J.; Johnson, I.; Cunningham, P.T.

    1976-07-01

    The feasibility of using fluidized-bed combustors in power and steam plants is being evaluated. The concept involves burning fuels such as coal in a fluidized bed of either a limestone (CaCO/sub 3/) or a synthetically prepared calcium-containing stone. The calcium reacts with the sulfur to form CaSO/sub 4/, which remains in the bed, thus decreasing the level of SO/sub 2/ in the flue gas. Levels of NO/sub x/ in the flue gas are low. In a separate step, the CaSO/sub 4/ is regenerated to CaO by reductive decomposition at Ca/sub solar/ 1100/sup 0/C for reuse in the combustor. Progress is reported on the following: the effect of regeneration operating variables on extent of regeneration and SO/sub 2/ concentration in the off-gas using coal as the source of reducing agent and of heat; the alternate combustion and regeneration behavior of stone; the rate and extent of sulfation of agents impregnated on Al/sub 2/O/sub 3/; the effect of variables on sorption and release of sulfur for CaO-impregnated stone; attrition resistance of stone; the kinetic and structural changes occurring during half-calcination of dolomite; the CaS-CaSO/sub 4/ regeneration reaction; and the volatility of trace elements when heating coal ash. Procurement and disposal of regenerated stone, minimum fluidization studies, modeling of a gas-solid combustion reaction and of the regeneration process, combustion studies using different sizes of coal and additive and also using lignite are reported.

  12. Characteristics modeling for supercritical circulating fluidized bed boiler working in oxy-combustion technology

    Science.gov (United States)

    Balicki, Adrian; Bartela, Łukasz

    2014-06-01

    Among the technologies which allow to reduce greenhouse gas emission, mainly carbon dioxide, special attention deserves the idea of `zeroemission' technology based on boilers working in oxy-combustion technology. In the paper the results of analyses of the influence of changing two quantities, namely oxygen share in oxidant produced in the air separation unit, and oxygen share in oxidant supplied to the furnace chamber on the selected characteristics of a steam boiler including the degree of exhaust gas recirculation, boiler efficiency and adiabatic flame temperature, was examined. Due to the possibility of the integration of boiler model with carbon dioxide capture, separation and storage installation, the subject of the analysis was also to determine composition of the flue gas at the outlet of a moisture condensation installation. Required calculations were made using a model of a supercritical circulating fluidized bed boiler working in oxy-combustion technology, which was built in a commercial software and in-house codes.

  13. Gaseous emissions from sewage sludge combustion in a moving bed combustor.

    Science.gov (United States)

    Batistella, Luciane; Silva, Valdemar; Suzin, Renato C; Virmond, Elaine; Althoff, Chrtistine A; Moreira, Regina F P M; José, Humberto J

    2015-12-01

    Substantial increase in sewage sludge generation in recent years requires suitable destination for this residue. This study evaluated the gaseous emissions generated during combustion of an aerobic sewage sludge in a pilot scale moving bed reactor. To utilize the heat generated during combustion, the exhaust gas was applied to the raw sludge drying process. The gaseous emissions were analyzed both after the combustion and drying steps. The results of the sewage sludge characterization showed the energy potential of this residue (LHV equal to 14.5 MJ kg(-1), db) and low concentration of metals, polycyclic aromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF). The concentration of CO, NOx, BTEX (benzene, toluene, ethylbenzene and xylenes) emitted from the sludge combustion process were lower than the legal limits. The overall sludge combustion and drying process showed low emissions of PCDD/PCDF (0.42 ng I-TEQ N m(-3)). BTEX and PAH emissions were not detected. Even with the high nitrogen concentration in the raw feed (5.88% db), the sludge combustion process presented NOx emissions below the legal limit, which results from the combination of appropriate feed rate (A/F ratio), excess air, and mainly the low temperature kept inside the combustion chamber. It was found that the level of CO emissions from the overall sludge process depends on the dryer operating conditions, such as the oxygen content and the drying temperature, which have to be controlled throughout the process in order to achieve low CO levels. The aerobic sewage sludge combustion process generated high SO2 concentration due to the high sulfur content (0.67 wt%, db) and low calcium concentration (22.99 g kg(-1)) found in the sludge. The high concentration of SO2 in the flue gas (4776.77 mg N m(-3)) is the main factor inhibiting PCDD/PCDF formation. Further changes are needed in the pilot plant scheme to reduce SO2 and particulate matter emissions

  14. Experimental Investigations of Extracted Rapeseed Combustion Emissions in a Small Scale Stationary Fluidized Bed Combustor

    Directory of Open Access Journals (Sweden)

    Dieter Steinbrecht

    2009-02-01

    Full Text Available The objective of this study was to observe the combustion process of extracted rapeseed (ER grist in a stationary fluidized bed combustor (SFBC and evaluate the chemical compositions of the flue gas emissions. The experimental tests of ER combustion in the 90 to 200 kW (Kilowatt SFB combustion test facility show that the optimal ER combustion temperature is within the range from 850 to 880° C. Temperature and the concentration of exhausted emissions (e.g. O2, CO, CO2, NO, NO2, SO2, Corg were measured with dedicated sensors distributed within the combustor, along its height and in the flue gas duct. The experimental results showed that with respect to German emission limits the concentration of SO2 and NOx in the flue gas were high whereas that of CO was low. This study furthermore is applicable for the abundant biomass residue resources in Vietnam (rice husk, rice straw, bagasse, cassava residues, coconut shell etc., which have similar chemical compositions to ER.

  15. Residues characterisation from the fluidised bed combustion of East London's solid recovered fuel.

    Science.gov (United States)

    Balampanis, D E; Pollard, S J T; Simms, N; Longhurst, P; Coulon, F; Villa, R

    2010-07-01

    Waste thermal treatment in Europe is moving towards the utilisation of the combustible output of mechanical, biological treatment (MBT) plants. The standardisation of solid recovered fuels (SRF) is expected to support this trend and increase the amount of the generated combustion residues. In this work, the residues and especially the fly ashes from the fluidised bed combustion (FBC) of East London's NCV 3, Cl 2, and Hg 1 class SRF, are characterised. The following toxicity indicators have been studied: leachable chlorine, organochlorides expressed as pentachlorobenzene and hexachlorobenzene, and the heavy metals Cu, Cr, Cd, Zn, Ni, and Pb. Furthermore the mineralogical pattern of the ashes has been studied by means of XRD and SEM-EDS. The results suggest that these SRF derived ashes have significantly lower quantities of Cu, Cd, Pb, Zn, leachable Cl, and organochlorides when compared to other literature values from traditional waste thermal treatment applications. This fact highlights the importance of modern separation technologies employed in MBT plants for the removal of components rich in metals and chlorine from the combustible output fraction of SRF resulting to less hazardous residues. PMID:20231082

  16. Circulating fluidized bed combustion ash characterization. The case of the Provence 250 MW unit

    Energy Technology Data Exchange (ETDEWEB)

    Lecuyer, I.; Leduc, M. [Electricite de France (EDF), 78 - Chatou (France). Direction des Etudes et Recherches; Lefevre, R.; Ausset, P. [Paris-12 Univ., Creteil (France). Lab. Interuniversitaire des Systemes Atmospheriques

    1997-05-01

    The Provence 250 MW Circulating Fluidized Bed Combustion Unit (Gardanne, France) is burning a high sulfur (2 to 4%), high ash content (30%) local lignite. This peculiar fuel already contains about 15% of CaO which allows it to capture the sulfur dioxide in situ without adding any complementary sorbent. The ash chemical composition (bed ash and ESP ash) that reflects the particularities of the coal is presented. SEM and DRX observations confirm the presence of anhydrite CaSO{sub 4}, lime, CaS, quartz and traces of hematite. Most of particles are roughly-shaped but microspheres can also be detected in fly ash. The very high sulfate content may be worrying for the environment in disposals. Hardened samples do not seem to retain compounds from leaching: high quantities of calcium and sulfates are still leached from these crushed samples. (author) 10 refs.

  17. Biomass fueled fluidized bed combustion: atmospheric emissions, emission control devices and environmental regulations

    International Nuclear Information System (INIS)

    Fluidized bed combustors have become the technological choice for power generation from biomass fuels in California. Atmospheric emission data obtained during compliance tests are compared for five operating 18 to 32 MW fluidized bed combustion power plants. The discussion focuses on the impact of fuel properties and boiler design criteria on the emission of pollutants, the efficiency of pollution control devices, and regulations affecting atmospheric emissions. Stack NOx emission factors are shown not to vary substantially among the five plants which burn fuels with nitrogen concentrations between 0.3 and 1.1% dry weight. All facilities use at least one particular control device, but not all use limestone injection or other control techniques for sulfur and chlorine. The lack of control for chlorine suggests the potential for emission of toxic species due to favorable temperature conditions existing in the particulate control devices, particularly when burning fuels containing high concentrations of chlorine. (Author)

  18. Material handling systems for the fluidized-bed combustion boiler at Rivesville, West Virginia

    Science.gov (United States)

    Branam, J. G.; Rosborough, W. W.

    1977-01-01

    The 300,000 lbs/hr steam capacity multicell fluidized-bed boiler (MFB) utilizes complex material handling systems. The material handling systems can be divided into the following areas: (1) coal preparation; transfer and delivery, (2) limestone handling system, (3) fly-ash removal and (4) bed material handling system. Each of the above systems are described in detail and some of the potential problem areas are discussed. A major potential problem that exists is the coal drying system. The coal dryer is designed to use 600 F preheated combustion air as drying medium and the dryer effluent is designed to enter a hot electrostatic precipitator (730 F) after passage through a cyclone. Other problem areas to be discussed include the steam generator coal and limestone feed system which may have operating difficulties with wet coal and/or coal fines.

  19. Ash and heavy metals in fluidized bed-combustion; Tuhka ja raskasmetallit puuperaeisen jaetteen kerrosleijupoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Kaessi, T.; Aittoniemi, P. [IVO International, Vantaa (Finland)

    1996-12-01

    Combustion ashes and submicron fly ash particles were characterized in two industrial boilers (bubbling vs. circulating fluidized bed) burning paper mill deinking sludge and bark or wood as support fuel. Bulk samples from fly ash, circulating ash and bottom ash were analyzed. Fine particles in fly ash were monitored and sampled for microscopic studies. The mass size distribution of fly ash was measured and the chemical composition according to particle size was analyzed. The results showed that ash consists of large and friable clusters formed by sintering of small mineral particles originating from paper fillers. Very few ash particles were fused and they were found only among the smallest particles. No agglomerates of fused particles were found. If the residence time in furnace is long enough sintering may proceed further and ash structure grows more dense. No indication of ash vaporization was detected. These results were similar for bubbling and circulating fluidized bed boilers. (author)

  20. Results concerning a clean co-combustion technology of waste biomass with fossil fuel, in a pilot fluidised bed combustion facility

    Energy Technology Data Exchange (ETDEWEB)

    Ionel, Ioana; Trif-Tordai, Gavril; Ungureanu, Corneliu; Popescu, Francisc; Lontis, Nicolae [Politehnica Univ. Timisoara (Romania). Faculty for Mechanical Engineering

    2008-07-01

    The research focuses on a facility, the experimental results, interpretation and future plans concerning a new developed technology of using waste renewable energy by applying the cocombustion of waste biomass with coal, in a fluidised bed system. The experimental facility is working entirely in accordance to the allowed limits for the exhaust flue gas concentration, with special concern for typical pollutants. The experiments conclude that the technology is cleaner, has as main advantage the possibility to reduce both the SO{sub 2} and CO{sub 2} exhaust in comparison to standard fossil fuel combustion, under comparable circumstances. The combustion is occurring in a stable fluidised bed. (orig.)

  1. Studies on ash behavior during co-combustion of paper sludge in fluidized bed boilers

    OpenAIRE

    Coda, Beatrice

    2004-01-01

    The present work analysis the ash behaviour and the environmental impact with respect to the toxic trace metals (e.g. Cu, Pb, Zn, Cd, Mn, Cr, Ni) upon co-combustion of paper sludge, a waste deriving from the treatment of recovered paper, with coal and coal/biomass blends in fluidised bed combustors designed for energy production or steam generation. The study, conducted in the framework of a European research project aiming at widening the spectrum of fuels utilised by coal-fired and coal...

  2. Optimum temperature for sulphur retention in fluidised beds working under oxy-fuel combustion conditions

    OpenAIRE

    Diego Poza, Luis F. de; Rufas, Aránzazu; García Labiano, Francisco; Obras-Loscertales, Margarita de las; Abad Secades, Alberto; Gayán Sanz, Pilar; Adánez Elorza, Juan

    2013-01-01

    Oxy-fuel combustion is one of the leading options for power generation with CO 2 capture. The process consists of burning the fuel with a mixture of nearly pure oxygen and a CO 2 -rich recycled flue gas, result- ing in a product flue gas from the boiler containing mainly CO 2 and H 2 O. Among the possible boiler types, fluidised bed combustors are very appropriate for the oxy-fuel process because they allow the in situ des- ulphurisation by feeding Ca-based...

  3. The environmental and economical advantages of fluidized bed combustion for biomass and wastes

    International Nuclear Information System (INIS)

    Government and individuals in the United Kingdom are both working towards improvements in the environment. This article examines the economic and environmental advantages which might accrue from fluidized bed combustion of biomass and various waste products. Not only are waste products reused and recycled but electric power is generated without the harmful emissions of CO2 and SO2 which accompany thermal power plant use. Energy generation technologies are now being developed which are acceptable to the community and use renewable energy sources. (UK)

  4. Methane combustion by moving bed fuel reactor with Fe2O3/Al2O3 oxygen carriers

    International Nuclear Information System (INIS)

    Highlights: • Moving bed reactor employed to methane combustion using iron-based oxygen carrier. • Fe2O3/Al2O3 oxygen carriers was prepared and provided with applicable performance. • Carbon formation was enhanced with increased retention time at 900 °C. • Full CH4 conversion was reached without carbon formation by moving bed operation. • FeO and FeAl2O4 were formed in the reacted oxygen carriers out of the reactor. - Abstract: Fe2O3/Al2O3 composite oxygen carriers were prepared for chemical looping combustion (CLC) with methane in a lab-scale moving bed fuel reactor provided with reasonable crush strength, reactivity and recyclability. Carbon formation was observed during the combustion process in the empty bed at 900 °C through methane decomposition reaction, and was enhanced for experiments conducted with increased retention time. Carbon formation was obviously reduced for experiments conducted in the moving bed fuel reactor with oxygen carrier-to-fuel ratio (ϕ) higher than 1.14. The oxygen carriers that moving out of the moving bed reactor were composed of mainly FeO and FeAl2O4, characterized by X-ray diffraction (XRD) analysis. The formation of FeO and FeAl2O4 indicated that further utilization of oxygen in iron-based oxygen carriers can be achieved by moving bed operation

  5. Data summary of municipal solid waste management alternatives. Volume 5, Appendix C, Fluidized-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    None

    1992-10-01

    This appendix provides information on fluidized-bed combustion (FBC) technology as it has been applied to municipal waste combustion (MWC). A review of the literature was conducted to determine: (1) to what extent FBC technology has been applied to MWC, in terms of number and size of units was well as technology configuration; (2) the operating history of facilities employing FBC technology; and (3) the cost of these facilities as compared to conventional MSW installations. Where available in the literature, data on operating and performance characteristics are presented. Tabular comparisons of facility operating/cost data and emissions data have been complied and are presented. The literature review shows that FBC technology shows considerable promise in terms of providing improvements over conventional technology in areas such as NOx and acid gas control, and ash leachability. In addition, the most likely configuration to be applied to the first large scale FBC dedicated to municipal solid waste (MSW) will employ circulating bed (CFB) technology. Projected capital costs for the Robbins, Illinois 1600 ton per day CFB-based waste-to-energy facility are competitive with conventional systems, in the range of $125,000 per ton per day of MSW receiving capacity.

  6. The calcination and sulphation behaviour of sorbents in fluidized bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Haji-Sulaiman, M.Z.; Scaroni, A.W. (Pennsylvania State University, University Park, PA (USA). Combustion Laboratory)

    1991-02-01

    A study was performed on the effects of the CO{sub 2} partial pressure in the calcining gas and sorbent impurities on the structure of calcines produced and on subsequent sulphation behaviour under fluidized bed combustion conditions. It was found that the average pore size and the BET surface area were affected markedly by these two parameters, but their effect on pore volume was not significant. Increasing both parameters increased the average pore size and decreased the surface area as a consequence of sintering. During sulphation the presence of impurities delayed pore closure due to the formation of CaSO{sub 4}. Hence, higher calcium utilization was achieved from the lower purity stones. The results highlight the importance of considering chemical composition in addition to initial physical properties in the selection of sorbents for use during fluidized bed coal combustion, since chemical composition controls, to a large extent, the physical properties developed upon calcination, and the structure of the calcine affects sulphation behaviour. 30 refs., 7 figs., 2 tabs.

  7. Multi-scale simulation of chemical looping combustion in dual circulating fluidized bed

    International Nuclear Information System (INIS)

    Highlights: • A modified multi-scale gas–solid flow-reaction coupled model is developed. • Multi-scale characteristic of chemical looping combustion system is investigated. • Predicted results show a good agreement with experimental data. - Abstract: Chemical looping combustion (CLC) in an interconnected fluidized bed has attracted more and more attention owing to its novel technology with inherent separation of CO2. In recent years, some models have been developed to investigate the gas-particle flow and reactive characteristics during the CLC process. However, multi-scale structures in reactors make it complex to perform a simulation. In the current work, a multi-scale gas–solid flow-reaction coupled model is developed and applied to the simulation of the CLC process in a dual circulating fluidized bed (DCFB) system with consideration of the impact of multi-scale structures on chemical reactions, mass and heat transfer. By comparisons of gas pressure and gas components with experimental data, the present model shows a better prediction. The influence of clusters on the gas compositions and temperature field is analyzed

  8. Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Ping Pan; Yan Cao; John Smith

    2008-05-31

    On February 14, 2002, President Bush announced the Clear Skies Initiative, a legislative proposal to control the emissions of nitrogen oxides (NO{sub x}), sulfur dioxide (SO{sub 2}), and mercury from power plants. In response to this initiative, the National Energy Technology Laboratory organized a Combustion Technology University Alliance and hosted a Solid Fuel Combustion Technology Alliance Workshop. The workshop identified multi-pollutant control; improved sorbents and catalysts; mercury monitoring and capture; and improved understanding of the underlying reaction chemistry occurring during combustion as the most pressing research needs related to controlling environmental emissions from fossil-fueled power plants. The Environmental Control Technology Laboratory will help meet these challenges and offer solutions for problems associated with emissions from fossil-fueled power plants. The goal of this project was to develop the capability and technology database needed to support municipal, regional, and national electric power generating facilities to improve the efficiency of operation and solve operational and environmental problems. In order to effectively provide the scientific data and the methodologies required to address these issues, the project included the following aspects: (1) Establishing an Environmental Control Technology Laboratory using a laboratory-scale, simulated fluidized-bed combustion (FBC) system; (2) Designing, constructing, and operating a bench-scale (0.6 MW{sub th}), circulating fluidized-bed combustion (CFBC) system as the main component of the Environmental Control Technology Laboratory; (3) Developing a combustion technology for co-firing municipal solid waste (MSW), agricultural waste, and refuse-derived fuel (RDF) with high sulfur coals; (4) Developing a control strategy for gaseous emissions, including NO{sub x}, SO{sub 2}, organic compounds, and heavy metals; and (5) Developing new mercury capturing sorbents and new

  9. Prevention of Bed Agglomeration Problems in a Fluidized Bed Boiler by Finding the Trigging Value of Sewage Sludge Dosage Added to Combustion of Biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Kajsa; Gervind, Pernilla

    2009-07-01

    Agglomeration of bed sand is a common problem during combustion of biofuels with high ash content in fluidized bed boilers. Former studies have shown that co-combustion of biofuels with sewage sludge increases the agglomeration temperature. Sewage sludge has a low heating value and high ash content. It would therefore be better to use sludge as an additive to the combustion than as a co-combusted biofuel. In this study the trigging value of sludge addition to the combustion of some biofuel was investigated. The effect of adding sludge with different precipitation chemicals, iron sulphate and aluminium sulphate, was investigated. The biofuels used for the experiments were bark, refused derived fuel (RDF) and a mixture of wood and straw, 75/25 % on energy basis. All experiments were carried out in a laboratory scale fluidized bed reactor. Analyses of chemical composition of bed sand and SEM/EDX analyses were performed after the combustion. Eventually agglomeration tests were performed in order to find the agglomeration temperature of the samples. Some of the samples sintered during the combustion and were not tested for the agglomeration temperature. SEM/EDX showed that all samples of bed sand contained sand particles with more or less coatings. In some cases the coatings seemed to consist of one dense inner layer and one more porous outer layer. From SEM/EDX and chemical composition analyses it was found that the total amount of phosphorous in the bed sand samples was increased with an increased addition of sludge in all experiments. The concentration of phosphorous was especially higher in the outer layers/coatings. It was also found that elements from the sludge seem to get caught by a sticky layer at the bed sand surface and form a non-sticky or less sticky layer that prevents agglomeration. The total amount of aluminium was increased with an increased addition of sludge for the wood/straw samples, while it increased with an increased amount of combusted fuel for

  10. Kinetics of pyrolysis and combustion of spherical wood particles in a fluidized bed

    International Nuclear Information System (INIS)

    Highlights: • H2, CO2, CO and CH4 released during wood pyrolysis were experimentally monitored. • CO2 formed by burning the residual tar/char mixture was experimentally determined. • The kinetics of species production was reproduced with two simplified models. • The increase of the bed reactor temperature statistically enhanced the gas yield. • The pyrolysis time is statistically reduced by decreasing the particle size. - Abstract: The kinetics of wood pyrolysis and combustion of residual fuel at different particle diameters and temperatures was investigated. A known mass of wooden spheres was fed at the top of a fluidized bed reactor filled with olivine particles and fluidized with nitrogen. The concentration of H2, CO2, CO and CH4 was on-line monitored with gas analyzers. An irreversible first order reaction was applied to describe the biomass pyrolysis. The rate constant was dependent on the average temperature of wood particle, obtained by solving the transient one-dimensional problem of heat conduction in a sphere. The rate for an irreversible second order reaction between the residual fuel and oxygen at the fluid–solid interface, which takes a finite resistance to mass transfer into account, was adopted to describe the combustion. The semi-empirical kinetic models for pyrolysis and combustion were able to describe, with certain limitations inherent to model simplifications, the experimental transient results of molar flow rates of major released species. A statistical model based on the results of the factorial design of experiments (32) confirmed a statistical significant effect of temperature and wood particle diameter on the gas yield and time of pyrolysis, respectively

  11. Experimental results of combustion and desulphurization in fluidized bed. Implementation opportunities

    International Nuclear Information System (INIS)

    Possibilities of both stationary fluidized bed combustion (SFBC) and circulating fluidized bed combustion (CFBC) technologies for desulfurization of Romanian coal-fired power plants have been studied since the 70's. The results of research on a 2 MWh SFBC semi-industrial pilot hot water boiler and an 1 MWh CFBC pilot plant are presented. 4 sorts of lignite (3 Romanian and 1 Albanian) are used in the study. The combustion efficiencies for SFBC are between 82 - 84% and for CFBC - between 84 - 87%. The heat transfer coefficients for lignite and peat coal have been determined for different zones, different levels of ash recirculation rate and various operating loads. Experiments with 2 sorts of sorbents: dolomite and limestone, under different temperature conditions and at Ca/S molar ratio 0.5 - 3.5 have been carried out. The temperature range for the maximum values of desulfurization efficiency is 840-870oC for limestone and 820-860oC for dolomite. The following efficiency values are obtained for lignite in the SFBC pilot plant: 1) over 80%, when using dolomite as a sorbent and the Ca/S molar ratio is greater than 2.5; 2) 75 - 90%, when limestone has been used and the Ca/S molar ratio is in the range 2-3. Desulfurization efficiency in CFBC plant for lignite using limestone is 80-93% for Ca/S ratio between 2 and 3. The necessity to commission a demonstrative installation with low pollutant emissions is pointed out. The Comanesti Power Plant has been chosen for this purpose. An old 75 t/h steam boiler will be replaced with 45 MWh CFBC boiler for combined heat and steam production. The overall estimated investment costs for this plant are about 6 million $US. 1 tabs., 5 refs

  12. A new fluidized bed combustion system to capture CO{sub 2} with CaO

    Energy Technology Data Exchange (ETDEWEB)

    J. Carlos Abanades; Diego Alvarez; Gemma Grasa; Enric Soley; Jesus Pajares [Instituto Nacional del Carbon (CSIC), Oviedo (Spain)

    2005-07-01

    A combustion system that includes CO{sub 2} capture, and comprises three interconnected fluidized beds, is described. Coal is first burned in a circulating fluidised bed combustor at temperatures around 1000{sup o}C in the presence of a large flow of CaO, that is acting here as a heat carrier. After heat recovery, these gases enter a second circulating fluidized bed operating at around 650{sup o}C where they meet again CaO particles, capturing the CO{sub 2} in the flue gas as CaCO{sub 3}. The CaCO{sub 3} particles are separated from the gas and sent to a calciner fluidized by steam and CO{sub 2}. The heat required for calcination is supplied by the particles of CaO circulating from the high temperature combustor. Since the separation of CO{sub 2} is carried out at high temperatures, there are negligible efficiency penalties. In this work we focus on the effect of sorbent performance on the operating variables expected in the different units. Multicycle carbonation-calcination-combustion tests have been carried out with natural limestones at conditions representative of their life in the circulating system. The decay in sorbent capacity has been measured up to 500 cycles. The consequences of the rapid decay, but also the stability found in long cycle numbers (between 5-10% Ca conversion) are discussed in terms of the solid flow requirements to achieve a given CO{sub 2} separation efficiency. It is shown that this is a promising system where only relatively modest make up flows of limestone are required to maintain the activity in the CO{sub 2} capture loop and to purge the system of inert components. 22 refs., 6 figs., 2 tab.

  13. Polycyclic aromatic hydrocarbons and organic matter associated to particulate matter emitted from atmospheric fluidized bed coal combustion

    International Nuclear Information System (INIS)

    The polycyclic aromatic hydrocarbons (PAH) and the organic matter (OM) content associated with particulate matter (PM) emissions from atmospheric fluidized bed coal combustion have been studied. The two main aims of the work have been (a) to study OM and PAH emissions as a function of the coal fluidized bed combustion (FBC) variables in solid phase and (b) to check if there is any correlation between OM and PAH contained in the PM. The combustion was carried out in a laboratory scale plant at different combustion conditions: temperature, percentage of oxygen excess, and total air flow. PAH associated on the particulate matter have been analyzed by fluorescence spectroscopy in the synchronous mode (FS) after PM extraction by sonication with dimethylformamide (DMF). It can be concluded that there is not a direct relationship between the OM content and the PAH supported in the PM emitted. In addition, neither PM or OM show dependence between themselves

  14. The distribution of heavy metals during fluidized bed combustion of sludge (FBSC)

    International Nuclear Information System (INIS)

    During combustion of wastewater treatment sludge, the inorganic constituents are converted into ash which contains the major fraction of the heavy metals present. The behaviour of heavy metals in combustion processes has been studied extensively for mostly coal combustion and waste incineration. For biomass and sludge, literature data are scarce and mostly limited to laboratory experiments. The present paper assesses the partitioning of eight heavy metals (Hg, As, Cd, Cu, Pb, Cr, Ni and Zn) in the different residues from a large-scale fluidized bed sludge combustor of 4.4 m i.d. The origin of the sludge is mostly from treating urban wastewaters (>90%), although some mixed sludge (urban + industrial, <10%) is also burnt. The different residues (bottom ash, fly ash, filter cake, scrubber effluent and stack emissions) were sampled and analysed during 33 weeks, spread over a period of 1 year. The mass balance of relevant heavy metals closes for 96.5%, inaccuracies being related to the unsteadiness of the process, the accuracy of the mass flow data monitored at the plant, and on collecting representative samples. It is also shown that all heavy metals under scrutiny, except Hg, are concentrated in the fly ash as collected in the electrostatic precipitator

  15. Distribution of polycyclic aromatic hydrocarbons in fly ash during coal and residual char combustion in a pressurized fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Hongcang Zhou; Baosheng Jin; Rui Xiao; Zhaoping Zhong; Yaji Huang [Nanjing University of Information Science and Technology, Nanjing (China)

    2009-04-15

    To investigate the distribution of polycyclic aromatic hydrocarbons (PAHs) in fly ash, the combustion of coal and residual char was performed in a pressurized spouted fluidized bed. After Soxhlet extraction and Kuderna-Danish (K-D) concentration, the contents of 16 PAHs recommended by the United States Environmental Protection Agency (U.S. EPA) in coal, residual char, and fly ash were analyzed by a high-performance liquid chromatography (HPLC) coupled with fluorescence and diode array detection. The experimental results show that the combustion efficiency is lower and the carbon content in fly ash is higher during coal pressurized combustion, compared to the residual char pressurized combustion at the pressure of 0.3 MPa. Under the same pressure, the PAH amounts in fly ash produced from residual char combustion are lower than that in fly ash produced from coal combustion. The total PAHs in fly ash produced from coal and residual char combustion are dominated by three- and four-ring PAHs. The amounts of PAHs in fly ash produced from residual char combustion increase and then decrease with the increase of pressure in a fluidized bed. 21 refs., 1 fig., 4 tabs.

  16. Pollutant emission characteristics of rice husk combustion in a vortexing fluidized bed incinerator

    Institute of Scientific and Technical Information of China (English)

    Feng Duan; Chiensong Chyang; Yucheng Chin; Jim Tso

    2013-01-01

    Rice husk with high volatile content was burned in a pilot scale vortexing fiuidized bed incinerator.The fluidized bed incinerator was constructed of 6 mm stainless steel with 0.45 m in diameter and 5 m in height.The emission characteristics of CO,NO,and SO2 were studied.The effects of operating parameters,such as primary air flow rate,secondary air flow rate,and excess air ratio on the pollutant emissions were also investigated.The results show that a large proportion of combustion occurs at the bed surface and the freeboard zone.The SO2 concentration in the flue gas decreases with increasing excess air ratio,while the NOx concentration shows reverse trend.The flow rate of secondary air has a significant impact on the CO emission.For a fixed primary air flowrate,CO emission decreases with the secondary air flowrate.For a fixed excess air ratio,CO emission decreases with the ratio of secondary to primary air flow.The minimum CO emission of 72 ppm is attained at the operating condition of 40% excess air ratio and 0.6 partition air ratio.The NOx and SO2 concentrations in the flue gas at this condition are 159 and 36 ppm,which conform to the EPA regulation of Taiwan.

  17. Rivesville multicell fluidized bed boiler. Annual technical progress report. July 1978-June 1979

    Energy Technology Data Exchange (ETDEWEB)

    1980-08-01

    Design, construction and test program of a 300,000 lb/hr steam generating capacity multicell fluidized bed boiler (MFB), as a pollution free method of burning high-sulfur or highly corrosive coals, is being carried out. The concept involves burning fuels such as coal, in a fluidized bed of limestone particles that react with the sulfur compounds formed during combustion to reduce air pollution. Nitrogen oxide emissions are also reduced at the lower combustion temperatures. The CaSO/sub 4/ produced in the furnace is discharged with the ash or regenerated to CaO for reuse in the fluidized bed. Information is presented on continued operation of the Rivesville MFB steam generating plant in a commercial mode and for determining performance and emission characteristics; studies and tests on flyash characterization and reinjection, fuel feed eductors and needles, air distributor, corrosion-erosion and sulfur capture; engineering studies to improve MFB performance and reliability.

  18. Assessment of the rice husk lean-combustion in a bubbling fluidized bed for the production of amorphous silica-rich ash

    International Nuclear Information System (INIS)

    Rice husk lean-combustion in a bubbling and atmospheric fluidized bed reactor (FBR) of 0.3 m diameter with expansion to 0.4 m in the freeboard zone and 3 m height was investigated. Experiment design - response surface methodology (RSM) - is used to evaluate both excess air and normal fluidizing velocity influence (independent and controllable variables), in the combustion efficiency (carbon transformation), bed and freeboard temperature and silica content in the ashes. Hot gases emissions (CO2, CO and NOx), crystallographic structure and morphology of the ash are also shown. A cold fluidization study is also presented. The values implemented in the equipment operation, excess air in the range of 40-125% and normal fluidization velocities (0.13-0.15 Nm/s) show that the values near the lower limit, encourage bed temperatures around 750 oC with higher carbon transformation efficiencies around 98%. However, this condition deteriorated the amorphous potential of silica present in the ash. An opposite behavior was evidenced at the upper limit of the excess air. This thermochemical process in this type of reactor shows the technical feasibility to valorize RH producing hot gases and an amorphous siliceous raw material.

  19. Release of alkali salts and coal volatiles affecting internal components in fluidized bed combustion systems

    Directory of Open Access Journals (Sweden)

    Arias del Campo, E.

    2003-12-01

    Full Text Available In spite of the potential advantages of atmospheric fluidized bed systems, experience has proved that, under certain environments and operating conditions, a given material employed for internal components could lead to catastrophic events. In this study, an attempt is made to establish material selection and operational criteria that optimize performance and availability based on theoretical considerations of the bed hydrodynamics, thermodynamics and combustion process. The theoretical results may indicate that, for high-volatile coals with particle diameters (dc of 1-3 mm and sand particle size (ds of 0.674 mm, a considerable proportion of alkali chlorides may be transferred into the freeboard region of fluidized bed combustors as vapor phase, at bed temperatures (Tb < 840 °C, excess air (XSA ≤ 20 %, static bed height (Hs ≤ 0.2 m and fluidizing velocity (Uo < 1 m/s. Under these operating conditions, a high alkali deposition may be expected to occur in heat exchange tubes located above the bed. Conversely, when the combustors operate at Tb > 890 °C and XSA > 30 %, a high oxidation rate of the in-bed tubes may be present. Nevertheless, for these higher Tb values and XSA < 10 %, corrosion attack of metallic components, via sulfidation, would occur since the excessive gas-phase combustion within the bed induced a local oxygen depletion.

    A pesar de las ventajas potenciales de los sistemas atmosféricos de lecho fluidizado, la experiencia ha demostrado que, bajo ciertas atmósferas y condiciones de operación, un material que se emplea como componente interno podría experimentar una falla y conducir a eventos catastróficos. En este estudio, se intenta establecer un criterio tanto operativo como de selección del material que permita optimizar su disponibilidad y funcionalidad basados en consideraciones teóricas de la hidrodinámica del lecho, la termodin

  20. Emissions from the combustion of eucalypt and pine chips in a fluidized bed reactor.

    Science.gov (United States)

    Vicente, E D; Tarelho, L A C; Teixeira, E R; Duarte, M; Nunes, T; Colombi, C; Gianelle, V; da Rocha, G O; Sanchez de la Campa, A; Alves, C A

    2016-04-01

    Interest in renewable energy sources has increased in recent years due to environmental concerns about global warming and air pollution, reduced costs and improved efficiency of technologies. Under the European Union (EU) energy directive, biomass is a suitable renewable source. The aim of this study was to experimentally quantify and characterize the emission of particulate matter (PM2.5) resulting from the combustion of two biomass fuels (chipped residual biomass from pine and eucalypt), in a pilot-scale bubbling fluidized bed (BFB) combustor under distinct operating conditions. The variables evaluated were the stoichiometry and, in the case of eucalypt, the leaching of the fuel. The CO and PM2.5 emission factors were lower when the stoichiometry used in the experiments was higher (0.33±0.1 g CO/kg and 16.8±1.0 mg PM2.5/kg, dry gases). The treatment of the fuel by leaching before its combustion has shown to promote higher PM2.5 emissions (55.2±2.5 mg/kg, as burned). Organic and elemental carbon represented 3.1 to 30 wt.% of the particle mass, while carbonate (CO3(2-)) accounted for between 2.3 and 8.5 wt.%. The particulate mass was mainly composed of inorganic matter (71% to 86% of the PM2.5 mass). Compared to residential stoves, BFB combustion generated very high mass fractions of inorganic elements. Chloride was the water soluble ion in higher concentration in the PM2.5 emitted by the combustion of eucalypt, while calcium was the dominant water soluble ion in the case of pine. PMID:27090717

  1. Experiences in sulphur capture in a 30 MWth Circulating Fluidized Bed boiler under oxy-combustion conditions

    International Nuclear Information System (INIS)

    CO2 and SO2 from fossil fuel combustion are contributors to greenhouse effect and acid rain respectively. Oxy-combustion technology produces a highly concentrated CO2 stream almost ready for capture. Circulating Fluidized Bed (CFB) boiler technology allows in-situ injection of calcium-based sorbents for efficient SO2 capture. CIUDEN's 30 MWth CFB boiler, supplied by Foster Wheeler and located at the Technology Development Centre for CO2 Capture and Transport (es.CO2) in Spain, is the first of its kind for executing test runs at large pilot scale under both air-combustion and oxy-combustion conditions. In this work, SO2 emissions under different scenarios have been evaluated. Variables such as limestone composition, Ca/S molar ratio and bed temperature among others have been considered along different test runs in both air-combustion and oxy-combustion conditions to analyse its influence on SO2 abatement. Fly and bottom ash, together with flue gas analysis have been carried-out. Desulphurization performance tests results are presented. - Highlights: •Sulphur capture efficiency (%) was higher in oxy-combustion compared to air-combustion in a 30 MW thermal CFB boiler using anthracite and limestone as sulphur sorbent. •For a Ca/S molar ratio higher than 2.6 there was barely any improvement on sulphur capture efficiency for both air-combustion and oxy-combustion conditions in a 30 MW thermal CFB boiler using anthracite and limestone as sulphur sorbent. •Optimum temperature for sulphur capture at a fixed Ca/S molar ratio is around 880–890 °C under oxy-combustion conditions and for anthracite coal with limestone as sorbent in a 30 MW thermal CFB boiler

  2. Effects of circulating fluidized bed combustion (CFBC) fly ashes as filler on the performances of asphalt

    Energy Technology Data Exchange (ETDEWEB)

    Qin Li; Hui Xu; Xiaoru Fu; Chen Chen; Jianping Zhai [Nanjing University, Nanjing (China). State Key Laboratory of Pollution Control and Resource Reuse

    2009-03-15

    This work investigated the potential of utilizing circulating fluidized bed combustion (CFBC) fly ashes (CFAs) as alternative filler, substituting mineral powders (MPs) that are widely used in asphalt concrete. Physico-chemical characteristics of the CFAs and MPs, as well as effects of different mix designs of CFAs and asphalt on asphalt performances were examined, including moisture susceptibility, viscosity, ductility, softening point, penetration, and antiaging performances. The results of the study show that generally the CFAs have greater effects than the MPs on improving the performances of asphalt, and that the specific surface area (SSA), free CaO (f-CaO), morphology, and mineralogical phases of the CFAs are more favorable than those of the MPs respectively, while the alkaline values, hydrophilic coefficients, particle size distributions (PSDs), and water contents of the two fillers are similar. It is suggested that CFAs may be more suitable than MPs for the use as asphalt concrete filler.

  3. Study on Reactivity of Circulating Fluidized Bed Combustion Fly Ashes in the Presence of Water

    Directory of Open Access Journals (Sweden)

    Salain I.M.A.K.

    2010-01-01

    Full Text Available A study on reactivity of four different Circulating Fluidized Bed Combustion (CFBC fly ashes has been realized in the presence of water. Paste of each ash was prepared and analyzed for its setting time, expansion and strength. The products of hydration, and their evolutions over a period of time were identified by X-ray diffraction and differential thermal analysis. The results of this study show that the reactivity of the CFBC fly ashes is strongly related to their chemical composition, essentially to their quantity of silica, alumina, lime and sulfate, which promote principally the formation of ettringite, gypsum and C-S-H. It is further noted that the intensity and the proportion of these phases determine the hydration behavior of the CFBC fly ashes.

  4. Fabrication and properties of foam geopolymer using circulating fluidized bed combustion fly ash

    Institute of Scientific and Technical Information of China (English)

    Ze Liu; Ning-ning Shao; Dong-min Wang; Jun-feng Qin; Tian-yong Huang; Wei Song; Mu-xi Lin; Jin-sha Yuan; Zhen Wang

    2014-01-01

    In recent years, circulating fluidized bed combustion fly ash (CFA) is used as a raw material for geopolymer synthesis. Hydrogen peroxide was employed as a foaming agent to prepare CFA-based foam geopolymer. The particle distribution, mineral composition, and chemical composition of CFA were examined firstly. Geopolymerization products were characterized by mechanical testing, scanning elec-tron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence (XRF). The CFA-based foam geopolymer was successfully fabri-cated with different contents of hydrogen peroxide and exhibited uncompleted alkali reaction and reasonable strength with relative low atomic ratios of Si/Al and Si/Na. Type-C CFA in this research could be recycled as an alternative source material for geopolymer production.

  5. Modified graphical autocatalytic set model of combustion process in circulating fluidized bed boiler

    Science.gov (United States)

    Yusof, Nurul Syazwani; Bakar, Sumarni Abu; Ismail, Razidah

    2014-07-01

    Circulating Fluidized Bed Boiler (CFB) is a device for generating steam by burning fossil fuels in a furnace operating under a special hydrodynamic condition. Autocatalytic Set has provided a graphical model of chemical reactions that occurred during combustion process in CFB. Eight important chemical substances known as species were represented as nodes and catalytic relationships between nodes are represented by the edges in the graph. In this paper, the model is extended and modified by considering other relevant chemical reactions that also exist during the process. Catalytic relationship among the species in the model is discussed. The result reveals that the modified model is able to gives more explanation of the relationship among the species during the process at initial time t.

  6. Reduction of SO sub 2 emission from a fluidized-bed under staged combustion by coarse limestone

    International Nuclear Information System (INIS)

    A study was performed to investigate the effect of course limestone on the reduction of SO sub 2 emission from a fluidized-bed under staged combustion. The limestone of 1.2-2.5 mm size was premixed with fine coal of 1-3 mm size and fed under bed. The staging levels, bed height, and Ca/S ratio was fixed at 70:30, 30 cm and 3:1, respectively. A maximum of around 50% reduction in SO sub 2 emissions was achieved at both excess air of 20 and 40% and at 830 deg. C. bed temperature. The SO sub 2 emissions were very sensitive to bed temperature. The course limestone was found better in desulfurization efficiency at lower temperature than fine limestone. (author)

  7. Sulphation of calcium-based sorbents in circulating fluidised beds under oxy-fuel combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Francisco Garcia-Labiano; Luis F. de Diego; Alberto Abad; Pilar Gayan; Margarita de las Obras-Loscertales; Aranzazu Rufas; Juan Adanez [Instituto de Carboquimica (CSIC), Zaragoza (Spain). Dept. Energy and Environment

    2009-07-01

    Sulphur Retention (SR) by calcium-based sorbents is a process highly dependent on the temperature and CO{sub 2} concentration. In circulating fluidised beds combustors (CFBC's) operating under oxy-fuel conditions, the sulphation process takes place in atmospheres enriched in CO{sub 2} with bed concentrations that can vary from 40 to 95%. Under so high CO{sub 2} concentrations, very different from that in conventional coal combustion atmosphere with air, the calcination and sulphation behaviour of the sorbent must be defined to optimise the SR process in the combustor. The objective of this work was to determine the SO{sub 2} retention capacity of a Spanish limestone at typical oxy-fuel conditions in CFBC's. Long term duration tests of sulphation (up to 24 h), to simulate the residence time of sorbents in CFBC's, were carried out by thermogravimetric analysis (TGA). Clear behaviour differences were found under calcining and non-calcining conditions. Especially relevant was the result obtained at calcining conditions but close to the thermodynamic temperature given for sorbent calcination. This situation must be avoided in CFBC's because the CO{sub 2} produced inside the particle during calcination can destroy the particles if a non-porous sulphate product layer has been formed around the particle. The effect of the main variables on the sorbent sulphation such as SO{sub 2} concentration, temperature, and particle size were analysed in the long term TGA tests. These data were also used to determine the kinetic parameters for the sulphation under oxy-fuel combustion conditions, which were able to adequately predict the sulphation conversion values in a wide range of operating conditions. 20 refs., 5 figs., 2 tabs.

  8. Desulfurization under Conditions of Substoichiometric Pressurized Fluidized Bed Combustion of Coal - Comparison with TG-Tests and Equilibrium Limits

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Karel; Hartman, Miloslav; Čermák, Jiří; Pohořelý, Michael

    2001-01-01

    Roč. 11, č. 120 (2001), s. 39-53. ISSN 1211-1929 R&D Projects: GA AV ČR IAA4072801; GA MŠk OK 349 Institutional research plan: CEZ:AV0Z4072921 Keywords : desulfurization * sub-stoichiometric * pressurized fluidized bed combustion Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  9. Investigations into the control of agglomeration and defluidisation during fluidised-bed combustion of low-rank coals

    Energy Technology Data Exchange (ETDEWEB)

    Vuthaluru, H.B.; Linjewile, T.M.; Zhang, D.; Manzoori, A.R. [University of Adelaide, Adelaide, SA (Australia). Dept. of Chemical Engineering

    1999-03-01

    A laboratory scale spouted bed combustor was used to study the effectiveness of various control methodologies in alleviating ash-related problems such as particle agglomeration and bed defluidisation during bed combustion of low-rank coals. The three control techniques investigated are: (1) the use of mineral additives; (2) alternative bed materials; and (3) pretreatment of coal. Mineral additives including dolomite, two clays and gibbsite, were injected into the spouted bed combustor while burning a South Australian low-rank coal at 800{degree}C. Samples of the same coal treated with Al, water washing and acid washing were also tested in the spouted bed combustor. In addition, experiments were also conducted with alternative bed materials including bauxite and calcined sillimanite. Experiments showed that the three techniques reported in this paper are effective to different extents in reducing particle agglomeration and defluidisation. Among the mineral additives tested, gibbsite and a clay additive rich in kaolinite and sillimanite were found to be most effective. The use of calcined sillimanite and bauxite as alterative bed materials extended the combustion time before defluidisation occurred by 7 and 10 times, respectively, compared to silica sand. While A1 pretreatment and water-washing were found effective for control of agglomeration and defluidisation, acid-washing did not improve the operation of the bed burning this particular coal. Al enrichment in ash coating of bed particles which suppress the formation of Na and S rich eutectics was identified as the main mechanism for prevention of agglomeration and defluidisation by these control techniques. 10 refs., 4 figs., 3 tabs.

  10. Combustion of palm kernel shell in a fluidized bed: Optimization of biomass particle size and operating conditions

    International Nuclear Information System (INIS)

    Highlights: • Safe burning of palm kernel shell is achievable in a FBC using alumina as the bed material. • Thermogravimetric analysis of the shell with different particle sizes is performed. • Optimal values of the shell particle size and excess air lead to the minimum emission costs. • Combustion efficiency of 99.4–99.7% is achievable when operated under optimal conditions. • CO and NO emissions of the FBC are at levels substantially below national emission limits. - Abstract: This work presents a study on the combustion of palm kernel shell (PKS) in a conical fluidized-bed combustor (FBC) using alumina sand as the bed material to prevent bed agglomeration. Prior to combustion experiments, a thermogravimetric analysis was performed in nitrogen and dry air to investigate the effects of biomass particle size on thermal and combustion reactivity of PKS. During the combustion tests, the biomass with different mean particle sizes (1.5 mm, 4.5 mm, 7.5 mm, and 10.5 mm) was burned at a 45 kg/h feed rate, while excess air was varied from 20% to 80%. Temperature and gas concentrations (O2, CO, CxHy as CH4, and NO) were recorded along the axial direction in the reactor as well as at stack. The experimental results indicated that the biomass particle size and excess air had substantial effects on the behavior of gaseous pollutants (CO, CxHy, and NO) in different regions inside the reactor, as well as on combustion efficiency and emissions of the conical FBC. The CO and CxHy emissions can be effectively controlled by decreasing the feedstock particle size and/or increasing excess air, whereas the NO emission can be mitigated using coarser biomass particles and/or lower excess air. A cost-based approach was applied to determine the optimal values of biomass particle size and excess air, ensuring minimum emission costs of burning the biomass in the proposed combustor. From the optimization analysis, the best combustion and emission performance of the conical FBC is

  11. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Ping Pan; Kunlei Liu; John T. Riley

    2004-04-01

    The purpose of this report is to present the progress made on the project ''Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion (CFBC) System'' during the quarter January--March 2004. The following tasks have been completed. First, plans for the renovation of space for a new Combustion Laboratory for the CFBC Facility have progressed smoothly. Second, the design calculations, including the mass balances, energy balances, heat transfer, and strength calculations have been completed. Third, considerable modifications have been made on the draft design of the CFBC Facility based on discussions conducted during the project kick-off meeting held on January 13, 2004 at the National Energy Technology Laboratory (NETL). Comments received from various experts were also used to improve the design. Finally, the drawings of all assembly parts have been completed in order to develop specifications for the fabrication of individual parts. At the same time, the proposed work for the next quarter has been outlined in this report.

  12. Characteristics modeling for supercritical circulating fluidized bed boiler working in oxy-combustion technology

    Directory of Open Access Journals (Sweden)

    Balicki Adrian

    2014-06-01

    Full Text Available Among the technologies which allow to reduce greenhouse gas emission, mainly carbon dioxide, special attention deserves the idea of ‘zeroemission’ technology based on boilers working in oxy-combustion technology. In the paper the results of analyses of the influence of changing two quantities, namely oxygen share in oxidant produced in the air separation unit, and oxygen share in oxidant supplied to the furnace chamber on the selected characteristics of a steam boiler including the degree of exhaust gas recirculation, boiler efficiency and adiabatic flame temperature, was examined. Due to the possibility of the integration of boiler model with carbon dioxide capture, separation and storage installation, the subject of the analysis was also to determine composition of the flue gas at the outlet of a moisture condensation installation. Required calculations were made using a model of a supercritical circulating fluidized bed boiler working in oxy-combustion technology, which was built in a commercial software and in-house codes.

  13. Co-Combustion of Municipal Sewage Sludge and Hard Coal on Fluidized Bed Boiler WF-6

    Directory of Open Access Journals (Sweden)

    Rajczyk Rafał

    2014-12-01

    Full Text Available According to data of the Central Statistical Office, the amount of sludge produced in municipal wastewater treatment plants in 2010 amounted to 526000 Mg d.m. The forecast of municipal sewage sludge amount in 2015 according to KPGO2014 will reach 642400 Mg d.m. and is expected to increase in subsequent years. Significant amounts of sludge will create problems due to its utilization. In order to solve this problem the use of thermal methods for sludge utilization is expected. According to the National Waste Management Plan nearly 30% of sewage sludge mass should be thermally utilized by 2022. The article presents the results of co-combustion of coal and municipal sewage sludge in a bubbling fluidized bed boiler made by SEFAKO and located in the Municipal Heating Company in Morag. Four tests of hard coal and sewage sludge co-combustion have been conducted. Boiler performance, emissions and ash quality were investigated.

  14. Studies on nitrogen oxides (NOx and N2O) in pressurized fluidized bed combustion

    International Nuclear Information System (INIS)

    This thesis describes the experimental studies of nitrogen oxide (NO, NO2, N2O) emissions in pressurized fluidized bed combustion (PFBC). In the first part of the thesis the background and the objectives of this study are introduced. The second part summarizes the fundamental knowledge about the formation and destruction of nitrogen oxides in coal combustion, particularly in the conditions of PFBC. The instrumentation of test facilities, measurement and data analysis is described in the third part. Then the most important experimental results follow in the next parts. The forth part describes the results from a PFBC test rig and an empirical modelling for predicting the emissions of NOx and N2O. Finally, the fundamental work on coal combustion and fuel nitrogen conversion in a PFBC batch reactor is presented. These studies clearly confirm the potential of PFBC technology in the control nitrogen of oxide emissions. The research in the test rig was concentrated on determining the effects of process parameters on the emissions of nitrogen oxides with different fuels. Another objective was to examine the reduction of nitrogen oxides with the control methods in PFBC conditions, including ammonia injection and air staging combustion for reducing NO, and high temperature operations for reducing N20. The results indicate that pressurized operation suppresses the conversion of fuel-N to nitrogen oxides and favors with employing the reduction methods for further nitrogen oxide reduction, for instance the temperature window of NO reduction with ammonia injection has been found to be widened to even lower temperature range. Maximum reductions of 80-85 % with ammonia injection and 75-80 % with air staging combustion were achieved in the conditions examined. Considerably low emissions of N2O (2O control, and thermal decomposition proved to be the laming pathway of N2O destruction in PFBC. In the examined pressure range, increasing pressure causes a decrease of NO emission but a

  15. Atmospheric fluidized bed combustion for small scale market sectors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ashworth, R.A.; Plessinger, D.A.; Sommer, T.M. [Energy and Environmental Research Corp., Orville, OH (United States); Keener, H.M. [Ohio Agricultural Research and Development Center, OH (United States); Webner, R.L. [Will-Burt Co., Orrville, OH (United States)

    1997-03-31

    The objective of this project was to demonstrate and promote the commercialization of coal-fired atmospheric fluidized bed combustion (AFBC) systems, with limestone addition for SO{sub 2} emissions control and a baghouse for particulate emissions control. This AFBC system was targeted for small scale industrial-commercial-institutional space and process heat applications. A cost effective and environmentally acceptable AFBC technology in this size range would displace a considerable amount of gas/oil with coal while resulting in significant total cost savings to the owner/operators. In the Proof-of-Concept Phase, a 2.2 x 10{sup 6} Btu/hr unit was installed and successfully operated at Cedar Lane Farms (CLF), a commercial nursery in Ohio. The heat from the fluidized bed was used to heat hot water which was recirculated through greenhouses for cool weather heating. The system was designed to be fully automated with minimal operator attention required. The AFBC system installed at CLF was an improved design that incorporated flyash/sorbent reinjection and an underbed feed system to improve limestone utilization. With these additions it was possible to lower the Ca/S ratio from {approximately} 3.0 to 2.0, and still maintain an SO{sub 2} emissions level of 1.2 lb/10{sup 6} Btu when burning the same high sulfur Ohio coal tested at OARDC.

  16. CFD based combustion model for sewage sludge gasification in a fluidized bed

    Institute of Scientific and Technical Information of China (English)

    Yiqun WANG; Lifeng YAN

    2009-01-01

    Gasification is one potential way to use sewage sludge as renewable energy and solve the environmental problems caused by the huge amount of sewage sludge. In this paper, a three-dimensional Computational Fluid Dynamics (CFD) model has been developed to simulate the sewage sludge gasification process in a fluidized bed. The model describes the complex physical and chemical phenomena in the gasifier including turbulent flow, heat and mass transfer, and chemical reactions. The model is based on the Eulerian-Lagrangian concept using the non-premixed combustion modeling approach. In terms of the CFD software FLUENT, which represents a powerful tool for gasifIer analysis, the simulations provide detailed information on the gas products and temperature distribution in the gasifier. The model sensitivity is analyzed by performing the model in a laboratory-scale fluidized bed in the literature, and the model validation is carried out by comparing with experimental data from the literature. Results show that reasonably good agreement was achieved. Effects of temperature and Equivalence Ratio (ER) on the quality of product syngas (H2 + CO) are also studied.

  17. Advanced air staging techniques to improve fuel flexibility, reliability and emissions in fluidized bed co-combustion

    Energy Technology Data Exchange (ETDEWEB)

    Aamand, Lars-Erik; Leckner, Bo [Chalmers Technical Univ., Goeteborg (Sweden); Luecke, Karsten; Werther, Joachim [Technical Univ. of Hamburg-Harburg (Germany)

    2001-12-01

    A joint research project between the Technical University of Hamburg-Harburg and Chalmers Technical University. For operation under co-combustion the following results should be considered: The high ash content of the sewage sludge results in significantly increased ash flows. Although high alkali metal concentrations are found in the sewage sludge ash, no critical concentrations were reached and tendencies to fouling were not observed. The trace metal input rises with increased sludge fraction. However, emissions of metal compounds were well below legal limits. The trace metals tend to accumulate on the fly ash. In general, very low fuel nitrogen conversions to NO and N{sub 2}O of 2 - 4 % are achievable. With coal as a base fuel alternative air staging with secondary air supply after solids separation attains even lower NO emissions than normal staging without strongly affecting CO and SO{sub 2} emissions. Alternative staging also reduces N{sub 2}O emissions. An optimum for the excess air ratio in the riser of 1.05 was found for a total excess air ratio of 1.2. The higher the volatile content of the fuel is, the less effective the NO reduction due to air staging becomes. The measurements suggest that the optimum gas residence time regarding the emissions in CFB combustors is around 6 to 7 s. These times are achieved in commercial scale plants due to their large cyclones that perhaps partly can replace a large afterburner chamber. The circulating fluidized bed boiler can be operated in a very flexible way with various fuel mixtures up to an energy fraction of sludge of 25% without exceeding legal emission limits.

  18. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

    International Nuclear Information System (INIS)

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

  19. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lapa, N. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)]. E-mail: ncsn@fct.unl.pt; Barbosa, R. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Lopes, M.H. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Mendes, B. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Abelha, P. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Gulyurtlu, I. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Santos Oliveira, J. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)

    2007-08-17

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

  20. Release of K, Cl, and S during combustion and co-combustion with wood of high-chlorine biomass in bench and pilot scale fuel beds

    DEFF Research Database (Denmark)

    Johansen, Joakim Myung; Aho, Martti; Paakkinen, Kari;

    2013-01-01

    Studies of the release of critical ash-forming elements from combustion of biomass are typically conducted with small sample masses under well controlled conditions. In biomass combustion on a grate, secondary recapture and release reactions in the fuel-bed may affect the overall release and...... release profile was observed for Cl, from 65% to nearly 100%. Complete release of S was achieved at 1234°C with a linear increase from 70% at 906°C. Co-combustion of corn stover with low-Cl wood chips served to increase the bed temperature, resulting in complete and close to complete release of Cl and S......, respectively. An increase in the relative K-release was observed when increasing the wood chip fraction from 40% to 100% (energy basis). Pilot scale flue gas results indicate that the share of Cl released as HCl decreases towards 0% as the share of wood chips is increased towards 100%. Hence, co-combustion of...

  1. Characterization of ashes from a 100 kWth pilot-scale circulating fluidized bed with oxy-fuel combustion

    International Nuclear Information System (INIS)

    Highlights: → Oxy-fuel combustion was carried out in a 100 kWth circulating fluidized bed. → Coal and petroleum coke are fuels together with limestone added for SO2 capture. → The ashes produced are characterized and compared with air-firing CFBC ash. → The dominant calcium compounds in the ash are CaCO3 and CaSO4 rather than CaO. - Abstract: Oxy-fuel combustion experiments have been carried out on an oxygen-fired 100 kWth mini-circulating fluidized bed combustion (CFBC) facility. Coal and petroleum coke were used as fuel together with different limestones (and fixed Ca:S molar ratios) premixed with the fuel, for in situ SO2 capture. The bed ash (BA) and fly ash (FA) samples produced from this unit were collected and characterized to obtain physical and chemical properties of the ash samples. The characterization methods used included X-ray fluorescence (XRF), X-ray diffraction (XRD), char carbon and free lime analysis, thermogravimetric analysis (TGA), and surface analysis. The main purpose of this work is to characterize the CFBC ashes from oxy-fuel firing to obtain a better understanding of the combustion process, and to identify any significant differences from the ash generated by a conventional air-fired CFBC. The primary difference in the sulfur capture mechanism between atmospheric air-fired and oxy-fuel FBC, at typical FBC temperatures (∼850 oC), is that, in the air-fired case the limestone sorbents calcine, whereas the partial pressure of CO2 in oxy-fuel FBC is high enough to prevent calcination, and hence the sulfation process should mimic that seen in pressurized FBC (PFBC). Here, the char carbon content in the fly ash was much higher than that in the bed ash, and was also high by comparison with ash obtained from conventional commercial air-firing CFBC units. In addition, measurements of the free lime content in the bed and fly ash showed that the unreacted Ca sorbent was present primarily as CaCO3, indicating that sulfur capture in the oxy

  2. Clean utilization of high sulphur petroleum coke by circulating fluidized bed combustion (CFBC) in Romania

    International Nuclear Information System (INIS)

    The economic and environmental problems caused by inefficient utilization of residual high-sulphur petroleum coke resulted from oil cracking in Romania is discussed. A special research programme applying CFBC technology has been carried out in the Institute for Power Equipment, Bucharest. The results from both laboratory facilities and pilot plant are presented. The main operating conditions and parameters are pointed out. Data on quality and composition of petroleum coke, combustion efficiency, temperature range in different zones and flue gas composition at distinct operating loads are given. The results obtained will be used for innovative design of CFBC boilers based on petroleum coke. A project for implementing a CFBC boiler in one of the Romanian oil refineries is being developed. An analysis of technical and economic advantages of these boilers for energy generation is presented

  3. Fluidized-bed-combustion ash for the solidification and stabilization of a metal-hydroxide sludge.

    Science.gov (United States)

    Knoll, K L; Behr-Andres, C

    1998-01-01

    Fluidized-bed-combustion (FBC) ash is a by-product from a developing technology for coal-fired power plants that will economically reduce air emissions to meet requirements of the Clean Air Act. FBC ash has physical and chemical properties similar to Portland cement, but only has moderate success as a pozzolan in concrete applications due to low compressive strengths. However, FBC ash has proven effective for use as a binder for the solidification and stabilization (S/S) of metal-bearing sludges. Physical and chemical characterization procedures were used to analyze FBC ash and a metal-bearing sludge obtained from a hazardous waste treatment facility to develop 12 different S/S mix designs. The mix designs consist of four binder designs to evaluate sludge-to-binder ratios of approximately 0, 0.5, and 1. Portland cement is used as a control binder to compare unconfined compressive strengths and Toxicity Characteristic Leaching Procedure (TCLP) analyses from different ratios of the FBC ash streams: fly ash, char, and spent bed material (SBM). Compressive strengths ranging from 84 lbs per square inch (psi) to 298 psi were obtained from various mix designs containing different sludge-to-ash ratios cured for 28 days. All the mix designs passed the TCLP. Recoveries from leaching for each metal were less than 5% for most mix designs. Results of unconfined compressive strengths, TCLP, and percent recovery calculations indicate that the mix design containing approximately a 1:1 ratio of fly ash to char-and-sludge is the best mix design for the S/S of the metal-bearing sludge. PMID:15655996

  4. Flue gas desulfurization under simulated oxyfiring fluidized bed combustion conditions: The influence of limestone attrition and fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Scala, F.; Salatino, P. [CNR, Naples (Italy)

    2010-01-01

    Flue gas desulfurization by means of limestone injection under simulated fluidized bed oxyfiring conditions was investigated, with a particular focus on particle attrition and fragmentation phenomena. An experimental protocol was applied, based on the use of complementary techniques that had been previously developed for the characterization of attrition of sorbents in air-blown atmospheric fluidized bed combustors. The extent and pattern of limestone attrition by surface wear in the dense phase of a fluidized bed were assessed in bench scale fluidized bed experiments under simulated oxyfiring conditions. Sorbent samples generated during the oxyfiring tests were further characterized from the standpoint of fragmentation upon high velocity impact by means of a particle impactor. The experimental results were compared with those previously obtained with the same limestone under air-blown atmospheric fluidized bed combustion conditions. The profound differences in the attrition and fragmentation extents and patterns associated with oxyfiring as compared to air-blown atmospheric combustion and the role played by the different attrition/fragmentation paths were highlighted. In particular, it was noted that attrition could effectively enhance particle sulfation under oxyfiring conditions by continuously disclosing unconverted calcium to the sulfur-bearing atmosphere.

  5. Combustion of liquid paint wastes in fluidized bed boiler as element of waste management system in the paint factory

    Energy Technology Data Exchange (ETDEWEB)

    Soko, W.A.; Biaecka, B. [Central Mining Inst., Katowice (Poland). National Center for Implementation of Cleaner Production

    1998-12-31

    In this paper the solution to waste problems in the paint industry is presented by describing their combustion in a fluidized bed boiler as a part of the waste management system in the paint factory. Based on the Cleaner Production idea and concept of integration of design process with a future exploitation of equipment, some modifications of the waste management scheme in the factory are discussed to reduce the quantity of toxic wastes. To verify this concept combustion tests of paint production wastes and cocombustion of paint wastes with coal in an adopted industrial boiler were done. Results of these tests are presented in the paper.

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

    Energy Technology Data Exchange (ETDEWEB)

    DeLallo, M.; Zaharchuk, R.

    1994-01-01

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

  7. Modeling oxy-fuel combustion in a 3D circulating fluidized bed using the hybrid Euler–Lagrange approach

    International Nuclear Information System (INIS)

    Results of experiments and numerical simulations of the coal oxy-fuel combustion process in an experimental circulating fluidized bed (CFB) are presented in this paper. The simulations were carried out using the hybrid Euler–Lagrange approach to model the dense particle transport in the CFB pilot installation combined with a model of the combustion process. The main aim of presented work is to demonstrate the applicability of the hybrid Euler–Lagrange technique for modeling the particle transport process in the CFB, which also includes the coal combustion process modeling. To the best knowledge of the authors, there is no implementation of the hybrid Euler–Lagrange Dense Discrete Phase Model (DDPM) approach for modeling the CFB in the 3D domain with combustion process simulations, which is available in literature. Both the experiments and numerical simulations were carried out for three oxidizer compositions O2/CO2, i.e. 21, 30, and 35% of the oxygen volume fraction. In order to investigate the numerical model sensitivity when combustion conditions change, additional tests were evaluated for case with 35% of the oxygen for three excess oxygen ratios equal to 1.05, 1.15, and 1.25. The important aspect of modeling the radiative heat transfer during the fluidization process combined with oxy-fuel combustion was also investigated. The set of numerical simulations was performed for different radiation model configurations. The numerical results were compared with the temperature profile measured within the combustion chamber of the pilot test rig. - Highlights: • Hybrid Euler–Lagrange approach has been used for modelling particle transport. • Numerical results have been validated against experimental data. • New strategy for resolving particle transport in circulating fluidized bed has been shown

  8. Three phase Eulerian-granular model applied on numerical simulation of non-conventional liquid fuels combustion in a bubbling fluidized bed

    Directory of Open Access Journals (Sweden)

    Nemoda Stevan Đ.

    2016-01-01

    Full Text Available The paper presents a two-dimensional CFD model of liquid fuel combustion in bubbling fluidized bed. The numerical procedure is based on the two-fluid Euler-Euler approach, where the velocity field of the gas and particles are modeled in analogy to the kinetic gas theory. The model is taking into account also the third - liquid phase, as well as its interaction with the solid and gas phase. The proposed numerical model comprise energy equations for all three phases, as well as the transport equations of chemical components with source terms originated from the component conversion. In the frame of the proposed model, user sub-models were developed for heterogenic fluidized bed combustion of liquid fuels, with or without water. The results of the calculation were compared with experiments on a pilot-facility (power up to 100 kW, combusting, among other fuels, oil. The temperature profiles along the combustion chamber were compared for the two basic cases: combustion with or without water. On the basis of numerical experiments, influence of the fluid-dynamic characteristics of the fluidized bed on the combustion efficiency was analyzed, as well as the influence of the fuel characteristics (reactivity, water content on the intensive combustion zone. [Projekat Ministarstva nauke Republike Srbije, br. TR33042: Improvement of the industrial fluidized bed facility, in scope of technology for energy efficient and environmentally feasible combustion of various waste materials in fluidized bed

  9. Feasibility of manufacturing geopolymer bricks using circulating fluidized bed combustion bottom ash.

    Science.gov (United States)

    Chen, Chen; Li, Qin; Shen, Lifeng; Zhai, Jianping

    2012-06-01

    This paper presents a study on geopolymer bricks manufactured using bottom ash from circulating fluidized bed combustion (CFBC). The alkali activators used for synthesis were sodium silicate, sodium hydroxide, and potassium hydroxide and lithium hydroxide solutions. The study included the impact of alkali activator on compressive strength. The reaction products were analysed by XRD, FT-IR and SEM/EDS. The compressive strength of bricks was dependent on the modulus of the sodium silicate activator and the type and concentration of alkali activator. The highest compressive strength could be gained when the modulus was 1.5, and the value could reach 16.1 MPa (7 d after manufacture) and 21.9 MPa (28 d after manufacture). Under pure alkaline systems, the compressive strength was in the order of 10 M KOH > 10 M NaOH > 5 M LiOH > 5 M KOH > 5 M NaOH. Quartz was the only crystalline phase in the original bottom ash, and no new crystalline phase was found after the reaction. The main product of reaction was amorphous alkali aluminosilicate gel and a small amount of crystalline phase was also found by SEM. PMID:22856304

  10. Atmospheric fluidized-bed combustion (AFBC) co-firing of coal and hospital waste

    International Nuclear Information System (INIS)

    The proposed project involves co-firing of coal and medical waste (including infectious medical waste) in an atmospheric fluidized-bed combustor (AFBC) to safely dispose of medical waste and produce steam for hospital needs. Combustion at the design temperature and residence time (duration) in the AFBC has been proven to render infectious medical waste free of disease producing organisms. The project would be located at the Veterans Affairs (VA) Medical Center in Lebanon, Pennsylvania. The estimated cost of the proposed AFBC facility is nearly $4 million. It would be jointly funded by DOE, Veterans Affairs, and Donlee Technologies, Inc., of York, Pennsylvania, under a cooperative agreement between DOE and Donlee. Under the terms of this agreement, $3.708 million in cost-shared financial assistance would be jointly provided by DOE and the Veterans Affairs (50/50), with $278,000 provided by Donlee. The purposes of the proposed project are to: (1) provide the VA Medical Center and the Good Samaritan Hospital (GSH), also of Lebanon, Pennsylvania, with a solution for disposal of their medical waste; and (2) demonstrate that a new coal-burning technology can safely incinerate infectious medical waste, produce steam to meet hospital needs, and comply with environmental regulations

  11. Atmospheric fluidized-bed combustion (AFBC) co-firing of coal and hospital waste. Environmental Assessment

    Energy Technology Data Exchange (ETDEWEB)

    1993-02-01

    The proposed project involves co-firing of coal and medical waste (including infectious medical waste) in an atmospheric fluidized-bed combustor (AFBC) to safely dispose of medical waste and produce steam for hospital needs. Combustion at the design temperature and residence time (duration) in the AFBC has been proven to render infectious medical waste free of disease producing organisms. The project would be located at the Veterans Affairs (VA) Medical Center in Lebanon, Pennsylvania. The estimated cost of the proposed AFBC facility is nearly $4 million. It would be jointly funded by DOE, Veterans Affairs, and Donlee Technologies, Inc., of York, Pennsylvania, under a cooperative agreement between DOE and Donlee. Under the terms of this agreement, $3.708 million in cost-shared financial assistance would be jointly provided by DOE and the Veterans Affairs (50/50), with $278,000 provided by Donlee. The purposes of the proposed project are to: (1) provide the VA Medical Center and the Good Samaritan Hospital (GSH), also of Lebanon, Pennsylvania, with a solution for disposal of their medical waste; and (2) demonstrate that a new coal-burning technology can safely incinerate infectious medical waste, produce steam to meet hospital needs, and comply with environmental regulations.

  12. Acid mine drainage abatement using fluidized bed combustion ash grout after geophysical site characterization

    International Nuclear Information System (INIS)

    Pyritic coal refuse and pit cleanings buried in a 15-ha (37-acre) surface mine produce severe acid mine drainage (AMD). The pyritic material had been buried in discrete piles or pods in the backfill. The pods and the resulting contaminant plumes were initially defined using geophysical techniques and were confirmed by drilling. Fluidized bed combustion (FBC) ash, mixed with water to form a grout, was used in different ways to isolate the pyritic material from water and oxygen. In the first approach, grout was pressure injected directly into the buried pods to fill the void spaces within the pods and to coat the pyritic materials with a cementitious layer. A second approach used the grout to divert water from specific areas. Pods which did not accept grout because of a clay matrix were isolated from percolating water with a cap and trench seal of the grout. The grout was also used in certain areas to blanket the clay pit floor since clays are believed to be a primary source of aluminum at this site. In certain areas, the AMD migrates downward though fractures in the pit floor to the groundwater table. Grout was injected along the fractures in some of these areas to seal them. This would inhibit further AMD migration toward one of the receiving streams. The initial postgrouting water quality data have been encouraging

  13. Effect of air preheating and fuel moisture on combustion characteristics of corn straw in a fixed bed

    International Nuclear Information System (INIS)

    Experiments were carried out on a one-dimensional bench combustion tests rig. The effect of air preheating and moisture level in the fuel on combustion characteristics of corn straw was investigated. The bed temperature distribution and the mass loss of fuel and gas components such as O2, CO, CO2 and NO were measured in the bed. The average burning rate and ignition front propagation velocity increased with increasing primary air preheating temperature. The total burning time was shorter under the higher primary air preheating temperature and the higher primary air preheating temperature produced a lower ignition front flame temperature in the bed. The variation of the flue gas O2, CO and CO2 concentrations with time was more intensive at a higher primary air preheating temperature during the ignition front propagation period and the char oxidation period. With the increase of the fuel moisture, average burning rate and ignition front propagation velocity decreased. As the fuel moisture was less than 30.71%, with the increase of the fuel moisture, residual mass loss rate decreased and ignition front flame temperature increased at a fixed air flow rate. Drier fuels resulted in fuel-rich combustion and higher CO concentration. The NO concentration decreased with increasing the moisture level in the fuel

  14. Experimental study on fuel oil combustion in circulating fluidized bed; Estudio experimental sobre la combustion de combustoleo en lecho fluidizado circulante

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Rangel, Ricardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The Instituto de Investigaciones Electricas (IIE) developed a circulating fluidized bed combustor of 0.5 thermal MW unique in its type in Latin America. The Bachelor`s thesis entitled ``Experimental Study on Fuel Oil Combustion in Circulating Fluidized Bed`` was performed operating this combustor with the purpose of determining the feasibility of burning heavy fuel oil in a stable and sustained form, as well as the effect of the addition of calcium carbonate to the combustor. The results of the experimental trials showed heavy fuel oil can be burned in a circulating fluidized bed, with low sulfur dioxide emissions. During the conduction of the experiments a sulfur retention of 43% was achieved with a Ca/S relationship of 4.5. [Espanol] El Instituto de Investigaciones Electricas (IIE) desarrollo un combustor de lecho fluidizado circulante de 0.5 MW termicos de potencia, unico en su tipo en Latinoamerica. La tesis de licenciatura titulada Estudio Experimental sobre la Combustion de Combustoleo en Lecho Fluidizado Circulante se realizo operando dicho combustor, con el proposito de determinar la factibilidad de quemar combustoleo pesado en forma estable y autosostenida, asi como la influencia que tiene la adicion de carbonato de calcio al lecho. Los resultados de los ensayos experimentales mostraron que se puede quemar combustoleo pesado en un lecho fluidizado circulante, con bajas emisiones de bioxido de azufre. Durante la experimentacion se logro una retencion de azufre del 43%, con una relacion Ca/S de 4.5.

  15. Ash related bed agglomeration during fluidized bed combustion, further development of the classification method based on CCSEM; CCSEM-luokitusmenetelmaen jatkokehittaeminen tuhkan aiheuttaman agglomeroitumisen tutkimisessa leiju- ja kiertopetipoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Laitinen, R.; Patrikainen, T.; Heikkinen, R.; Tiainen, M.; Virtanen, M. [Oulu Univ. (Finland). Inst. of Chemistry

    1997-10-01

    The scope of this project is to use the information and experience gained from the development of classification method to predict ash related problems like bed agglomeration during fluidised combustion. If boilers have to be shut down due to slagging or agglomeration of the bed material may cause significant economic losses for the entire energy production chain. Mineral classification methods based on the scanning electron microscopy are commonly used for coal ash investigation. In this work different biomass, peat, and peat-wood ash, fluidised-bed materials, and bed agglomerates were analysed with SEM-EDS combined with automatic image analysis software. The properties of ash particles are different depending on the fuel type. If biomass like wood or bark are added to peat the resulting ash has different properties. Due to the low mineral content in the original peat and to the fact that the majority of inorganic material is bound to the organic matrix, the classification has turned out to be less informative than was hoped. However, good results are obtained the by use of quasiternary diagrams. With these diagrams the distribution of particle composition is easily illustrated and thus meaningful prediction can be made of the slagging and agglomerating properties of ash. The content of ten different elements are determined for each particle by SEM-EDS combined with Link AIA software. The composition of the diagram corners can be varied Freely within these ten elements. (orig.)

  16. Influence of simulated MSW sizes on the combustion process in a fixed bed: CFD and experimental approaches.

    Science.gov (United States)

    Sun, Rui; Ismail, Tamer M; Ren, Xiaohan; El-Salam, M Abd

    2016-03-01

    This work presents the effect of the simulated sizes of Municipal Solid Waste (MSW) on the combustion process in a fixed bed experimentally and numerically. The effect of temperature, gas emissions, flame front velocity and process rate are discussed for three different sizes of MSW: 10, 30, and 50mm. The study found that for the operating conditions of the current model, when the diameter of particles is decreased, the bulk density of the material is increased, resulting in a decrease of convective heat transfer as well as combustion speed. As the diameter size of the material particles increase, the height of the post-combustion zone is increased, while the temperature in a high temperature area is decreased, due to the decrease in the material's bulk density and the excessive increase in porosity. Results also show that the average emission concentration of CO and CO2 decreases gradually with an increase in the particle diameter size. PMID:26750870

  17. Occurrence of bromine in fluidised bed combustion of solid recovered fuel

    Energy Technology Data Exchange (ETDEWEB)

    Vainikka, P.

    2011-12-15

    Corrosive ash species are the single most important factor limiting the electric efficiency of steam boiler plants fired with waste or biomass. Chlorine has been found to have a central role in the chemistry involved as it reduces the melting temperature of ash, forms corrosive vapour and gas species in the furnace and halogenated deposits on boiler heat transfer surfaces. In this context chlorine has been extensively researched. At the time of writing this thesis there was hardly any published data available on the occurrence of bromine (Br) in the aforementioned context. The objective of this work was to review the occurrence of bromine in solid fuels and characterise the behaviour of bromine in full-scale fluidised bed combustion. The review on the occurrence of bromine in solid fuels revealed that in anthropogenic wastes bromine is mainly found in connection to flame retarded substances. Several weight percentages of bromine can be found in plastics treated with brominated flame retardants (BFRs). Bromine is typically found some 100-200 mg kg-1 in mixed municipal solid wastes (MSW). Bromine may be enriched in fuels with high share of plastics, such as solid recovered fuel (SRF) or refuse derived fuel (RDF). Up to 2000 mg kg-1 was found as a monthly average in SRF, typical levels being 20-200 mg kg-1. Wastewater sludge from paper mills may contain bromine 20-100 mg kg-1 due the use of bromine based biocides. In other fuels bromine may be found in significant amounts in marine influenced coal deposits and peat as well as in biomass treated with brominated pesticides. In the experimental part SRF, spruce bark and wastewater sludge from a paper mill were co-fired in a full- scale bubbling fluidised bed (BFB) boiler, and the collected fuels, aerosols and waterwall deposits were analysed with the focus on the fate of bromine. Bromine was mainly found to form water soluble high vapour pressure alkali metal halides in the furnace - in the form of KBr(g) and NaBr(g) as

  18. Atmospheric fluidized bed combustion advanced system concepts applicable to small industrial and commercial markets. Topical report, Level 2

    Energy Technology Data Exchange (ETDEWEB)

    Ake, T.R.; Dixit, V.B.; Mongeon, R.K.

    1992-09-01

    As part of an overall strategy to promote FBC coal combustion and to improve the marketability of the eastern coals, the US Department of Energy`s Morgantown Energy Research Center awarded a three level contract to Riley Stoker Corporation to develop advanced Multi Solids Fluidized Bed (MSFB) boiler designs. The first level of this contract targeted the small package boiler (10,000--50,000 lb/hr steam) and industrial size boiler (75,000--150,000 lb/hr steam) markets. Two representative sizes, 30,000 lb/hr and 110,000 lb/hr of steam, were selected for the two categories for a detailed technical and economic evaluation. Technically, both the designs showed promise, however, the advanced industrial design was favored on economic considerations. It was thus selected for further study in the second level of the contract. Results of this Level-2 effort, presented in this report, consisted of testing the design concept in Riley`s 4.4 MBtu/hr pilot MSFB facility located at Riley Research Center in Worcester, Mass. The design and economics of the proof of concept facility developed in Level-1 of the contract were then revised in accordance with the findings of the pilot test program. A host site for commercial demonstration in Level-3 of the contract was also secured. It was determined that co-firing coal in combination with paper de-inking sludge will broaden the applicability of the design beyond conventional markets. International Paper (IP), the largest paper company in the world, is willing to participate in this part of the program. IP has offered its Hammermill operation at Lockhaven, Pa, site of a future paper de-inking plant, for the proof of concept installation. This plant will go in operation in 1994. It is recommended that METC proceed to the commercial demonstration of the design developed. The approach necessary to satisfy the needs of the customer while meeting the objectives of this program is presented along with a recommended plan of action.

  19. Formation of chlorinated organic compounds in fluidized bed combustion of recycled fuels

    International Nuclear Information System (INIS)

    Four tests of co-combustion of recycled fuels (REP) with peat and coal in the 15 kW fluidized bed reactor were performed. The recycled fuel was so-called dry fraction in four vessels sampling at Keltinmaeki. In three tests a part of peat energy was replaced with coal. The mixtures were prepared so that in all mixtures 25 % of energy was recycled fuel and 75 % was either peat or the mixture of peat and coal. The concentrations of polyaromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and chlorophenols decreased with increasing part of coal due to the increasing sulphur/chlorine ratio. Principal Component Analysis (PCA) and Partial Least Square regression analysis (PLS) showed that the chlorine, copper and sulphur contents of the fuel effected most on the concentrations of chlorophenols, chlorobenzenes, PCBs and PCDDs/PCDFs. Other variables influencing on a model were the lead concentration and the sulphur/chlorine ratio in fuel and the hydrogen chloride concentration of the flue gas. The concentrations of chlorophenols and chlorobenzenes were also significant for PCDD/PCDF concentrations in flue gas. The sulphur, chlorine, copper and chromium contents in fly ash and the temperature of the reactor influenced on the chlorophenol, chlorobenzene, PCB and PCDD/PCDF concentrations in fly ash. The chlorophenol and chlorobenzene contents in fly ash, the sulphur/chlorine ratio and the lead content in fuel, the sulphur dioxide, hydrogen chloride and carbon monoxide concentrations in flue gas had also influence on PCDD/PCDF concentrations in fly ash

  20. Properties of geopolymer from circulating fluidized bed combustion coal bottom ash

    International Nuclear Information System (INIS)

    Research highlights: → Dry cured geopolymers exhibit a heterogeneous and porous gel matrix. → The Si/Na atomic ratio of the main reaction product (N-A-S-H gel) is close to 1. → Low Si/Na ratio (0.5) correspond to a more crystalline stage of the N-A-S-H gel. → N-A-S-H gel has small pores which facilitate the escape of moisture when it is heated. → N-A-S-H gel became more amorphous, attaining higher Si/Al ratio of 4.54 at 800 deg. C. - Abstract: Compressive strength, atomic ratios and microstructure of geopolymer mortars (GM) made from circulating fluidized bed combustion (CFBC) coal bottom ash (CBA) were investigated to observe the effect of air curing at ambient temperature (AC) at 20 deg. C and 90% RH, dry curing (DC) at 80 deg. C and 40% RH for 20 h. The 28-d compressive strength of GM exposed to AC (GM-AC) and DC (GM-DC) were 26.23 and 24.14 MPa, respectively. The Si/Na atomic ratio of the main reaction product (N-A-S-H gel) was close to 1. Geopolymer gel (apparently crystalline) having low Si/Na ratio (0.5) may correspond to a more advanced or developed stage of the aluminosilicate gel. It was observed that the geopolymerization was completed before the N-A-S-H gel formed when Si/Na ratio of GM is close to 2. The color of the GM changed from pink to grey and the structure became denser with almost no pores, when the temperature increased from 400 to 800 deg. C. The N-A-S-H gel became more amorphous due to the sintering reactions attaining Si/Al and Si/Na ratios of 4.54 and 0.98, respectively.

  1. Characterization of a fluidized-bed combustion ash to determine potential for environmental impact. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hassett, D.J.; Henderson, A.K.; Pflughoeft-Hassett, D.F.; Mann, M.D.; Eylands, K.E.

    1997-10-01

    A 440-megawatt, circulating fluidized-bed combustion (CFBC), lignite-fired power plant is planned for construction in Choctaw County north of Ackerman, Mississippi. This power plant will utilize Mississippi lignite from the first lignite mine in that state. Malcolm Pirnie, Inc., is working with the power plant developer in the current planning and permitting efforts for this proposed construction project. In order to accommodate Mississippi state regulatory agencies and meet appropriate permit requirements, Malcolm Pirnie needed to provide an indication of the characteristics of the by-products anticipated to be produced at the proposed plant. Since the Mississippi lignite is from a newly tapped mine and the CFBC technology is relatively new, Malcolm Pirnie contacted with the Energy and Environmental Research Center (EERC) to develop and perform a test plan for the production and characterization of ash similar to ash that will be eventually produced at the proposed power plant. The work performed at the EERC included two primary phases: production of by-products in a bench-scale CFBC unit using lignite provided by Malcolm Pirnie with test conditions delineated by Malcolm Pirnie to represent expected operating conditions for the full-scale plant; and an extensive characterization of the by-products produced, focusing on Mississippi regulatory requirements for leachability, with the understanding that return of the by-product to the mine site was an anticipated by-product management plan. The overall focus of this project was the environmental assessment of the by-product expected to be produced at the proposed power plant. Emphasis was placed on the leachability of potentially problematic trace elements in the by-products. The leaching research documented in this report was performed to determine trends of leachability of trace elements under leaching conditions appropriate for evaluating land disposal in monofills, such as returning the by-products to the mine

  2. Development and application of a high-temperature sampling probe for burning chamber conditions of fluidized-bed combustion; Korkean laempoetilan naeytteenottosondin kehittaeminen ja soveltaminen leijukerrospolton tulipesaeolosuhteisiin

    Energy Technology Data Exchange (ETDEWEB)

    Larjava, K.; Paerkkae, M.; Jormanainen, P.; Roine, J.; Paakkinen, K. [VTT Chemistry, Espoo (Finland); Linna, V. [VTT Energy, Jyvaeskylae (Finland)

    1996-12-01

    A sampling probe for the burning chamber conditions of fluidized-bed combustion will be developed in this project. The probe will be suitable for sampling vaporous heavy and alkali metals and other condensing compounds (e.g. chlorides) as well combustion gases and alternatively also flue gas particles at high temperatures. The knowledge gained with the probe will help understanding, developing and modeling combustion processes and will thus aid the manufacturers of the boilers. (author)

  3. Characterization of ashes from a 100 kWth pilot-scale circulating fluidized bed with oxy-fuel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y.H.; Wang, C.B.; Tan, Y.W.; Jia, L.F.; Anthony, E.J. [Natural Resources Canada, Ottawa, ON (Canada)

    2011-09-15

    Oxy-fuel combustion experiments have been carried out on an oxygen-fired 100 kW(th) mini-circulating fluidized bed combustion (CFBC) facility. Coal and petroleum coke were used as fuel together with different limestones (and fixed Ca:S molar ratios) premixed with the fuel, for in situ SO{sub 2} capture. The bed ash (BA) and fly ash (FA) samples produced from this unit were collected and characterized to obtain physical and chemical properties of the ash samples. The characterization methods used included X-ray fluorescence (XRF), X-ray diffraction (XRD), char carbon and free lime analysis, thermogravimetric analysis (TGA), and surface analysis. The main purpose of this work is to characterize the CFBC ashes from oxy-fuel firing to obtain a better understanding of the combustion process, and to identify any significant differences from the ash generated by a conventional air-fired CFBC. The primary difference in the sulfur capture mechanism between atmospheric air-fired and oxy-fuel FBC, at typical FBC temperatures (similar to 850{sup o}C), is that, in the air-fired case the limestone sorbents calcine, whereas the partial pressure of CO{sub 2} in oxy-fuel FBC is high enough to prevent calcination, and hence the sulfation process should mimic that seen in pressurized FBC (PFBC). Here, the char carbon content in the fly ash was much higher than that in the bed ash, and was also high by comparison with ash obtained from conventional commercial air-firing CFBC units. In addition, measurements of the free lime content in the bed and fly ash showed that the unreacted Ca sorbent was present primarily as CaCO{sub 3}, indicating that sulfur capture in the oxy-fuel combustor occurred via direct sulfation.

  4. Numerical and experimental studies on effects of moisture content on combustion characteristics of simulated municipal solid wastes in a fixed bed

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Rui, E-mail: Sunsr@hit.edu.cn [School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001 (China); Ismail, Tamer M., E-mail: temoil@aucegypt.edu [Department of Mechanical Engineering, Suez Canal University, Ismailia (Egypt); Ren, Xiaohan [School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001 (China); Abd El-Salam, M. [Department of Basic Science, Cairo University, Giza (Egypt)

    2015-05-15

    Highlights: • The effects of moisture content on the burning process of MSW are investigated. • A two-dimensional mathematical model was built to simulate the combustion process. • Temperature distributions, process rates, gas species were measured and simulated. • The The conversion ratio of C/CO and N/NO in MSW are inverse to moisture content. - Abstract: In order to reveal the features of the combustion process in the porous bed of a waste incinerator, a two-dimensional unsteady state model and experimental study were employed to investigate the combustion process in a fixed bed of municipal solid waste (MSW) on the combustion process in a fixed bed reactor. Conservation equations of the waste bed were implemented to describe the incineration process. The gas phase turbulence was modeled using the k–ε turbulent model and the particle phase was modeled using the kinetic theory of granular flow. The rate of moisture evaporation, devolatilization rate, and char burnout was calculated according to the waste property characters. The simulation results were then compared with experimental data for different moisture content of MSW, which shows that the incineration process of waste in the fixed bed is reasonably simulated. The simulation results of solid temperature, gas species and process rate in the bed are accordant with experimental data. Due to the high moisture content of fuel, moisture evaporation consumes a vast amount of heat, and the evaporation takes up most of the combustion time (about 2/3 of the whole combustion process). The whole bed combustion process reduces greatly as MSW moisture content increases. The experimental and simulation results provide direction for design and optimization of the fixed bed of MSW.

  5. Numerical and experimental studies on effects of moisture content on combustion characteristics of simulated municipal solid wastes in a fixed bed

    International Nuclear Information System (INIS)

    Highlights: • The effects of moisture content on the burning process of MSW are investigated. • A two-dimensional mathematical model was built to simulate the combustion process. • Temperature distributions, process rates, gas species were measured and simulated. • The The conversion ratio of C/CO and N/NO in MSW are inverse to moisture content. - Abstract: In order to reveal the features of the combustion process in the porous bed of a waste incinerator, a two-dimensional unsteady state model and experimental study were employed to investigate the combustion process in a fixed bed of municipal solid waste (MSW) on the combustion process in a fixed bed reactor. Conservation equations of the waste bed were implemented to describe the incineration process. The gas phase turbulence was modeled using the k–ε turbulent model and the particle phase was modeled using the kinetic theory of granular flow. The rate of moisture evaporation, devolatilization rate, and char burnout was calculated according to the waste property characters. The simulation results were then compared with experimental data for different moisture content of MSW, which shows that the incineration process of waste in the fixed bed is reasonably simulated. The simulation results of solid temperature, gas species and process rate in the bed are accordant with experimental data. Due to the high moisture content of fuel, moisture evaporation consumes a vast amount of heat, and the evaporation takes up most of the combustion time (about 2/3 of the whole combustion process). The whole bed combustion process reduces greatly as MSW moisture content increases. The experimental and simulation results provide direction for design and optimization of the fixed bed of MSW

  6. Stabilization of ash from combustion of MSW in a fluidised bed boiler

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Wilewska, Magda [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Environmental Inorganic Chemistry

    2004-06-01

    Due to restrictions against the land filling of combustible waste and directives from authorities that favour energy recovery from the waste, combustion of household waste is becoming more common. Even though combustion of MSW reduces the volume of waste to be handled by approximately 90%, it produces ash residues containing most of the metals present in the original fuel and a number of other species carried through the boiler or formed during combustion. The residues can be divided into three categories: 1. Stable, inert ash that can be utilised in, for example, construction applications 2. Ash that is stable enough to be land filled as nonhazardous waste 3. Ash that contains large amounts of soluble components and potentially toxic metal species. The regulations considering leaching of ash components set limits for the release of soluble salts and toxic metals. Some fly ashes show low leachability for metals but gives a salt release that is too close to the limit for total dissolved solids. Since fly ash from FBC boilers represent the largest volume of ash from these boilers there is a need for a simple and cheap treatment method that reduces the amount of soluble salts, i.e. NaCl, KCl etc, in the ash. After stabilisation, the ash is supposed to go into a more stable category. The aim of this project has been to investigate the applicability of a method to wash such an ash with water. The work included laboratory studies of the ash properties, the water washing process, filtration properties of the ash slurry and also tests of the method in pilot scale at a full scale boiler. This work has been concentrated towards the investigation of cyclone ash from a bubbling fluidised bed boiler in Lidkoeping fired with 100% household waste. Elemental composition of ash samples before and after washing/filtration was determined by AAS or ICP after a suitable dissolution of the sample. The mineralogy of ash samples was analysed using X-ray powder diffractometry. This method

  7. The sixth international congress on toxic combustion byproducts. Technical program and abstract book

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    Topics of this proceedings volume are: technical approaches - waste treatment; general toxicology of combustion byproducts; reaction mechanisms (e.g. formation and decomposition of hydrocarbons and chlorinated hydrocarbons, nitrogen oxides); thermal treatment - reactionas at low temperatures; heterogeneous reactions - heterogeneous systems. (SR)

  8. Measurement and prediction of the emission of pollutants from the combustion of coal and biomass in a fixed bed furnace

    Energy Technology Data Exchange (ETDEWEB)

    Ross, A.B.; Jones, J.M.; Chaiklangmuang, S.; Pourkashanian, M.; Williams, A.; Kubica, K.; Andersson, J.T.; Kerst, M.; Danihelka, P.; Bartle, K.D. [University of Leeds, Leeds (United Kingdom). Dept. of Fuel and Energy

    2002-03-01

    The effect of co-combustion of coal and biomass has been studied for a fixed bed appliance originally designed for coal and in widespread use in many parts of the world especially Eastern Europe. Organic, inorganic and gaseous emissions have been measured. Organic compounds have been determined for a range of fuel combinations. These include polycyclic aromatic hydrocarbons PAH, alkyl PAH, a range of oxygenated compounds (including phenols, aldehydes, and ketones, oxygenated polycyclic aromatic compounds (O-PAC) and dioxins), polycyclic aromatic sulphur hydrocarbons (PASH), nitrogenated polycyclic aromatic compounds (N-PAC) and common volatile organic compounds (VOC). Inorganic species include trace heavy metals, as well as the gases, CO, CO{sub 2}, SO{sub x} and NOx. The concentration of the trace metals in the ash and fly ash have been compared to equilibrium calculations of the emission profiles during co-combustion. 18 refs., 8 figs., 8 tabs.

  9. Gaseous emissions from co-combustion of sewage sludge and coal/wood in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    B. Leckner; L.-E. Aamand; K. Luecke; J. Werther [Chalmers University of Technology, Goeteborg (Sweden). Department of Energy Conversion

    2004-03-01

    Co-combustion of sewage sludge together with coal or wood has been investigated in two circulating fluidized bed (CFB) plants, a laboratory scale plant and a pilot scale 12MWth CFB boiler, in both of which the gas residence times are comparable to those in commercial plant. The investigation focuses on emissions of harmful gases from co-combustion compared to mono-combustion in CFB and the influence of air supply. The result shows that co-combustion can be carried out in CFB plant designed for the base fuel without exceeding EU or German emission limits for sludge energy fractions of less than 25%, except for the chlorine emission that may have to be reduced by flue gas treatment. Although sewage sludge contains large quantities of nitrogen and sulfur, the beneficial properties of CFB lead to considerable reduction of nitrogen oxides, and only a few percent of the nitrogen was effectively converted to NO or N{sub 2}O. Sulfur can be captured by conventional limestone addition, but for wood as a base fuel this method is not as efficient as for coal. 7 refs., 8 figs., 3 tabs.

  10. Experimental investigation of wood combustion in a fixed bed with hot air

    Energy Technology Data Exchange (ETDEWEB)

    Markovic, Miladin, E-mail: m.markovic@utwente.nl; Bramer, Eddy A.; Brem, Gerrit

    2014-01-15

    Highlights: • Upward combustion is a new combustion concept with ignition by hot primary air. • Upward combustion has three stages: short drying, rapid devolatilization and char combustion. • Variation of fuel moisture and inert content have little influence on the combustion. • Experimental comparison between conventional and upward combustion is presented. - Abstract: Waste combustion on a grate with energy recovery is an important pillar of municipal solid waste (MSW) management in the Netherlands. In MSW incinerators fresh waste stacked on a grate enters the combustion chamber, heats up by radiation from the flame above the layer and ignition occurs. Typically, the reaction zone starts at the top of the waste layer and propagates downwards, producing heat for drying and devolatilization of the fresh waste below it until the ignition front reaches the grate. The control of this process is mainly based on empiricism. MSW is a highly inhomogeneous fuel with continuous fluctuating moisture content, heating value and chemical composition. The resulting process fluctuations may cause process control difficulties, fouling and corrosion issues, extra maintenance, and unplanned stops. In the new concept the fuel layer is ignited by means of preheated air (T > 220 °C) from below without any external ignition source. As a result a combustion front will be formed close to the grate and will propagate upwards. That is why this approach is denoted by upward combustion. Experimental research has been carried out in a batch reactor with height of 4.55 m, an inner diameter of 200 mm and a fuel layer height up to 1 m. Due to a high quality two-layer insulation adiabatic conditions can be assumed. The primary air can be preheated up to 350 °C, and the secondary air is distributed via nozzles above the waste layer. During the experiments, temperatures along the height of the reactor, gas composition and total weight decrease are continuously monitored. The influence of

  11. Experimental investigation of wood combustion in a fixed bed with hot air

    International Nuclear Information System (INIS)

    Highlights: • Upward combustion is a new combustion concept with ignition by hot primary air. • Upward combustion has three stages: short drying, rapid devolatilization and char combustion. • Variation of fuel moisture and inert content have little influence on the combustion. • Experimental comparison between conventional and upward combustion is presented. - Abstract: Waste combustion on a grate with energy recovery is an important pillar of municipal solid waste (MSW) management in the Netherlands. In MSW incinerators fresh waste stacked on a grate enters the combustion chamber, heats up by radiation from the flame above the layer and ignition occurs. Typically, the reaction zone starts at the top of the waste layer and propagates downwards, producing heat for drying and devolatilization of the fresh waste below it until the ignition front reaches the grate. The control of this process is mainly based on empiricism. MSW is a highly inhomogeneous fuel with continuous fluctuating moisture content, heating value and chemical composition. The resulting process fluctuations may cause process control difficulties, fouling and corrosion issues, extra maintenance, and unplanned stops. In the new concept the fuel layer is ignited by means of preheated air (T > 220 °C) from below without any external ignition source. As a result a combustion front will be formed close to the grate and will propagate upwards. That is why this approach is denoted by upward combustion. Experimental research has been carried out in a batch reactor with height of 4.55 m, an inner diameter of 200 mm and a fuel layer height up to 1 m. Due to a high quality two-layer insulation adiabatic conditions can be assumed. The primary air can be preheated up to 350 °C, and the secondary air is distributed via nozzles above the waste layer. During the experiments, temperatures along the height of the reactor, gas composition and total weight decrease are continuously monitored. The influence of

  12. Experimental Study of Stabilized Soil Utilizing Circulating Fluidized Bed Combustion Desulfurization Ash with Carbide Slag and Desulfurization Gypsum

    OpenAIRE

    Shao, Dezhi; Liu, Jinlong; Huang, Xin

    2015-01-01

    This paper discusses the feasibility of preparing soil stabilizer which is circulating fluidized bed combustion ash-based, supplemented with carbide slag and desulfurization gypsum, composed entirely of complete industrial wastes. The results show that CFBC ash has better pozzolanic activity than fly ash. When stabilizer total content is 10% and the ratio of CFBC ash : carbide slag : desulfurization gypsum is 7.2 : 1.8 : 1, compressive strength of stabilized soil can reach the maximum of 2.12...

  13. Combustion of gases released from peat or biomass in fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Raiko, R. [Tampere Univ. of Technology (Finland). Energy and Process Engineering

    1996-12-01

    Temperature and gas concentration experiments have been conducted to determine at what temperature carbon monoxide, methane and propane begin to react within the particulate phase of a bubbling fluidized bed. The fluidized bed reactor used in these experiments was a stainless-steel tube with an internal diameter of 50 mm surrounded by an electric heater. Two different natural quartz sands were used (d{sub p} =0.35 mm and 0.6 mm). The bed height used varied between 100 and 260 mm (in unfluidized state). A porous plate distributor, made of kaowool, was used to avoid jets appearing at the distributor. The bed was operated at incipient fluidization (u = 5.9-9 cm/s). The bed temperatures used ranged from 600 deg C to 850 deg C. It was found that carbon monoxide, methane and propane react inside a fluidized bed, but often other conditions than temperature have a considerable effect on the rate of the reaction. The critical temperature was found to be 650 deg C for propane and carbon monoxide and 700 deg C for methane. With under-stoichiometric mixture of carbon monoxide and air the heat release can be over 2.5 MW/m{sup 3} when bed temperature is 650 deg C. According to these experiments it is obvious that the reaction mechanism for carbon monoxide oxidation inside a fluidized bed differs greatly from that of gas phase only. The results of our more than 1300 test runs show clearly the varying effects of the different bed materials. Even with the same bed material totally different results can be obtained. In order to elucidate the possible changes of particle surface, microscopic and porosimetric studies was conducted with both fresh bed particles and used bed particles. Also the effect of commonly used ingredients, like limestone and dolomite, was tested. A global model for carbon monoxide oxidation inside a fluidized bed was introduced. The model was tested against measured data from the laboratory-scale fluidized bed test rig. (Abstract Truncated)

  14. Strategies to reduce gaseous KCl and chlorine in deposits during combustion of biomass in fluidised bed boilers

    Energy Technology Data Exchange (ETDEWEB)

    Kassman, Haakan

    2012-11-01

    Combustion of a biomass with an enhanced content of alkali and chlorine (Cl) can result in operational problems including deposit formation and superheater corrosion. The strategies applied to reduce such problems include co-combustion and the use of additives. In this work, measures were investigated in order to decrease the risk of superheater corrosion by reducing gaseous KCl and the content of chlorine in deposits. The strategies applied were sulphation of KCl by sulphur/sulphate containing additives (i.e. elemental sulphur (S) and ammonium sulphate (AS)) and co-combustion with peat. Both sulphation of KCl and capture of potassium (K) in ash components can be of importance when peat is used. The experiments were mainly performed in a 12 MW circulation fluidised bed (CFB) boiler equipped for research purposes but also in a full-scale CFB boiler. The results were evaluated by means of IACM (on-line measurements of gaseous KCl), conventional gas analysis, deposit and corrosion probe measurements and ash analysis. Ammonium sulphate performed significantly better than elemental sulphur. Thus the presence of SO{sub 3} (i.e. AS) is of greater importance than that of SO{sub 2} (i.e. S) for sulphation of gaseous KCl and reduction of chlorine in deposits. Only a minor reduction of gaseous KCl was obtained during co-combustion with peat although chlorine in the deposits was greatly reduced. This reduction was supposedly due to capture of K by reactive components from the peat ash in parallel to sulphation of KCl. These compounds remained unidentified. The effect of volatile combustibles on the sulphation of gaseous KCl was investigated. The poorest sulphation was attained during injection of ammonium sulphate in the upper part of the combustion chamber during the lowest air excess ratio. The explanation for this is that SO{sub 3} was partly consumed by side reactions due to the presence of combustibles. These experimental results were supported by modelling, although the

  15. Process costs and flowsheets, bed defluidization characteristics, stone reactivity changes and attrition losses for a regenerative fluidized-bed combustion process

    Energy Technology Data Exchange (ETDEWEB)

    Swift, W.M.; Montagna, J.C.; Smith, G.W.; Smyk, E.B.

    1980-05-01

    As a means of significantly reducing the amount of limestone required by the fluidized-bed combustion of coal, a limestone regeneration process has been developed which allows the sorbent to be recycled back to the combustor for reuse. To further the development of regeneration, experiments were performed to (1) evaluate the effects of repeated utilization on the sorbent reactivity for sulfation and regeneration and (2) characterize the minimum fluidizing-gas velocity required for the regeneration process to prevent agglomeration and defluidization of the bed. This report presents the results of those investigations plus (1) the development of process flowsheets and (2) an estimation of process costs and the economics of regeneration. The results of the experimental regeneration process studies confirm the potentially large reductions in the amount of sorbent required by FBC's which can be achieved by regeneration, possibly as high as 80%. The economic projections indicate that at current limestone prices, regeneration is not clearly justified on an economic basis; i.e., the cost of the regeneration process slightly exceeds the anticipated savings in limestone raw material cost which results from the regeneration process. However, the cost of limestone disposal has not been thoroughly addressed. Hence, if disposal costs due to environmental considerations, particularly the Resource Conservation and Recovery Act, become significant, the economic attractiveness of regeneration would be greatly enhanced.

  16. Combustion

    CERN Document Server

    Glassman, Irvin

    1987-01-01

    Combustion, Second Edition focuses on the underlying principles of combustion and covers topics ranging from chemical thermodynamics and flame temperatures to chemical kinetics, detonation, ignition, and oxidation characteristics of fuels. Diffusion flames, flame phenomena in premixed combustible gases, and combustion of nonvolatile fuels are also discussed. This book consists of nine chapters and begins by introducing the reader to heats of reaction and formation, free energy and the equilibrium constants, and flame temperature calculations. The next chapter explores the rates of reactio

  17. Pre-combustion capture of carbon dioxide in a fixed bed reactor using the clathrate hydrate process

    International Nuclear Information System (INIS)

    Hydrate based gas separation (HBGS) process with silica sand and silica gel as contact medium was employed to capture CO2 from fuel gas mixture. Gas uptake measurement at three different pressures (7.5, 8.5 and 9.0 MPa) and 274.15 K were conducted for hydrate formation kinetics and overall conversion of water to hydrate, rate of hydrate formation were determined. Water conversion of up to 36% was achieved with silica sand bed compared to 13% conversion in the silica gel bed. Effect of driving force on the rate of hydrate formation and gas consumption was significant in silica sand bed whereas it was found to be insignificant in silica gel bed. Hydrate dissociation experiments by thermal stimulation (at constant pressure) alone and a combination of depressurization and thermal stimulation were carried out for complete recovery of the hydrated gas. A driving force of 23 K was found to be sufficient to recover all the hydrated gas within 1 h. This study indicates that silica sand can be an effective porous media for separation of CO2 from fuel gas when compared to silica gel. - Highlights: ► The clathrate process for pre-combustion capture of carbon dioxide in a novel fixed bed reactor is presented. ► Performance of two contact media (silica gel and silica sand) was investigated. ► Water to hydrate conversion was higher in a silica sand column. ► A pressure reduction and thermal stimulation approach is presented for a complete recovery of the hydrated gas

  18. Bed agglomeration risk related to combustion of cultivated fuels (wheat straw, red canary grass, industrial hemp) in commercial bed materials; Baeddagglomereringsrisk vid foerbraenning av odlade braenslen (hampa, roerflen, halm) i kommersiella baeddmaterial

    Energy Technology Data Exchange (ETDEWEB)

    Erhardsson, Thomas; Oehman, Marcus; Geyter, Sigrid de; Oehrstroem, Anna

    2006-12-15

    The market of forest products is expanding and thus resulting in more expensive biomass fuels. Therefore research within the combustion industry for alternative fuels is needed, for example cultivated fuels. Combustion and gasification research on these cultivated fuels are limited. The objectives of this work was to increase the general knowledge of silicon rich cultivated fuels by study the agglomeration characteristics for wheat straw, reed canary grass and industrial hemp in combination with commercial bed materials. Controlled fluidized bed agglomeration tests was conducted in a 5 kW, bench-scale, bubbling fluidized bed reactor. The tendencies of agglomeration were determined with the three cultivated fuels in combination with various minerals present in natural sand (quarts, plagioclase and potassium feldspar) and an alternative bed material (olivine). During the experiments bed samples and formed agglomerates were collected for further analyses with a scanning electron microscope (SEM) and with X-ray microanalysis (EDS). Wheat straw had the highest agglomeration tendency of the studied fuels followed by reed canary grass and industrial hemp. No significant layer formation was found around the different bed particles. Instead, the ash forming matter were found as individual ash sticky (partial melted) particles in the bed. The bed material mineralogical composition had no influence of the agglomeration process because of the non layer formation propensities of the used silicon rich fuels.

  19. Coupling of a radiative heat transfer model and a three-dimensional combustion model for a circulating fluidized bed furnace

    International Nuclear Information System (INIS)

    A 3D semi-empirical model for reactive two-phase flow in a circulating fluidized bed furnace (CFB3D) is modified by implementing the radiative zone method to solve the radiation heat transfer. The radiative properties of the gas and particle phase have been calculated using detailed information of gas and particle distribution obtained from the CFB3D model. A recently published WSGGM for oxygen-fired combustion has been used to calculate the absorption coefficient of gaseous combustion products. The results of implementing the radiative zonal approach have been compared with those obtained using empirical radiative correlations. The temperature field obtained by using the radiative zone method is more uniform than the one obtained by empirical correlation, and the total heat flux to the wall is slightly higher. The long distance effect of radiation has been found more important in the upper furnace where the gas is the dominant phase. Detailed discussion concerning the obtained results is presented.- Highlights: • Radiative zone model is used to analyze a large scale CFB furnace. • A semi-empirical model for CFB processes is presented. • The radiative effect of long distance is taken into account. • The geometric optic is used for radiative properties of particles. • The WSGGM is used for radiative properties of combustion gases

  20. Chemical-looping combustion of methane with CaSO4 oxygen carrier in a fixed bed reactor

    International Nuclear Information System (INIS)

    Chemical-looping combustion is a promising technology for the combustion of gas or solid fuel with efficient use of energy and inherent separation of CO2. Chemical-looping combustion of methane with calcium sulfate as a novel oxygen carrier was conducted in a laboratory scale fixed bed reactor. The effects of reaction temperature, gas flow rate, sample mass, and particle size on reduction reactions were investigated and an optimum operating condition was determined. The results show that this novel oxygen carrier has a high reduction reactivity and stability in a long-time reduction/oxidation test. The conversions of CH4 increased with a higher temperature, smaller gas flow rate, larger sample mass and smaller particle size. The suitable reaction temperature seems to be around 950 deg. C. Low temperatures lead to a low CH4 conversion, but a significant SO2 formation was observed at a higher temperature. The release of SO2, CO, H2 via a series of side reactions, carbon deposition and agglomeration were also discussed. The formation of SO2, CO, H2, and carbon can be avoided by optimization of the operating conditions

  1. The combustion of solid fuels and wastes

    CERN Document Server

    Tillman, David

    1991-01-01

    Careful organization and empirical correlations help clarify the prodigious technical information presented in this useful reference.Key Features* Written for practicing engineers, this comprehensive book supplies an overall framework of the combustion process; It connects information on specific reactions and reaction sequences with current applications and hardware; Each major group of combustion solids is evaluated; Among the many topics covered are:* Various biomass forms* The coalification process* Grate, kiln, and suspension firing* Fluidized bed combustion

  2. Reprint of “Experiences in sulphur capture in a 30 MWth Circulating Fluidized Bed boiler under oxy-combustion conditions”

    International Nuclear Information System (INIS)

    CO2 and SO2 from fossil fuel combustion are contributors to greenhouse effect and acid rain respectively. Oxy-combustion technology produces a highly concentrated CO2 stream almost ready for capture. Circulating Fluidized Bed (CFB) boiler technology allows in-situ injection of calcium-based sorbents for efficient SO2 capture. CIUDEN's 30 MWth CFB boiler, supplied by Foster Wheeler and located at the Technology Development Centre for CO2 Capture and Transport (es.CO2) in Spain, is the first of its kind for executing test runs at large pilot scale under both air-combustion and oxy-combustion conditions. In this work, SO2 emissions under different scenarios have been evaluated. Variables such as limestone composition, Ca/S molar ratio and bed temperature among others have been considered along different test runs in both air-combustion and oxy-combustion conditions to analyse its influence on SO2 abatement. Fly and bottom ash, together with flue gas analysis have been carried-out. Desulphurization performance tests results are presented. - Highlights: • Sulphur capture efficiency (%) was higher in oxy-combustion compared to air-combustion in a 30 MW thermal CFB boiler using anthracite and limestone as sulphur sorbent. • For a Ca/S molar ratio higher than 2.6 there was barely any improvement on sulphur capture efficiency for both air-combustion and oxy-combustion conditions in a 30 MW thermal CFB boiler using anthracite and limestone as sulphur sorbent. • Optimum temperature for sulphur capture at a fixed Ca/S molar ratio is around 880–890 °C under oxy-combustion conditions and for anthracite coal with limestone as sorbent in a 30 MW thermal CFB boiler

  3. Flow visualizing study of fluidized bed for incineration and/or coal combustion technology

    Energy Technology Data Exchange (ETDEWEB)

    Ozawa, Mamoru [Kansai Univ., Suita, Osaka (Japan). Faculty of Engineering

    1997-02-01

    A simulated fluidized-bed heat exchanger was visualized using a neutron radiography system. The void fraction distribution and its fluctuation were obtained by means of an image processing technique. On the basis of the processed image, the mechanism of a large particle movement and the flow pattern in the tube bank immersed in the bed were investigated. Observed flow pattern in the tube bank indicated an importance of the tube arrangement on the void fraction fluctuation and thus the heat transfer around tubes. (author)

  4. Combustion characteristics of Douglas Fir planer shavings. Technical progress report No. 4, September 16, 1977--September 15, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Junge, D.C.

    1978-12-01

    Significant quantities of wood residue fuels are presently being used in industrial steam generating facilities. Recent studies indicate that substantial additional quantities of wood residue fuels are available for energy generation in the form of steam and/or electricity. A limited data base on the combustion characteristics of wood residue fuels has resulted in the installation and operation of inefficient combustion systems for these fuels. This investigation of the combustion characteristics of wood residue fuels was undertaken to provide a data base which could be used to optimize the combustion of such fuels. Optimization of the the combustion process in industrial boilers serves to improve combustion efficiency and to reduce air pollutant emissions generated in the combustion process. This report presents data on the combustion characteristics of Douglas Fir planer shavings. The data were obtained in a pilot scale combustion test facility at Oregon State Univerisity. Other technical reports present data on the combustion characteristics of: Douglas Fir bark, Red Alder sawdust, Red Alder bark, Ponderosa pine bark, Hemlock bark, and Eastern White Pine bark. An executive summary report is also available which compares the combustion characteristics of the various fuel species.

  5. Experimental Study of Stabilized Soil Utilizing Circulating Fluidized Bed Combustion Desulfurization Ash with Carbide Slag and Desulfurization Gypsum

    Directory of Open Access Journals (Sweden)

    Dezhi Shao

    2015-01-01

    Full Text Available This paper discusses the feasibility of preparing soil stabilizer which is circulating fluidized bed combustion ash-based, supplemented with carbide slag and desulfurization gypsum, composed entirely of complete industrial wastes. The results show that CFBC ash has better pozzolanic activity than fly ash. When stabilizer total content is 10% and the ratio of CFBC ash : carbide slag : desulfurization gypsum is 7.2 : 1.8 : 1, compressive strength of stabilized soil can reach the maximum of 2.12 MPa at the age of 28 d of curing. Stabilizer can meet the strength requirements of cement-soil mixing pile composite foundation and cement-soil mixing pile waterproof curtain.

  6. Energy analysis of two stage packed-bed chemical looping combustion configurations for integrated gasification combined cycles

    International Nuclear Information System (INIS)

    Chemical looping combustion is a promising technology for power production with integrated CO2 capture. High overall efficiencies can be reached, if the CLC reactors are operated at elevated pressures and high temperature, which can be accommodated in packed bed reactors. More possible oxygen carriers can be selected if the desired temperature rise for power production is achieved in a two stage chemical looping combustion (TS-CLC) process. In this work, the TS-CLC configuration using copper and manganese based oxygen carriers has been integrated in a complete power plant based on coal gasification (IG-CLC). An extensive energy analysis based on the combined use of a packed bed reactor modeling tool and a complete process simulation has been undertaken. An economic estimation of the reactors capital cost has also been carried out. From the material and energy balances the IG-CLC with one stage nickel-based CLC process results in a net electric efficiency of 41.1% on low heating value basis. In case of TS-CLC, efficiencies of 40.3%–40.8% have been obtained. This demonstrated that IGCC (integrated gasification combined cycles) adopting a TS-CLC process can also achieve high efficiency compared to conventional CO2 capture technologies. Although a larger reactor volume is required for TS-CLC, the total estimated investment costs are a factor two lower, because the oxygen carriers are much cheaper. - Highlights: • Complete IG-CLC power plants have been evaluated for different CLC configurations. • Novel operation strategy for the TS-CLC has been proposed: TS-CLC parallel. • The estimated capital costs of TS-CLC are a factor two smaller than one stage CLC. • The process efficiency of TS-CLC is demonstrated to be close to the one stage CLC

  7. Analysis of Flue Gas Emission Data from Fluidized Bed Combustion Using Self-Organizing Maps

    OpenAIRE

    Yrjö Hiltunen; Teri Hiltunen; Eero Hälikkä; Mikko Heikkinen; Mika Liukkonen

    2010-01-01

    Efficient combustion of fuels with lower emissions levels has become a demanding task in modern power plants, and new tools are needed to diagnose their energy production. The goals of the study were to find dependencies between process variables and the concentrations of gaseous emission components and to create multivariate nonlinear models describing their formation in the process. First, a generic process model was created by using a self-organizing map, which was clustered with the k-mea...

  8. An Experimental Study on Axial Temperature Distribution of Combustion of Dewatered Poultry Sludge in Fluidized bed combustor

    Directory of Open Access Journals (Sweden)

    Abbas A.H.

    2016-01-01

    Full Text Available A laboratory scale bubbling fluidized bed combustor was designed and fabricated to study the combustion of dewatered poultry sludge at different operational parameters. This paper present a study on the influence of equivalent ratio, secondary to primary air ratio and the fuel feed rate on the temperature distribution along the combustor. The equivalent ratio has been changed between 0.8 to 1.4% under poultry sludge feed rate of 10 kg/h and from 0.8 to 1 under poultry sludge feed rate of 15 kg/h. The secondary to primary air ratio was varied from 0.1 to 0.5 at 0.65 m injection height and 1.25 equivalent ratio. The results showed that these factors had a significant influence on the combustion characteristics of poultry sludge. The temperature distribution along the combustor was found to be strongly dependent on the fuel feed rate and the equivalent ratio and it increased when these two factors increased. However, the secondary air ratio increased the temperature in the lower region of the combustor while no significant effect was observed at the upper region of the combustor. The results suggested that the poultry sludge can be used as a fuel with high thermal combustor efficiency.

  9. Rotary Bed Reactor for Chemical-Looping Combustion with Carbon Capture. Part 1: Reactor Design and Model Development

    KAUST Repository

    Zhao, Zhenlong

    2013-01-17

    Chemical-looping combustion (CLC) is a novel and promising technology for power generation with inherent CO2 capture. Currently, almost all of the research has been focused on developing CLC-based interconnected fluidized-bed reactors. In this two-part series, a new rotary reactor concept for gas-fueled CLC is proposed and analyzed. In part 1, the detailed configuration of the rotary reactor is described. In the reactor, a solid wheel rotates between the fuel and air streams at the reactor inlet and exit. Two purging sectors are used to avoid the mixing between the fuel stream and the air stream. The rotary wheel consists of a large number of channels with copper oxide coated on the inner surface of the channels. The support material is boron nitride, which has high specific heat and thermal conductivity. Gas flows through the reactor at elevated pressure, and it is heated to a high temperature by fuel combustion. Typical design parameters for a thermal capacity of 1 MW have been proposed, and a simplified model is developed to predict the performances of the reactor. The potential drawbacks of the rotary reactor are also discussed. © 2012 American Chemical Society.

  10. Major gaseous and PAH emissions from a fluidized-bed combustor firing rice husk with high combustion efficiency

    International Nuclear Information System (INIS)

    This experimental work investigated major gaseous (CO and NOx) and PAH emissions from a 400 kWth fluidized-bed combustor with a cone-shaped bed (referred to as 'conical FBC') firing rice husk with high, over 99%, combustion efficiency. Experimental tests were carried out at the fuel feed rate of 80 kg/h for different values of excess air (EA). As revealed by the experimental results, EA had substantial effects on the axial CO and NOx concentration profiles and corresponding emissions from the combustor. The concentration (mg/kg-ash) and specific emission (μg/kW h) of twelve polycyclic aromatic hydrocarbons (PAHs), acenaphthylene, fluorene, phenanthrene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene and indeno[1,2,3-cd]pyrene, were quantified in this work for different size fractions of ash emitted from the conical FBC firing rice husk at EA = 20.9%. The total PAHs emission was found to be predominant for the coarsest ash particles, due to the effects of a highly developed internal surface in a particle volume. The highest emission was shown by acenaphthylene, 4.1 μg/kW h, when the total yield of PAHs via fly ash was about 10 μg/kW h. (author)

  11. Ignition of Combustible Fuel Beds by Hot Particles:An Experimental and Theoretical Study

    OpenAIRE

    Hadden, Rory M.; Scott, Sarah; Lautenberger, Chris; Fernandez-Pello, A. Carlos

    2011-01-01

    The process of spotting occurs in wildland fires when fire-lofted embers or hot particles land downwind, leading to ignition of new, discrete fires. This common mechanism of wildland fire propagation can result in rapid spread of the fire, potentially causing property damage and increased risk to life safety of both fire fighters and civilians. Despite the increasing frequency and losses in wildland fires, there has been relatively little research on ignition of fuel beds by embers and hot pa...

  12. THE EXPERIMENTAL STUDY OF COMBUSTION STABILITY IN THE INTERNAL CIRCULATING FLUIDIZED BED%内旋流流化床燃烧稳定性研究

    Institute of Scientific and Technical Information of China (English)

    田文栋; 魏小林; 黎军; 吴东垠; 盛宏至

    2001-01-01

    Invariable and even combustion temperature is necessary for the municipal solid waste (MSW) incineration to decrease the emission of air pollutants. In thispaper, The combustion temperature stability in the dense phase bed zone and temperature distributions in the incinerator have been studied by adjustin gmass of processed waste, types of waste and particles thickness of bed in theinternal circulating fluidized bed (ICFB).%城市生活垃圾焚烧需要稳定均匀的温度来减少燃烧产生的大气污染物。采用内旋流流化床进行了垃圾焚烧实验,通过改变垃圾处理量、垃圾种类和流化床浓相床区高度,研究了浓相床区温度的稳定性和焚烧炉内温度分布。

  13. Pilot development of polygeneration process of circulating fluidized bed combustion combined with coal pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Qu, X. [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan (China); Graduate School, Chinese Academy of Sciences, Beijing (China); Liang, P. [College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao (China); Wang, Z. [Ningbo Branch of Academy of Ordnace Science, Ningbo (China); Zhang, R.; Sun, D.; Bi, J. [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan (China); Gong, X. [Hengyuan Coal Electrochemical Co., Ltd, Fugu (China); Gan, Z. [State Key Laboratory of Low Carbon Energy, ENN Science and Technology Ltd, Langfang (China)

    2011-01-15

    A pilot polygeneration process of a 75 t h{sup -1} circulating fluidized bed (CFB) boiler combined with a moving bed coal pyrolyzer was developed based on laboratory-scale experimental results. The process operation showed good consistency and integration between boiler and pyrolyzer. Some critical operating parameters such as hot ash split flow from the CFB boiler to the pyrolyzer, mixing of hot ash and coal particles, control of pyrolysis temperature and solid inventory in the pyrolyzer, and pyrolysis gas clean-up were investigated. Yields of 6.0 wt-% tar and 8.0 wt-% gas with a heating value of about 26 MJ m{sup -3} at 600 C were obtained. Particulate content in tar was restrained less than 4.0 wt-% by using a granular filter of the moving bed. Operation results showed that this pilot polygeneration process was successfully scaled up. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Temperatures of coal particle during devolatilization in fluidized bed combustion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Komatina, M.; Manovic, V.; Saljnikov, A. [University of Belgrade, Belgrade (Serbia). Faculty of Mechanical Engineering

    2006-11-15

    The purpose of this study was to investigate the thermal behavior of coal during devolatilization in fluidized bed. Temperatures in the center of single coal particle were measured by thermocouple. Two coals were tested (brown coal Bogovina and lignite Kosovo), using dry coal particle, shaped into spherical form of diameters 7 and 10 mm, in temperature range from 300 to 850{sup o}C. Unsteady behavior of coal particle during heating and devolatilization in fluidized bed was described by a model that takes into account heat transfer between bed and particle surface, heat transfer through particle and an endothermic chemical reaction of first-order. Based on the mathematical model analysis and compared with experimental results, values of heat conductivity {lambda}{sub C} and heat capacity (C-p) of coal were determined. The best agreement was obtained for constant thermal properties, for brown coal {lambda}{sub C} = 0.20 W/mK and C{sub p} = 1200 J/kgK and for lignite {lambda}{sub C} = 0.17 W/mK and C-p = 1100 J/kgK.

  15. Review of the Technical Status on the Debris Bed Cooling Model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eui Kwang; Cho, Chung Ho; Lee, Yong Bum

    2007-09-15

    Preliminary safety analyses of the KALIMER-600 design have shown that the design has inherent safety characteristics and is capable of accommodating double-fault initiators such as ATWS events without coolant boiling or fuel melting. However, for the future design of sodium cooled fast reactor, the evaluation of the safety performance and the determination of containment requirements may be worth due consideration of triple-fault accident sequences of extremely low probability of occurrence that leads to core melting. For any postulated accident sequence which leads to core melting, in-vessel retention of the core debris will be required as a design requirement for the future design of sodium cooled fast reactor. Also, proof of the capacity of the debris bed cooling is an essential condition to solve the problem of in-vessel retention of the core debris. In this study, review of the technical status on the debris bed cooling model was carried out for in-vessel retention of the core debris0.

  16. Standard technical specifications: Combustion engineering plants. Volume 1, Revision 1: Specifications

    International Nuclear Information System (INIS)

    This report documents the results of the combined effort of the NRC and the industry to produce improved Standard Technical Specifications (STS), Revision 1 for Combustion Engineering Plants. The changes reflected in Revision 1 resulted from the experience gained from license amendment applications to convert to these improved STS or to adopt partial improvements to existing technical specifications. This NUREG is the result of extensive public technical meetings and discussions between the Nuclear Regulatory Commission (NRC) staff and various nuclear power plant licensees, Nuclear Steam Supply System (NSSS) Owners Groups, NSSS vendors, and the Nuclear Energy Institute (NEI). The improved STS were developed based on the criteria in the Final Commission Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors, dated July 22, 1993. The improved STS will be used as the basis for individual nuclear power plant licensees to develop improved plant-specific technical specifications. This report contains three volumes. Volume 1 contains the Specifications for all chapters and sections of the improved STS. Volume 2 contains the Bases for Chapters 2.0 and 3.0, and Sections 3.1--3.3 of the improved STS. Volume 3 contains the Bases for Sections 3.4--3.9 of the improved STS

  17. Studies on nitrogen oxides (NO{sub x} and N{sub 2}O) in pressurized fluidized bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yong

    1998-09-01

    This thesis describes the experimental studies of nitrogen oxide (NO, NO{sub 2}, N{sub 2}O) emissions in pressurized fluidized bed combustion (PFBC). In the first part of the thesis the background and the objectives of this study are introduced. The second part summarizes the fundamental knowledge about the formation and destruction of nitrogen oxides in coal combustion, particularly in the conditions of PFBC. The instrumentation of test facilities, measurement and data analysis is described in the third part. Then the most important experimental results follow in the next parts. The forth part describes the results from a PFBC test rig and an empirical modelling for predicting the emissions of NO{sub x} and N{sub 2}O. Finally, the fundamental work on coal combustion and fuel nitrogen conversion in a PFBC batch reactor is presented. These studies clearly confirm the potential of PFBC technology in the control nitrogen of oxide emissions. The research in the test rig was concentrated on determining the effects of process parameters on the emissions of nitrogen oxides with different fuels. Another objective was to examine the reduction of nitrogen oxides with the control methods in PFBC conditions, including ammonia injection and air staging combustion for reducing NO, and high temperature operations for reducing N{sub 2}0. The results indicate that pressurized operation suppresses the conversion of fuel-N to nitrogen oxides and favors with employing the reduction methods for further nitrogen oxide reduction, for instance the temperature window of NO reduction with ammonia injection has been found to be widened to even lower temperature range. Maximum reductions of 80-85 % with ammonia injection and 75-80 % with air staging combustion were achieved in the conditions examined. Considerably low emissions of N{sub 2}O (<7 ppm) were obtained in the tests of N{sub 2}O control, and thermal decomposition proved to be the laming pathway of N{sub 2}O destruction in PFBC. In

  18. A Novel Method for Pre-combustion CO2 Capture in Fluidized Bed

    OpenAIRE

    Herce Fuente, Carlos; Cumo, Maurizio; Cortés Gracia, Cristóbal

    2014-01-01

    La comunidad internacional está realizando enormes esfuerzos para mitigar los efectos de las emisiones de gases de efecto invernadero (GEI) en el cambio climático. Aproximadamente le 25% de las emisiones globales de GEI (fundamentalmente CO2) son generados por la combustión de combustibles fósiles en el sector eléctrico. La captura y almacenamiento de CO2 se ha propuesto como una alternativa para reducir las emisiones de GEI en centrales térmicas. Numerosas tecnologías para la captura de CO2 ...

  19. Internal combustion engines for alcohol motor fuels: a compilation of background technical information

    Energy Technology Data Exchange (ETDEWEB)

    Blaser, Richard

    1980-11-01

    This compilation, a draft training manual containing technical background information on internal combustion engines and alcohol motor fuel technologies, is presented in 3 parts. The first is a compilation of facts from the state of the art on internal combustion engine fuels and their characteristics and requisites and provides an overview of fuel sources, fuels technology and future projections for availability and alternatives. Part two compiles facts about alcohol chemistry, alcohol identification, production, and use, examines ethanol as spirit and as fuel, and provides an overview of modern evaluation of alcohols as motor fuels and of the characteristics of alcohol fuels. The final section compiles cross references on the handling and combustion of fuels for I.C. engines, presents basic evaluations of events leading to the use of alcohols as motor fuels, reviews current applications of alcohols as motor fuels, describes the formulation of alcohol fuels for engines and engine and fuel handling hardware modifications for using alcohol fuels, and introduces the multifuel engines concept. (LCL)

  20. Improvement of the combustion technical properties of by- products of mechanical forest industry

    International Nuclear Information System (INIS)

    The objective of the research is to improve the combustion technical properties of by-products formed in mechanical forest industry by developing the fuel storage and processing. The research is divided into three projects: (1) research on the factors effecting on the combustion technical properties of bark, and the optimization of the storage, (2) reduction of the moisture content of the by-products, and (3) removal of harmful substances from the fuel. The research will be carried out in cooperation with Swedish Agricultural University (SLU), which is starting a similar research project. The objective of the research is to study how the different storage methods effect on the DS-losses of bark, the quality of the bark, the processibility and environmental effects. Instructions for optimization of the storage will be prepared on the basis of the results. In addition to these the objective of the project is to study the techno-economic applicability of mechanical compression and the new type HT drying technology for drying of bark and to determine the effects of snow and ice in the bark on the moisture content of bark. The amount and quality of by-products containing impurities (stones and sand) in the sawmill industry will be determined, as well as the methods suitable for removal of these impurities

  1. The influence of temperature on limestone sulfation and attrition under fluidized bed combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Montagnaro, Fabio [Dipartimento di Chimica - Universita degli Studi di Napoli Federico II, Complesso Universitario del Monte di Sant' Angelo, 80126 Napoli (Italy); Salatino, Piero [Istituto di Ricerche sulla Combustione - CNR, Piazzale Vincenzo Tecchio 80, 80125 Napoli (Italy); Dipartimento di Ingegneria Chimica - Universita degli Studi di Napoli Federico II, Piazzale Vincenzo Tecchio 80, 80125 Napoli (Italy); Scala, Fabrizio [Istituto di Ricerche sulla Combustione - CNR, Piazzale Vincenzo Tecchio 80, 80125 Napoli (Italy)

    2010-04-15

    The influence of temperature on attrition of two limestones during desulfurization in a fluidized bed reactor was investigated. Differences in the microstructure of the two limestones were reflected by a different thickness of the sulfate shell formed upon sulfation and by a different value of the ultimate calcium conversion degree. Particle attrition and fragmentation were fairly small under moderately bubbling fluidization conditions for both limestones. An increase of temperature from 850 C to 900 C led to an increase of the attrition rate, most likely because of a particle weakening effect caused by a faster CO{sub 2} evolution during calcination. This weakening effect, however, was not sufficiently strong to enhance particle fragmentation in the bed. The progress of sulfation, associated to the build-up of a hard sulfate shell around the particles, led in any case to a decrease of the extent of attrition. Sulfation at 900 C was less effective than at 850 C, and this was shown to be related to the porosimetric features of the different samples. (author)

  2. Inhibition of the limestone sulphation process during fluidized bed combustion - a theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Burdett, N.A.

    1983-12-01

    The extents and rates of absorption of sulphur oxides by limestone (or similar) sorbents are important factors which influence operating costs of fluidized-bed combustors for power generation with simultaneous flue gas desulphurization. Laboratory experiments have been conducted in order to ascertain the parameters affecting the kinetics of the sulphation, and a simple mathematical model has been constructed. It is shown that when the reaction conditions are altered to favour the production of SO/sub 3/, in general the extent of sulphation is reduced. The model has been used to predict the effect of temperature on sulphation, and it is shown that the presence of SO/sub 3/ as an intermediate in the reaction provides an explanation for the optimum sulphation temperature commonly observed in FBC operation.

  3. Fast Pyrolysis of Biomass in a Spout-fluidized Bed Reactor--Analysis of Composition and Combustion Characteristics of Liquid Product from Biomass

    Institute of Scientific and Technical Information of China (English)

    陈明强; 王君; 王新运; 张学才; 张素平; 任铮伟; 颜涌捷

    2006-01-01

    In order to gain insight into the fast pyrolysis mechanism of biomass and the relationship between bio-oil composition and pyrolysis reaction conditions, to assess the possibility for the raw bio-oil to be used as fuel, and to evaluate the concept of spout-fluidized bed reactor as the reactor for fast pyrolysis of biomass to prepare fuel oil, the composition and combustion characteristics of bio-oil prepared in a spout-fluidized bed reactor with a designed maximum capacity 5 kg/h of sawdust as feeding material, were investigated by GC-MS and thermogravimetry. 14 aromatic series chemicals were identified. The thermogravimetric analysis indicated that the bio-oil was liable to combustion, the combustion temperature increased with the heating rate, and only minute ash was generated when it burned. The kinetics of the combustion reaction was studied and the kinetic parameters were calculated by both Ozawa-Flynn-Wall and Popsecu methods. The results agree well with each other. The most probable combustion mechanism functions determined by Popescu method are f(α)=k(1-α)2(400~406 ℃), f(α)=1/2k(1-α)3 (406~416 ℃) and f( α)=2k(1-α)3/2 (416~430 ℃) respectively.

  4. Application of noncatalytic gas-solid reactions for a single pellet of changing size to the modeling of fluidized-bed combustion of coal char containing sulfur

    Energy Technology Data Exchange (ETDEWEB)

    Rehmat, A.; Saxena, S.C.; Land, R.H.

    1980-09-01

    A mechanistic model is developed for coal char combustion, with sulfur retention by limestone or dolomite sorbent, in a gas fluidized bed employing noncatalytic single pellet gas-solid reactions. The shrinking core model is employed to describe the kinetics of chemical reactions taking place on a single pellet; changes in pellet size as the reaction proceeds are considered. The solids are assumed to be in back-mix condition whereas the gas flow is regarded to be in plug flow. Most char combustion occurs near the gas distributor plate (at the bottom of the bed), where the bubbles are small and consequently the mass transfer rate is high. For such a case, the analysis is considerably simplified by ignoring the bubble phase since it plays an insignificant role in the overall rate of carbon conversion. Bubble-free operation is also encounterd in the turbulent regime, where the gas flow is quite high and classical bubbles do not exist. Formulation of the model includes setting up heat and mass balance equations pertaining to a single particle (1) exposed to a varying reactant concentration along the height of the bed and (2) whose size changes during reaction. These equations are then solved numerically to account for particles of all sizes in the bed in obtaining the overall carbon conversion efficiency and resultant sulfur retention. In particular, the influence on sorbent requirement of several fluid-bed variables such as oxygen concentration profile, particle size, reaction rate for sulfation reaction, and suflur adsorption efficiency are examined.

  5. Energy recovery from municipal solid waste and sewage sludge using multi-solid fluidized bed combustion technology

    Science.gov (United States)

    1981-07-01

    The concept is to recover energy as high and low pressure steam, simultaneously. High pressure steam would be generated from flue gas using a conventional tubular boiler. Low pressure steam would be generated by direct contact drying of DSS (as 4 percent solids) with hot sand in a fluidized bed that is an integral part of the MS-FBC process. It is proposed that high pressure steam could be used for district heating or electricity generation. The low pressure steam could be used for close proximity building heat. The results of the investigation show that the MS-FBC process concept for the co-utilization of MSW and DSS is technically feasible and that the thermal efficiency of the process is 76 to 82 percent based on experiments conducted in a 70 to 85 lb/h pilot plant and calculations on three conceptual cases.

  6. Gaseous emissions in pressurised fluidised-bed combustion. Analysis and summary of the pilot experiments; Kaasumaiset paeaestoet paineistetussa leijukerrospoltossa. Koetulosten kaesittely ja yhteenveto

    Energy Technology Data Exchange (ETDEWEB)

    Korpela, T.; Hippinen, I.; Konkola, M. [Helsinki Univ. of Technology, Espoo (Finland)

    1996-12-01

    The influence of operating conditions on gaseous emissions in pressurised fluidised-bed combustion have been studied. The research objectives have been behaviour of sulphur absorbents and reduction of sulphur dioxide emissions, reduction of nitrogen oxide emissions, release of vapour-phase alkalimetals and carbon monoxide emissions. The sulphur capture capacities of calcium-based sorbents under PFBC conditions have been studied at a pressurised fluidised-bed reactor and at a pressurised thermogravimetric apparatus. The project has also connected results of the experimental PFBC at HUT/EVO. (author)

  7. Electrodialytic treatment for metal removal from sewage sludge ash from fluidized bed combustion.

    Science.gov (United States)

    Pazos, M; Kirkelund, G M; Ottosen, L M

    2010-04-15

    Sewage sludge contains several potentially hazardous compounds such as heavy metals, PCBs, PAHs, etc. However, elements with high agricultural value (P, K or Ca) are also present. During the last years, the fluidized bed sludge combustor (FBSC) is considered an effective and novel alternative to treat sewage sludge. By its use, the high amount of sludge is reduced to a small quantity of ash and thermal destruction of toxic organic constituents is obtained. Conversely, heavy metals are retained in the ash. In this work the possibility for electrodialytic metal removal for sewage sludge ash from FBSC was studied. A detailed characterization of the sewage sludge ash was done initially, determining that, with the exception of Cd, the other heavy metals (Cr, Cu, Pb, Ni and Zn) were under the limiting levels of Danish legislation for the use of sewage sludge as fertilizer. After 14 days of electrodialytic treatment, the Cd concentration was reduced to values below the limiting concentration. In all experiments the concentrations of other metals were under limiting values of the Danish legislation. It can be concluded that the electrodialytic treatment is an adequate alternative to reduce the Cd concentration in FBSC ash prior to use as fertilizer. PMID:20034740

  8. Engineering systems analysis of pressurized fluidized-bed-combustion power systems

    Energy Technology Data Exchange (ETDEWEB)

    Graves, R.L.; Griffin, F.P.; Lackey, M.E.

    1982-04-01

    This effort was conducted to provde supporting data for the research and development program on pressurized fluidized bed combustor (PFBC) systems being continued under the auspices of the Office of Coal Utilization of DOE. This report deals with the first phase of the effort, designated Task 1, which was scoped to be a somewhat broad review of PFBC technology and an analysis to determine its potential and sensitivity to key development needs. Background information pertaining to the application of PFBC to the market for coal-fired technology is included. The status of development is reviewed and the deficiencies in data are identified. Responses to a survey of PFBC developers are reviewed with emphasis on the high risk areas of the PFBC concept. Some of these problems are: uncertainty of life of gas turbine components; lack of demonstration of load following; and hot solids handling. Some high risk areas, such as the gas cleanup or gas turbine systems, can be relieved by reducing the severity of design conditions such as the turbine inlet temperature. Alternate turbine designs or plant configurations are also possible solutions. Analyses were performed to determine whether the advantages held by PFBC systems in cost, efficiency, and emissions would be nullified by measures taken to reduce risk. In general, the results showed that the attractive features of the PFBC could be preserved.

  9. Reactivation of spent limestone for sulphur capture in fluidized bed combustion : hydration and sulphation behavior

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.; Wu, Y.; Anthony, E.J. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre

    2003-07-01

    From an economic and environmental perspective, there is a need to reuse partially sulphated limestone sorbent to control sulphur dioxide (SO{sub 2}) emissions. Currently, limestone is not used efficiently for in-situ capture in fluidized bed combustors (FBC) because of incomplete sulphation of CaO. Spent limestone can be reactivated by hydrating the FBC ash. This allows the ash to take up SO{sub 2} as SO{sub 2} sorbent. In this study, ashes from a large FBC were hydrated. Sulphation tests were then conducted on the hydrated ashes with particular attention to their kinetic behaviour. Temperature, particle size and hydration time were the factors that affected the rate and efficiency of the reactivation process. A comparative evaluation between the behaviour of hydration with liquid water and steam was conducted along with a comparison of the behaviour of sulphation following hydration. The effect of hydration on the sulphation rate was analyzed in terms of changes to the solid particle's microstructure. The results of this study were compared with those reported in literature and with other studies on enhanced hydration through grinding and sonication.

  10. The inhibition of the limestone sulphation process during fluidized bed combustion --- a theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Burdett, N.A.

    1983-12-01

    The extents and rates of absorption of sulfur oxides by limestone (or similar) sorbents are important factors which influence operating costs of fluidized bed combustors for power generation with simultaneous flue gas desulphurization. Laboratory experiments have been conducted in order to ascertain the parameters affecting the kinetics of the sulfation and a simple mathematical model has been constructed assuming that the critical factor in the process is the production of SO/sub 3/ by oxidation of SO/sub 2/ within the pores of the stone. It is shown that when reaction conditions are altered so as to favour the production of SO/sub 3/ in general the extent of sulfation is reduced owing to a more rapid formation of a shell of CaSO/sub 4/ around the outer edge of the particle, and hence a faster rate of pore-blocking. The model has been used to predict the effect of temperature upon sulfation, and it is shown that the presence of SO/sub 3/ as an intermediate in the reaction provides an explanation for the optimum sulfation temperature commonly observed in FBC operation.

  11. Studies on nitrogen oxides (NO{sub x} and N{sub 2}O) in pressurized fluidized bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yong

    1998-09-01

    This thesis describes the experimental studies of nitrogen oxide (NO, NO{sub 2}, N{sub 2}O) emissions in pressurized fluidized bed combustion (PFBC). In the first part of the thesis the background and the objectives of this study are introduced. The second part summarizes the fundamental knowledge about the formation and destruction of nitrogen oxides in coal combustion, particularly in the conditions of PFBC. The instrumentation of test facilities, measurement and data analysis is described in the third part. Then the most important experimental results follow in the next parts. The forth part describes the results from a PFBC test rig and an empirical modelling for predicting the emissions of NO{sub x} and N{sub 2}O. Finally, the fundamental work on coal combustion and fuel nitrogen conversion in a PFBC batch reactor is presented. These studies clearly confirm the potential of PFBC technology in the control nitrogen of oxide emissions. The research in the test rig was concentrated on determining the effects of process parameters on the emissions of nitrogen oxides with different fuels. Another objective was to examine the reduction of nitrogen oxides with the control methods in PFBC conditions, including ammonia injection and air staging combustion for reducing NO, and high temperature operations for reducing N{sub 2}0. The results indicate that pressurized operation suppresses the conversion of fuel-N to nitrogen oxides and favors with employing the reduction methods for further nitrogen oxide reduction, for instance the temperature window of NO reduction with ammonia injection has been found to be widened to even lower temperature range. Maximum reductions of 80-85 % with ammonia injection and 75-80 % with air staging combustion were achieved in the conditions examined. Considerably low emissions of N{sub 2}O (<7 ppm) were obtained in the tests of N{sub 2}O control, and thermal decomposition proved to be the laming pathway of N{sub 2}O destruction in PFBC. In

  12. Feasibility study on solidification of municipal solid waste incinerator fly ash with circulating fluidized bed combustion coal fly ash.

    Science.gov (United States)

    Liu, Wenshi; Hou, Haobo; Zhang, Chuhao; Zhang, Dajie

    2009-05-01

    The objective of this study was to assess the feasibility of solidification of municipal solid waste incinerator (MSWI) fly ash with circulation fluidized bed combustion (CFBC) fly ash, which is unsuitable as a cement replacement due to its high amounts of carbon, lime and anhydrite. The solidification process was conducted on samples prepared from MSWI fly ash, binders (cement clinkers and CFBC fly ash were mixed at two replacement ratios) and water (water/solid weight ratio = 0.4), among which the MSWI fly ash replaced each binder at the ratio of 0, 20, 40, 60 and 80% by dry weight. The samples were subjected to compressive strength tests and Toxicity Characteristic Leaching Procedure and the results showed that all solidified MSWI fly ash can meet the landfill standard imposed by US EPA after 28 days of curing. Micro-analysis (X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectrophotometry) revealed that the main hydrate products were C-S-H gel and ettringite, which have a positive effect on heavy metals retention. Therefore, this method provides a possibility to achieve a cheap and effective solution for MSWI fly ash management and use for CFBC fly ash. PMID:19423575

  13. Development of methane and nitrous oxide emission factors for the biomass fired circulating fluidized bed combustion power plant.

    Science.gov (United States)

    Cho, Chang-Sang; Sa, Jae-Hwan; Lim, Ki-Kyo; Youk, Tae-Mi; Kim, Seung-Jin; Lee, Seul-Ki; Jeon, Eui-Chan

    2012-01-01

    This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB) boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH(4)), Nitrous oxide (N(2)O). The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF), RDF and Refused Plastic Fuel (RPF) of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH(4) and N(2)O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH(4) and N(2)O exhausted from the CFB boiler. As a result, the emission factors of CH(4) and N(2)O are 1.4 kg/TJ (0.9-1.9 kg/TJ) and 4.0 kg/TJ (2.9-5.3 kg/TJ) within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N(2)O emission, compared to the emission factor of the CFB boiler using fossil fuel. PMID:23365540

  14. Development of Methane and Nitrous Oxide Emission Factors for the Biomass Fired Circulating Fluidized Bed Combustion Power Plant

    Directory of Open Access Journals (Sweden)

    Chang-Sang Cho

    2012-01-01

    Full Text Available This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH4, Nitrous oxide (N2O. The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF, RDF and Refused Plastic Fuel (RPF of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH4 and N2O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH4 and N2O exhausted from the CFB boiler. As a result, the emission factors of CH4 and N2O are 1.4 kg/TJ (0.9–1.9 kg/TJ and 4.0 kg/TJ (2.9–5.3 kg/TJ within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N2O emission, compared to the emission factor of the CFB boiler using fossil fuel.

  15. Measurement and model based interpretation of the temperature distribution in combustion chambers of industrial scale fluidized-bed combustion power plants; Messung und modellgestuetzte Interpretation von Temperaturverteilungen in den Brennkammern grosstechnischer Wirbelschichtkraftwerke

    Energy Technology Data Exchange (ETDEWEB)

    Ratschow, L.; Wischnewski, R.; Hartge, E.U.; Werther, J. [Technische Universitaet Hamburg-Harburg, Hamburg (Germany). Institut fuer Feststoffverfahrenstechnik und Partikeltechnologie

    2009-07-01

    The cross section of the combustion chamber directly results from the performance of the power station. For example, Block 3 of the power station Turow in Poland has a combustion cross section of 200 m{sup 2} with an output of 250 MW{sub e}. If the height of approximately 45 m still is considered additionally, a very large reaction volume results. From this, locally different reaction conditions result. But straight the transverse mixture of gas and solid is small in the circulating fluidised bed. As a result, in the area of the fluidized bed three-dimensional concentration distributions are formed out involving a temperature distribution. In the contribution under consideration the authors report on measurements and simulations of such temperature distributions in a three-dimensional model.

  16. Three phase Eulerian-granular model applied on numerical simulation of non-conventional liquid fuels combustion in a bubbling fluidized bed

    OpenAIRE

    Nemoda Stevan Đ.; Mladenović Milica R.; Paprika Milijana J.; Erić Aleksandar M.; Grubor Borislav D.

    2016-01-01

    The paper presents a two-dimensional CFD model of liquid fuel combustion in bubbling fluidized bed. The numerical procedure is based on the two-fluid Euler-Euler approach, where the velocity field of the gas and particles are modeled in analogy to the kinetic gas theory. The model is taking into account also the third - liquid phase, as well as its interaction with the solid and gas phase. The proposed numerical model comprise energy equations for all three...

  17. Simulations of a Circulating Fluidized Bed Chemical Looping Combustion System Utilizing Gaseous Fuel Simulation de la combustion en boucle chimique d’une charge gazeuse dans un lit fluidisé circulant

    OpenAIRE

    Mahalatkar K.; Kuhlman J.; Huckaby E.D.; O’Brien T.

    2011-01-01

    Numerical studies using Computational Fluid Dynamics (CFD) have been carried out for a complete circulating fluidized bed chemical looping combustor described in the literature (Abad et al., 2006 Fuel 85, 1174-1185). There have been extensive experimental studies in Chemical Looping Combustion (CLC), however CFD simulations of this concept are quite limited. The CLC experiments that were simulated used methane as fuel. A 2-D continuum model was used to describe both the gas and solid phases. ...

  18. Investigations about the behaviour and recycling of fines during fluidized bed combustion in the head-end for HTGR-fuel elements

    International Nuclear Information System (INIS)

    Fluidized bed burning, favoured for removal of HTGR-fuel element matrix graphite, is equipped with a fines recycling system, designed either as ''external recycling'' or ''in-bed-filter cartridge assembly'' in order to keep steady state conditions. Due to the introduction of the LEU-fuel element concept higher demands are placed on fines handling, as low enriched uranium oxide in the fluidized bed is converted to the mechanically fairly unstable component of U3O8 and this causes considerably increased fines generation. The present study is concerned with investigations about the occurrence and behaviour of fines with regard to both recycling systems. In flow experiments (at room temperature) elutriation and residence time of fines are studied using radioactively labelled fines fractions. The efficiency of in-bed-filter recycling can thus be shown. The relationships between mean residence time of fines and flow velocity, fluidized bed mass and injection height are defined. In real fluidized bed combustion experiments (at c. 900-9500C) fines elutriation and graphite conversion - correlated to CO-content - are found to be greater in external than in integrated recycling and generally show an increase with higher gas velocities, all other parameters being kept constant. From a process engineering point of view fluidized beds with their intensive mixing can be regarded as a continuous stirred tank reactor, while their chemical reaction mechanism is that of a plug flow reactor. It is particularly noteworthy that a main reaction zone is formed in the lower parts of the fluidized bed, comprising of only about 10% of total bed height. With respect to special requirements in nuclear application the external recycling is marked by its greater inherent flexibility in addition to process engineering advantages. (orig.)

  19. Operational experience with a system of coupled fluidized beds for chemical looping combustion of solid fuels using ilmenite as oxygen carrier

    International Nuclear Information System (INIS)

    Highlights: • Successful operation of a coupled fluidized bed system for CLC of coal. • Two-stage design worked well, i.e. the 2nd stage has an significant effect on fuel conversion. • Solids circulation rates were determined. • High carbon capture rate (ηCC > 96%), which might be attributed to the very fine coal. - Abstract: A system of coupled fluidized beds for chemical looping combustion of solid fuels was successfully commissioned. The facility has a rated thermal power of 25 kW and consists of a circulating fluidized bed coupled with a two-stage bubbling fluidized bed. The two-stage bubbling fluidized bed is the fuel reactor and the riser of the circulating fluidized bed is the air reactor. In the experiments Australian ilmenite with a particle size in the range of 100–400 μm was used as the oxygen carrier. The solid fuel was lignite dust with more than 70% of the mass having a particle size smaller than 150 μm. The influence of the operational parameters, i.e. reactor temperature, coal feed rate and composition of the fuel reactor feed gas on the operational behaviour of the system was investigated. The two-stage fuel reactor performed well and CO2-concentrations in the dry fuel reactor off-gas of above 90 vol.% were achieved. The reason for the appearance of unconverted combustible gases in the fuel reactor off-gas needs further investigation. Solids circulation rates based on the riser cross-section were determined under hot operating conditions and turned out to be between 56 and 70 kg/m2 s. The carbon slip to the air reactor was small in all tests: only 1.5–6.5 wt.% of the fixed carbon introduced with the coal were oxidized in the air reactor

  20. Summary of Technical Meeting To Compare US/French Approaches for Physical Protection Test Beds

    Energy Technology Data Exchange (ETDEWEB)

    Mack, Thomas Kimball [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Martinez, Ruben [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Thomas, Gerald [National Nuclear Security Administration (NNSA), Washington, DC (United States); Palut, Jean-Michel [French Alternative and Atomic Energy Commission (CEA), Fontenay Aux Roses (France)

    2016-01-01

    In September 2015, representatives of the US Department of Energy/National Nuclear Security Administration, including test bed professionals from Sandia National Laboratories, and representatives of the French Alternative Energies and Atomic Energy Commission participated in a one-week workshop to share best practices in design, organization, operations, utilization, improvement, and performance testing of physical protection test beds. The intended workshop outcomes were to (1) share methods of improving respective test bed methodologies and programs and (2) prepare recommendations for standards regarding creating and operating testing facilities for nations new to nuclear operations. At the workshop, the French and American subject matter experts compared best practices as developed at their respective test bed sites; discussed access delay test bed considerations; and presented the limitations/ constraints of physical protection test beds.

  1. Neutron-induced gamma spectrometry for on-line compositional analysis in coal conversion and fluidized-bed combustion plants

    International Nuclear Information System (INIS)

    All available methods of analysis of process streams in coal conversion and fluidized-bed combustion systems require the physical removal and conditioning of a sample from the system before the actual analysis. The inherent time lag makes these measurements unsuitable for process control, and the size and conditioning of the sample raise doubts about the similarity of the composition of the analyzed sample to that of the process stream. What is needed is an on-line analysis of the entire stream cross section, preferably by a non-invasive technique. We are evaluating neutron-capture gamma techniques for this application. Both neutrons and gamma rays are sufficiently penetrating that the sampled volume is comparable to the full section of pipe being irradiated, offering the possibility of non-invasive, continuous on-line instrumental monitoring of composition which is representative of the full process stream. Our studies and those of other groups have established the feasibility of using neutron-induced gamma spectrometry to obtain elemental abundances in coal. Several irradiation assemblies utilizing 252Cf neutron sources have been built and used with lithium-drifted germanium detectors and associated electronics. Samples of a variety of independently analyzed coals and simulated coals have been measured. The spectral responses from H, C, Fe, Si, S, Al, Cl, Ca, Ti, and N have been examined. The evidence indicates that quantitative determination of H, Fe, Si, S, Cl, Ca, and Ti will be possible, and that other constituents such as N, K, and Na may be quantitatively determined with further refinement of the technique. We are also working with fast neutrons from a pulsed 14 MeV neutron generator in order to obtain reliable analyses of the carbon and oxygen content of the coal process stream, as well as analyses for additional elements

  2. Stearic acid coating on circulating fluidized bed combustion fly ashes and its effect on the mechanical performance of polymer composites

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Nina [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Zhang, Ping, E-mail: pingzhang@swust.edu.cn [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Song, Lixian; Kang, Ming; Lu, Zhongyuan [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Zheng, Rong [Sichuan Jinhe Group Co., Ltd., Mianyang 621010 (China)

    2013-08-15

    The aim of this work was to test circulating fluidized bed combustion fly ashes (CFAs) for its potential to be utilized in polymer composites manufacturing to improve its toughness. CFAs was coated by stearic acid and used in the composite of polypropylene/ethylene vinyl acetate/high density polyethylene (PP/EVA/HDPE) by molding process method. The resulting coated and uncoated CFAs were fully characterized by particle size analyzer, contact angles, powder X-ray diffraction (XRD), thermogravimetric analysis/differential thermal analysis (TGA/DTA), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The stearic acid coated onto the surface of CFAs particles in the physical and chemical ways, and the total clad ratio reached 2.05% by measuring TGA/DTA curve. The percentage of CFAs particles focused to a narrow range 2–4 μm and the median mean size was 3.2 μm more than uncoated CFAs. The properties of hydrophobic and dispersive of CFAs particles improved and original activity was reserved after stearic acid coating. The stearic acid was verified as a coupling agent by how much effect it had on the mechanical properties. It showed the elongation at break of PP/EVA/HDPE reinforced with 15 wt% coated CFAs (c-CFAs) was 80.20% and higher than that of the uncoated. The stearic acid treatment of CFAs is a very promising approach to improve the mechanical strength due to the incorporation of stearic acid on the CFAs surface, and hence, further enhances the potential for recycling CFAs as a suitable filler material in polymer composites.

  3. Formation of chlorinated organic compounds in fluidized bed combustion of recycled fuels; Kloorattujen orgaanisten yhdisteiden muodostuminen kierraetyspolttoaineiden leijukerrospoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Vesterinen, R.; Kallio, M.; Kirjalainen, T.; Kolsi, A.; Merta, M. [VTT Energy, Jyvaeskylae (Finland)

    1997-10-01

    Four tests of co-combustion of recycled fuels (REP) with peat and coal in the 15 kW fluidized bed reactor were performed. The recycled fuel was so-called dry fraction in four vessels sampling at Keltinmaeki. In three tests a part of peat energy was replaced with coal. The mixtures were prepared so that in all mixtures 25 % of energy was recycled fuel and 75 % was either peat or the mixture of peat and coal. The concentrations of polyaromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and chlorophenols decreased with increasing part of coal due to the increasing sulphur/chlorine ratio. Principal Component Analysis (PCA) and Partial Least Square regression analysis (PLS) showed that the chlorine, copper and sulphur contents of the fuel effected most on the concentrations of chlorophenols, chlorobenzenes, PCBs and PCDDs/PCDFs. Other variables influencing on a model were the lead concentration and the sulphur/chlorine ratio in fuel and the hydrogen chloride concentration of the flue gas. The concentrations of chlorophenols and chlorobenzenes were also significant for PCDD/PCDF concentrations in flue gas. The sulphur, chlorine, copper and chromium contents in fly ash and the temperature of the reactor influenced on the chlorophenol, chlorobenzene, PCB and PCDD/PCDF concentrations in fly ash. The chlorophenol and chlorobenzene contents in fly ash, the sulphur/chlorine ratio and the lead content in fuel, the sulphur dioxide, hydrogen chloride and carbon monoxide concentrations in flue gas had also influence on PCDD/PCDF concentrations in fly ash

  4. Stearic acid coating on circulating fluidized bed combustion fly ashes and its effect on the mechanical performance of polymer composites

    International Nuclear Information System (INIS)

    The aim of this work was to test circulating fluidized bed combustion fly ashes (CFAs) for its potential to be utilized in polymer composites manufacturing to improve its toughness. CFAs was coated by stearic acid and used in the composite of polypropylene/ethylene vinyl acetate/high density polyethylene (PP/EVA/HDPE) by molding process method. The resulting coated and uncoated CFAs were fully characterized by particle size analyzer, contact angles, powder X-ray diffraction (XRD), thermogravimetric analysis/differential thermal analysis (TGA/DTA), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The stearic acid coated onto the surface of CFAs particles in the physical and chemical ways, and the total clad ratio reached 2.05% by measuring TGA/DTA curve. The percentage of CFAs particles focused to a narrow range 2–4 μm and the median mean size was 3.2 μm more than uncoated CFAs. The properties of hydrophobic and dispersive of CFAs particles improved and original activity was reserved after stearic acid coating. The stearic acid was verified as a coupling agent by how much effect it had on the mechanical properties. It showed the elongation at break of PP/EVA/HDPE reinforced with 15 wt% coated CFAs (c-CFAs) was 80.20% and higher than that of the uncoated. The stearic acid treatment of CFAs is a very promising approach to improve the mechanical strength due to the incorporation of stearic acid on the CFAs surface, and hence, further enhances the potential for recycling CFAs as a suitable filler material in polymer composites.

  5. Development and application of a high-temperature sampling probe for burning chamber conditions in fluidized-bed combustion; Korkean laempoetilan naeytteenottosondin kehittaeminen ja soveltaminen leijukerrospolton tulipesaeolosuhteisiin

    Energy Technology Data Exchange (ETDEWEB)

    Larjava, K.; Paerkkae, M. [VTT Chemical Technology, Espoo (Finland); Linna, V. [VTT Energy, Jyvaeskylae (Finland). Environmental Technology

    1997-10-01

    Determination of heavy and alkali metals and other condensing compounds (e.g. chlorides) in combustion chamber conditions is limited by the poor suitability of traditional methods for sampling at high temperatures. IFRF has developed a high-temperature sampling probe for sampling HCN and NH{sub 3}, which has been tested for sampling of NH{sub 3} by Chalmers University of Technology in Sweden. VTT Chemical Technology and Chalmers University of Technology have in their preliminary experiments determined contents of vaporous heavy metals in the combustion chamber of a 12 MW circulating fluidized-bed boiler using this probe. According to the results, the modified probe is suitable for heavy metal determination in combustion chamber. Based on this series of experiments, modification of the probe has been started on the own financing of VTT Chemical Technology and a field measurement was performed in November 1994 to test the present version of the probe. Based on the results of that measurement, the probe has been modified further on as a part of this LIEKKI 2 project. Similar kind of a principle has been applied in the probe which has been developed by VTT Energy during 1994. The probe is built for determination of gas composition of fluidized bed in full-scale boilers. The purpose of this project is to develop and test a sampling probe for fluidized bed combustion. The main advantage of the probe is that condensation losses in sampling due to high temperature gradients can be avoided. Thus, the probe is very suitable for sampling vaporous heavy and alkali metals and other condensing species as well as burning gases and alternatively also solids at high temperatures

  6. Some test results of Maritsa East lignite mine- first large-scale circulating fluidized bed combustion - as the basis of the restructuring process

    International Nuclear Information System (INIS)

    One of the consequences of energy sector restructuring in the transition countries is an increasing number of shareholders interested in profitable power plants. The traditional energy sector structural and operating paradigms evolved together, in symbiosis. power generation from coal is still negatively associated with severe pollutant emissions like NOx, SO2. In Bulgaria particularly power generation relies on the Maritsa-East coal mine as the single national energy source. The coal has an extremely poor quality (high sulphur, ash and water content) yielding high emissions of pollutants during combustion. The first large-scale test of circulating fluidized bed combustion (CFB) of Maritsa-East coal mine took place in 1998. For this purpose, test facilities in Austria Energy and Environment (AEE) and RWE's power plant Niederraussen were used. This analysis is very important for the management of National Energy Company as regards restructuring and privatisation. (author)

  7. Effects of blending hydrothermally treated municipal solid waste with coal on co-combustion characteristics in a lab-scale fluidized bed reactor

    International Nuclear Information System (INIS)

    Highlights: ► Proper MSW disposal and mitigation of coal consumption can be achieved through co-combustion. ► The hydrothermal treatment (HT) was utilized to convert raw MSW to solid fuel. ► A coal-fired combustor was studied aiming at less major modifying when used for co-combustion. ► Synergic reactions between coal and MSW were identified in terms of emissions. ► It is possible to increase the blending ratio of HT treated MSW up to 30 %. -- Abstract: Experiments on co-combustion of municipal solid waste (MSW) and coal were conducted in a bubbling fluidized bed (BFB). The MSW sample was pretreated through hydrothermal treatment (HT) for obtaining uniform characteristics. MSW blending ratios as 10%, 20%, 30% and 50% were selected and tested at 700, 800, 900 °C to verify to which extent coal can be substituted with HT MSW in terms of emissions and unburnt carbon (UC) in fly ash (FA). The results obtained in this study showed that the lowest CO and NO emissions were found at 20% and 30% HT MSW blending respectively. Moreover, the SO2 emissions decreased with the HT MSW addition and the HCl emissions were below 5 ppm. Furthermore, the UC contents decreased at the mixing ratio below 30% at low temperature. Positive synergistic relationships were identified and it is possible to accept 30% MSW combustion in a coal-fired BFB reactor.

  8. Cofiring of difficult fuels: The effect of Ca-based sorbents on the gas chemistry in fluidised bed combustion; Kalsiumpohjaisten lisaeaineiden vaikutus leijukerrospolton kaasukemiaan vaikeiden polttoaineiden sekapoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Aeijaelae, M.; Partanen, J.; Fabritius, M.; Elo, T.; Virta, A.K. [Imatran Voima Oy, Vantaa (Finland)

    1997-10-01

    The objective of this project is to establish the effects of Ca-based sorbents on sulphur, halogen and alkaline chemistry in fluidised bed combustion of difficult fuels, and to find out any restrictions on the use of these sorbents. The aim is to acquire sufficient knowledge to ensure the operational reliability of power plants and to minimise the emissions and costs of flue gas cleaning. The results enable the owner to anticipate necessary changes associated with slagging, fouling and emission control in the existing power plants, when there are plans to increase the range of fuels used. (orig.)

  9. Effects of operating conditions and fuel properties on emission performance and combustion efficiency of a swirling fluidized-bed combustor fired with a biomass fuel

    International Nuclear Information System (INIS)

    This work reports an experimental study on firing 80 kg/h rice husk in a swirling fluidized-bed combustor (SFBC) using an annular air distributor as the swirl generator. Two NOx emission control techniques were investigated in this work: (1) air staging of the combustion process, and (2) firing rice husk as moisturized fuel. In the first test series for the air-staged combustion, CO, NO and CxHy emissions and combustion efficiency were determined for burning 'as-received' rice husk at fixed excess air of 40%, while secondary-to-primary air ratio (SA/PA) was ranged from 0.26 to 0.75. The effects of SA/PA on CO and NO emissions from the combustor were found to be quite weak, whereas CxHy emissions exhibited an apparent influence of air staging. In the second test series, rice husks with the fuel-moisture content of 8.4% to 35% were fired at excess air varied from 20% to 80%, while the flow rate of secondary air was fixed. Radial and axial temperature and gas concentration (O2, CO, NO) profiles in the reactor, as well as CO and NO emissions, are discussed for the selected operating conditions. The temperature and gas concentration profiles for variable fuel quality exhibited significant effects of both fuel-moisture and excess air. As revealed by experimental results, the emission of NO from this SFBC can be substantially reduced through moisturizing rice husk, while CO is effectively mitigated by injection of secondary air into the bed splash zone, resulting in a rather low emission of CO and high (over 99%) combustion efficiency of the combustor for the ranges of operating conditions and fuel properties.

  10. Proceedings of the 2006 Combustion Institute Canadian Section spring technical meeting

    International Nuclear Information System (INIS)

    This conference provided a networking opportunity for academic, government and industrial combustion researchers from across Canada. All aspects of combustion were discussed, particularly those related to new engine technologies that reduce exhaust gas emissions while maintaining performance. Major engine operating and fuelling control parameters that improve combustion efficiency were identified. The conference was divided into several sessions dealing with combustion emissions and pollutants such as soot and particulates; alternative fuels including biofuels and fuel cells; chemical kinetics; droplet and spray combustion; combustion synthesis of materials; detonations, explosions, fires, flammability, flares and incineration; environmental issues and hazard analysis; and, numerical modeling and simulation. The conference featured 61 presentations, of which 39 have been catalogued separately for inclusion in this database

  11. Processes and parameters involved in modeling radionuclide transport from bedded salt repositories. Final report. Technical memorandum

    International Nuclear Information System (INIS)

    The parameters necessary to model radionuclide transport in salt beds are identified and described. A proposed plan for disposal of the radioactive wastes generated by nuclear power plants is to store waste canisters in repository sites contained in stable salt formations approximately 600 meters below the ground surface. Among the principal radioactive wastes contained in these canisters will be radioactive isotopes of neptunium, americium, uranium, and plutonium along with many highly radioactive fission products. A concern with this form of waste disposal is the possibility of ground-water flow occurring in the salt beds and endangering water supplies and the public health. Specifically, the research investigated the processes involved in the movement of radioactive wastes from the repository site by groundwater flow. Since the radioactive waste canisters also generate heat, temperature is an important factor. Among the processes affecting movement of radioactive wastes from a repository site in a salt bed are thermal conduction, groundwater movement, ion exchange, radioactive decay, dissolution and precipitation of salt, dispersion and diffusion, adsorption, and thermomigration. In addition, structural changes in the salt beds as a result of temperature changes are important. Based upon the half-lives of the radioactive wastes, he period of concern is on the order of a million years. As a result, major geologic phenomena that could affect both the salt bed and groundwater flow in the salt beds was considered. These phenomena include items such as volcanism, faulting, erosion, glaciation, and the impact of meteorites. CDM reviewed all of the critical processes involved in regional groundwater movement of radioactive wastes and identified and described the parameters that must be included to mathematically model their behavior. In addition, CDM briefly reviewed available echniques to measure these parameters

  12. Semi-Technical Cryogenic Molecular Sieve Bed for the Tritium Extraction System of the Test Blanket Module for ITER

    International Nuclear Information System (INIS)

    The tritium extraction from the ITER Helium Cooled Pebble Bed (HCPB) Test Blanket Module purge gas is proposed to be performed in a two steps process: trapping water in a cryogenic Cold Trap, and adsorption of hydrogen isotopes (H2, HT, T2) as well as impurities (N2, O2) in a Cryogenic Molecular Sieve Bed (CMSB) at 77K. A CMSB in a semi-technical scale (one-sixth of the flow rate of the ITER-HCPB) was design and constructed at the Forschungszentrum Karlsruhe. The full capacity of CMSB filled with 20 kg of MS-5A was calculated based on adsorption isotherm data to be 9.4 mol of H2 at partial pressure 120 Pa. The breakthrough tests at flow rates up to 2 Nm3h-1 of He with 110 Pa of H2 conformed with good agreement the adsorption capacity of the CMSB. The mass-transfer zone was found to be relatively narrow (12.5 % of the MS Bed height) allowing to scale up the CMSB to ITER flow rates

  13. Quantitative evaluation of minerals in fly ashes of biomass, coal and biomass-coal mixture derived from circulating fluidised bed combustion technology

    International Nuclear Information System (INIS)

    The chemical and mineralogical composition of fly ash samples collected from laboratory scale circulating fluidised bed (CFB) combustion facility have been investigated. Three fly ashes were collected from the second cyclone in a 50 kW laboratory scale boiler, after the combustion of different solid fuels. Characterisation of the fly ash samples was conducted by means of X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Quantitative analysis of the crystalline (mineral) and amorphous phases in each ash sample was carried out using the Rietveld-based Siroquant system, with an added spike of ZnO to evaluate the amorphous content. SiO2 is the dominant oxide in the fly ashes, with CaO, Al2O3 and Fe2O3 also present in significant proportions. XRD results show that all three fly ashes contain quartz, anhydrite, hematite, illite and amorphous phases. The minerals calcite, feldspar, lime and periclase are present in ashes derived from Polish coal and/or woodchips. Ash from FBC combustion of a Greek lignite contains abundant illite, whereas illite is present only in minor proportions in the other ash samples.

  14. Quantitative evaluation of minerals in fly ashes of biomass, coal and biomass-coal mixture derived from circulating fluidised bed combustion technology

    Energy Technology Data Exchange (ETDEWEB)

    Koukouzas, N.; Ward, C.R.; Papanikolaou, D.; Li, Z.S.; Ketikidis, C. [Institute of Solid Fuels Technology & Applications, Athens (Greece)

    2009-09-15

    The chemical and mineralogical composition of fly ash samples collected from laboratory scale circulating fluidised bed (CFB) combustion facility have been investigated. Three fly ashes were collected from the second cyclone in a 50 kW laboratory scale boiler, after the combustion of different solid fuels. Characterisation of the fly ash samples was conducted by means of X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Quantitative analysis of the crystalline (mineral) and amorphous phases in each ash sample was carried out using the Rietveld-based Siroquant system, with an added spike of ZnO to evaluate the amorphous content. SiO{sub 2} is the dominant oxide in the fly ashes, with CaO, Al{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} also present in significant proportions. XRD results show that all three fly ashes contain quartz, anhydrite, hematite, illite and amorphous phases. The minerals calcite, feldspar, lime and periclase are present in ashes derived from Polish coal and/or woodchips. Ash from FBC combustion of a Greek lignite contains abundant illite, whereas illite is present only in minor proportions in the other ash samples.

  15. Quantitative evaluation of minerals in fly ashes of biomass, coal and biomass-coal mixture derived from circulating fluidised bed combustion technology

    Energy Technology Data Exchange (ETDEWEB)

    Koukouzas, Nikolaos, E-mail: koukouzas@certh.gr [Centre for Research and Technology Hellas, Institute for Solid Fuels Technology and Applications, Mesogeion Ave. 357-359, 15231 Halandri, Athens (Greece); Ward, Colin R. [School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052 (Australia); Papanikolaou, Dimitra [Centre for Research and Technology Hellas, Institute for Solid Fuels Technology and Applications, Mesogeion Ave. 357-359, 15231 Halandri, Athens (Greece); Li, Zhongsheng [School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052 (Australia); Ketikidis, Chrisovalantis [Centre for Research and Technology Hellas, Institute for Solid Fuels Technology and Applications, Mesogeion Ave. 357-359, 15231 Halandri, Athens (Greece)

    2009-09-30

    The chemical and mineralogical composition of fly ash samples collected from laboratory scale circulating fluidised bed (CFB) combustion facility have been investigated. Three fly ashes were collected from the second cyclone in a 50 kW laboratory scale boiler, after the combustion of different solid fuels. Characterisation of the fly ash samples was conducted by means of X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Quantitative analysis of the crystalline (mineral) and amorphous phases in each ash sample was carried out using the Rietveld-based Siroquant system, with an added spike of ZnO to evaluate the amorphous content. SiO{sub 2} is the dominant oxide in the fly ashes, with CaO, Al{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} also present in significant proportions. XRD results show that all three fly ashes contain quartz, anhydrite, hematite, illite and amorphous phases. The minerals calcite, feldspar, lime and periclase are present in ashes derived from Polish coal and/or woodchips. Ash from FBC combustion of a Greek lignite contains abundant illite, whereas illite is present only in minor proportions in the other ash samples.

  16. Three-zonal engineering method of heat calculation for fluidized bed furnaces based on data on commercial investigations of heat generation distribution during biomass combustion

    Science.gov (United States)

    Litun, D. S.; Ryabov, G. A.

    2016-02-01

    A three-zonal method of heat calculation of furnaces for combustion of biomass and low-caloric fuel in the fluidized bed is described. The method is based on equations of thermal and material balances that account for heat generation by fuel in the zone, heat-and-mass transfer heat exchange between the furnace media and surfaces that bound the zone, and heat-and-mass transfer between furnace zones. The calculation procedure for heat generation by fuel in the fluidized bed (FB) using the heat generation portion by the fuel is proposed. Based on commercial investigations, the main factors that affect the average temperature in the FB and the portion of fuel heat that is released in the FB are determined. Results of commercial investigations showed that the airflow coefficient in the FB should be recognized as the main operation parameter that affects the average temperature in the FB and, consequently, heat generation in the FB. The gas flow rate in the FB can be marked out as the second factor that affects the consumption degree of oxidizer supplied in the FB. Commercial investigations revealed that mixing is affected by the gas flow rate in the FB and the bed material particle size, which may be changed during the boiler operation because of the agglomeration of particles of sand and ash. The calculation processing of commercial investigations on a KM-75-40M boiler of a CHP-3 of an Arkhangelsk Pulp and Paper Mill (APPM), which was carried out using the inverse problem procedure by means of a developed computer program, determined the range of the fuel heat release share in the FB, which was 0.26-0.45 at an excess air factor of 0.59-0.93 in the bed, and the heat release share in the maximum temperature zone in the total heat release in the superbed space. The heat release share in the bed is determined as an approximating function of the excess air factor in the bed and the fluidization number. The research results can be used during designing boilers with the

  17. Thermoelastic analyses of spent fuel repositories in bedded and dome salt. Technical memorandum report RSI-0054

    Energy Technology Data Exchange (ETDEWEB)

    Callahan, G.D.; Ratigan, J.L.

    1978-10-13

    Global thermoelastic analyses of bedded and dome salt models showed a slight preference for the bedded salt model through the range of thermal loading conditions. Spent fuel thermal loadings should be less than 75 kW/acre of the repository pending more accurate material modeling. One should first limit the study to one or two spent fuel thermal loading (i.e. 75 kW/acre and/or 50 kW/acre) analyses up to a maximum time of approximately 2000 years. Parametric thermoelastic type analyses could then be readily obtained to determine the influence of the thermomechanical properties. Recommendations for further study include parametric analyses, plasticity analyses, consideration of the material interfaces as joints, and possibly consideration of a global joint pattern (i.e. jointed at the same orientation everywhere) for the non-salt materials. Subsequently, the viscoelastic analyses could be performed.

  18. Improved combustion performance of waste-fired FB-boilers -The influence of the dynamics of the bed on the air-/fuel interaction; Foerbaettrad foerbraenningsprestanda vid avfallsfoerbraenning i FB-pannor -Baeddynamikens inverkan paa luft-/braensleomblandningen

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Johanna (Hoegskolan i Boraas (Sweden)); Pallares, David; Thunman, Henrik; Johnsson, Filip (Chalmers (Sweden)); Andersson, Bengt-Aake (E.on/Hoegskolan i Boraas (Sweden)); Victoren, Anders (Metso Power AB (Sweden)); Johansson, Andreas (SP, Boraas (Sweden))

    2010-07-01

    One of the key benefits of fluidized bed combustion is that the bed - through mixing of fuel and air and accumulated heat - facilitates combustion at low stoichiometry and with low emissions. Even so, it is not unusual that waste-fired FB-boilers are operated at 6-8% oxygen that corresponds to 30-40% higher flows of gas than theoretically needed. In addition to that and in comparison to grate furnaces, FB-boiler can cause high pressure drop losses because of the fluidization of the bottom bed, which in turn are associated with high costs for power (fans). This work aims therefore at increasing the knowledge for how the dynamics of the bed affects the air and fuel mixture. Methods to explain and characterize the phenomenon have been derived within this work showing: - Distribution of air in a bed for various cases and the influence of pressure drop, bed height and fluidization velocity - A semi-empiric method to calculate an even bubble distribution - The relation between fluidization and fuel distribution for various fluidization flows and fuels - Dispersion rates for various fuels - Volatilization rates for waste in relation to biomass The result can be useful when optimizing units, for instance through finding as low pressure drops as possible with an even bubble distribution, low risk for sintering and unwanted emissions. The work has thereby reached its ultimate goal of increasing the generic knowledge about waste combustion in FB-boiler

  19. Second-generation pressurized fluidized-bed combustion plant: Conceptual design and optimization of a second-generation PFB combustion plant. Phase 2, Annual report, October 1991--September 1992

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, A.; Domeracki, W.; Newby, R.; Rehmat, A.; Horazak, D.

    1992-10-01

    After many years of experimental testing and development work, coal-fired pressurized fluidized bed (PFB) combustion combined-cycle power plants are moving toward reality. Under the US Department of Energy`s Clean Coal Technology Program, a 70-MWe PFB combustion retrofit, utilizing a 1525{degrees}F gas turbine inlet temperature, has been built and operated as a demonstration plant at the American Electric Power Company`s Tidd Plant in Brilliant, Ohio. As PFB combustion technology moves closer and closer to commercialization, interest is turning toward the development of an even more efficient and more cost-effective PFB combustion plant. The targeted goals of this ``second-generation`` plant are a 45-percent efficiency and a cost of electricity (COE) that is at least 20 percent lower than the COE of a conventional pulverized-coal (PC)-fired plant with stack gas scrubbing. In addition, plant emissions should be within New Source Performance Standards (NSPS) and the plant should have high availability, be able to burn different ranks of coal, and incorporate modular construction technologies. In response to this need, a team of companies led by Foster Wheeler Development Corporation (FWDC). The key components in the proposed second-generation plant are the carbonizer, CPFBC, ceramic cross-flow filter, and topping combustor. Unfortunately, none of these components has been operated at proposed plant operating conditions, and experimental tests must be conducted to explore/determine their performance throughout the proposed plant operating envelope. The major thrust of Phase 2 is to design, construct, test, and evaluate the performance of the key components of the proposed plant.

  20. Standard technical specifications: Combustion engineering plants. Volume 3, Revision 1: Bases (Sections 3.4--3.9)

    International Nuclear Information System (INIS)

    This report documents the results of the combined effort of the NRC and the industry to produce improved Standard Technical Specifications (STS), Revision 1 for Combustion Engineering Plants. The changes reflected in Revision 1 resulted from the experience gained from license amendment applications to convert to these improved STS or to adopt partial improvements to existing technical specifications. This NUREG is the result of extensive public technical meetings and discussions between the Nuclear Regulatory Commission (NRC) staff and various nuclear power plant licensees, Nuclear Steam Supply System (NSSS) Owners Groups, NSSS vendors, and the Nuclear Energy Institute (NEI). The improved STS were developed based on the criteria in the Final Commission Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors, dated July 22, 1993. The improved STS will be used as the basis for individual nuclear power plant licensees to develop improved plant-specific technical specifications. This report contains three volumes. Volume 1 contains the Specifications for all chapters and sections of the improved STS. Volume 2 contains the Bases for Chapters 2.0 and 3.0, and Sections 3.1--3.3 of the improved STS Volume 3 contains the Bases for Sections 3.4--3.9 of the improved STS

  1. Nucla circulating atmospheric fluidized bed demonstration project. Quarterly technical progress report, October--December 1990

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-31

    During the fourth quarter of 1990, steady-state performance testing at the Nucla Circulating Fluidized Bed (CFB) resumed under sponsorship of the US Department of Energy. Co-sponsorship of the Demonstration Test Program by the Electric Power Research Institute (EPRI) was completed on June 15, 1990. From October through December, 1990, Colorado-Ute Electric Association (CUEA) completed a total of 23 steady-state performance tests, 4 dynamic tests, and set operating records during November and December as the result of improved unit operating reliability. Highlight events and achievements during this period of operation are presented.

  2. Modelling of a fluidized bed carbonator reactor to capture CO{sub 2} from a combustion flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, M.; Rodriguez, N.; Grasa, G.; Abanades, J.C. [CSIC, Oviedo (Spain)

    2009-03-15

    In recent years several processes incorporating a carbonation-calcination loop in an interconnected fluidized bed reactor have been proposed as a way to capture CO{sub 2} from flue gases. This paper is a first approximation to the modelling of a fluidized bed carbonator reactor. In this reactor the flue gas comes into contact with an active bed composed of particles with very different activities, depending on their residence time in the bed and in the carbonation-calcination loop. The model combines the residence time distribution functions with existing knowledge about sorbent deactivation rates and sorbent reactivity. The fluid dynamics of the solids (CSTR) and gases (PF) in the carbonator are based on simple assumptions. The carbonation rates are modelled defining a characteristic time for the transition between a fast reaction regime to a regime with a zero reaction rate. On the basis of these assumptions the model is able to predict the CO{sub 2} capture efficiency for the flue gas depending on the operating and design conditions. Operating windows with high capture efficiencies are discussed, as well as those conditions where only modest capture efficiencies are possible.

  3. Effect of Air Staging and Limestone Addition on Emissions of SO2 and NOx in Circulating Fluidized Bed Combustion

    International Nuclear Information System (INIS)

    The object of this work is to provide more detailed knowledge about the effect of air staging and its relation to the addition of limestone on the emissions of SO2 and NOx from fluidized bed combustors. This knowledge can be used in models of (circulating) fluidized bed combustors for the development of control strategies. The effect of air staging can be divided in to two parts: (1) The effect on the hydrodynamics in a circulating fluidized bed; and (2) The effect on the local gas concentrations, especially the O2 concentration. In this work the influence of both these effects on the SO2 and NOx emissions from (circulating) fluidized bed combustors with air staging was investigated. In Chapter 2 the influence air staging and the use of secondary air injection on the hydrodynamics in a circulating fluidized beds is described. In the first section of that chapter a literature review is given. In the second section an experimental study is presented on the solids distribution and circulation rate under different air staging conditions. Chapter 3 presents fixed bed studies on the SO2 retention by limestone. To understand the influence of air staging, the effect of oxygen on the SO2 retention was investigated. The kinetics were determined and the so-called grain model was used to model the SO2 retention. In Chapter 4 an extensive study was made on the kinetics of the formation of NO from NH3 and the influence of oxygen on these reactions. The kinetics and the activation energies of both homogenous reactions and reactions catalyzed by limestone were determined and the effect of oxygen was investigated. Chapter 5 presents an experimental study and modeling work on the effect of water and CO2 on the reactivity of limestone. It was found that the presence of water reduced the reactivity of limestone significantly. In Chapter 6 the oxidation of NH3 over partially sulphated limestone is studied. A model is developed that describes the NO formation and selectivity as a

  4. Performance prediction in advanced coal fired boilers - fluctuations in combustion systems - Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Malmgren, Alf; Nilsson, Torbjoern; Tao Lixin [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-04-01

    Turbulence, unstable flow conditions or resonance phenomena can all cause fluctuations in combustion systems. The molecules of gas and fuel particles travel trough a combustion system along a large number of trajectories causing a residence time distribution characteristic for each configuration. The result of the fluctuations and residence time distribution is that the temperature, chemical composition of the gas, etc. in one point varies with time and can also be described by a distribution curve. Computer codes for the calculation of the residence time distribution curves, the dampening of fluctuations in combustion systems and the combustion of coal particles in a combustion chamber has been developed. The codes can be used to calculate the distribution curves for residence time, temperature and gas composition in different positions. The calculations are verified against measurements of residence time distributions and fluctuations of gas temperature in a coal flame in the IFRF furnace no 1. Measurements and calculations show good agreement. The frequency where the amplitude of fluctuations is halved during the passage of the investigated flame is calculated to 0.047 Hz (a period of 21 seconds) which agree with observations. The rapid dampening of fluctuations in this type of systems will not allow them to survive long enough to travel through the flame.

  5. Viability study for application of combined reheater cycle (CRC) to fluidized bed combustion plants; Estudio de Viabilidad para la Aplicacion del Ciclo de Recalentamiento Combinado (CRC) a Plantas de Combustion de Lecho Fuido Atmosferico

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    Basically, the project try to analyze the application viability of a first reheating in steam cycles of little power plants, useful mainly for biomass and wastes, in our case with coal blends; and a second reheating of the steam in conventional and fluidized bed combustion plants. Using in both cases the thermic energy of the exhaust gases from one gas turbine. The advantages of the CRC cycle are: (1) Reduction of the moisture in the turbine, increasing the energy efficiency and blade protection. (2) To take advantage of the waste gas energy from the gas turbine in optimum way. (3) Great operation flexibility under good efficiency results. In general, the system can use the synergy between gas, coal and waste energies with the highest global efficiency. (Author)

  6. Preliminary assessment of the health and environmental impacts of fluidized-bed combustion of coal as applied to electrical utility systems

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-02-01

    The objective of this study was to assess the health and environmental impacts of fluidized-bed combustion of coal (FBC), specifically as applied to base-load generation of electrical energy by utilities. The public health impacts of Fluidized-Bed Combustion (FBC) plants are expected to be quite similar to those for Low Sulfur Coal (LSC) and Flue Gas Desulfurization (FGD) plants because all appear to be able to meet Federal emission standards; however, there are emissions not covered by standards. Hydrocarbon emissions are higher and trace element emissions are lower for FBC than for conventional technologies. For FBC, based on an analytical model and a single emission data point, the polycyclic organic material decreases the anticipated lifespan of the highly exposed public very slightly. Added health protection due to lower trace element emissions is not known. Although there is a large quantity of solid wastes from the generating plant, the environmental impact of the FBC technology due to solid residue appears lower than for FGD, where sludge management requires larger land areas and presents problems due to the environmentally noxious calcium sulfite in the waste. Fixing the sludge may become a requirement that increases the cost of wet-limestone FGD but makes that system more acceptable. The potential for aquatic or terrestrial impacts from hydrocarbon emissions is low. If application of AFBC technology increases the use of local high-sulfur coals to the detriment of western low-sulfur coal, a sociological benefit could accrue to the FBC (or FGD) technology, because impacts caused by western boom towns would decrease. The infrastructure of areas that mine high-sulfur coal in the Midwest are better equipped to handle increased mining than the West.

  7. Technical Challenges and Progress in Fluidized Bed Chemical Vapor Deposition of Polysilicon

    Institute of Scientific and Technical Information of China (English)

    李建隆; 陈光辉; 张攀; 王伟文; 段继海

    2011-01-01

    Various methods for production of polysilicon have been proposed for lowering the production cost andenergy consumption, and enhancing productivity, which are critical for industrial applications. The fluidized bed chemical vapor deposition (FBCVD) method is a most promising alternative to conventional ones, but the homogeneous reaction of silane in FBCVD results in unwanted formation of fines, which will affect the product qualityand output. There are some other problems, such as heating degeneration due to undesired polysilicon deposition on the walls of the reactor and the heater. This article mainly reviews the technological development on FBCVD of polycrystalline silicon and the research status for solving the above problems. It also identifies a number of challenges to tackle and principles should be followed in the design ofa FBCVD reactor.

  8. The structure of a combustion front propagating in a fixed bed of crushed oil shale : co-current configuration

    OpenAIRE

    Ferreira Martins, Marcio

    2008-01-01

    La propagation d'un front de combustion au sein d'un milieu poreux réactif met en œuvre des mécanismes thermiques, chimiques et de transfert, avec de forts couplages. Afin de caractériser la structure thermique et chimique du front, un dispositif expérimental finement instrumenté permettant la réalisation d'expériences de combustion co-courant 1D a été mis au point, puis validé avec un milieu poreux modèle : un mélange carbone/sable. Ce réacteur à lit fixe vertical est alimenté en air descend...

  9. Characterisation of polycyclic aromatic hydrocarbons in flue gas and residues of a full scale fluidized bed combustor combusting non-hazardous industrial waste.

    Science.gov (United States)

    Van Caneghem, J; Vandecasteele, C

    2014-11-01

    This paper studies the fate of PAHs in full scale incinerators by analysing the concentration of the 16 EPA-PAHs in both the input waste and all the outputs of a full scale Fluidized Bed Combustor (FBC). Of the analysed waste inputs i.e. Waste Water Treatment (WWT) sludge, Refuse Derived Fuel (RDF) and Automotive Shredder Residue (ASR), RDF and ASR were the main PAH sources, with phenanthrene, fluoranthene and pyrene being the most important PAHs. In the flue gas sampled at the stack, naphthalene was the only predominant PAH, indicating that the PAHs in FBC's combustion gas were newly formed and did not remain from the input waste. Of the other outputs, the boiler and fly ash contained no detectable levels of PAHs, whereas the flue gas cleaning residue contained only low concentrations of naphthalene, probably adsorbed from the flue gas. The PAH fingerprint of the bottom ash corresponded rather well to the PAH fingerprint of the RDF and ASR, indicating that the PAHs in this output, in contrast to the other outputs, were mainly remainders from the PAHs in the waste inputs. A PAH mass balance showed that the total PAH input/output ratio of the FBC ranged from about 100 to about 2600 depending on the waste input composition and the obtained combustion conditions. In all cases, the FBC was clearly a net PAH sink. PMID:25002370

  10. Comparisons of Fly Ash and Deposition Between Air and Oxy-Fuel Combustion in Bench-Scale Fluidized Bed with Limestone Addition

    Institute of Scientific and Technical Information of China (English)

    Zhimin Zheng; Hui Wang∗; Yongjun Guo; Li Yang; Shuai Guo; Shaohua Wu

    2015-01-01

    In Oxy⁃fuel circulating fluidized bed, the residual CaO particles may react with high concentration of CO2 in flue gas to form bonded deposit on heat transfer surfaces in backpass when limestone is used as a sorbent to capture SO2 .In this paper, experiments were designed on ash deposition in a bench⁃scale fluidized bed under oxy⁃fuel and air atmosphere. A novel ash deposit sampling probe was used to simulate the tubes of tail surfaces. The chemical composition of fly ash and ash deposit from both air⁃firing and oxy⁃fuel firing cases were analyzed by Inductively Coupled Plasma⁃Atomic Emission Spectrometry ( ICP⁃AES ) and Scanning Electron Microscopy ( SEM) , respectively. The degrees of carbonation reaction of ash deposits were measured by Thermo Gravimetric Analysis. The results showed that there are distinct differences in fly ash deposition rate between oxy⁃fuel and air firing cases, and oxy⁃fuel combustion with limestone addition can affect chemical composition of fly ash and ash deposit, especially for elements of Ca, Na, K, and S. However, the carbonation reaction degree of ash deposits is found weak, which is due to the relatively low CaO content in ash deposit or not long enough of the sampling time.

  11. Kinetics of gasification and combustion of residues, biomass and coal in a bubbling fluidized bed; Die Kinetik der Vergasung und Verbrennung unterschiedlicher Abfaelle, Biomassen und Kohlen in der blasenbildenden Wirbelschicht

    Energy Technology Data Exchange (ETDEWEB)

    Hamel, S.; Krumm, W. [Siegen Univ. (Gesamthochschule) (Germany). Lehrstuhl fuer Energie- und Umweltverfahrenstechnik

    1998-09-01

    The combustion and gasification characteristics of Rhenish brown coal, domestic waste, waste plastics, wood and sewage sludge were investigated in a bubbling atmospheric fluidized bed in the laboratory scale. The materials were pyrolyzed in the fluidized bed in a nitrogen atmosphere. The residual coke was combuted in the presence of oxygen with varying operating parameters or else gasified in the presence of carbon dioxide. The different materials were characterized by global combustion rates, and kinetic parameters were determined for residual coke combustion. (orig.) [Deutsch] Das Verbrennungs- und Vergasungsverhalten von Rheinischer Braunkohle, Hausmuell, Restkunststoff, Holz und Klaerschlamm wurde in einer blasenbildenden, atmosphaerischen Laborwirbelschicht untersucht. Die Einsatzstoffe wurden in der mit Stickstoff fluidisierten Wirbelschicht pyrolysiert. Der verbleibende Restkoks wurde anschliessend unter Variation der Betriebsparameter mit Sauerstoff verbrannt oder mit Kohlendioxid vergast. Die unterschiedlichen Einsatzstoffe wurden durch globale Vebrennungsraten charakterisiert. Fuer die Restkoksverbrennung wurden kinetische Parameter ermittelt. (orig.)

  12. Formation and destruction mechanisms of nitrogen oxides during coal combustion in circulating fluidized beds; Mecanismes de formation et de destruction des oxydes d`azote lors de la combustion du charbon en lit fluidise circulant

    Energy Technology Data Exchange (ETDEWEB)

    Borrel, G.; Lecuyer, I. [Universite du Haut-Rhin, 68 - Mulhouse (France)

    1997-01-01

    Formation and reduction of nitrogen oxides (NO and N{sub 2}O) during coal combustion in a circulating fluidized bed (CFBC) are very complicated and yet badly known. The aim of the present study was to better characterize these phenomena on a small-sized experimental unit (reactor diameter: 5 cm), with the possibility to re-inject the solids in the bottom of the furnace, as in a real industrial unit. This should allow then to develop a numerical set of chemical reactions involving the nitrogen oxides. The experimental results showed that coal ash plays a great role in reducing nitrogen oxides, the determining parameter being the quantity of unburnt carbon remaining in the ash. The study then detailed the interaction between nitrogen oxides and de-volatilized (char) according to the temperature, NO{sub x} concentration and the mass of solid. In the absence of oxygen small quantities of char can very significantly reduce NO as well as N{sub 2}O. It was possible to establish destruction kinetics on these particles, and orders of reaction could be determined versus the NO{sub x} concentration and the char particle mass (heterogeneous phase chemical reactions). Then, the coal pyrolysis study enabled to identify the products released during coal devolatilization and thermogravimetric analyses displayed several successive weight losses due CO, CO{sub 2} and CH{sub 4} releases, during a linear temperature increase. Lastly coal combustion was studied in the small pilot with variable experimental conditions. Using the previous experimental was studied in the small pilot with variable experimental conditions. Using the previous experimental results, a model was developed to calculate NO{sub x} concentrations during the coal combustion and validated. The NO and N{sub 2}O contents calculated are thoroughly correlated with the experimental data whatever the injection carbon/oxygen ratio is. (author) 96 refs.

  13. CRITERIA POLLUTANT EMISSIONS FROM INTERNAL COMBUSTION ENGINES IN THE NATURAL GAS INDUSTRY VOLUME 1. TECHNICAL REPORT

    Science.gov (United States)

    The report summarizes emission factors for criteria pollutants (NOx, CO, CH4, C2H6, THC, NMHC, and NMEHC) from stationary internal combustion engines and gas turbines used in the natural gas industry. The emission factors were calculated from test results from five test campaigns...

  14. Assessment of an atmospheric fluidized-bed coal-combustion gas-turbine cogeneration system for industrial application

    Energy Technology Data Exchange (ETDEWEB)

    Graves, R. L.; Holcomb, R. S.; Tallackson, J. R.

    1979-10-01

    This study was initiated to provide information on the future potential industrial market for a cogeneration system consisting of a fluidized-bed coal combustor coupled to a gas-turbine (Brayton cycle) power system that uses air as the working fluid. In assessing the potential applications for the system, the process heat energy consumption by industry is identified, with special detail included on the six most energy-intensive industries. The potential impact on the nation's oil and natural gas consumption that would result from wide-spread utilization of coal for process heat is also estimated. The fraction of industrial process heat that the system could feasibly satisfy from a thermodynamic viewpoint is estimated, and the performance (potential fuel efficiency and heat/power ratio) of the atmospheric fluidized-bed gas-turbine system is calculated. Also treated are several specific case studies of industries in which the system could be incorporated. Major parameters are specified, and flow sheets are derived for systems that would satisfy the heat and power requirements of the process or industry. The overall fuel utilization efficiency, thermal power rating, and potential number of installations are specified for these case studies. The findings of the study indicate that there is a sizable potential market for the system, with over 1000 possible installations disclosed after reviewing only 8 specific industries from 6 major Standard Industrial Classification (SIC) groups. The potential displacement of oil and gas by coal in process heating is shown to be about 1.60 m/sup 3//sec (870,000 bbl/d) of oil and 4590 m/sup 3//sec (14.0 billion ft/sup 3//d) of natural gas for all industries combined. Continued development of the fluidized-bed coal combustor and power system is recommended so that this potential may be at least partially realized.

  15. Development of Methane and Nitrous Oxide Emission Factors for the Biomass Fired Circulating Fluidized Bed Combustion Power Plant

    OpenAIRE

    Chang-Sang Cho; Jae-Hwan Sa; Ki-Kyo Lim; Tae-Mi Youk; Seung-Jin Kim; Seul-Ki Lee; Eui-Chan Jeon

    2012-01-01

    This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB) boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH4), Nitrous oxide (N2O). The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF), RDF and Refused Plastic Fuel (RPF) of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH4 and N2O were me...

  16. Pyrite thermochemistry, ash agglomeration, and char fragmentation during pulverized coal combustion. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Akan-Etuk, A.; Diaz, R.; Niksa, S.

    1991-10-01

    The objective of the present work is to introduce an experimental program that will eventually lead to time-resolved iron ash composition over the technological operating domain. The preceding literature survey suggests two important stipulations on any such experimental program. The first stipulation is that good control must be established over the operating conditions, to accurately quantify their effects. The other is that data must be obtained rapidly, to thoroughly cover the important operating domain. This work presents a series of studies that has characterized the desulfurization of pyrite during the early stages of combustion. An experimental system was established and used to monitor the effects of oxygen, temperature, and residence time on the evolution of condensed phase products of the combustion of pure pyrite. (VC)

  17. Technical-economic evaluation of O2/CO2 recycle combustion power plant based on life-cycle

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this study, a detailed technical-economic analysis on a O2/CO2 recycle combustion power plant (Oxy-combustion plant) retrofitted from the existing coal-fired plant (with a capacity of 2×300 MW) in China was carried out by using life cycle assessment (LCA) and life cycle cost (LCC) method. The CO2 emissions, investment cost, cost of electricity and CO2 avoidance cost within the life cycle were calculated respectively. The results showed that the CO2 emission avoidance rate of retrofitted Oxy-combustion plant in the life cycle was about 77.09% without taking account of the CO2 compression; the annual cost increased by 5.9% approximately, the net power decreased by 21.33%, the cost of electricity increased by 34.77%, and the CO2 avoidance cost was about 28.93 USD/t. Considering the compression process of CO2, the avoidance rate of CO2 emission was about 73.35% or so; the annual cost increased by 9.35% approximately, the net power decreased by about 26.70%, the cost of electricity increased by 49.13%, and the CO2 avoidance cost was about 45.46 USD/t. The carbon tax (the CO2 tax) should be more than about 24 USD/t and 34 USD/t under the condition of considering CO2 compression or not, respectively, which is beneficial to promote transformation of existing coal-fired plant for reducing the CO2 emissions.

  18. A Novel High-Heat Transfer Low-NO{sub x} Natural Gas Combustion System. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Abbasi, H.

    2004-01-01

    technical and economic analyses, energy savings and waste reduction predictions, evaluation of environmental effects, and outline issues concerning manufacturing, marketing, and financing. Combustion Tec, Owens Corning, and GTI will all take active roles in defining this Plan. During Phase I, the first three objectives were addressed and completed along with the design component of the fourth objective. In Phase II, the fabrication component of the fourth objective was completed along with objectives five and six. Results of the Phase I work were reported in the Phase I Final Report and are summarized in this Final Technical Report. Work for Phase II was divided in four specific Tasks. Results of the Phase II work were reported in the Phase II Final Report and are also summarized in this Final Technical Report. No Phase III Final Report was prepared, so this Final Technical Report presents the results of Phase III commercial demonstration efforts. A description of each Task in Phases I, II, and III is presented in this report.

  19. Organic emissions from co-combustion of RDF with wood chips and milled peat in a bubbling fluidized bed boiler

    International Nuclear Information System (INIS)

    Refuse derived fuel (RDF) has been burned with wood chips and milled peat in a 4 MW bubbling fluidized bed boiler. Emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in flue gases expressed as TCDD-equivalents were significantly below the emission limit 0.1 ng/m3n I-TEQ (11 % O2). Also the PCDD/F-concentrations of fly ashes separated by an electrostatic precipitator are significantly below the 1 ng/g I-TEQ limit for agricultural soil in Germany. The carbon monoxide content was rather high, but typical for many small district heating plants. The concentrations of other chlorinated aromatic compounds were also low, in some tests below the detection limit. The concentrations of polyaromatic hydrocarbons (PAH) were rather high. The leachable metal content of the fly ash generated were analyzed using U.S. EPA TCLP test (Toxicity Characteristic Leaching Procedure). All concentrations fell below boundary levels. (author)

  20. Effect of hydrogen combustion reaction on the dehydrogenation of ethane in a fixed-bed catalytic membrane reactor

    Institute of Scientific and Technical Information of China (English)

    Masoud Hasany; Mohammad Malakootikhah; Vahid Rahmanian; Soheila Yaghmaei

    2015-01-01

    A two-dimensional non-isothermal mathematical model has been developed for the ethane dehydrogenation reaction in a fixed-bed catalytic membrane reactor. Since ethane dehydrogenation is an equilibrium reaction, removal of produced hydrogen by the membrane shifts the thermodynamic equilibrium to ethylene production. For further displacement of the dehydrogenation reaction, oxidative dehydrogenation method has been used. Since ethane dehydrogenation is an endothermic reaction, the energy produced by the oxidative dehydrogena-tion method is consumed by the dehydrogenation reaction. The results show that the oxidative dehydrogenation method generated a substantial improvement in the reactor performance in terms of high conversions and significant energy saving. It was also established that the sweep gas velocity in the shell side of the reactor is one of the most important factors in the effectiveness of the reactor.

  1. Influence of shape and size on the combustion time of solid waste in a fluidized bed furnace; Ryudosoro niokeru kokeihaikibutsu no nenshojikan ni oyobosu keijo to ookisa no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Kita, Teruyuk; Sugiyama, Hideko; Kamiya, Hidehiro; Horio, Masayuki [Tokyo Unversity of Agriculture and Technology, Tokyo (Japan)

    1999-02-05

    The combustion time of volatile matters and fixed carbon matters in a model waste having various shapes, sizes and materials in a fluidized bed furnace was theoretically and experimentally examined. Concerning the combustion of volatile matters, an estimation model of volatile matter combustion time was developed for the cases when a fixed carbon layer was formed or not formed. The estimation values of combustion time almost agreed with the experimental results of a model waste combustion having various shapes and sizes when the Carman shape coefficient {phi}{sub s0} was in the range of 0.3 to 0.9. In the case of the formation of a fixed carbon layer, combustion time of volatile matter was estimated by using a numerical analysis method for the moving boundary problem, and its results were confirmed to agree with the un-reacting karyotype heat transfer model solution in assumption of quasistationary heat transfer and experimental results. According to these results, it could be proved that the combustible time of volatile matter in the case of formation of a fixed carbon layer could be simply estimated by the un-reacting karyotype heat transfer model. (translated by NEDO)

  2. Coal combustion under conditions of blast furnace injection; [Quarterly] technical report, September 1--November 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Crelling, J.C.

    1993-12-31

    A potentially new use for Illinois coal is its use as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. This study is unique in that it will be the first North American effort to directly determine the nature of the combustion of coal injected into a blast furnace. This proposal is a follow-up to one funded for the 1992--1993 period. It is intended to complete the study already underway with the Armco Inc. steel company and to initiate a new cooperative study along somewhat similar lines with the Inland Steel Company. The results of this study will lead to the development of a testing and evaluation protocol that will give a unique and much needed understanding of the behavior of coal in the injection process and prove the potential of Illinois coals f or such use.

  3. 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.

  4. Simulations of a Circulating Fluidized Bed Chemical Looping Combustion System Utilizing Gaseous Fuel Simulation de la combustion en boucle chimique d’une charge gazeuse dans un lit fluidisé circulant

    Directory of Open Access Journals (Sweden)

    Mahalatkar K.

    2011-05-01

    Full Text Available Numerical studies using Computational Fluid Dynamics (CFD have been carried out for a complete circulating fluidized bed chemical looping combustor described in the literature (Abad et al., 2006 Fuel 85, 1174-1185. There have been extensive experimental studies in Chemical Looping Combustion (CLC, however CFD simulations of this concept are quite limited. The CLC experiments that were simulated used methane as fuel. A 2-D continuum model was used to describe both the gas and solid phases. Detailed sub-models to account for fluid-particle and particleparticle interaction forces were included. Global models of fuel and carrier chemistry were utilized. The results obtained from CFD were compared with experimental outlet species concentrations, solid circulation rates, solid mass distribution in the reactors, and leakage and dilution rates. The transient CFD simulations provided a reasonable match with the reported experimental data. Des études numériques de simulation des écoulements (CFD ont été réalisées sur un lit fluidisé circulant opérant en combustion par boucle chimique (CLC décrit dans la littérature (Abad et al., 2006 Fuel 85, 1174-1185. Si de nombreuses études expérimentales ont été conduites pour étudier le procédé CLC, les études concernant la simulation des écoulements par CFD de ce concept sont très limitées. Le système de combustion en boucle chimique simulé dans cette étude concerne la combustion d’une charge gazeuse (méthane. Un modèle 2-D à deux phases continues a été utilisé pour décrire les phases gaz et solide avec des sous-modèles détaillés pour décrire les forces d’interactions entre fluideparticule et particule-particule. Des modèles cinétiques globaux ont été intégrés pour décrire les réactions de combustion et de transformation du matériau transporteur d’oxygène. Les résultats obtenus par CFD ont été comparés aux concentrations expérimentales mesurées des diff

  5. Pulse Detonation Engine Test Bed Developed

    Science.gov (United States)

    Breisacher, Kevin J.

    2002-01-01

    A detonation is a supersonic combustion wave. A Pulse Detonation Engine (PDE) repetitively creates a series of detonation waves to take advantage of rapid burning and high peak pressures to efficiently produce thrust. NASA Glenn Research Center's Combustion Branch has developed a PDE test bed that can reproduce the operating conditions that might be encountered in an actual engine. It allows the rapid and cost-efficient evaluation of the technical issues and technologies associated with these engines. The test bed is modular in design. It consists of various length sections of both 2- and 2.6- in. internal-diameter combustor tubes. These tubes can be bolted together to create a variety of combustor configurations. A series of bosses allow instrumentation to be inserted on the tubes. Dynamic pressure sensors and heat flux gauges have been used to characterize the performance of the test bed. The PDE test bed is designed to utilize an existing calorimeter (for heat load measurement) and windowed (for optical access) combustor sections. It uses hydrogen as the fuel, and oxygen and nitrogen are mixed to simulate air. An electronic controller is used to open the hydrogen and air valves (or a continuous flow of air is used) and to fire the spark at the appropriate times. Scheduled tests on the test bed include an evaluation of the pumping ability of the train of detonation waves for use in an ejector and an evaluation of the pollutants formed in a PDE combustor. Glenn's Combustion Branch uses the National Combustor Code (NCC) to perform numerical analyses of PDE's as well as to evaluate alternative detonative combustion devices. Pulse Detonation Engine testbed.

  6. Upgrade of deep bed filtration with activated carbon dosage for compact micropollutant removal from wastewater in technical scale.

    Science.gov (United States)

    Löwenberg, Jonas; Zenker, Armin; Krahnstöver, Thérèse; Boehler, Marc; Baggenstos, Martin; Koch, Gerhard; Wintgens, Thomas

    2016-05-01

    The removal of micropollutants from drinking and wastewater by powdered activated carbon (PAC) adsorption has received considerable attention in research over the past decade with various separation options having been investigated. With Switzerland as the first country in the world having adopted a new legislation, which forces about 100 wastewater treatment plants to be upgraded for the removal of organic micropollutants from municipal wastewater, the topic has reached practical relevance. In this study, the process combination of powdered activated carbon (PAC) adsorption and deep bed filtration (DBF) for advanced municipal wastewater treatment was investigated over an extended period exceeding one year of operation in technical scale. The study aimed to determine optimum process conditions to achieve sufficient micropollutant removal in agreement with the new Swiss Water Ordinance under most economic process design. It was shown that the addition of PAC and Fe(3+) as combined coagulation and flocculation agent improved effluent water quality with respect to dissolved organic pollutants as well as total suspended solids (TSS), turbidity and PO4-P concentration in comparison to a DBF operated without the addition of PAC and Fe(3+). Sufficient micropollutant (MP) removal of around 80% was achieved at PAC dosages of 10 mg/L revealing that PAC retained in the filter bed maintained considerable adsorption capacity. In the investigated process combination the contact reactor serves for adsorption as well as for flocculation and allowed for small hydraulic retention times of minimum 10 min while maintaining sufficient MP removal. The flocculation of two different PAC types was shown to be fully concluded after 10-15 min, which determined the flocculation reactor size while both PAC types proved suitable for the application in combination with DBF and showed no significant differences in MP removal. Finally, the capping of PAC dosage during rain water periods, which

  7. Coal combustion under conditions of blast furnace injection. Technical report, March 1, 1994--May 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Crelling, J.C. [Southern Illinois Univ., Carbondale, IL (United States)

    1994-09-01

    A potentially new use for Illinois coal is its use as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. This proposal is a follow-up to one funded for the 1992-93 period. It is intended to complete the study already underway with the Armco Inc. Steel Company and to initiate a new cooperative study along somewhat similar lines with the Inland Steel Company. The results of this study will lead to the development of a testing and evaluation protocol that will give a unique and much needed understanding of the behavior of coal in the injection process and prove the potential of Illinois coals for such use. During this quarter samples of two feed coals and the IBCSP 112 (Herrin No. 6) were prepared for reactivity testing and compared to blast furnace coke, and char fines taken from an active blast furnace. As the initial part of a broad reactivity analysis program, these same samples were also analyzed on a thermogravimetric analyzer (TGA) to determine their combustion and reactivity properties.

  8. Effect of fluidized bed combustion ashes used in metal polluted soil remediation on life history traits of the oligochaeta Eisenia andrei

    Energy Technology Data Exchange (ETDEWEB)

    Grumiaux, F.; Demuynck, S.; Schikorski, D.; Lemiere, S.; Vandenbulcke, F.; Lepretre, A. [University of Science Technology in Lille, Villeneuve Dascq (France)

    2007-11-15

    The aim of the present work was to investigate the effects of two fluidized bed combustion (FBC) ashes (silico-aluminous and sulfo-calcical) used as immobilizing agents for metals in contaminated soils, on the earthworm Eisenia andrei life history traits in OECD artificial soil. A significant mortality of either juveniles or mature worms was observed following silico-aluminous (> 60% mortality) or sulfo-calcical (100% mortality) ashes addition. This effect was due to a transient pH rise of soil. No mortality occurred when worms were introduced eight weeks after soils were amended with FBC ashes. However, growth rates were significantly reduced for both treatments and both ashes exhibited sub-lethal effects likely to affect population dynamics. Thus, cocoon productions were reduced for both amendments and no hatching was recorded with suffo-calcical ashes. Most of the harmful effects observed on worms growth and reproduction could be attributed to an increase of pH and/or an osmotic disturbance caused by FBC ashes, especially suffo-calcical ones.

  9. Mineralogical and elemental composition of fly ash from pilot scale fluidised bed combustion of lignite, bituminous coal, wood chips and their blends

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaos Koukouzas; Jouni Hamalainen; Dimitra Papanikolaou; Antti Tourunen; Timo Jantti [Institute for Solid Fuels Technology and Applications, Ptolemais (Greece). Centre for Research and Technology Hellas

    2007-09-15

    The chemical and mineralogical composition of fly ash samples collected from different parts of a laboratory and a pilot scale CFB facility has been investigated. The fabric filter and the second cyclone of the two facilities were chosen as sampling points. The fuels used were Greek lignite (from the Florina basin), Polish coal and wood chips. Characterization of the fly ash samples was conducted by means of X-ray fluorescence (XRF), inductive coupled plasma-optical emission spectrometry (ICP-OES), thermogravimetric analysis (TGA), particle size distribution (PSD) and X-ray diffraction (XRD). According to the chemical analyses the produced fly ashes are rich in CaO. Moreover, SiO{sub 2} is the dominant oxide in fly ash with Al{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} found in considerable quantities. Results obtained by XRD showed that the major mineral phase of fly ash is quartz, while other mineral phases that are occurred are maghemite, hematite, periclase, rutile, gehlenite and anhydrite. The ICP-OES analysis showed rather low levels of trace elements, especially for As and Cr, in many of the ashes included in this study compared to coal ash from fluidised bed combustion in general. 23 refs., 3 figs., 5 tabs.

  10. Agglomeration of ash during combustion of peat and biomass in fluidized-bed reactors. Development of image analysis technique based on scanning electron microscopy; Tuhkan muuntuminen leijukerroskaasutuksessa ja -poltossa. Haitallisten hivenmetallien vapautuminen ja alkalien kaeyttaeytyminen

    Energy Technology Data Exchange (ETDEWEB)

    Kauppinen, E. [VTT Chemistry, Espoo (Finland); Arpiainen, V.; Jokiniemi, J. [VTT Energy, Espoo (Finland)] [and others

    1996-12-01

    The objective of the project is to study the behaviour of alkali metals (Na and K) and hazardous trace elements (Sb, As, Be, Cd, Cr, Co, Pb, Mn, Ni, Se and Zn) during fluidized bed combustion and gasification of solid fuels. The areas of interest are the release of elements studied from the bed and the behaviour of gaseous and particle-phase species after the release from the bed. During 1995 combustion and gasification experiments of Polish coal in bubbling bed were carried out with a laboratory scale fluidized bed gasifier in atmospheric pressure. Flue gas samples were drawn from the freeboard of the reactor and cooled quickly using a dilution probe. Ash particle size distributions were determined using low pressure impactors and differential mobility analyser. The morphology of the ash particles was studied with a scanning electron microscope (SEM) and will be further studied with transmission electron microscopy (TEM). The ash matrix elements (Si, Al, Fe, Ca and Mg) and the alkali metals (Na and K) were not significantly vaporized during the combustion process. More than 99 % of each of these elements was found in ash particles larger than 0.4 {mu}m. In Polish coal the alkali metals are bound mainly in silicates. The alkali metals were not released from the silicate minerals during the combustion process. A significant fraction of As, Cd and Pb was vaporized, released as gaseous species from the fuel particle and condensed mainly on the fine ash particles. 20 - 34 % of cadmium was present in fly ash particles smaller than 0.6 {mu}m (during combustion in 950 deg C), whereas only 1 % of the total ash was in this size fraction. All of the hazardous trace elements studied (As, Be, Cd, Co, Cr, Mn and Zn) were enriched in ash size fraction 0.6 - 5 {mu}m. The enrichment of Co, Cr, Mn, Ni, Pb and Sb was more significant during combustion in 950 deg C than in lower temperature (850 deg C)

  11. Rotary Bed Reactor for Chemical-Looping Combustion with Carbon Capture. Part 2: Base Case and Sensitivity Analysis

    KAUST Repository

    Zhao, Zhenlong

    2013-01-17

    Part 1 (10.1021/ef3014103) of this series describes a new rotary reactor for gas-fueled chemical-looping combustion (CLC), in which, a solid wheel with microchannels rotates between the reducing and oxidizing streams. The oxygen carrier (OC) coated on the surfaces of the channels periodically adsorbs oxygen from air and releases it to oxidize the fuel. A one-dimensional model is also developed in part 1 (10.1021/ef3014103). This paper presents the simulation results based on the base-case design parameters. The results indicate that both the fuel conversion efficiency and the carbon separation efficiency are close to unity. Because of the relatively low reduction rate of copper oxide, fuel conversion occurs gradually from the inlet to the exit. A total of 99.9% of the fuel is converted within 75% of the channel, leading to 25% redundant length near the exit, to ensure robustness. In the air sector, the OC is rapidly regenerated while consuming a large amount of oxygen from air. Velocity fluctuations are observed during the transition between sectors because of the complete reactions of OCs. The gas temperature increases monotonically from 823 to 1315 K, which is mainly determined by the solid temperature, whose variations with time are limited within 20 K. The overall energy in the solid phase is balanced between the reaction heat release, conduction, and convective cooling. In the sensitivity analysis, important input parameters are identified and varied around their base-case values. The resulting changes in the model-predicted performance revealed that the most important parameters are the reduction kinetics, the operating pressure, and the feed stream temperatures. © 2012 American Chemical Society.

  12. A Technical Review of Compressed Natural Gas as an Alternative Fuel for Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Semin

    2008-01-01

    Full Text Available Natural gas is promising alternative fuel to meet strict engine emission regulations in many countries. Compressed natural gas (CNG has long been used in stationary engines, but the application of CNG as a transport engines fuel has been considerably advanced over the last decade by the development of lightweight high-pressure storage cylinders. Engine conversion technology is well established and suitable conversion equipment is readily available. For spark ignition engines there are two options, a bi-fuel conversion and use a dedicated to CNG engine. For compression ignition engines converted to run on natural gas, there are two main options discussed, there are dual-fuel engines and normal ignition can be initiated. Natural gas engines can operate at lean burn and stoichiometric conditions with different combustion and emission characteristics. In this paper, the CNG engines research and development fueled using CNG are highlighted to keep the output power, torque and emissions of natural gas engines comparable to their gasoline or diesel counterparts. The high activities for future CNG engines research and development to meet future CNG engines is recorded in the paper.

  13. Study on mercury migration in a circulating fluidized bed combustion boiler%循环流化床燃煤锅炉中的汞迁移研究

    Institute of Scientific and Technical Information of China (English)

    武成利; 曹晏; 李寒旭; 潘伟平

    2012-01-01

    采用美国环保署颁布的吸附剂吸附汞采样方法30B(USEPA 40 CFR Part 60 30B)采集燃煤烟气中汞.选择一循环流化床燃煤机组进行现场采样,吸附剂吸附烟囱处烟气中的汞、入炉煤样、锅炉底灰、静电除尘器飞灰等样品同时采集.对该机组中汞质量平衡率进行衡算,通过汞质量平衡率说明了汞采样方法的准确性和有效性.评价了汞在飞灰、底灰和烟气中的分布,循环流化床锅炉底灰中对脱汞的贡献率仅0.55%,飞灰脱除汞的效率高达83.37%,剩余的16.08%的汞排放入大气环境,表明循环流化床机组是有效控制汞的清洁煤燃烧技术.%Mercury concentrations in the flue gas at the stack were measured using a sorbent trap method as per United States Environmental Protection Agency Method 30B (I. E. , USEPA 40 CFR Part 60 30B), and the sampling method has merits of convenient setup, simply operation and fast analysis. Field tests were conducted at a unit of the Circulating Fluidized Bed Combustion (CFBC). During the course of sampling the mercury in the flue gas, coal samples, bottom ash and fly ash were collected and analyzed. Rates of mercury material balance though the unit were calculated, and correctness and validity of mercury sampling method were certified. Mercury distributions in fly ash, bottom ash and flue gas were evaluated, and the results showed that firstly bottom ash of CFBC removed only 0. 55% of total mercury, secondly removal efficiency of fly ash reaching 83. 37% , in the end 16.08% of total mercury was emitted to the air. The determined data of mercury emissions show that the CFBC is a clean coal combustion technology of effectively removing mercury.

  14. Enhanced kinetics for the clathrate process in a fixed bed reactor in the presence of liquid promoters for pre-combustion carbon dioxide capture

    International Nuclear Information System (INIS)

    In this work, we present enhanced kinetics of hydrate formation for the clathrate process in the presence of two liquid promoters namely THF (tetrahydrofuran) and TBAB (tetra-n-butyl ammonium bromide) in a FBR (fixed bed reactor) for pre-combustion capture of CO2. Silica sand was used as a medium to capture CO2 from CO2/H2 gas mixture by hydrate crystallisation. Experiments were performed at different temperatures (274.2 K and 279.2 K) and 6.0 MPa to determine the total gas uptake, induction time and rate of hydrate formation. The observed trends indicated that higher driving force resulted in higher gas consumption and significantly reduced induction time. For the same driving force, higher gas consumption and shorter induction time was achieved by THF as compared to TBAB. 5.53 mol% THF attained higher gas consumption than 1.0 mol% THF whereas 3.0 mol% TBAB attained lower gas consumption than 0.3 mol% TBAB. A highest gas uptake of 51.95 (±5.183) mmol of gas/mol of water and a highest rate of 51.21(±8.91) mol.min−1.m−3 were obtained for 5.53 mol% THF at 6.0 MPa and 279.2 K. Overall, this study indicated better hydrate formation kinetics with the use of THF in an FBR configuration for CO2 capture from a fuel gas mixture. - Highlights: • Better kinetic performance with THF compared to TBAB for CO2 capture in a fixed bed reactor. • Highest CO2 uptake (126.99 ± 12.67 mg of gas/g of water) was obtained for 5.53 mol% THF. • Highest growth rate (51.21 ± 8.91 mol min−1.m−3) for 30 min was obtained for 5.53 mol% THF. • Waste heat (ΔT = 20) is sufficient to recover all the hydrated gas

  15. Combustion of coffee husks

    Energy Technology Data Exchange (ETDEWEB)

    Saenger, M.; Hartge, E.-U.; Werther, J. [Technical Univ. Hamburg-Harburg, Chemical Engineering 1, Hamburg (Germany); Ogada, T.; Siagi, Z. [Moi Univ., Dept. of Production Engineering, Eldoret (Kenya)

    2001-05-01

    Combustion mechanisms of two types of coffee husks have been studied using single particle combustion techniques as well as combustion in a pilot-scale fluidized bed facility (FBC), 150 mm in diameter and 9 m high. Through measurements of weight-loss and particle temperatures, the processes of drying, devolatilization and combustion of coffee husks were studied. Axial temperature profiles in the FBC were also measured during stationary combustion conditions to analyse the location of volatile release and combustion as a function of fuel feeding mode. Finally the problems of ash sintering were analysed. The results showed that devolatilization of coffee husks (65-72% volatile matter, raw mass) starts at a low temperature range of 170-200degC and takes place rapidly. During fuel feeding using a non water-cooled system, pyrolysis of the husks took place in the feeder tube leading to blockage and non-uniform fuel flow. Measurements of axial temperature profiles showed that during under-bed feeding, the bed and freeboard temperatures were more or less the same, whereas for over-bed feeding, freeboard temperatures were much higher, indicating significant combustion of the volatiles in the freeboard. A major problem observed during the combustion of coffee husks was ash sintering and bed agglomeration. This is due to the low melting temperature of the ash, which is attributed to the high contents of K{sub 2}O (36-38%) of the coffee husks. (Author)

  16. Combustion of char-coal waste pellets for high efficiency and low NO{sub x}. Technical report, September 1--November 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, S. [Southern Illinois Univ., Carbondale, IL (United States)

    1994-12-31

    Illinois coals are prime candidates for use in Integrated Gasification Combined Cycle (IGCC) plants because of their high volatility and good char reactivity. In these plants, partial gasification of the coal in the presence of limestone eliminates the major portion of the sulfur species in the product gases, which are used as fuel for the topping cycle. The char produced is high in ash content, the major portion of which is calcium sulfide. It is also low in volatiles and of low density, compared to the parent coal. The economic success of the gasification route depends on the subsequent utilization of the residual char for raising steam for use in a Rankine cycle bottoming plant and/or preheating the air to the gasifier. Fluidized bed combustion of the char appears an attractive way of utilizing the char. Areas of concern in the fluidized bed combustion of the high ash, low volatility char are: attainment of high carbon conversion efficiencies; reduction of oxides of nitrogen emissions; reduction/elimination of corrosive chlorine species; reduction/elimination of sodium and other alkali species; and efficient usage of the calcium present in the ash to reduce sulfur compounds. The aim of the present project is to investigate ways of improving the carbon conversion efficiency, sulfur capture efficiency and NO{sub x} reduction during the fluidized bed combustion by pelletizing the low density char with coal and coal wastes using cornstarch or wood lignin as binder. During this first quarter, the parent coals and the chars to be tested have been analyzed. Particle size distributions have been measured. Sample pellets have been made evaluation of their properties.

  17. Reduced ash related operational problems (slagging, bed agglomeration, corrosion and fouling) by co-combustion biomass with peat; Minskade askrelaterade driftsproblem (belaeggning, slaggning, hoegtemperatur-korrosion, baeddagglomerering) genom inblandning av torv i biobraenslen

    Energy Technology Data Exchange (ETDEWEB)

    Oehman, Marcus; Boman, Christoffer; Erhardsson, Thomas; Gilbe, Ram; Pommer, Linda; Bostroem, Dan; Nordin, Anders; Samuelsson, Robert; Burvall, Jan

    2006-12-15

    Combustion studies were performed in both a fluidized bed (5 kW) and in an under-feed pellets burner (20 kW) to elucidate the responsible mechanisms for the positive effects on ash related operational problems (i.e. slagging, fouling, corrosion and bed agglomeration) during co-combustion of several problematic biomass with peat. Three typical carex-containing Swedish peat samples with differences in e.g. silicon-, calcium- and sulfur contents were co-fired with logging residues, willow and straw in proportions corresponding to 15-40 weight %d.s. Mixing of corresponding 20 wt-% of peat significantly reduced the bed agglomeration tendencies for all fuels. The fuel specific agglomeration temperature were increased by 150-170 deg C when adding peat to the straw fuel and approximately 70-100 deg C when adding peat to the logging residue- and the willow fuel. The increased level of calcium in the inner bed particle layer caused by the added reactive calcium from the peat and/or removing alkali in the gas phase to a less reactive particular form via sorption and/or reaction with reactive peat ash (containing calcium, silica etc.) during which larger particles (>1{mu}m) are formed where collected potassium is present in a less reactive form, is considered to be the dominated reason for the increased agglomeration temperatures during combustion of logging residues and willow. During straw combustion, the ash forming matter were found as individual ash sticky particles in the bed. The iron, sulphur and calcium content of these individual ash particles were significantly increased when adding peat to the fuel mix thereby decreasing the stickiness of these particles i.e. reducing the agglomeration tendencies. Adding peat to the relatively silicon-poor fuels (willow and logging residues) resulted in higher slagging tendencies, especially when the relative silicon rich peat fuel (Brunnskoelen) was used. However, when co-combusting peat with the relatively silicon and potassium

  18. INVESTIGATION OF FUEL CHEMISTRY AND BED PERFORMANCE IN A FLUIDIZED BED BLACK LIQUOR STEAM REFORMER

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Whitty

    2003-12-01

    The University of Utah project ''Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer'' (DOE award number DE-FC26-02NT41490) was developed in response to a solicitation for projects to provide technical support for black liquor and biomass gasification. The primary focus of the project is to provide support for a DOE-sponsored demonstration of MTCI's black liquor steam reforming technology at Georgia-Pacific's paper mill in Big Island, Virginia. A more overarching goal is to improve the understanding of phenomena that take place during low temperature black liquor gasification. This is achieved through five complementary technical tasks: (1) construction of a fluidized bed black liquor gasification test system, (2) investigation of bed performance, (3) evaluation of product gas quality, (4) black liquor conversion analysis and modeling and (5) computational modeling of the Big Island gasifier. Four experimental devices have been constructed under this project. The largest facility, which is the heart of the experimental effort, is a pressurized fluidized bed gasification test system. The system is designed to be able to reproduce conditions near the black liquor injectors in the Big Island steam reformer, so the behavior of black liquor pyrolysis and char gasification can be quantified in a representative environment. The gasification test system comprises five subsystems: steam generation and superheating, black liquor feed, fluidized bed reactor, afterburner for syngas combustion and a flue gas cooler/condenser. The three-story system is located at University of Utah's Industrial Combustion and Gasification Research Facility, and all resources there are available to support the research.

  19. Lightweight combustion residues-based structural materials for use in mines. Technical report, September 1--November 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Chugh, Y.P.; Zhang, Y.; Ghosh, A.K.; Palmer, S.R. [Southern Illinois Univ., Carbondale, IL (United States)

    1994-12-31

    The overall goal of the project is to develop a 70--80 pcf, 2,500--3,000 psi-compressive-strength cellular concrete-type product from PCC fly ash, PCC bottom ash, and/or FBC spent bed ash alone or in suitable combination thereof. The developed combustion residue-based lightweight structural material will be used to replace wooden posts and crib members in underground mines. This report outlines the work completed in the first quarter of the project. The density gradient centrifuge (DGC) has been used to separate a power plant fly ash sample into fractions of different density. Each of the fly ash fractions obtained by DGC, an aliquot of the unseparated fly ash and an aliquot of a magnetic component of the fly ash, were digested in strong acids following the procedures outlined in ASTM 3050. Preliminary experiments have also been carried out to study the effect of mix proportions and curing regimes on the strength and density on the developed material. The DGC separation test reveals that most of the fly ash sample (approx. 90%) has a density above 1.9 g/cm{sup 3}. Indeed, nearly half of the sample has a density greater than 2.4 g/cm{sup 3}. Since only a very small amount of this fly ash has a reasonably low specific gravity, it appears unlikely at this time that enough low density material would be isolated to significantly enhance lightweight concrete production using fractionated material. A series of mixes have been made using fly ash, sodium silicate, cement, sand and water. Preliminary tests show that both cement and sodium silicate can be used as the binders to develop residues-based lightweight concrete. To date, compressive strength as high as 1,290 psi have been achieved with a density of 133 pcf, with 50 g of cement, 50 g of fly ash and 300 g of sand. Most of the work during the first quarter was done to understand the characteristics of the component materials.

  20. ENVIRONMENTAL ASSESSMENT OF NOX CONTROL ON A SPARK-IGNITED LARGE BORE RECIPROCATING INTERNAL COMBUSTION ENGINE. VOLUME 1. TECHNICAL RESULTS

    Science.gov (United States)

    Volume I of the report gives emission results for a spark-ignited, largebore, reciprocating, internal-combustion engine operating both under baseline (normal) conditions, and with combustion modification controls to reduce NOx emissions to levels below the proposed new source per...

  1. Combustion of char-coal waste pellets for high efficiency and low NO{sub x}. Technical report, March 1--May 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, S.

    1995-12-31

    To maintain market share, new uses must be found for Illinois coals in the largest end use area, namely power generation. To this end, the suitability of Illinois coal for high efficiency power plants like combined cycles must be investigated. This approach involves partial gasification of the coal to produce fuel gas for the topping cycle gas turbines, while the residual char is burnt in the gas turbine exhaust to produce steam for the Rankine bottoming cycle. This project seeks to improve the combustion characteristics of the residual char by pelletizing it with waste coal in order to improve its combustor residence time and carbon conversion efficiency. At the same time, attempts are made to reduce pollutant emissions. During this quarter, the residual char produced by Foster Wheeler Development Corporation in their pyrolyzer has been pelletized with Illinois gob coal in various proportions. Combustion tests have been performed in a laboratory scale circulating fluidized bed combustor. Preliminary results show that the pellets are much easier to burn and exhibit high carbon conversion efficiencies. Further combustion tests are in progress.

  2. Characterization of limestone reactivity with SO{sub 2} and sulfur capture modelling under fluidized bed combustion conditions; Bestaemning av kalkstensreaktivitet med avseende paa SO{sub 2} och modellering av avsvavling foer foerbraenning i fluidiserad baedd

    Energy Technology Data Exchange (ETDEWEB)

    Mattisson, T. [Chalmers Univ. of Technology and Univ. of Goeteborg, Goeteborg (Sweden). Dept. of Inorganic Chemistry; Lyngfelt, A. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion

    1996-12-01

    During combustion of fossil fuels, SO{sub 2} is released to the atmosphere. Because of environmental concern with acid rain, the capture of SO{sub 2} is a very important process. Fluidized bed combustion (FBC) is a combustion method where limestone may be added to the furnace chamber to capture SO{sub 2} as the stable product CaSO{sub 4}. In the present work a relatively simple laboratory method has been developed for characterizing limestone reactivity with SO{sub 2}. The reactivity data from such investigations are used, together with residence time and particle size distribution, in a sulfur capture model for fluidized bed boilers that predicts the sulfur capture as a function of the Ca/S molar ratio. In addition, the model predicts the conversion of CaO to CaSO{sub 4} for all particle sizes present in a boiler. The model was developed and verified using data from two boilers, a 12 and a 40 MW circulating fluidized bed boiler, and showed reasonable agreement for both boilers. In addition to the development of a sulfur capture model, the effects of SO{sub 2} and CO{sub 2} concentrations, particle size, temperature variations, and reducing conditions on the sulfation reaction was studied using a fixed-bed quartz reactor. The sulfation reaction was also studied for long periods of time, up to 60 hours. This was done because of the long residence times of certain particle sizes that may exist in a fluidized bed boiler. From the parameter study it was found that particle size and variations between oxidizing and reducing conditions had a large effect on the sulfation behaviour. The investigation of long sulfation times showed that the reaction continued even at high degrees of conversion, although at a very slow rate. CO{sub 2} concentration had a moderate effect on the sulfation reaction while temperature variations showed no effect on the final conversion between CaO and CaSO{sub 4}. 29 refs, 25 figs, 4 tabs

  3. Particle-bed gas-cooled fast reactor (PB-GCFR) design. Project final technical report (Sept 2001 - Aug 2003)

    International Nuclear Information System (INIS)

    The objective of this project is to develop a conceptual design of a particle-bed, gas-cooled fast reactor (PB-GCFR) core that meets the advanced reactor concept and enhanced proliferation-resistant goals of the US Department of Energy's NERI program. The key innovation of this project is the application of a fast neutron spectrum environment to enhance both the passive safety and transmutation characteristics of the advanced particle-bed and pebble-bed reactor designs. The PB-GCFR design is expected to produce a high-efficiency system with a low unit cost. It is anticipated that the fast neutron spectrum would permit small-sized units (∼ 150 MWe) that can be built quickly and packaged into modular units, and whose production can be readily expanded as the demand grows. Such a system could be deployed globally. The goals of this two-year project are as follows: (1) design a reactor core that meets the future needs of the nuclear industry, by being passively safe with reduced need for engineered safety systems. This will entail an innovative core design incorporating new fuel form and type; (2) employ a proliferation-resistant fuel design and fuel cycle. This will be supported by a long-life core design that is refueled infrequently, and hence, reduces the potential for fuel diversion; (3) incorporate design features that permit use of the system as an efficient transmuter that could be employed for burning separated plutonium fuel or recycled LWR transuranic fuel, should the need arise; and (4) evaluate the fuel cycle for waste minimization and for the possibility of direct fuel disposal. The application of particle-bed fuel provides the promise of extremely high burnup and fission-product protection barriers that may permit direct disposal

  4. 加氢进料燃烧炉衬里改造%Lining Technical Innovation of Hydrogenation Feed Combustion Furnace

    Institute of Scientific and Technical Information of China (English)

    尹琦岭; 张杰; 秦昀亮; 王团亮; 黄小林; 汪昌保; 刘志强

    2013-01-01

    The structure and lining form of the hydrogenation feed combustion furnace of tail gas treatment unit in natural gas purification plant were introduced .Part lining of the hydrogenation feed combustion furnace was suffered for damage ,subside ,or even fall at beginning ,which lead to over temperature of combustion furnace wall and affected normal production .Reformation plan was proposed to solve the problem existed in lining of hydrogenation feed combustion furnace .%  对普光气田天然气净化装置、尾气处理单元加氢进料燃烧炉及衬里结构进行了介绍。由于衬里损坏、下沉及脱落导致燃烧炉外壁超温,影响了装置正常的生产,提出了相应的改造方案。

  5. Control and reduction of NOx emissions on light hydrocarbons combustion in fluidized bed combustors: a technological prospection surveys; Controle e reducao de emissoes de NOx durante queima de hidrocarbonetos leves em combustores a leito fluidizado: um estudo de prospeccao tecnologica

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Douglas Alves; Winter, Eduardo [Instituto Nacional da Propriedade Industrial (INPI), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The present paper aims a technological prospecting study of the main technological agents involved in industrial light hydrocarbons combustion process. More specifically, the work approaches technologies applied to nitrogen oxides emissions control and reduction. Nitrogen oxides are typically known as 'NOx' (NO, N{sub 2}O, NO{sub 2}). 'NOx' are byproducts from fuel burning in combustion systems, including also in fluidized bed combustion systems. The technological prospecting study employed 'technology foresight' as tool for evaluating the technological perspectives of the thermal generation, basis on environment protection. Such technological perspectives of the thermal generation were evaluated through invention patent documents. The query methodology for obtaining of patent documents employed a free patent base, known as ESPACENET. Additionally, the documents obtained were evaluated, considering beyond the countries and the publication dates, technological perspectives employed to 'NOx' emissions control and reduction. It is very important to highlight around 70% of the industrial technological information are just found in invention patent documents. (author)

  6. Technical aspects of the production of dried extract of Maytenus ilicifolia leaves by jet spouted bed drying.

    Science.gov (United States)

    Cordeiro, Daniel S; Oliveira, Wanderley P

    2005-08-11

    This work presents an evaluation of the performance of jet spouted bed with inert particles for production of dried extracts of Maytenus ilicifolia leaves. The development of the extraction procedure was carried-out with the aid of three factors and three levels Box-Behnken design. The effects of the extraction variables, temperature (Text); stirring time (theta); and the ratio of the plant to solvent mass (m(p)/m(s)) on the extraction yield were investigated. The drying performance and product properties were evaluated through the measurement of the product size distribution, loss on drying (Up), flavonoid degradation (D) and, process thermal efficiency (eta). These parameters were measured as a function of the inlet temperature of the spouting gas (Tgi), the feed mass flow rate of the concentrated extract relative to mass flow rate of the spouting gas (Ws/Wg), the ratio between the feed flow rate of spouting gas relative to feed flow rate at a minimum spouting condition (Q/Qms) and the static bed height (H0). A powder product with a low degradation of active substances and good physical properties were obtained for selected operating conditions. These results indicate the feasibility of this drying equipment for the production of dried extracts of M. ilicifolia Martius ex Reiss leaves. PMID:15978755

  7. Comparative analysis between a PEM fuel cell and an internal combustion engine driving an electricity generator: Technical, economical and ecological aspects

    International Nuclear Information System (INIS)

    In the recent years the fuel cells have received much attention. Among various technologies, the Proton Exchange Membrane Fuel Cell (PEMFC) is currently the most appropriate and is used in several vehicles prototype. A comparative technical, economical and ecological analysis between an Internal Combustion Engine fueled with Diesel driving an electricity Generator (ICE-G) and a PEMFC fed by hydrogen produced by ethanol steam reforming was performed. The technical analysis showed the advantages of the PEMFC in comparison to the ICE-G based in energetic and exergetic aspects. The economic analysis shows that fuel cells are not economic competitive when compared to internal combustion engine driving an electricity generator with the same generation capacity; it will only be economically feasible in a long term; due to the large investments required. The environmental analysis was based on concepts of CO2 equivalent, pollution indicator and ecological efficiency. Different to the ICE-G system, the Fuel Cell does not emit pollutants directly and the emission related to this technology is linked mainly with hydrogen production. The ecological efficiency of PEMFC was 96% considering the carbon dioxide cycle, for ICE-G system this parameter reach 51%. -- Highlights: • The exergetic efficiency of ICE-G was 22% and for the fuel cell was 40%. • The PEM fuel cell at long-term become economically competitive compared to ICE-G. • The ecological efficiency of PEM fuel cell was 96% and Diesel ICE-G was 51%

  8. CaMn0.875Ti0.125O3 as oxygen carrier for chemical-looping combustion with oxygen uncoupling (CLOU)—Experiments in a continuously operating fluidized-bed reactor system

    KAUST Repository

    Rydén, Magnus

    2011-03-01

    Particles of the perovskite material CaMn0.875Ti0.125O3 has been examined as oxygen carrier for chemical-looping with oxygen uncoupling, and for chemical-looping combustion of natural gas, by 70h of experiments in a circulating fluidized-bed reactor system. For the oxygen uncoupling experiments, it was found that the particles released O2 in gas phase at temperatures above 720°C when the fuel reactor was fluidized with CO2. The effect increased with increased temperature, and with the O2 partial pressure in the air reactor. At 950°C, the O2 concentration in the outlet from the fuel reactor was in the order of 4.0vol%, if the particles were oxidized in air. For the chemical-looping combustion experiments the combustion efficiency with standard process parameters was in the order of 95% at 950°C, using 1000kg oxygen carrier per MW natural gas, of which about 30% was located in the fuel reactor. Reducing the fuel flow so that 1900kg oxygen carrier per MW natural gas was used improved the combustion efficiency to roughly 99.8%. The particles retained their physical properties, reactivity with CH4 and ability to release gas-phase O2 reasonably well throughout the testing period and there were no problems with the fluidization or formation of solid carbon in the reactor. X-ray diffraction showed that the particles underwent changes in their phase composition though. © 2010 Elsevier Ltd.

  9. ENVIRONMENTAL ASSESSMENT OF NOX CONTROL ON A COMPRESSION IGNITION LARGE BORE RECIPROCATING INTERNAL COMBUSTION ENGINE. VOLUME 1. TECHNICAL RESULTS

    Science.gov (United States)

    Volume I of the report gives emission results from field tests of the exhaust gas from a large-bore, compression-ignition reciprocating engine burning diesel fuel. An objective of the tests was to evaluate the operating efficiency of the engine with combustion modification NOx co...

  10. Toxic substances from coal combustion -- a comprehensive assessment. Quarterly technical progress report, 1 April 1996--30 June 1996

    Energy Technology Data Exchange (ETDEWEB)

    Bool, L.E. III; Senior, C.L. [PSI Technologies, Andover, MA (United States); Huggins, F.; Huffman, G.P.; Shah, N. [Univ. of Kentucky, Lexington, KY (United States)] [and others

    1996-07-01

    Before electric utilities can plan or implement emissions minimization strategies for hazardous pollutants, they must have an accurate and site-specific means of predicting emissions in all effluent streams for the broad range of fuels and operating conditions commonly utilized. Development of a broadly applicable emissions model useful to utility planners first requires a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion (specifically in Phase I, As, Se, Cr, and possibly Hg). PSI Technologies (PSIT) and its team members will achieve this objective through the development of an {open_quotes}Engineering Model{close_quotes} that accurately predicts the formation and partitioning of toxic species as a result of coal combustion. The {open_quotes}Toxics Partitioning Engineering Model{close_quotes} (ToPEM) will be applicable to all conditions including new fuels or blends, low-NO{sub x} combustion systems, and new power systems being advanced by DOE in the Combustion 2000 program. This report describes the mineralogy and chemical analysis of bituminous coal samples.

  11. A comparison between the two different combustion methods of Grate-firing and Fluidized bed, applied to a CHP-plant with MSW as fuel

    OpenAIRE

    Hasan, Belkiz; Ahsant, Aidin

    2015-01-01

    In this study, the two most frequently used incineration systems, fluidized bed and grate-firing have been compared and analyzed. The performance of Mälarenergi’s combined heat and power (CHP) plant in Västerås, which consists of a fluidized bed incinerator, has been used as benchmark to elaborate the different calculations made in this study. It extracts electricity and heat amounting to 50 and 100 MW respectively.   On average, 75-85% of the weight of Municipal Solid Waste (MSW) is converte...

  12. Standard technical specifications combustion engineering plants: Bases (Sections 2.0--3.3). Volume 2, Revision 1

    International Nuclear Information System (INIS)

    This report documents the results of the combined effort of the NRC and the industry to produce improved Standard Technical Specifications (STS), Revision 1 for General Electric BWR/6 Plants. The changes reflected in Revision 1 resulted from the experience gained from license amendment applications to convert to these improved STS or to adopt partial improvements to existing technical specifications. This NUREG is the result of extensive public technical meetings and discussions between the Nuclear Regulatory Commission (NRC) staff and various nuclear power plant licensees, Nuclear Steam Supply System (NSSS) Owners Groups, NSSS vendors, and the Nuclear Energy Institute (NEI). The improved STS were developed based on the criteria in the Final Commission Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors, dated July 22, 1993. The improved STS will be used as the basis for individual nuclear power plant licensees to develop improved plant-specific technical specifications. This report contains three volumes

  13. Technical Note: A numerical test-bed for detailed ice nucleation studies in the AIDA cloud simulation chamber

    Directory of Open Access Journals (Sweden)

    R. J. Cotton

    2007-01-01

    Full Text Available The AIDA (Aerosol Interactions and Dynamics in the Atmosphere aerosol and cloud chamber of Forschungszentrum Karlsruhe can be used to test the ice forming ability of aerosols. The AIDA chamber is extensively instrumented including pressure, temperature and humidity sensors, and optical particle counters. Expansion cooling using mechanical pumps leads to ice supersaturation conditions and possible ice formation. In order to describe the evolving chamber conditions during an expansion, a parcel model was modified to account for diabatic heat and moisture interactions with the chamber walls. Model results are shown for a series of expansions where the initial chamber temperature ranged from −20°C to −60°C and which used desert dust as ice forming nuclei. During each expansion, the initial formation of ice particles was clearly observed. For the colder expansions there were two clear ice nucleation episodes. In order to test the ability of the model to represent the changing chamber conditions and to give confidence in the observations of chamber temperature and humidity, and ice particle concentration and mean size, ice particles were simply added as a function of time so as to reproduce the observations of ice crystal concentration. The time interval and chamber conditions over which ice nucleation occurs is therefore accurately known, and enables the model to be used as a test bed for different representations of ice formation.

  14. Report of the technic visit made in Fegueira uraniferous bed, Brasil between 21 and 24 of may in 1985

    International Nuclear Information System (INIS)

    The technical visit to the deposit uraniferous of Figueira allowed to visualize different aspects stratigraphic , environmental and structurals.The geological cut across the highway BR-376, it understands practically the whole succession e stratigraphic of the Gondwana of the basin of the Parana, as also sequences of the Pre cambric and of the Devonian one Inferior.- The formations observed during this tour, they are correlation with our formations Cerrezuelo, Native of Cordoba, Three Islands, Dead Friar, Mangrullo, Step Aguiar, Yaguari and Tacuarembo.- The deposit is in the formation- Nice Rio (Three Islands), Member I Triumph, of age Permian Low As(according to) them the study carried out definite well units are demonstrated; This geological model is propitious for the accumulation of uranium due to: - Porous sandstones - carbonaceous sediments.The interaction of these two types of sediments provide in an environment with good

  15. Characterization of Inorganic Elements in Woody Biomass Bottom Ash from a Fixed-bed Combustion System, a Downdraft Gasifier and a Wood Pellet Burner by Fractionation

    OpenAIRE

    Adrian K. James; Steve S. Helle; Thring, Ronald W.; Gurkaran S. Sarohia; P. Michael Rutherford

    2014-01-01

    The direct combustion of biomass residues produces large quantities of bottom ash. Environmental sustainable management requires that ash recycling should be carried out whenever possible. Suitable applications of bottom ash are based predominantly on its chemical properties. The presence of major ash forming and trace elements along with other intrinsic properties unique to bottom ash, suggest its potential as a soil additive. But, ash quality must be of a high standard to prevent environmen...

  16. Combustion gas from biomass - innovative plant concepts on the basis of circulating fluidized bed gasification; Brenngas aus Biomasse - innovative Anlagenkonzepte auf Basis der Zirkulierenden Wirbelschichtvergasung

    Energy Technology Data Exchange (ETDEWEB)

    Greil, C.; Hirschfelder, H. [Lurgi Umwelt GmbH, Frankfurt am Main (Germany)

    1998-09-01

    The contribution describes the applications of the Lurgi-ZWS gas generator. There are three main fields of application: Direct feeding of combustion gas, e.g. into a rotary kiln, as a substitute for coal or oil, without either dust filtering or gas purification. - Feeding of the combustion gas into the steam generator of a coal power plant after dust filtering and, if necessar, filtering of NH{sub 3} or H{sub 2}S. - Combustion in a gas turbine or gas engine after gas purification according to specifications. The applications are described for several exemplary projects. (orig./SR) [Deutsch] Im folgenden wird ueber die Anwendung des Lurgi-ZWS-Gaserzeugers berichtet. Nach heutiger Sicht stehen drei Anwendungsgebiete im Vordergrund: - direkte Einspeisung des Brenngases in z.B. einen Zementdrehrohrofen zur Substitution von Kohle oder Oel, ohne Entstaubung und Gasreinigung. - Einspeisung des Brenngases nach Entstaubung und gegebenenfalls Entfernung weiterer Komponenten wie NH{sub 3} oder H{sub 2}S in den Dampferzeuger eines Kohlekraftwerkes - Einsatz des Brenngases in einer Gasturbine oder Gasmotor nach spezifikationsgerechter Gasreinigung. Die aufgefuehrten Einsatzmoeglichkeiten werden am Beispiel von Projekten beschrieben. (orig./SR)

  17. Investigation and modelling of fuel utilisation in the zone near the burner of technical combustion systems. Final report; Untersuchung und Modellierung der Brennstoffumsetzung im Brennernahbereich technischer Verbrennungssysteme. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H.; Wirtz, S.

    1999-06-01

    Optimisation and development of technical combustion systems in order to generate energy efficiently and reduce pollution is an ever-increasing challenge. Mathematical and numerical simulations play a very important role in this context. This project was dedicated to the implementation and improvement of mathematical models and subsequent verification of the modelling concepts. Verification used data measured by the university department for combined cyle turbines. The focal point of interest was the reaction zone near the burner. Further points of interest: development and improvement of models for two-phase effects, fuel consumption and turbulence interaction as well as further development of the methods of numerical simulation. Simulating the combustion chamber of the combined cycle turbines was prioritised.(orig.) [German] Die Optimierung und Weiterentwicklung technischer Verbrennungssysteme mit dem Ziel einer moeglichst effizienten und schadstoffarmen Energiebereitstellung stellt eine staendig wachsende Herausforderung dar. Bei der technologischen Umsetzung dieses Ziels kommt der mathematisch-numerischen Simulation eine immer groessere Bedeutung zu. In diesem Projekt sollte die Implementierung und Verbesserung von mathematischen Modellierungsansaetzen sowie die anschliessende Verifikation der Modellierungskonzepte anhand der Messdaten des Lehrstuhls fuer Dampf- und Gasturbinen (LDuG) durchgefuehrt werden. Der Schwerpunkt lag in der brennernahen Reaktionszone. Konkrete Arbeitsschwerpunkte waren die Weiterentwicklung und Verbesserung der Modellansaetze fuer Zweiphaseneffekte, Brennstoffumsatz und Turbulenzinteraktion sowie die Weiterentwicklung der Methodik der numerischen Simulation. Dabei stand die Simulation der Brennkammer des LDuG im Vordergrund. (orig.)

  18. An experimental study of the effect of a pilot flame on technically pre-mixed, self-excited combustion instabilities

    Science.gov (United States)

    O'Meara, Bridget C.

    Combustion instabilities are a problem facing the gas turbine industry in the operation of lean, pre-mixed combustors. Secondary flames known as "pilot flames" are a common passive control strategy for eliminating combustion instabilities in industrial gas turbines, but the underlying mechanisms responsible for the pilot flame's stabilizing effect are not well understood. This dissertation presents an experimental study of a pilot flame in a single-nozzle, swirl-stabilized, variable length atmospheric combustion test facility and the effect of the pilot on combustion instabilities. A variable length combustor tuned the acoustics of the system to excite instabilities over a range of operating conditions without a pilot flame. The inlet velocity was varied from 25 -- 50 m/s and the equivalence ratio was varied from 0.525 -- 0.65. This range of operating conditions was determined by the operating range of the combustion test facility. Stability at each operating condition and combustor length was characterized by measurements of pressure oscillations in the combustor. The effect of the pilot flame on the magnitude and frequency of combustor stability was then investigated. The mechanisms responsible for the pilot flame effect were studied using chemiluminescence flame images of both stable and unstable flames. Stable flame structure was investigated using stable flame images of CH* chemiluminescence emission. The effect of the pilot on stable flame metrics such as flame length, flame angle, and flame width was investigated. In addition, a new flame metric, flame base distance, was defined to characterize the effect of the pilot flame on stable flame anchoring of the flame base to the centerbody. The effect of the pilot flame on flame base anchoring was investigated because the improved stability with a pilot flame is usually attributed to improved flame anchoring through the recirculation of hot products from the pilot to the main flame base. Chemiluminescence images

  19. Designing a Bubbling Fluidized Bed (BFB) Boiler for Research Purposes

    OpenAIRE

    Castiella Franco, Daniel

    2013-01-01

    This project is part of the efforts made by Savonia University of Applied Sciences to design the future EU-funded combustion research laboratory that will be located on Varkaus Campus. The main objective of the present thesis was to carry out an optimal design, in technical, environmental and economical terms, of a small-sized bubbling fluidized bed (BFB) boiler, which will be used mainly for research purposes. This design takes as a reference a former BFB boiler that was located at L...

  20. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, second quarter 1994, April 1994--June 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NOx combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NOx reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NOx burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NOx reductions of each technology and evaluate the effects of those reductions on other combustion parameters. Results are described.

  1. The technical and economic feasibility of Cynara cardunculus L. gasification

    OpenAIRE

    Gómez García, Alberto

    2012-01-01

    This PhD Thesis analyses the technical and economic feasibility of the gasification of one of the most promising energy crops in terms of biomass yield and plantation costs: Cynara cardunculus L. (cynara). The aim of this analysis is to assess the bioenergy production via fluidized bed gasification (FBG) and the ulterior treatment of the synthesis gas (syngas) produced in the FBG reactor to adequate it to end-use applications such as gas turbines and internal combustion engines. To achieve th...

  2. Transfer of reaction-technical findings from pilot-scale nitrogen elimination to technical-scale organic packed beds; Uebertragung von reaktionstechnischen Erkenntnissen an Pilotanlagen zur Stickstoffentfernung auf grosstechnische Biofestbettanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Ante, A.; Brambach, R. [Lurgi Bamag GmbH, Butzbach (Germany)

    1999-07-01

    Organic packed beds offer some process engineering advantages: first of all an enormously high turnover rate per unit of space, low temperature dependence and, because of the flow pipe characteristics, the possibility to achieve very low effluent concentrations. In addition, the filtration effect binds solids, hence the concentration of solids in the effluent is very low. The formation of biofilm enhances this filter effect. Decisive kinetic parameters for nitrification systems are the rated temperature, the ratio of COD to N, and peak loads. For denitrification the design parameters are, beside temperature, loading with solids, the specific surface of the carrier material and filtration speed. In extensive investigations process variants were studied. They enhance the rate of turnover of nitrification with the aid of auxiliaries or through oxygen enrichment of process air to such an extent as to permit aimed buffering of peak ammonium freights. This constitutes a process-technical solution to one of the gravest drawbacks of packed-bed technology. (orig.) [German] Biofestbettanlagen bieten einige verfahrenstechnische Vorteile, in erster Linie eine enorm hohe Raumumsatzleistung, eine geringere Temperaturabhaengigkeit und aufgrund der Stroemungsrohrcharakteristik die Moeglichkeit sehr geringe Ablaufkonzentrationen zu erreichen. Zudem ist mit der Filtration aufgrund der Filterwirkung eine sehr geringe Feststoffkonzentration im Ablauf verbunden. Diese Filterwirkung wird durch die Ausbildung des Biofilmes noch untestuetzt. Die entscheidenden kinetischen Auslegungsgroessen fuer die Nitrifikation sind die Auslegungstemperatur, das CSB:N-Verhaeltnis sowie die Spitzenbelastungen. Fuer die Denitrifikation stellen neben der Temperatur, die Feststoffbeladung, die spezifische Oberflaeche des Traegermaterials sowie die Filtergeschwindigkeit die Auslegungsparameter dar. Durch umfangreiche Untersuchungen wurden Verfahrensvarianten erforscht, welche durch den Einsatz von

  3. Industrial application of fluidized bed combustion. Phase I, task 4: sub-scale unit testing and data analysis. Volume I. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Goodstine, S.L.; Accortt, J.I.; Harris, R.D.; Kantersaria, P.P.; Matthews, F.T.; Jones, B.C.; Jukkola, G.D.

    1979-12-01

    Combustion Engineering, under contract with the Department of Energy, has developed, designed, and is constructing a 50,000 lbs steam/hr Industrial FBC Demonstration Plant. The plant will provide steam for space heating at the Great Lakes Naval Base in North Chicago, Illinois. Its operation will enable industry to objectively appraise the performance, reliability, and economics of FBC technology. A hot sub-scale unit (SSU), simulating the operating conditions of the demonstration plant, has been constructed and operated at Combustion Engineering's Kreisinger Development Laboratory in Windsor, Connecticut. The SSU facility has served as a valuable developmental tool in establishing the performance characteristics of the FBC process and equipment as used in the larger Demonstration Plant. Experience gained during more than 2000 hours of operation, including the analytical results derived from an extensive test program of 1500 hours operation, has defined problems and identified solutions in engineering the larger FBC Demonstration Plant. This report presents documentation of the results of the SSU test program.

  4. Homogeneous chemistry of NO/sub x/ production and removal from fossil fuel combustion gases. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Silver, J.A.; Gozewski, C.M.; Kolb, C.E.

    1980-11-01

    The reduction of NO/sub x/ emissions from stationary combustion sources by non-catalytic homogeneous chemical addition is a promising technique. Demonstrations in laboratory experiments and on a number of field scale combustors have shown that the addition of ammonia to the exhaust flow significantly reduces the NO concentrations in a narrow temperature range. This report summarizes the work performed to understand the detailed chemical mechanism which makes this reduction occur. A model describing the NH/sub i//NO/sub x/ chemical system is developed, and rates of the key reactions identified are measured in a high temperature fast flow reactor. Product channels for certain important reactions are also identified. The experimental results are incorporated into the computer code, and the model predictions are compared with laboratory and field test results. Possible additives other than ammonia are evaluated and discussed.

  5. Quantitative laser diagnostics of the mixing process in technical combustion systems; Quantitative laserdiagnostische Untersuchung der Gemischaufbereitung in technischen Verbrennungssystemen

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, D.

    1995-01-01

    The mixing processes in an oil-fuelled heating burner and in a spark ignitionengine were investigated by means of planar laser-induced fluorescence. The following aspects are discussed: Detection method; experimental set-up; Fuil distribution in a heating burner; fuel distribution in the combustion chamber of a spark ignition engine; fluorescence behaviour of the tracer under engine conditions; analysis of the gas mixture produced. (HW) [Deutsch] In der vorliegenden Arbeit wurde die Gemischaufbereitung in einem oelgefeuerten Heizungsbrenner sowie in einem Otto-Motor mittels planarer laserinduzierter Fluorescence untersucht. Im einzelnen werden in der Arbeit folgende Aspekte diskutiert: - Nachweismethode; - Experimenteller Aufbau; - Brennstoffverteilung in einem Heizungsbrenner; - Kraftstoffverteilung im Brennraum eines Otto-Motors; - Fluorescenzeverhalten des Tracers unter Motorbedingungen; - Untersuchung des Endgases. (HW)

  6. Status of the fluidized bed unit

    International Nuclear Information System (INIS)

    Rocky Flats has a serious mixed waste problem. No technology or company has a license and available facilities to remedy this dilemma. One solution under study is to use a catalytic fluidized bed unit to destroy the combustible portion of the mixed waste. The fluidized bed thermal treatment program at Rocky Flats is building on knowledge gained over twenty years of successful development activity. The FBU has numerous technical advantages over other thermal technologies to treat Rocky Flats' mixed waste, the largest being the lower temperature (700 degrees C versus 1000 degrees C) which reduces acid corrosion and mechanical failures and obviates the need for ceramic lining. Successful demonstrations have taken place on bench, pilot, and full-scale tests using radioactive mixed wastes. The program is approaching implementation and licensing of a production-scale fluidized bed system for the safe treatment of mixed waste. The measure for success on this project is the ability to work closely with the community to jointly solve problems and respond to concerns of mixed waste treatment at Rocky Flats

  7. Experimental investigation and mathematical modelling of the combustion of brown coal, refuse and mixed fuels in a circulating fluidized bed combustor; Experimentelle Untersuchung und mathematische Modellierung der Verbrennung von Braunkohle, Abfallstoffen und Mischbrennstoffen in einer zirkulierenden Wirbelschichtfeuerung

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, W.; Brunne, T.; Hiller, A. [Technische Univ. Dresden (Germany). Inst. fuer Energietechnik; Albrecht, J. [Lurgi Umwelt GmbH, Frankfurt am Main (Germany); Quang, N. [Polytechnic Inst., Danang (Viet Nam)

    1998-09-01

    Extensive experiments on combustion of biological materials and residues in fluidized bed combustors and dust combustors have been carried out at the Department of Power Plant Engineering of Dresden University since the early nineties. Particular interest was taken in mixing brown coal with sewage sludge, sugar pulp and waste wood. The experiments were supplemented by modelling in a research project funded jointly by the BMBF and Messrs. Lurgi since early 1997. A combustion cell model designed by Siegen University is being modified for the new mixed fuels, and preliminary investigations were carried out on a batch reactor while the modelling work was continued. (orig.) [Deutsch] An dem Lehrstuhl fuer Kraftwerkstechnik der TU Dresden werden seit Anfang der 90-iger Jahre umfangreiche experimentelle Untersuchungen zur Verbrennung von Bio- und Reststoffen in Wirbelschicht- und Staubfeuerungen durchgefuehrt. Dabei war vor allem die Zufeuerung dieser Stoffe in Waermeerzeugeranlagen auf Braunkohlenbasis von besonderem Interesse. Experimentell konnte nachgewiesen werden, dass sowohl Biobrennstoffe als auch Abfaelle in zirkulierenden Wirbelschichtfeuerungen umweltschonend zur Waermeerzeugung eingesetzt werden koennen. Als Beispiel wird das an Hand von Braunkohle-Klaerschlammgemischen sowie Bagasse- und Holz-Braunkohlegemischen gezeigt. Neben den experimentellen Untersuchungen bietet die Modellierung der Verbrennungsvorgaenge ein geeignetes Mittel um Voraussagen zu anderen Mischungsanteilen sowie anderen geometrischen Abmessungen machen zu koennen. Seit Anfang 1997 wird dazu ein vom BMBF und der Firma Lurgi gefoerdertes Forschungsvorhaben bearbeitet. Ein von der Universitaet Gesamthochschule Siegen fuer die Braunkohleverbrennung konzipiertes Zellenmodell wird auf die neuen Brennstoffgemische erweitert. Da grundsaetzlich andere Stoffzusammensetzungen vorliegen, wurden an einem Batch-Reaktor Voruntersuchungen zum Pyrolyseverhalten der Brennstoffe durchgefuehrt. Erste

  8. Coal combustion under conditions of blast furnace injection. [Quarterly] technical report, 1 December 1993--28 February 1994

    Energy Technology Data Exchange (ETDEWEB)

    Crelling, J.C. [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Geology

    1994-06-01

    A potentially new use for Illinois coal is its use as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This proposal is a follow-up to one funded for the 1992--1993 period. It is intended to complete the study already underway with the Armco Inc. Steel Company and to initiate a new cooperative study along somewhat similar lines with the Inland Steel Company. The results of this study will lead to the development of a testing and evaluation protocol that will give a unique and much needed understanding of the behavior of coal in the injection process and prove the potential of Illinois coals for such use. During this quarter a sample of the feed coal that is being used for injection into the No. 7 Blast Furnace of Inland Steel has been analyzed petrographically and compared to both the Herrin No. 6 coal and Armco feed coal. Additional characterization is underway and an advanced program of pyrolysis and reactivity testing has been initiated.

  9. Investigation of a rotary valving system with variable valve timing for internal combustion engines: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Cross, P.C.; Hansen, C.N.

    1994-11-18

    The objective of the program was to provide a functional demonstration of the Hansen Rotary Valving System with Variable Valve timing (HRVS/VVT), capable of throttleless inlet charge control, as an alternative to conventional poppet-valves for use in spark ignited internal combustion engines. The goal of this new technology is to secure benefits in fuel economy, broadened torque band, vibration reduction, and overhaul accessibility. Additionally, use of the variable valve timing capability to vary the effective compression ratio is expected to improve multi-fuel tolerance and efficiency. Efforts directed at the design of HRVS components proved to be far more extensive than had been anticipated, ultimately requiring that proof-trial design/development work be performed. Although both time and funds were exhausted before optical or ion-probe types of in-cylinder investigation could be undertaken, a great deal of laboratory data was acquired during the course of the design/development work. This laboratory data is the basis for the information presented in this Final Report.

  10. Chemical Processes Related to Combustion in Fluidised Bed. Report for the period 2002-07-01 to 2004-06-30

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Lindqvist, Oliver [Chalmers University of Technology, Goeteborg (Sweden). Dep. of Environmental Inorganic Chemistry

    2005-02-01

    One part of the project was an investigation of the mechanism and kinetics of the absorption of potassium and cadmium in kaolin. Addition of kaolin has been suggested as a method to decrease problems like ash sintering, fouling and corrosion. The results showed that kaolin binds potassium effectively, especially if it is present as chloride or hydroxide. Reducing atmosphere and the presence of water vapour favours the absorption. The products are mainly silicates with low solubility. Cadmium is also absorbed by kaolin in a similar way. In the second part of the project, the chemical forms of some metals present in fly ash from combustion of MSW and bio fuels were studied. The most common Cd-compounds found were sulphate, oxide, chloride and silicate. It was also shown that Cd often is incorporated in calcium minerals, such as calcium silicates, CaO and CaC0{sub 3}, due to the fact that the ions Ca{sup 2+} and Cd{sup 2+} are almost similar in size and charge.

  11. A Comparative Study of Fouling and Bottom Ash from Woody Biomass Combustion in a Fixed-Bed Small-Scale Boiler and Evaluation of the Analytical Techniques Used

    Directory of Open Access Journals (Sweden)

    Lara Febrero

    2015-05-01

    Full Text Available In this work, fouling and bottom ash were collected from a low-power boiler after wood pellet combustion and studied using several analytical techniques to characterize and compare samples from different areas and determine the suitability of the analysis techniques employed. TGA results indicated that the fouling contained a high amount of organic matter (70%. The XRF and SEM-EDS measurements revealed that Ca and K are the main inorganic elements and exhibit clear tendency in the content of Cl that is negligible in the bottom ash and increased as it penetrated into the innermost layers of the fouling. Calcite, magnesia and silica appeared as the major crystalline phases in all the samples. However, the bottom ash was primarily comprised of calcium silicates. The KCl behaved identically to the Cl, preferably appeared in the adhered fouling samples. This salt, which has a low melting point, condenses upon contact with the low temperature tube and played a crucial role in the early stages of fouling formation. XRD was the most useful technique applied, which provided a semi-quantitative determination of the crystalline phases. FTIR was proven to be inadequate for this type of sample. The XRF and SEM-EDS, techniques yield similar results despite being entirely different.

  12. Co-combustion feasibility study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Handcock, D.J. [Clough, Harbour and Associates, Albany, NY (United States)

    1995-01-01

    This report investigates the technical and economic feasibility of co-combusting municipal sewage sludge produced by the Saratoga County Sewer District No. 1 with paper mill sludge produced by the Cottrell Paper Company, Encore Paper Company, International Paper Company, Mohawk Paper Mills, and TAGSONS Papers at the Saratoga County Sewer District No. 1`s secondary wastewater treatment plant and recovering any available energy products. The co-combustion facility would consist of sludge and wood chip storage and conveying systems, belt filter presses, screw presses, fluidized-bed incinerators, venturi scrubbers and tray cooling systems, ash dewatering facilities, heat recovery steam generators, gas-fired steam superheaters, and a back-pressure steam turbine system. Clean waste wood chips would be used as an auxiliary fuel in the fluidized-bed incinerators. It is recommended that the ash produced by the proposed facility be beneficially used, potentially as a raw material in the manufacture of cement and/or as an interim barrier layer in landfills.

  13. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume VII. FBC Data-Base-Management System (FBC-DBMS) users manual

    Energy Technology Data Exchange (ETDEWEB)

    Louis, J.F.; Tung, S.E.

    1980-10-01

    The primary goal of the Fluidized Bed Combustor Data Base (FBCDB) is to establish a data repository for the express use of designers and research personnel involved in FBC development. FBCDB is implemented on MIT's 370/168 computer, using the Model 204 Data Base Management System (DBMS) developed by Computer Corporation of America. DBMS is a software that provides an efficient way of storing, retrieving, updating and manipulating data using an English-like query language. The primary content of FBCDB is a collection of data points defined by the value of a number of specific FBC variables. A user may interactively access the data base from a computer terminal at any location, retrieve, examine, and manipulate the data as well as produce tables or graphs of the results. More than 20 program segments are currently available in M204 User Language to simplify the user interface for the FBC design or research personnel. However, there are still many complex and advanced retrieving as well as applications programs to be written for this purpose. Although there are currently 71 entries, and about 2000 groups reposited in the system, this size of data is only an intermediate portion of our selection. The usefulness of the system at the present time is, therefore, limited. This version of FBCDB will be released on a limited scale to obtain review and comments. The document is intended as a reference guide to the use of FBCDB. It has been structured to introduce the user to the basics of FBCDB, summarize what the available segments in FBCDB can do, and give detailed information on the operation of FBCDB. This document represents a preliminary draft of a Users Manual. The draft will be updated when the data base system becomes fully implemented. Any suggestions as to how this manual may be improved will be appreciated.

  14. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume VI. FBC-Data Base-Management-System (FBC-DBMS) development

    Energy Technology Data Exchange (ETDEWEB)

    Louis, J.F.; Tung, S.E.

    1980-10-01

    The primary goal of the Fluidized Bed Combustor Data Base, (FBCDB), situated in MIT's Energy laboratory, is to establish a data repository for the express use of designers and research personnel involved in FBC development. DBMS is a software that provides an efficient way of storing, retrieving, updating and manipulating data using an English-like query language. It is anticipated that the FBCDB would play an active and a direct role in the development of FBC technology as well as in the FBC commercial application. After some in-house experience and after a careful and extensive review of commercially available database systems, it was determined that the Model 204 DBMS by Computer Corporation of America was the most suitable to our needs. The setup of a prototype in-house database also allowed us to investigate and understand fully the particular problems involved in coordinating FBC development with a DBMS. Various difficult aspects were encountered and solutions had been sought. For instance, we found that it was necessary to rename the variables to avoid repetition as well as to increase usefulness of our database and, hence, we had designed a classification system for which variables were classified under category to achieve standardization of variable names. The primary content of FBCDB is a collection of data points defined by the value of a number of specific FBC variables. A user may interactively access the database from a computer terminal at any location, retrieve, examine, and manipulate the data as well as produce tables or graphs of the results.

  15. Phosphorus-fixation by hydrated lime in fluidized bed combustion of yellow phosphorus tail gas%流化床燃烧黄磷尾气过程中Ca(OH)2的固磷作用

    Institute of Scientific and Technical Information of China (English)

    王磊; 王重华; 宁平; 蒋明; 覃扬颂

    2013-01-01

    Hydrated lime was tested for removing phosphoric pentoxide during the premixed combustion of yellow phosphorus tail gas in fluidized bed. The effect of temperature on the retention of phosphoric pentoxide in hydrated lime was examined by changing air fuel ratio. XRD, SEM and EDS techniques were used to analyze and characterize fresh sorbent and sorbent after reaction. The computer software package FactSage6.2 was used to predict solid product. The results show that the highest temperature of yellow phosphorus tail gas premixed combustion in fluidized bed is 1 060 ℃. Within flow ratio of air to fuel from 1.7 to 4.2, the temperature can be stabilized above 870 ℃. The sorbent can react with phosphoric pentoxide and removal efficiencies increase with the increase of the temperature. Phosphoric pentoxide removal by hydrated lime is 86% at 1 060 ℃, 47% at 920 ℃, and 30% at 870 ℃ in fluidized bed, respectively. The sorbent reacts with phosphoric pentoxide firstly forming basic calcium phosphate, and then changing into calcium phosphate. At high temperature, calcium phosphate changes into calcium pyrophosphate. Solid product predicted results are consistent with the experimental results.%通过流化床预混燃烧黄磷尾气,在燃烧过程中加入氢氧化钙,对黄磷尾气燃烧产生的五氧化二磷进行去除.改变空燃比考察反应温度对去除率的影响,对吸收剂进行XRD,SEM,EDS物相表征和微区元素分析,采用FactSage6.2热力学软件对生成的固体产物进行预测.研究结果表明:流化床预混燃烧黄磷尾气,最高温度1 060℃,在空燃比1.7~4.2的范围内炉内温度能稳定在870℃以上.吸收剂可同五氧化二磷反应,吸收率随温度升高而增加,1 060℃时吸收率为86%,920℃时吸收率为50%,870℃时吸收率为30%;氢氧化钙同五氧化二磷首先形成碱式磷酸钙,之后变为磷酸钙,在高温下磷酸钙转变为焦磷酸钙.固体产物的预测结果与实验结果一致.

  16. Mineralogy and chemistry of conventional and fluidised bed coal ashes

    Directory of Open Access Journals (Sweden)

    Sulovský P

    2002-03-01

    Full Text Available Coal combustion residues represent very abundant inorganic waste materials. The change from conventional combustion of powdered North Bohemian brown coal to its combustion in fluidised bed boilers in several Czech power and heating plants calls for detailed mineralogical and geochemical characterisation of the combustion residues. The main differences between fly ashes from both combustion systems result from different burning temperatures and differing systems of desulphurisation (coeval with combustion / post-combustion. Both these factors influence the chemical and phase compositions as well as the speciation of trace elements. The study further shows that the validity of the surface enrichment model (Linton et al. 1975 can be limited.

  17. Dual fluidized bed design for the fast pyrolysis of biomass

    Science.gov (United States)

    A mechanism for the transport of solids between fluidised beds in dual fluidised bed systems for the fast pyrolysis of biomass process was selected. This mechanism makes use of an overflow standpipe to transport solids from the fluidised bed used for the combustion reactions to a second fluidised be...

  18. Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence - phase II - small scale field demonstration. Topical report, December 1, 1996--February 28, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Ziemkiewicz, P.F.; Head, W.J.; Gray, D.D.; Siriwardane, H.J.; Sack, W.A.

    1998-01-01

    It has been proposed that a mix made from fly and bottom ash from atmospheric pressure fluidized bed coal combusters (FBC ash), water, and stabilizers be injected from the surface into abandoned room and pillar coal mines through boreholes. Besides ash disposal, this process would prevent subsidence and acid mine drainage. Such a mix (called `grout`) needs to be an adequately stable and flowable suspension for it to spread and cover large areas in the mine. This is necessary as the drilling of the boreholes will be an expensive operation and the number such holes should be minimized. Addition of bentonite was found to be needed for this purpose. A suitable grout mix was tested rheologically to determine its fluid flow properties. Finding little published information on such materials, tests were performed using a commercial rotational viscometer with a T-bar rotor and a stand which produced a helical rotor path. Existing mixer viscometer test methods were modified and adapted to convert the measurements of torque vs. angular speed to the material properties appearing in several non-Newtonian constitutive equations. Yield stress was measured by an independent test called the vane method. The rheological behavior was a close fit to the Bingham fluid model. Bleed tests were conducted to ascertain the stability of the mixtures. Spread tests were conducted to compare the flowability of various mixes. Using the flow parameters determined in the laboratory, numerical simulations of grout flow were performed and compared with the results of scale model and field tests. A field injection of this grout was performed at the Fairfax mines in Preston county, W.V.. The observations there proved that this FBC ash grout flows as desired, is a very economical way of disposing the environmentally menacing ash, while also preventing the subsidence and acid mine drainage of the mines.

  19. Ash behaviour in fluidized bed gasification and combustion: release of harmful trace elements and the behavior of alkalis; Tuhkan muuntuminen leijukerroskaasutuksessa ja -poltossa: Haitallisten hivenmetallien vapautuminen ja alkalien kaeyttaeytyminen

    Energy Technology Data Exchange (ETDEWEB)

    Kauppinen, E.; Valmari, T. [VTT Chemical Technology, Espoo (Finland)

    1997-10-01

    During 1996 the behaviour of alkaline metals (K and Na) during circulating fluidized bed combustion of forest residue was studied in a real-scale plant using aerosol measurement instruments (filters, impactor, DMA). Prior to heat exchangers (850 deg C) the ash mass-concentration was 1.0 - 1.3 g/Nm{sup 3} with 1 % of ash forming constituents as vapours. At least 98 % of sulphur, over 90 % of sodium and over 80 % of potassium were found in particulate phase prior to heat exchangers. On the other hand, at least 80 % of the chlorine was in vapour phase. 98 % of the ash was in coarse (> 0.3 {mu}m) particles. Coarse ash particles had an irregular surface structure often consisting of fine primary particles. The remaining 2 % was observed in fine particles of about 0.1 {mu}m. Both rounded and cornered (suggesting crystal structure) fine particles were found. The fine particles were composed of alkali chlorides and sulphates, mainly of KCl. About 80 % of the ash on mass basis was deposited onto heat exchanger surfaces when soot-blowing was not carried out. Practically all of the particles larger than 10 {mu}m were deposited. The deposition was less significant for smaller particles. The fine particle concentration before and after the heat exchangers was the same within the experimental inaccuracy. The deposited fraction of potassium, sodium and sulphur was about the same than that of the total ash: However, the deposition of chlorine was much lower since the chlorine content was low in the coarse particles that were deposited most effectively. (orig.)

  20. 循环流化床富氧燃烧NO和N2O的排放特性%NO and N2O Emission Characteristics of Oxy-Fuel Circulating Fluidized Bed Combustion

    Institute of Scientific and Technical Information of China (English)

    李伟; 李诗媛; 徐明新; 吕清刚

    2015-01-01

    Experiments were carried out in a 50,kW circulating fluidized bed(CFB)combustor under the O2/CO2at-mosphere. The combustion temperature was within the range of 800—950,℃,and the inlet oxygen concentration was within the range of 25%—50%,. The effects of combustion temperature,inlet oxygen concentration and excess oxy-gen coefficient on NO and N2O emission characteristics were studied. The results show that the N conversion rate un-der the O2/CO2,firing mode is much lower than that under the air firing mode. As the inlet oxygen concentration in-creases,the NO emission increases and while N2O emission decreases. With the increase of excess oxygen coefficient,both NO and N2O emissions and N conversion rate increase. It can be concluded that increasing tempera-ture and inlet oxygen concentration and decreasing excess oxygen coefficient areboth beneficial to the decrease of N conversion rate oxy-fuel CFB combustion.%在50,kW循环流化床燃烧试验台上对大同煤和神木半焦进行了O2/CO2气氛的富氧燃烧试验,试验的进口氧气体积分数为25%,~50%,,燃烧温度为800~950,℃.试验研究的目标是获得燃烧温度、进口氧气体积分数和过量氧气系数等因素对循环流化床富氧燃烧过程中 NO 和 N2O 的排放特性以及燃料 N 转化率的影响.研究结果表明,与空气气氛相比,O2/CO2气氛下的燃料N转化率明显降低;随着进口氧气体积分数增加,NO的排放下降,而N2O 的排放则升高;随着过量氧气系数的增加,NO、N2O 的排放以及燃料 N 转化率均呈增加趋势.在循环流化床富氧燃烧中,提高燃烧温度、进口氧气体积分数以及降低过量氧气系数都能有效降低燃料N转化率,抑制氮氧化物的排放.

  1. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, fourth quarter 1991

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-21

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as parameters such as particulate characteristics and boiler efficiency.

  2. Boiler Modelling of Simple Combustion Processes

    OpenAIRE

    Radovan Nosek; Jozef Jandacka; Andrzej Szlek

    2012-01-01

    The aim of the work is to investigate coal combustion in fixed bed reactor. The experimental results were worked out in the form of approximation functions describing gas composition at the exit of fixed bed reactor. Furthermore, developed functions were applied for defining the boundary conditions at the interface between the fixed bed and gas phase using FLUENT. The simulations of a domestic boiler have been done and the relative effects of different factors in CFD code were evaluated by se...

  3. Direct Utilization of Circulating Fluidized Bed Combustion Ash of Distilled Spirits Lees as Fertilizer%白酒糟循环流化床燃烧灰直接肥料化利用

    Institute of Scientific and Technical Information of China (English)

    宋扬; 汪印; 姚常斌; 张玉明; 王昶; 易彬; 杨俊; 许光文

    2011-01-01

    研究了白酒糟循环流化床燃烧灰直接作为肥料的可能性和效果,以其为肥料种植油菜,考察了油菜在5种土壤中发芽和生长情况.结果表明,白酒糟燃烧灰对不同生长阶段的油菜有不同影响,对壤质土中的油菜发芽有抑制作用,但能明显改善粘性土壤中油菜的生长环境,油菜的净增量和产量都有明显增加.白酒糟燃烧灰还能提高酸性土壤pH值,使土壤环境向中性(pH 6.97~7.74)变,有利于腐殖酸分解和植物生长.土壤与白酒糟燃烧灰质量比为5:1时,与原土相比,泸州国窖红土壤、泸州青稞土壤及富阳土壤中油菜净增量分别为80.1%,80.9%,163.6%,表明利用白酒糟燃烧灰作为植物生长肥料是可行的.%The feasibility of utilizing the circulating fluidized bed combustion ash of distilled spirits lees as fertilizer was investigated. The rape culture experiment was carried out in 5 different kinds of soils, and the rape growth states in the germination and growth stages were measured to evaluate the effect of adding ash to the soils as fertilizer. The results show that the ash exhibited different effects on the rape growth in different culture stages. There was an antibiastic effect on the rape growth in the germination stage in a loamy soil, but the rape growth was much improved when adding the ash to a clayey soil. The latter led the mature rape to having obviously increased net height and weight. The ash could change the pH value of acid soil into neutral state, facilitating the humic acid decomposition and plant growth. Comparing the soils at soil:ash=5:l(ω) with original soil, the increased amplitudes of net height of rape in Guojiaohong Turang, Qingke Turang and Fuyang Turang were 80.1%, 80.9% and 163.6%, respectively. As consequence, it was feasible and effective to use directly the combustion ash of distilled spirits lees as fertilizer.

  4. Direct conversion of starch into ethanol in a gas-solid fluidized bed fermenter with technical amylases and baker's yeast

    Energy Technology Data Exchange (ETDEWEB)

    Moebus, O.; Teuber, M.

    1985-02-01

    Our experiments have shown that solid substrate fermentations in a gas-solid fluidized bed reactor can be used with starch for producing ethanol. Ground modified rice (0,3 mm mesh) was fluidized with pressed baker's yeast particles and powdered enzyme preparations of ..cap alpha..-amylase and amyloglucosidase in the reactor, gassed with carbon dioxide, which was added before fermentation or produced by the fermentation, and humidified by spraying deionized water with a two phase nozzle into the bed. The modified starch absorbed water, which allowed the amylases to attack the starch. The glucose set free was transformed by the yeast into ethanol and carbon dioxide. This system offers an alternative to the recently developed methods of coimmobilisation.

  5. Two stage fluid bed-plasma gasification process for solid waste valorisation: technical review and preliminary thermodynamic modelling of sulphur emissions.

    Science.gov (United States)

    Morrin, Shane; Lettieri, Paola; Chapman, Chris; Mazzei, Luca

    2012-04-01

    Gasification of solid waste for energy has significant potential given an abundant feed supply and strong policy drivers. Nonetheless, significant ambiguities in the knowledge base are apparent. Consequently this study investigates sulphur mechanisms within a novel two stage fluid bed-plasma gasification process. This paper includes a detailed review of gasification and plasma fundamentals in relation to the specific process, along with insight on MSW based feedstock properties and sulphur pollutant therein. As a first step to understanding sulphur partitioning and speciation within the process, thermodynamic modelling of the fluid bed stage has been performed. Preliminary findings, supported by plant experience, indicate the prominence of solid phase sulphur species (as opposed to H(2)S) - Na and K based species in particular. Work is underway to further investigate and validate this. PMID:21982278

  6. Two stage fluid bed-plasma gasification process for solid waste valorisation: technical review and preliminary thermodynamic modelling of sulphur emissions.

    OpenAIRE

    Morrin, S.; Lettieri, P.; Chapman, C.; Mazzei, L

    2011-01-01

    Gasification of solid waste for energy has significant potential given an abundant feed supply and strong policy drivers. Nonetheless, significant ambiguities in the knowledge base are apparent. Consequently this study investigates sulphur mechanisms within a novel two stage fluid bed-plasma gasification process. This paper includes a detailed review of gasification and plasma fundamentals in relation to the specific process, along with insight on MSW based feedstock properties and sulphur po...

  7. Fluidized bed heat exchanger utilizing angularly extending heat exchange tubes

    Science.gov (United States)

    Talmud, Fred M.; Garcia-Mallol, Juan-Antonio

    1980-01-01

    A fluidized bed heat exchanger in which air is passed through a bed of particulate material containing fuel disposed in a housing. A steam/water natural circulation system is provided and includes a steam drum disposed adjacent the fluidized bed and a series of tubes connected at one end to the steam drum. A portion of the tubes are connected to a water drum and in the path of the air and the gaseous products of combustion exiting from the bed. Another portion of the tubes pass through the bed and extend at an angle to the upper surface of the bed.

  8. Coal conversion. 1977 technical report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    The status and progress in US DOE's projects in coal gasification, liquefaction, and fluidized-bed combustion are reviewed with financing, flowsheets, history, progress and status of each (57 projects). (LTN)

  9. Development of a new method for improving load turndown in fluidized bed combustors: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.

    1988-12-01

    The objective of this research was to investigate a new concept in fluidized bed design that improves load turndown capability. This improvement is accomplished by independently controlling heat transfer and combustion in the combustor. The design consists of two fluidized beds, one central and one annular. The central bed serves as the combustion bed. The annular bed is fluidized separately from the combustion bed and its level of fluidization determine the overall heat transfer rate from the combustion bed to the surrounding water jacket. Early theoretical considerations suggested a load turndown exceeding ten was possible for this design. This research consisted of three major phases: development of a computational model to predict heat transfer in the two-bed combustor, heat transfer measurements in hot-and-cold flow models of the combustor, and combustion tests in an optimally designed combustor. The computation model was useful in selecting the design of the combustor. Annular bed width and particle sizes were chosen with the aid of the model. The heat transfer tests were performed to determine if the existing correlations for fluidized bed heat transfer coefficients were sufficiently accurate for high aspect ratio fluidized beds (such as the annular bed in the combustor). Combustion tests were performed in an optimally designed combustor. Three fuel forms were used: double screened, crushed coal, coal-water-limestone mixtures (CWLM), and coal-limestone briquettes. 18 refs., 30 figs., 8 tabs.

  10. Analysis and control of the METC fluid bed gasifier. Final report (includes technical progress report for October 1994--January 1995), September 1994--September 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    This document presents a modeling and control study of the Fluid Bed Gasification (FBG) unit at the Morgantown Energy Technology Center (METC). The work is performed under contract no. DE-FG21-94MC31384. The purpose of this study is to generate a simple FBG model from process data, and then use the model to suggest an improved control scheme which will improve operation of the gasifier. The work first developes a simple linear model of the gasifier, then suggests an improved gasifier pressure and MGCR control configuration, and finally suggests the use of a multivariable control strategy for the gasifier.

  11. Analysis of bed agglomeration during gasification of wheat straw in a bubbling fluidised bed gasifier using mullite as bed material

    OpenAIRE

    Mac an Bhaird, Seán T.; Walsh, Eilín; Hemmingway, Phil; McDonnell, Kevin; et al.

    2014-01-01

    The quantity and composition of the ash content of straw poses technical challenges to its thermal conversion and have been widely reported to cause severe ash sintering and bed agglomeration during fluidised bed gasification. Literature indicates that a combination of reactor design and bed material measures is required to avoid defluidisation at temperatures above 800 °C. Using scanning electron microscopy and energy dispersive X-ray spectroscopy this study investigated the initial agglomer...

  12. Data for modern boilers used in co-combustion; Moderna panndata inom samfoerbraenning

    Energy Technology Data Exchange (ETDEWEB)

    Thorson, Ola [S.E.P. Scandinavian Energy Project AB, Goeteborg (Sweden)

    2004-04-01

    This project is a survey and a description of today's technical status and future development trends in the field of co-combustion. The survey is done from an energy production company's point of view and two technical questions have been studied; the possibilities for high steam data and the possibilities for a wide load range. These parameters are limited by the corrosive properties of the fuel and the environmental requirements in the EU directive for combustion of waste. In the report following issues are discussed: Examples of and experiences from co-combustion plants and plants that combust problematic fuels and have high steam data. A future prospect of high steam data in co-combustion plants by the usage of modern technical solutions and a description of these solutions. Important research and development results from combustion of problematic fuels in combination with high steam data. Choice of firing technology, boiler design and auxiliary systems and its affection on the load range in a boiler for co-combustion. A literature survey has been done to get the latest results from combustion of problematic fuels. Then a number of interesting plants have been identified and facts about them have been collected by contacts with plant owners, suppliers and professional researchers and also through publications. The report shows that Sweden, Finland and Denmark are in the front line of using high steam data for co-combustion of biomass and waste fuels. There are/have been problems with superheater corrosion in many of these plants but a number of ways how to handle high steam data have been identified: Adjust the fuel mix or add additives; Use high alloy materials; Consider the final super heater as a part that is worn out by time; Place the final super heater in the particle loop seal/sand locker; Use an external separate fired super heater; Gasification and then co-combustion of the pyrolysis gas in a conventional existing boiler; Place the

  13. Experimental research on combustion fluorine retention using calcium-based sorbets during coal combustion (Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    QI Qing-jie; LIN Zhi-yan; LIU Jian-zhong; WU Xian; ZHOU Jun-hu; CEN Ke-fa

    2008-01-01

    In order to provide experimental guide to commercial use of fluorine pollution control during coal combustion, with fluorine pollution control during coal combustion in mind, this paper proposed the theory of combustion fluorine retention technology. Feasibility of fluorine retention reaction with calcium-based fluorine retention agent was analyzed through thermo-dynamic calculation during coal combustion. By simulating the restraining and retention effects and influential factors of calcium-based sorbets on vaporized fluoride during experimental combustion using fixed bed tube furnace, the paper systematically explored the influential law of such factors as combustion temperature, retention time, and added quantities of calcium-based sorbets on effects of fluorine retention. The research result shows that adding calcium-based fluorine retention agent in coal combustion has double effects of fluorine retention and sulfur retention, it lays an experimental foundation for commercial test of combustion fluorine retention.

  14. Proceedings of the 1999 international joint power generation conference (FACT-vol. 23). Volume 1: Fuels and combustion technologies; Gas turbines; and Nuclear engineering

    International Nuclear Information System (INIS)

    Papers are arranged under the following topical sections: Gas turbine combustion; Advanced energy conversion; Low NOx solutions; Burner developments; Alternative fuels combustion; Advanced energy conversion technologies; Numerical modeling of combustion; Fluidized bed combustion; Coal combustion; Combustion research; Gasification systems; Mercury emissions; Highly preheated air combustion; Selective catalytic reduction; Special topics in combustion research; Gas turbines and advanced energy; and How can the nuclear industry become more efficient? Papers within scope have been processed separately for inclusion on the database

  15. Computational Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C K; Mizobuchi, Y; Poinsot, T J; Smith, P J; Warnatz, J

    2004-08-26

    Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.

  16. Simulating Combustion

    Science.gov (United States)

    Merker, G.; Schwarz, C.; Stiesch, G.; Otto, F.

    The content spans from simple thermodynamics of the combustion engine to complex models for the description of the air/fuel mixture, ignition, combustion and pollutant formation considering the engine periphery of petrol and diesel engines. Thus the emphasis of the book is on the simulation models and how they are applicable for the development of modern combustion engines. Computers can be used as the engineers testbench following the rules and recommendations described here.

  17. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-12-31

    This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site-specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench

  18. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    None

    2000-06-30

    This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench

  19. The delineation of coal bed erosion zone with technical means of mine seismic exploration%利用矿井震波探测技术圈定煤层侵蚀带

    Institute of Scientific and Technical Information of China (English)

    魏恒一; 宋军

    2015-01-01

    The coal bed erosion is a problem in the process of coal production, and the delinenation of the erotion zone will help to select appropriate mining technology. This paper tells how to determine the boundary of the erotion zone with technical means of seismic exploration. On the basis of the lithology analysis,we can determine the scope of the erotion zone through organic arrangement of engineering.The work provided accurate geological information for the coal production and obtained good economic beneift.The technical means of mine seismic exploration will have a good prospect in solving the geological problems of the coal production.%针对综采工作面回采过程中发现的煤层侵蚀带,在进行岩性分析的基础上,应用矿井震波勘探技术,经过综合分析,系统布置勘探工程,迅速准确地圈定了工作面内部煤层侵蚀带范围,及时为煤矿生产决策提供了准确的地质信息,取得了良好的经济效益。矿井地震波勘探方法在解决矿井生产中的地质问题方面具有很好的应用前景。

  20. Analysis of combustion efficiency in CFB coal combustors

    Energy Technology Data Exchange (ETDEWEB)

    Afsin Gungor [Nigde University, Nigde (Turkey). Department of Mechanical Engineering, Faculty of Engineering and Architecture

    2008-06-15

    Fluidized bed technology is well known for its high combustion efficiency and is widely used in coal combustion. In this study, the combustor efficiency has been defined and investigated for CFB coal combustor based on the losses using a dynamic 2D model. The model is shown to agree well with the published data. The effect of operating parameters such as excess air ratio, bed operational velocity, coal particle diameter and combustor load and the effect of design variables such as bed height and bed diameter on the mean bed temperature, the overall CO emission and the combustion efficiency are analyzed for the small-scale of CFBC in the presently developed model. As a result of this analysis, it is observed that the combustion efficiency decreases with increasing excess air value. The combustion efficiency increases with the bed operational velocity. Increasing coal particle size results in higher combustion efficiency values. The coal feed rate has negative effect on the combustion efficiency. The combustor efficiency considerably increases with increasing combustor height and diameter if other parameters are kept unchanged. 46 refs., 16 figs., 6 tabs.

  1. Co-combustion of automotive shredder residue (ASR) and sewage sludge with a mixture of industrial and household waste in an 20MW fluidized bed combustor; Samfoerbraenning av bilfluff, roetslam och avfall i en 20 MW fluidbaeddpanna - Studier av braenslesammansaettningens paaverkan paa belaeggningsbildning

    Energy Technology Data Exchange (ETDEWEB)

    Eskilsson, David; Johansson, Andreas; Johansson, Linda; Wikstroem-Blomqvist, Evalena

    2007-07-01

    In order to prevent a further increased use of resources and to decrease the environmental impact from landfills, organic wastes are today diverted towards material and energy recovery. This creates a waste market with an increasing number of waste fractions that needs to be treated properly. As an example, in Sweden it has recently been prohibited to landfill source separated combustible waste (2002) and organic waste (2005). Wastes as automotive shredder residue (ASR) and sewage sludge can no longer be landfilled and needs to be either material or energy recovered, which challenge the waste treatment sector. This work investigates the effects of ASR and sewage sludge co-combustion in a 20 MW Energy-from-Waste plant (bubbling fluidised bed). The long term objective of the work is to increase the fuel flexibility, the boiler availability and the power production. This report focus on boiler operation and combustion performance in terms of agglomeration, deposit rates and emissions. In addition to the tests with ASR and sewage sludge, repeated measurements were performed during normal load as a reference. The results show that the co-combusted fractions of ASR and sewage sludge, which on mass basis constituted 6 % and 15 % respectively, did not increase the risk for agglomeration or deposits on heat-exchanging surfaces. Instead, compared to the two reference cases, the deposit rates decreased when sewage sludge was added. Only minor variation in the emissions was seen between the different cases. The levels of I-TEQs were far below the legislated values in all cases

  2. NO formation during agricultural straw combustion.

    Science.gov (United States)

    Ren, Qiangqiang; Zhao, Changsui; Duan, Lunbo; Chen, Xiaoping

    2011-07-01

    NO formation during combustion of four typical kinds of straw (wheat straw, rice straw, cotton stalk and corn stalk) which belong to soft straw and hard straw was studied in a tubular quartz fixed bed reactor under conditions relevant to grate boiler combustion. Regarding the real situation in biomass fired power plants in China, NO formation from blended straw combustion was also investigated. Nitrogen transfer during blended straw pyrolysis was performed using a thermogravimetric analyzer (TGA) coupled with a Fourier transform infrared (FTIR) spectrometer. The results show that NO conversion for the four straws during combustion is distinctive. Over 70% fuel-N converts into NO for cotton stalk, while only 37% for wheat straw under the same condition. When wheat straw and cotton stalk were mixed, N-NO conversion increases. The limestone addition promotes NO emission during cotton stalk combustion. The presence of SO(2) in atmosphere suppresses NO formation from straw combustion. PMID:21592786

  3. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report: First quarter 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. During this quarter, long-term testing of the LNB + AOFA configuration continued and no parametric testing was performed. Further full-load optimization of the LNB + AOFA system began on March 30, 1993. Following completion of this optimization, comprehensive testing in this configuration will be performed including diagnostic, performance, verification, long-term, and chemical emissions testing. These tests are scheduled to start in May 1993 and continue through August 1993. Preliminary engineering and procurement are progressing on the Advanced Low NOx Digital Controls scope addition to the wall-fired project. The primary activities during this quarter include (1) refinement of the input/output lists, (2) procurement of the distributed digital control system, (3) configuration training, and (4) revision of schedule to accommodate project approval cycle and change in unit outage dates.

  4. Technical retrofit of low Nox combustion for first 600 MW opposed firing boiler in China%国内首台600MW对冲燃烧锅炉低NOx燃烧技术改造

    Institute of Scientific and Technical Information of China (English)

    屠小宝; 胡伟锋; 徐良; 徐仲雄; 戴成峰; 应明良

    2011-01-01

    In order to minimize the possible negative effect after boiler low NOx combustion technical retrofit, the design optimization for staged combustion of main burner was emphasized, the larger chemical equivalent proportion of main burning area was adopted, the sensitivity and the dependence of chemical equivalent proportion of main burning area were reduced, and the heating surface was adjusted and rotating classifier for mill was installed in burner retrofit design. After the retrofit, the overall performance of the boiler achieves the expected goals and the NOx reduction rate reaches to 50%.%为将锅炉低NOx燃烧技术改造可能产生的负面影响减至最低程度,在燃烧器改造设计中,注重对主燃烧器分级燃烧的设计优化,采用较大的主燃烧区化学当量比,降低对主燃烧区低化学当量比的依赖度和敏感度,同时采取受热面调整和磨煤机增装动态分离器等配套措施.改造后锅炉总体性能良好,NOx减排幅度达到50%.

  5. Remediation of ash problems in fluidised-bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Vuthaluru, H.B.; Zhang, D.K. [Curtin University of Technology, Perth, WA (Australia). School of Chemical Engineering

    2001-03-01

    The paper reports the control methods for mitigating particle agglomeration and bed defluidisation during fluidised-bed combustion of low-rank coals. A laboratory scale spouted-bed combustion system is used to study the effectiveness of several control methods including the use of alternative bed materials, mineral additives, pretreatment of coal and coal blending. Sillimanite, bauxite, calcite and magnesite were used as alternative bed materials whereas mineral additives viz. clay, kaosil and bauxite were injected into the combustion system while burning South Australian low-rank coal at 800{degree}C. Samples of the same coal subjected to water-washing, Al pretreatment and Ca pretreatment are also tested in the spouted-bed combustor. In addition, experiments were conducted with several coal blends prepared at ratios of 50:50 and 90:10 from two lignites and one sub-bituminous coal. Experiments showed that all the control methods are effective to different extends in reducing ash problems and resulted in extended combustion operation. Tests with alternative bed materials and mineral additives showed trouble free-operation for longer periods (7-12 h at 800{degree}C) than with sand runs at the same bed temperature. Wet pretreatment and coal blending were also found to be effective and resulted in extended combustion operation (9-12 h at 800{degree}C). Chemical analyses indicated that formation of low temperature eutectics was suppressed by Al/Ca/Mg-rich phases in ash coating of bed particles. This was identified as the main mechanism for prevention of ash problems observed with the use of alternative bed materials, mineral additives, pretreated coals and coal blends. 23 refs., 9 figs., 7 tabs.

  6. The characteristics of bed agglomeration/defluidization in fluidized bed firing palm fruit bunch and rice straw

    International Nuclear Information System (INIS)

    The behaviors of bed particle agglomeration and defluidization were investigated during the combustion of oil palm bunch and rice straw in a laboratory scale bubbling fluidized bed reactor. The study focused on (1) the effects of fuel inorganic properties and operating variables on the bed agglomeration tendency and (2) the elucidation in the behaviors of fuel inorganic elements and the governing mode of the agglomeration. It was experimentally found that the defluidization caused by the bed agglomeration was clearly detectable from the decrease of measured bed pressure. The accumulation and growth of the agglomerates provided the partial to complete defluidization. The fuel inorganic composition was the significant influence on the bed agglomeration. The combustion of palm bunch showed higher in the bed agglomeration tendency than the straw combustion in every experimental condition. The defluidization was accelerated in response to the increase in bed temperature and bed particle size, and the decrease of air velocity and static bed height. In the SEM/EDS analysis, the agglomeration was attributed to the formation of the molten substance rich in silicon and fuel derived potassium, likely the potassium silicate compounds, which presented as the adhesive coating and bonding layer. The filling of irregularity on the bed particle surface by the liquid material to form the adhesive layer was dominated by the collision with burning fuel particles. The propagation/reaction inward the bed particles by some reactive constituents was found. The thermodynamic analysis on the ternary phase diagram corroborated that the formation of the liquid material derived from the fuel inorganic elements controlled the agglomeration; the large melt fraction in the adhesive materials at the observed bed temperature range (62–99%) was estimated. - Highlights: • The bed agglomeration was investigated during the FBC of palm bunch and rice straw. • Bed temperature, sand size, air

  7. APTI Course 427, Combustion Evaluation. Student Manual.

    Science.gov (United States)

    Beard, J. Taylor; And Others

    This student manual supplements a course designed to present fundamental and applied aspects of combustion technology which influence air pollutant emissions. Emphasis is placed on process control of combustion rather than on gas cleaning. The course is intended to provide engineers, regulatory and technical personnel, and others with familiarity…

  8. Industrial Medium-Btu Fuel Gas Demonstration-Plant Program. Technical support report: combustion system data. Part 2. Burner conversion survey

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-11-01

    This study was limited to an analysis of the feasibility of burning the IFG in the existing burners and combustion chambers among a group of prospective IFG customers. The results of this study indicate that the great majority of burner and equipment manufacturers recommend that the IFG can be utilized with their equipment. This is especially true with the boilers which make up the largest part of the load among the potential users of the IFG. A small number of burners representing a small part of the total potential load will probably have to be replaced. This study did not address the changes that would be required with respect to the fuel distribution piping within each facility. At a minimum of the existing regulators, flow meters, and control valves designed for the natural gas flow rates would have to be replaced to accommodate the higher fuel flow rates requiring with the IFG. In many facilities, the fuel distribution piping would have to be replaced. No changes, however, are requied for the combustion air fans or flues and stacks.

  9. Combustion detector

    Science.gov (United States)

    Trimpi, R. L.; Nealy, J. E.; Grose, W. L. (Inventor)

    1973-01-01

    A device has been developed for generating a rapid response signal upon the radiation-emitting combustion reaction of certain gases in order to provide a means for the detection and identification of such reaction and concurrently discriminate against spurious signals. This combustion might be the first stage of a coal mine explosion process, and thereby this device could provide a warning of the impending explosion in time to initiate quenching action. This device has the capability of distinguishing between the light emitted from a combustion reaction and the light emitted by miners' lamps, electric lamps, welding sparks or other spurious events so that the quenching mechanism is triggered only when an explosion-initiating combustion occurs.

  10. Issues in waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsson, Lennart; Robertson, Kerstin; Tullin, Claes [Swedish National Testing and Research Inst., Boraas (Sweden); Sundquist, Lena; Wrangensten, Lars [AaF-Energikonsult AB, Stockholm (Sweden); Blom, Elisabet [AaF-Processdesign AB, Stockholm (Sweden)

    2003-05-01

    The main purpose of this review is to provide an overview of the state-of-the-art on research and development issues related to waste combustion with relevance for Swedish conditions. The review focuses on co-combustion in grate and fluidised bed furnaces. It is primarily literature searches in relevant databases of scientific publications with to material published after 1995. As a complement, findings published in different report series, have also been included. Since the area covered by this report is very wide, we do not claim to cover the issues included completely and it has not been possitile to evaluate the referred studies in depth. Basic knowledge about combustion issues is not included since such information can be found elsewhere in the literature. Rather, this review should be viewed as an overview of research and development in the waste-to-energy area and as such we hope that it will inspire scientists and others to further work in relevant areas.

  11. Bed agglomeration in fluidized combustor fueled by wood and rice straw blends

    NARCIS (Netherlands)

    Thy, P.; Jenkins, B.M.; Williams, R.B.; Lesher, C.E.; Bakker, R.R.

    2010-01-01

    Petrographic techniques have been used to examine bed materials from fluidized bed combustion experiments that utilized wood and rice straw fuel blends. The experiments were conducted using a laboratory-scale combustor with mullite sand beds, firing temperatures of 840 to 1030 °C, and run durations

  12. Atmospheric fluidized bed combustor development program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ashworth, R.A.; Melick, T.A.; Plessinger, D.A.; Sommer, T.M. [Energy and Environmental Research Corp., Orville, OH (United States); Keener, H.M. [Ohio State Univ., Columbus, OH (United States). Ohio Agricultural Research and Development Center; Webner, R.L. [Will-Burt, Orrville, OH (United States)

    1995-12-01

    The objective of this project was to demonstrate and promote the commercialization of a coal-fired atmospheric fluidized bed combustion (AFBC) system, with limestone addition for SO{sub 2} emissions control and a baghouse for particulate emissions control. This AFBC system was targeted for small scale industrial-commercial-institutional space and process heat applications in the 1 x 10{sup 6} to 10 x 10{sup 6} Btu/hr capacity range. A cost effective and environmentally acceptable AFBC technology in this size range would displace a considerable amount of gas/oil with coal while resulting in significant total cost savings to the owner/operators. The project itself was separated into three levels: (1) feasibility, (2--3) subsystem development and integration, and (4) proof-of-concept. In Level (1), the technical and economic feasibility of a 1 million Btu/hr coal-fired AFBC air heater was evaluated. In Level (2--3), the complete EER fluidized bed combustor (1.5 million Btu/hr) system was developed and tested. The goal or reducing SO{sub 2} emissions to 1.2 lb/10{sup 6} Btu, from high sulfur Ohio coal, was achieved by adding limestone with a Ca/S (coal) ratio of {approximately} 3.0. Finally, in Level (4), the proof-of-concept system, a 2.2 million Btu/hr unit was installed and successfully operated at Cedar Lane Farms, a commercial nursery in Ohio.

  13. Chemical reactions in combustion of peat and biomass in two fluidized-bed boilers, CFB (25 MW) and BFB (25 MW) at Oestersund. The effect on SO2- and NOx-emissions by operating conditions and type of fuel

    International Nuclear Information System (INIS)

    Most of the air pollutants are emitted from different combustion processes and much work is therefore needed to reduce these emissions. The processes are however extremely complex and to be able to study them, fundamental chemical and physical principles have to be taken into account. The aim of the present work has been to show the importance of equilibrium chemistry to improve the knowledge of specific combustion problems as well as the processes as a whole. This will also increase the possibilities to reduce the pollutants. The measured values from two combustion units (CFB and BFB, 25 MW) show good agreement with the corresponding calculated equilibrium values. The following are some of the more important results obtained: - By co-firing peat with biomass, the total SO2 emissions can be reduced. The effects of variations in temperature and oxygen level on the SO2 emissions are also reported; - The NOx emission levels agree well with the equilibrium levels, that is they increase with temperature and oxygen levels. Therefore, the amount of nitrogen in the fuel has shown to have insignificant effect in these experiments; - Initial levels of N2O are effectively reduced by high temperatures (> 950 deg Centigrade). (Orig.). ( 36 refs., 26 figs., 18 tabs.)

  14. Pulsed atmospheric fluidized-bed combustor development

    International Nuclear Information System (INIS)

    Pulsed atmospheric fluidized-bed combustion (PAFBC) is a unique and innovative coal-fueled technology that has the potential to meet these conditions and provide heat and/or process steam to small industrial, commercial, institutional and residential complexes. The potential of Pulse Atmospheric Fluidized Bed Combustion (PAFBC) technology has been amply demonstrated under the sponsorship of a previous DOE/METC contract (DE-AC21-88MC25069). The environmental performance of a coal-fired laboratory-scale system (1.5 million British Thermal Units per hour) (MMBtu/hr) significantly surpassed that of conventional bubbling and circulating fluidized-bed combustion units (see Table 1 for performance comparison). Prompted by these encouraging results in combustion, sulfur capture, emissions control, and enhanced heat transfer, Island Creek Coal Company (ICC) and Baltimore Thermal Energy Corporation expressed interest in the technology and offered to participate by providing host sites for field testing. EA's have been submitted independently for each of these field test sites. This submission addresses the preliminary testing of the PAFBC unit at Manufacturing and Technology Conversion International's (MTCI) Baltimore, MD facility

  15. Bed mixing dryer for high moisture content fuels

    Energy Technology Data Exchange (ETDEWEB)

    Hulkkonen, S.; Heinonen, O. [Imatran Voima Oy, Vantaa (Finland)

    1997-07-01

    A bed mixing dryer is a new fuel drying technology used with fluidized bed combustion. Hot bed material is extracted from the fluidized bed and used directly as a heat source to dry the fuel. Imatran Voima Oy (IVO) in Finland has been developing the bed mixing drying technology since the early 1990s. The first pilot plant was built in 1994 at IVO's Kuusamo peat- and wood-fired power plant. The capacity of the plant is 6 MW of electricity and 20 MW of district heat. In Kuusamo the dryer is connected to a bubbling fluidized bed. Since its commissioning in 1994, the pilot dryer has been used successfully for about 3000 hours during the winter heating seasons. The next application of the bed mixing dryer will be a demonstration project in Orebro in Sweden. The fuel to be dried there is sawdust. (author)

  16. THE BAUXITES AND JELAR - BEDS

    Directory of Open Access Journals (Sweden)

    Krešimir Sakač

    1993-12-01

    Full Text Available Minor bauxite deposits and occurrences were formed in technically disturbed environments in the middle part of the Adriatic geotectonic unit in Dinarides, contemporary with the clastic Jelar-beds in the Late Lutetian time. Uneven chemical composition of these Eocene bauxites, their sporadic occurrences in developed paleorelief as well as characteristic petrographic composition of the immediate overlying rocks point out at different genetical conditions (the paper is published in Croatian.

  17. Reduction of fuel side costs due to biomass co-combustion.

    Science.gov (United States)

    Wils, Andrea; Calmano, Wolfgang; Dettmann, Peter; Kaltschmitt, Martin; Ecke, Holger

    2012-03-15

    The feasibility and influence of co-combustion of woody biomass on the fuel side costs is discussed for three hard coal power plants located in Berlin, Germany. Fuel side costs are defined as the costs resulting from flue gas cleaning and by-products. To have reliable data, co-firing tests were conducted in two power plants (i.e., slag tap furnace and circulating fluidising bed combustion). The amount of wood which was co-fired varied at levels below 11% of the fuel heat input. Wood chips originating from landscape management were used. The analyses show that co-combustion of woody biomass can lower the fuel side costs and that the co-combustion at a level below 10% of the thermal capacity is technically feasible without major problems. Furthermore, a flexible spreadsheet tool was developed for the calculation of fuel side costs and suggestions for operational improvements were made. For example, the adaptation of the Ca/S ratio (mass ratio of calcium in limestone to sulphur in the fuel) in one plant could reduce the fuel side costs up to 135 k€ yr(-1) (0.09 €M Wh(-1)). PMID:21514049

  18. Bubble Combustion

    Science.gov (United States)

    Corrigan, Jackie

    2004-01-01

    A method of energy production that is capable of low pollutant emissions is fundamental to one of the four pillars of NASA s Aeronautics Blueprint: Revolutionary Vehicles. Bubble combustion, a new engine technology currently being developed at Glenn Research Center promises to provide low emissions combustion in support of NASA s vision under the Emissions Element because it generates power, while minimizing the production of carbon dioxide (CO2) and nitrous oxides (NOx), both known to be Greenhouse gases. and allows the use of alternative fuels such as corn oil, low-grade fuels, and even used motor oil. Bubble combustion is analogous to the inverse of spray combustion: the difference between bubble and spray combustion is that spray combustion is spraying a liquid in to a gas to form droplets, whereas bubble combustion involves injecting a gas into a liquid to form gaseous bubbles. In bubble combustion, the process for the ignition of the bubbles takes place on a time scale of less than a nanosecond and begins with acoustic waves perturbing each bubble. This perturbation causes the local pressure to drop below the vapor pressure of the liquid thus producing cavitation in which the bubble diameter grows, and upon reversal of the oscillating pressure field, the bubble then collapses rapidly with the aid of the high surface tension forces acting on the wall of the bubble. The rapid and violent collapse causes the temperatures inside the bubbles to soar as a result of adiabatic heating. As the temperatures rise, the gaseous contents of the bubble ignite with the bubble itself serving as its own combustion chamber. After ignition, this is the time in the bubble s life cycle where power is generated, and CO2, and NOx among other species, are produced. However, the pollutants CO2 and NOx are absorbed into the surrounding liquid. The importance of bubble combustion is that it generates power using a simple and compact device. We conducted a parametric study using CAVCHEM

  19. Combustion apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, S.; Mitsudomi, H.

    1984-04-17

    A new burner provides the high temperatures required in the manufacture of high-grade china and artificial jewels by using air enriched with oxygen through an oxygen permselective membrane. Operators can vary the combustion air quantity and oxygen content as needed. Three flow paths arranged coaxially from a radially inner position to outside the burner supply it with the fuel, oxygen-enriched air, and combustion air. Each line is equipped with a control valve to allow variation in the furnace's heating power.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-04-01

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

  1. 乙醇-生物柴油-柴油混合燃料对柴油机性能和排放的影响%Impact of Combustion of BED Blend Fuel on Diesel Engine Performance and Emissions

    Institute of Scientific and Technical Information of China (English)

    雷基林; 申立中; 毕玉华; 谭泽飞; 陈泓; 刘少华

    2012-01-01

    According to the physicochemical property complementarity of bio-ethanol, biodiesel and petroleum diesel, a multi-component fuel ( BED fuel for short) with bio-ethanol, biodiesel and petroleum diesel was mixed. The compatibility and stability of the BED fuel were studied under four temperature (0℃、10℃ 、 15℃、 20℃ ) environments. The relation between the engine performance and emissions and the six groups of BED fuel in different proportions were studied with the experiments. The results indicated that, the engine power with BED fuel greatly reduced at high loads in intermediate speed and the reducing amplitude raised with the increasing proportion of ethanol and bio-diesel components, the drop ratio was up to 10. 2% compared with diesel. The equivalent brake specific fuel consumption ( EBSFC for short) was lower than that of pure diesel. The change of EBSFC with BED fuel in different proportions did not show regularity at low loads, while the EBSFC reduced with the increasing oxygen content in BED fuel, the drop ratio was up to 9. 2% compared with diesel. The CO emissions decreased significantly at high-loads and the biggest ratio was up to 70. 1% . The NOx emissions rose with the increasing of bio-diesel component and reduced with the increasing ethanol component, the biggest raised ratio was up to 29% at rated working conditions. The THC emissions reduced with the increasing bio-diesel component and rose with the increasing ethanol component, the biggest decreasing ratio was up to 32. 6% at rated working conditions.%基于乙醇、生物柴油和石化柴油物化性质的互补性,配制了乙醇-生物柴油-柴油混合的多组分燃料(简称BED燃料),在0℃、10℃、15℃、20℃环境下研究了BED燃料相溶性和稳定性,试验研究了6组不同比例BED燃料对柴油机性能和排放的影响.结果表明:在不对柴油机做任何改动的情况下,燃用BED燃料后在中间转速大负荷工况下动力下降较大,下降幅

  2. Turbulent combustion

    Energy Technology Data Exchange (ETDEWEB)

    Talbot, L.; Cheng, R.K. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    Turbulent combustion is the dominant process in heat and power generating systems. Its most significant aspect is to enhance the burning rate and volumetric power density. Turbulent mixing, however, also influences the chemical rates and has a direct effect on the formation of pollutants, flame ignition and extinction. Therefore, research and development of modern combustion systems for power generation, waste incineration and material synthesis must rely on a fundamental understanding of the physical effect of turbulence on combustion to develop theoretical models that can be used as design tools. The overall objective of this program is to investigate, primarily experimentally, the interaction and coupling between turbulence and combustion. These processes are complex and are characterized by scalar and velocity fluctuations with time and length scales spanning several orders of magnitude. They are also influenced by the so-called {open_quotes}field{close_quotes} effects associated with the characteristics of the flow and burner geometries. The authors` approach is to gain a fundamental understanding by investigating idealized laboratory flames. Laboratory flames are amenable to detailed interrogation by laser diagnostics and their flow geometries are chosen to simplify numerical modeling and simulations and to facilitate comparison between experiments and theory.

  3. Assessment of Literature Related to Combustion Appliance Venting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, V. H.; Less, B. D.; Singer, B. C.; Stratton, J. C.; Wray, C. P.

    2015-02-01

    In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents their technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.

  4. Decentralized heat and power supply from biogenic solid fuels. A technical and economic evaluation of the gasification in comparison to combustion. 2. ed.; Dezentrale Strom- und Waermeerzeugung aus biogenen Festbrennstoffen. Eine technische und oekonomische Bewertung der Vergasung im Vergleich zur Verbrennung

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, A.

    2007-04-15

    The previous technologies for the development of the decentralized combined heat and power generation are based on various concepts with different ripeness. Gasification is regarded as an energetically promising technology, which is not yet marketable. Under this aspect, the author of the contribution under consideration reports on an economic evaluation of the decentralized power and heat production by gasification of biogenic solid fuels and on a comparison with existing alternative technologies of combustion. In particular, the author examines the following central issues: (a) Which technologies of gasification can be regarded as promising with respect to a decentralized application?; (b) How are the technologies of gasification to be evaluated with respect to the alternative technologies of combustion from technical and economic view? For the comparative view of these different techniques, an electrical output of 500 W is specified as a uniform characteristic value of performance according to the decentralized gasification and combustion.

  5. AREVA Technical Days (ATD) session 2: operations of the back-end of the nuclear fuel cycle; AREVA Technical Days (ATD) session 2: les activites du pole Aval du cycle du combustible nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    These technical days organized by the Areva Group aims to explain the group activities in a technological and economic point of view, to provide an outlook of worldwide energy trends and challenges and to present each of their businesses in a synthetic manner. This second session deals with the reprocessing business, back-end financing mechanisms, technology transfer, environmental management, risk management programs, research and development contribution to waste volume reductions, issues and outlook of nuclear wastes, comparison of the open and closed cycles. (A.L.B.)

  6. Potential approaches to improve gasification of high water content biomass rich in cellulose in dual fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Li; Xu, Guangwen [State Key Laboratory of Multiphase Complex System, Institute of Process Engineering, Chinese Academy of Sciences, Beijing (China); Suda, Toshiyuki [Research Laboratory, IHI Corporation, Ltd., Yokohama (Japan); Murakami, Takahiro [National Institute of Advanced Science and Technology, Tsukuba (Japan)

    2010-08-15

    Biomass containing water of 30-65 wt.% and rich in cellulose, such as various grounds of drinking materials and the lees of spirit and vinegar, is not suitable for biological digestion, and the thermal conversion approach has to be applied to its conversion into bioenergy. The authors have recently worked on converting such biomass into middle heating-value gas via dual fluidized bed gasification (DFBG) integrated with various process intensification technologies. This article is devoted to highlighting those technical ways, including the choice of the superior technical deployment for a DFBG system, the impregnation of Ca onto fuel in fuel drying, the integration of gas cleaning with fuel gasification via two-stage DFBG (T-DFBG), and the decoupling of fuel drying/pyrolysis and char gasification via the decoupled DFBG (D-DFBG). The attained results demonstrated that the superior deployment of bed combination for the DFBG should be a bubbling/turbulent fluidized bed gasifier integrated with a pneumatic riser combustor. In terms of improving efficiency of fuel conversion into combustible gas and suppressing tar generation during gasification, the impregnation of Ca onto fuel exhibited distinctively high upgrading effect, while both the T-DFBG and D-DFBG were also demonstrated to be effective to a certain degree. (author)

  7. Parametric Study of NOx Emissions in Circulating Fluidized Bed Combustor

    International Nuclear Information System (INIS)

    Fluidized bed combustion behavior of coal and biomass is of practical interest due to its significant involvement in heating systems and power plant operations. This combustion behavior has been studied by many experimental techniques. . Use of biomass in coal-fired power plants results in high efficiencies and fuel diversity. Co-combustion experiments were carried out in a pilot scale test facility of circulating fluidized bed combustor (70KW). Effect of operating parameters on the NOx emissions is studied while burning coal with wheat straw. Relation between NOx emissions and operating parameters like bed temperature, excess air ratio, air staging, Ca/S molar ratio and fluidizing air velocity have been studied and discussed. (author)

  8. Proceedings - Fourth annual fluidized bed conference

    International Nuclear Information System (INIS)

    The proceedings contain 14 papers which deal with the following topics: anthracite culm combustion for process heat and cogeneration; case histories describing the performance of circulating fluidized bed combustors (CFBC); design and economics of CFBC; pulverizers for coal and sorbent preparation; ash removal systems; and the status of independent power generation and the Clean Coal Technology Program. Appendices contain manufacturers' installation lists with details of customers, fuels, steam conditions, and applications. All papers have been processed separately for inclusion on the data base

  9. Circulating fluidized bed boilers design and operations

    CERN Document Server

    Basu, Prabir

    1991-01-01

    This book provides practicing engineers and students with insight into the design and operation of circulating fluidized bed (CFB) boilers. Through a combination of theoretical concepts and practical experience, this book gives the reader a basic understanding of the many aspects of this subject.Important environmental considerations, including solid waste disposal and predicted emissions, are addressed individually in separate chapters. This book places an emphasis on combustion, hydrodynamics, heat transfer, and material issues, and illustrates these concepts with numerous examples of pres

  10. Advanced Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R. [NETL

    2013-03-11

    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  11. Hybrid Approach for Modeling Chemical Kinetics and Turbulence Effects on Combustion-Instability Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Combustion instabilities pose a significant technical risk in the development of liquid and solid rocket motors. Much of the effort in modeling combustion...

  12. Fabrication works on rotary kiln fluidized bed

    International Nuclear Information System (INIS)

    Rotary kiln has been widely used in incineration and studied by many researches. Solid wastes of various shapes, sizes and heat value can be fed into rotary kiln either in batches or continually. Waste combustion in rotary kiln involves rotation method and the residence time depends on the length and diameter of the rotary kiln and the total stichomythic air given to the system.Rocking system is another technology used in incinerator. In the rocking system, internal elements in the combustion chamber move to transports and mix the burning waste so that all combustible material in the waste is fully burnt. Another technology in incinerator is the fluidized bed. This method uses air to fluidized the sand thus enhancing the combustion process. The total air is controlled in order to obtain a suitable fluidized condition.This preliminary study was conducted to study the feasibility of an incinerator system when three components viz. the rotary kiln, rocking system and fluidized bed are combined. This research was also conducted to obtain preliminary data parameters of the three components such as the suitable temperature, the angle of the kiln, residence time, total air for fluidization, rocking speed and the devolatilization rate. The samples used in this research were the palm oil kernel shells. (Author)

  13. 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.

  14. Bed-To-Wall Heat Transfer in a Supercritical Circulating Fluidised Bed Boiler

    Directory of Open Access Journals (Sweden)

    Błaszczuk Artur

    2014-06-01

    Full Text Available The purpose of this work is to find a correlation for heat transfer to walls in a 1296 t/h supercritical circulating fluidised bed (CFB boiler. The effect of bed-to-wall heat transfer coefficient in a long active heat transfer surface was discussed, excluding the radiation component. Experiments for four different unit loads (i.e. 100% MCR, 80% MCR, 60% MCR and 40% MCR were conducted at a constant excess air ratio and high level of bed pressure (ca. 6 kPa in each test run. The empirical correlation of the heat transfer coefficient in a large-scale CFB boiler was mainly determined by two key operating parameters, suspension density and bed temperature. Furthermore, data processing was used in order to develop empirical correlation ranges between 3.05 to 5.35 m·s-1 for gas superficial velocity, 0.25 to 0.51 for the ratio of the secondary to the primary air, 1028 to 1137K for bed temperature inside the furnace chamber of a commercial CFB boiler, and 1.20 to 553 kg·m-3 for suspension density. The suspension density was specified on the base of pressure measurements inside the boiler’s combustion chamber using pressure sensors. Pressure measurements were collected at the measuring ports situated on the front wall of the combustion chamber. The obtained correlation of the heat transfer coefficient is in agreement with the data obtained from typical industrial CFB boilers.

  15. Combustion generated fine carbonaceous particles

    OpenAIRE

    Bockhorn, Henning; D'Anna, Andrea; Sarofim, Adel F.; Wang, Hai

    2009-01-01

    Soot is of importance for its contribution to atmospheric particles with their adverse health impacts and for its contributions to heat transfer in furnaces and combustors, to luminosity from candles, and to smoke that hinders escape from buildings during fires and that impacts global warming or cooling. The different chapters of the book adress comprehensively the different aspects from fundamental approaches to applications in technical combustion devices.

  16. Building America Expert Meeting. Combustion Safety

    Energy Technology Data Exchange (ETDEWEB)

    Brand, Larry [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States)

    2013-03-01

    This is an overview of "The Best Approach to Combustion Safety in a Direct Vent World," held June 28, 2012, in San Antonio, TX. The objective of this Expert Meeting was to identify gaps and barriers that need to be addressed by future research, and to develop data-driven technical recommendations for code updates so that a common approach for combustion safety can be adopted by all members of the building energy efficiency and code communities.

  17. Building America Expert Meeting: Combustion Safety

    Energy Technology Data Exchange (ETDEWEB)

    Brand, L.

    2013-03-01

    This is a meeting overview of 'The Best Approach to Combustion Safety in a Direct Vent World', held June 28, 2012, in San Antonio, Texas. The objective of this Expert Meeting was to identify gaps and barriers that need to be addressed by future research, and to develop data-driven technical recommendations for code updates so that a common approach for combustion safety can be adopted by all members of the building energy efficiency and code communities.

  18. Rock bed heat accumulators. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Riaz, M.

    1977-12-01

    The principal objectives of the research program on rock bed heat accumulators (or RBHA) are: (1) to investigate the technical and economic feasibility of storing large amounts of thermal energy (in the tens of MWt range) at high temperature (up to 500/sup 0/C) over extended periods of time (up to 6 months) using native earth or rock materials; (2) to conduct studies to establish the performance characteristics of large rock bed heat accumulators at various power and temperature levels compatible with thermal conversion systems; and (3) to assess the materials and environmental problems associated with the operation of such large heat accumulators. Results of the study indicate that rock bed heat accumulators for seasonal storage are both technically and economically feasible, and hence could be exploited in various applications in which storage plays an essential role such as solar power and total energy systems, district and cogeneration heating systems.

  19. Surviving Bed Rest

    Science.gov (United States)

    ... doctor will give you specific information about the duration of your bed rest. continue How Does Bed ... reading about high-risk pregnancy issues, learn about breastfeeding or how to encourage your child's development instead. ...

  20. Fluidized bed incineration process design for transuranic waste

    International Nuclear Information System (INIS)

    A fluidized bed incineration facility has been installed at the Rocky Flats Plant to develop and demonstrate a process for the combustion of transuranic waste. The unit's capacity is about 82 kg/hr of combustible solid waste, which is nine times higher than the rate for the operating pilot-scale unit. The facility utilizes nonaqueous, in situ neutralization of acid gases. These gases are generated during the combustion of halogen-containing materials. The low-temperature (550 0C) operation eliminates refractory-lined equipment

  1. LIEKKI 2 - Combustion technology is environmental technology

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M. [Aabo Akademi, Turku (Finland)

    1996-12-31

    Finland has wide experience in applications of various combustion technologies and fuels and in supplying energy to industry and municipalities. Furthermore, combustion hardware and equipment are amongst our most important export products. Above all, fluidized bed boilers, recovery boilers for pulp mills and heavy diesel engines and diesel power plants have achieved excellent success in the world markets. Exports of these products alone have amounted to several billions of Finnish marks of annual sales in recent years. Within modern combustion technology, the objective is to control flue gas emissions as far as possible in the process itself, thus doing away with the need for the separate scrubbing of flue gases. To accomplish this it has been necessary to conduct a large amount of research on the details of the chemistry of combustion emissions and the flows in furnaces and engine cylinders. A host of completely new products are being developed for the combustion technology field. The LIEKKI programme has been particularly interested in so-called combined-cycle processes based on pressurized fluidized bed technology

  2. Annual Report: Advanced Combustion (30 September 2012)

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey [NETL; Richards, George

    2012-09-30

    The Advanced Combustion Project addresses fundamental issues of fire-side and steam-side corrosion and materials performance in oxy-fuel combustion environments and provides an integrated approach into understanding the environmental and mechanical behavior such that environmental degradation can be ameliorated and long-term microstructural stability, and thus, mechanical performance can lead to longer lasting components and extended power plant life. The technical tasks of this effort are Oxy-combustion Environment Characterization, Alloy Modeling and Life Prediction, and Alloy Manufacturing and Process Development.

  3. Study of combustion parameters in a CNG engine and development of an ICE test rig for HCNG systems

    OpenAIRE

    Olivella Blanco, Albert

    2008-01-01

    Parameters of combustion in a Compressed Natural Gas (CNG) engine will be analyzed in order to proof the validity of a multizone combustion model comparing the calculated values of NO with the ones obtained on the engine bed. A test rig for a Hydrogen and Compressed Natural Gas (HCNG) system will be developed in order to acquire and process combustion outputs from an engine.

  4. High Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL's High-Pressure Combustion Research Facility in Morgantown, WV, researchers can investigate new high-pressure, high-temperature hydrogen turbine combustion...

  5. Effect of alternative solid fuels on desulfurization of fluidized bed boilers

    International Nuclear Information System (INIS)

    Laboratory research revealed a negative effect of ash formed during combustion of industrial and municipal waste in fluidized bed boilers. The reactivity of limestone used for desulfurization during the combustion reacts with the ash. The negative effect can be attributed to the oxides coating on the surface of calcined limestone. (author)

  6. Experimental study on combustion characteristics of municipal solid waste

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    As incineration provides a relatively safe means of disposal, significant reduction of weight and volume, and energy recovery from thewaste, it was adopted by many countries. For the experimental investigation on the combustion characteristics of municipal solid waste(MSW),a lab scale fluidized bed facility was constructed. Many kinds of combustion runs were conducted in this fluidized bed combustion facility. Theexamined parameters were bed temperature(773 to 1143K), form of fuels ( scrap or whole), moisture of fuels and so on. Concentration of CO2,CO,SO2, O2 and NOx in the flue gas were monitored and recorded every 5 seconds. The temperatures along the reactor are recorded every 10seconds. Experimental results were given and analyzed.

  7. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  8. Biomass ash-bed material interactions leading to agglomeration in FBC

    DEFF Research Database (Denmark)

    Visser, H.J.M.; van Lith, Simone Cornelia; Kiel, J.H.A.

    2008-01-01

    In (bubbling) fluidized-bed combustion and gasification of biomass, several potential problems are associated with the inorganic components of the fuel. A major problem area is defluidization due to bed agglomeration. The most common found process leading to defluidization in commercial-scale ins...

  9. Engineering bed models for solid fuel conversion process in grate-fired boilers

    DEFF Research Database (Denmark)

    Costa, M.; Massarotti, N.; Indrizzi, V.;

    2014-01-01

    A comparison between two numerical models describing the thermo-chemical conversion process of a solid fuel bed in a grate-fired boiler is presented. Both models consider the incoming biomass as subjected to drying, pyrolysis, gasification and combustion. In the first approach the biomass bed is ...

  10. Emissions from multiple-spouted and spout-fluid fluidized beds using rice husks as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Albina, D.O. [School of Engineering and Architecture, Mindanao Polytechnic State College, Cagayan de Oro City 9000 (Philippines)

    2006-10-15

    This paper presents the experimental results of the emissions of CO and CO{sub 2} using rice husks as fuel on different configurations of spout-fluidized beds namely, multiple-spouted and spout-fluid fluidized bed. The emission of pollutants from the multiple-spouted bed and spout-fluid bed was investigated with rice husk fuel. The operating parameters considered were the different levels of excess air, different primary-to-secondary air ratios at each level of excess air and method of feeding. It was found that emission of CO from the multiple-spouted bed seemed to be lower with under-bed feeding of the rice husk fuel compared to over-bed feeding. However, the emission of CO{sub 2} did not change significantly for both methods of feeding. Changes in excess air levels influenced the emissions of CO and CO{sub 2} from the multiple-spouted bed within the excess air range investigated. It was found that emission of CO was less at 10% excess air with over-bed feeding; emission of CO in the case of under-bed feeding was lowest at 20% excess air level. It was found that the method of feeding had not significantly influenced the emission of CO and CO{sub 2} in the spout-fluid bed. The combustion efficiency however, in general, was slightly higher in the case of under-bed feeding compared to over-bed feeding. Emission of CO was less in the spout-fluid bed compared with the emission of CO in the multiple-spouted bed. The result can be likely attributed to the higher combustion efficiency attained by the spout-fluid bed compared with that of multiple-spouted bed. (author)

  11. Top Ten Bed Bug Tips

    Science.gov (United States)

    ... have bed bugs, not fleas, ticks or other insects. You can compare your insect to the pictures on our Identifying bed bugs ... bedbugs Bed Bugs Home Learn about Bed Bugs — Characteristics of Bed Bugs — Finding Bed Bugs Protecting Your ...

  12. Biofluid process: fluidised-bed gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, A. [ATEKO a.s., Hradec Kralove (Czech Republic)

    1996-12-31

    Fluidised-bed gasification of biomass was developed by ATEKO by using long-term experience from coal gasification. An experimental unit was built and a number of tests, first with sawdust gasification, were carried out. A gas combustion engine combined with a power generator was installed and operated in power production. (orig.)

  13. Challenges in simulation of chemical processes in combustion furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M.; Kilpinen, P. [Aabo Akademi, Turku (Finland)

    1996-12-31

    The presentation gives an introduction to some of the present issues and problems in treating the complex chemical processes in combustion. The focus is in the coupling of the hydrocarbon combustion process with nitrogen oxide formation and destruction chemistry in practical furnaces or flames. Detailed kinetic modelling based on schemes of elementary reactions are shown to be a useful novel tool for identifying and studying the key reaction paths for nitrogen oxide formation and destruction in various systems. The great importance of the interaction between turbulent mixing and combustion chemistry is demonstrated by the sensitivity of both methane oxidation chemistry and fuel nitrogen conversion chemistry to the reactor and mixing pattern chosen for the kinetic calculations. The fluidized bed combustion (FBC) nitrogen chemistry involves several important heterogeneous reactions. Particularly the char in the bed plays an essential role. Recent research has advanced rapidly and the presentation proposes an overall picture of the fuel nitrogen reaction routes in circulating FBC conditions. (author)

  14. Theoretical and Experimental Investigations of Ignition, Combustion and Expansion Processes of Hypergolic Liquid Fuel Combinations at Gas Temperatures up to 3000 K. Thesis - Rhein-Westfalia Technical Coll., 1967

    Science.gov (United States)

    Schulz, Harry

    1987-01-01

    The ignition, combustion, and expansion characteristics of hypergolic liquid propellant mixtures in small rocket engines are studied theoretically and experimentally. It is shown by using the Bray approximation procedure that the reaction H + OH + M = H2O + M (where M is the molecular mass of the gas mixture) has a strong effect on the combustion efficiency. Increases in recombination energies ranging from 30 to 65% were obtained when the rate of this reaction was increased by a factor of 10 in gas mixtures containing 90% oxygen. The effect of aluminum additions and various injection techniques on the combustion process is investigated.

  15. New Developments in Spinning Fluidised Bed Incineration Technology

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    At the present time, the sewage treatment plants in the UK produce about 25 million tons of sewage sludge each year at a concentration of 4% solids. New regulations forbid sea dumping and in the near future new incinerators will be required to dispose of about 5 million tons per year. Bubbling fluidised bed incinerators are widely used to burn sewage sludge at a typical consumption rate of about 0.02kg(dry)·s-1·m2, and it follows that over 300 conventional fluidised bed incinerators of 3m diameter could be required to cope with the increased demand.At Sheffield University Waste Incineration Centre (SUWIC) research work is being carried out to develop a novel spinning fluidised bed incinerator. The key factor to note is that when air flows up through a bed of near mono-sized particles, it fluidises when the pressure drop across the bed is equal to the weight of the bed. Normally, the weight of the bed is determined by gravity. However, if the bed is contained by a cylindrical air distributor 'plate' that is rotating rapidly about its axis, then the effective weight of the bed can be increased dramatically. The airflow passing through the bed can be increased proportionally to the "g" level produced by the rotation and it follows that the process has been intensified. In exploratory tests with a spinning fluidised bed we have achieved combustion intensities with coal combustion as high as 100MW/m3. A problem with burning coal is that it was difficult to remove the heat and rotating water seals had to be used to transfer cooling water into the bed. In the case of sewage and other sludges, this problem does not exist since the flue gases can remove the small amount of heat released. The rotating fluidised bed sludge incinerator is a novel device, which is very compact. It is able to solve the turndown problem encountered with conventional fluidised beds by simply changing the rotation speed. Bearing in mind that a centrifugal sludge de-watering unit is already used

  16. Bed burners for grate boilers; Baeddbraennare foer rosterpannor

    Energy Technology Data Exchange (ETDEWEB)

    Sendelius, Mikael; Schuster, Robert [AaF-Energikonsult AB, Stockholm (Sweden)

    2003-10-01

    The objective of this work is to increase the knowledge of bed burners and their optimal positions in furnaces. The results from several computational fluid mechanics calculations are presented. An investigation concerning bed burners among plant owners is included as well. A bed burner is defined as a burner used for enhancing the combustion process on the bed i.e. it is used to dry incoming wet fuel. A load burner is used to quickly increase the boiler load and primarily not for creating better combustion conditions on the grate. Fluid mechanics calculations have been performed for five different cases, including the reference case. The following four bed burner arrangements have been examined: flat flame burner, six burners placed in the combustion chamber, two symmetric placed burners and two asymmetric placed burners. The same furnace model has been used through all the simulations. The incident radiation has been calculated in order to determine which one of the bed burners having the best possibility to improve the combustion process on the grate. The results showed that the flat flame burner and the six burners placed in the combustion chamber gave the most incident radiation on the first two grate zones. Bed burners placed further back in the furnace gave less good results. A comparison between the reference case (the case without burners) and the case with two burners showed that there was almost no difference in incident radiation between the two cases. The case with six burners placed in the combustion chamber gave most incident radiation, however this arrangement gave an irregular distribution of the radiation on the bed. Too high or irregular distributed radiation increases the risk for getting regions, on the grate, where the fuel is completely burnt. Primary air will pass through these regions. This phenomenon will lead to high temperatures that cause increased levels of emissions, in particular NO{sub x}. Reorganizing the burner positions and

  17. Status and future prospects of fluidised bed firing systems in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Nies, Michael [Stadtwerke Duisburg AG, Duisburg (Germany); Niemeyer, Peter [Ahlstrom Osnabrueck GmbH, Osnabrueck (Germany); Roeper, Bernhard [RWE Power AG, Grevenbroich (Germany); Werther, Joachim [Hamburg Univ. of Technology, Hamburg (Germany); Mueller, Ludwig [VGB PowerTech e.V., Essen (Germany)

    2012-07-01

    Until the 1990s, fluidised bed combustion was restricted to 350 MW of output, today, plants up to 600 MW are possible. The most important German concepts are presented by selected examples. These comprise mainly co-generation plants and industrial power plants with process steam extraction, biomass-fired plants with 20 MW as well as waste incineration plants and sewage sludge mono combustion system. According to market conditions, it is to be expected that decentralised plants with heat utilisation and flexible duo unit plants as well as fluidised bed combustion plants are going to be competitive. (orig.)

  18. Description of a 1.5D computer model for prediction of nitrogen oxides emissions from CFB combustion: Material balances and general program structure

    International Nuclear Information System (INIS)

    The purpose of the software described in the present technical report, is to study the formation of nitrogen oxides emissions in circulating fluidized bed combustion (CFBC). Especially, comparisons of different fuels and mixtures of fuels are expected to be the main scope of application of the developed software in the future. The need for CFBC model development comes from the fact that fluidized bed combustion technology today plays an important role in energy production. At the same time, the understanding of emission formation from CFB combustion is still far from complete. As basis for the numerical model a comprehensive description of homogeneous, catalytic and heterogeneous chemical kinetics and a simple 1.5 dimensional representation of fluid dynamics were chosen. The software has been widely tested in studies of coal and wood combustion in small size furnaces. It has also been used for simulation of combustion in an industrial size furnace and for studies of NO formation in co-combustion of wood, peat and coal. The present technical report describes the numerical model and its submodels in their present form with emphasis on material balances and general model structure, which have not been described in detail in earlier publications. The focus is on fluid dynamics and mass transfer, including mass transfer terms originating from attrition and fragmentation. Chemistry submodels, especially the models of homogeneous chemistry, are presented here only to the extent that is necessary for understanding the rest of the program description. The report is also meant to serve as a manual to the developers and users of the code. Hence the equations are presented in the form in which they are implemented in the code, usually in discretized form. Limitations of the code and ideas for further development are also included in the report. The report contains detailed instructions for writing an input file, for running the code and for interpreting and plotting the

  19. Oxygen-enhanced combustion

    CERN Document Server

    Baukal, Charles E

    2013-01-01

    Combustion technology has traditionally been dominated by air/fuel combustion. However, two developments have increased the significance of oxygen-enhanced combustion-new technologies that produce oxygen less expensively and the increased importance of environmental regulations. Advantages of oxygen-enhanced combustion include less pollutant emissions as well as increased energy efficiency and productivity. Oxygen-Enhanced Combustion, Second Edition compiles information about using oxygen to enhance industrial heating and melting processes. It integrates fundamental principles, applications, a

  20. Internal combustion engines history - a review

    International Nuclear Information System (INIS)

    In this article, a chronological analysis of the technologies and events that any way influenced in the evolution of the internal combustion engine is done everything it through the observation of the works carried out for scientific empiric and engineers whose technical and conceptual value meant the motivation of other people for the search of a better development in this engineering field

  1. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  2. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  3. Cellular ceramics in combustion environments

    Energy Technology Data Exchange (ETDEWEB)

    Fuessel, Alexander; Boettge, Daniela; Adler, Joerg; Marschallek, Felix; Michaelis, Alexander [Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Dresden (Germany)

    2011-11-15

    Cellular materials have become increasingly interesting for applications in combustion environments. Improvements like high power efficiency and low emissions are the main targets of technological development in combustion processes. However, despite scientific and technical success in developing new or improved burner concepts over recent years, a lot of problems remain to be solved in the field of materials science: due to the high power density of the burners the materials are subjected to high loads in terms of thermal shock, temperature and corrosion, especially in so-called porous burner technology. This article shows some examples of research and development strategies and results in developing improved cellular ceramics. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Thermodynamic Analysis of Trace Elements Partitioning in AFBC Combustion of Lignite

    Czech Academy of Sciences Publication Activity Database

    Smolík, Jiří; Ondráčková, Lucie; Schwarz, Jaroslav; Leitner, J.; Sýkorová, Ivana

    Vol. 1. Taipei, 2002 - (Wang, C.), s. 191-192 ISBN 986-80544-1-9. [International Aerosol Conference /6./. Taipei, (TW), 09.09.2002-13.09.2002] R&D Projects: GA ČR GA104/00/1297 Keywords : combustion aerosols * fluidised bed combustion * trace element partitioning Subject RIV: CF - Physical ; Theoretical Chemistry

  5. Ash management in circulating fluidized bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    K. Redemann; E.-U. Hartge; J. Werther [Hamburg University of Technology, Hamburg (Germany). Institute of Solids Process Engineering and Particle Technology

    2008-12-15

    Ash management in fluidized bed combustion systems means keeping the particle size distribution of the bed inventory in a given range. A dynamic particle population balancing model was developed for this purpose. It was successfully applied to a refuse-derived fuel fired combustor and a coal-fired circulating fluidized bed combustor. Both were large-scale commercial units. The model uses the concept of the attrited ash particle size distribution which represents the particle size distribution of the attrited ash including the generated fines and replaces the consideration of the particle attrition in the model calculations. The model offers the possibility to gain additional information about the particle size distributions and the solids mass flows at any location of the fluidized bed system. In addition, the model provides information about the dynamic behavior of the plant and about mean residence times of particle size classes in the plant. Uncertainties about the ash formation characteristics of fuels make the management of the bed inventory a very important issue. In this context the population balancing model is used to predict the plant behavior under various operating conditions. The results of the calculations carried out give useful information about the possibilities to manage the ash inventory of such a plant. It could be shown that the recirculation of a fine fraction of the bottom drain solids is a very effective method to manage the particle size distribution of the bed inventory. The calculation results further reveal that the mean residence time of particles is strongly dependent on their size. 21 refs., 19 figs., 4 tabs.

  6. Bed In Summer

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In winter I get up at night And dress by yellow candle-light. In summer, quite the other way, I have to go to bed by day. I have to go to bed and see The birds still hopping on the tree, Or hear the grown-up people' s feet Still going past me in the stree

  7. Fluidized bed incinerator development

    International Nuclear Information System (INIS)

    A fluidized bed incinerator is being developed for burning rad contaminated solid and liquid waste materials. In situ neutralization of acid gases by the bed material, catalytic afterburning, and gas filtration are used to produce a clean flue gas without the use of aqueous scrubbing

  8. Effect of bed temperature and bed composition on agglomeration during gasification of high-sodium, high-sulphur lignite in a spouted fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    D.P. McCullough; P.J. Mullinger; P.J. Ashman [University of Adelaide, Adelaide, SA (Australia). Cooperative Research Centre for Clean Power from Lignite, School of Chemical Engineering

    2003-07-01

    Fluidised bed gasification (FBG) is an alternative process for coal utilisation that delivers improved efficiencies and lower temperature operation compared to conventional technology. Agglomeration and defluidisation are phenomena that have the potential to occur within fluidised bed reactors, which can interrupt stable process operation. While extensive work has been carried out investigating fluidised bed combustion of lignite, relatively little work has been carried out for lignite under fluidised bed gasification conditions. Gasification of high sodium, high sulphur content lignite in a spouted bed gasifier (SBG) indicates that agglomeration and defluidisation is only an issue when maximum bed temperature exceeds approximately 850{degree}C and air/fuel ratios of 2.5 outside of these conditions, defluidisation is not detected. It is also demonstrated that defluidisation occurs before agglomeration, rather than as a result of agglomeration as previously thought. The Rosin-Rammler method of describing particle size distribution is found to yield appropriate variables for quantification of the extent of agglomeration taking place in cases where defluidisation is a factor. However, it has been shown by this method that while initial results indicated that agglomeration extent varies directly with maximum bed temperature, further results have shown that other variables, such as superficial velocity, have a significant impact on the extent of agglomeration. Investigations are currently continuing. 9 refs., 8 figs., 9 tabs.

  9. Control methods for remediation of ash-related problems in fluidized-bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Vuthaluru, H.B.; Zhang, D.

    1999-07-01

    The paper reports on investigations into control methodologies for mitigating ash-related problems such as particle agglomeration and bed defluidization during fluidized-bed combustion of low-rank coals. A laboratory scale spouted bed combustor is used to study the effectiveness of control methodologies. In the present work, two control methods are investigated viz., the use of alternative bed materials and pretreatment of coal. Bauxite and calcined sillimanite are used as alternative bed materials in the spouted bed combustor while burning South Australian low-rank coal. Samples of the same coal subjected to Al pretreatment, water washing and acid washing are also tested in the spouted bed combustor. Experiments showed that both methods are effective to different extents in reducing ash-related problems. Tests with calcined sillimanite and bauxite (as the bed material) showed trouble free operation for longer periods (7--12 hr at 800 C and 3--5 hr at 850 C) than with sand runs at the same bed temperatures. Al pretreatment and water-washing were also found to be effective and resulted in extended combustion operation. Al enrichment in ash coating of bed particles has been identified as the main mechanism for prevention of agglomeration and defluidization by these control methodologies. For water-washing, the principal reason behind agglomeration and defluidization control is the reduction in sodium levels.

  10. Pulsating combustion of gas fuel in the combustion chamber with closed resonant circuit

    International Nuclear Information System (INIS)

    In the combustion chambers of the pulsation of gas flow oscillation greatly accelerate heat dissipation to the walls of the combustion chamber and improve combustion efficiency as compared with a uniform combustion mode. This allows you to effectively solve a number of problems of industrial power, including an environmentally friendly combustion products. Significant drawback of such systems – the emitted noise exceeding the permissible requirements. One solution to this problem – the separation of the resonance tube into 2 parts connected at the output to the interference of sound waves. The results of theoretical studies pulsating combustion technical mixture of propane in the system, consisting of a combustion chamber and two resonance tubes forming a closed resonant circuit. Resonators have a variable length. Calculations have shown that under certain oscillation of the resonator length to the first resonant frequency of the system is achieved by reducing SPL more than 15 dB. For oscillations at a second resonant frequency is the complete elimination of noise while maintaining intense oscillations in the combustion chamber

  11. Limestone fragmentation and attrition during fluidized bed oxyfiring

    Energy Technology Data Exchange (ETDEWEB)

    Fabrizio Scala; Piero Salatino [Istituto di Ricerche sulla Combustione - CNR, Napoli (Italy)

    2010-04-15

    Attrition/fragmentation of limestone under simulated fluidized bed oxyfiring conditions was investigated by means of an experimental protocol that had been previously developed for characterization of attrition/fragmentation of sorbents in air-blown atmospheric fluidized bed combustors. The protocol was based on the use of different and mutually complementary techniques. The extent and pattern of attrition by surface wear in the dense phase of a fluidized bed were assessed in experiments carried out with a bench scale fluidized bed combustor under simulated oxyfiring conditions. Sorbent samples generated during simulated oxyfiring tests were further characterized from the standpoint of fragmentation upon high velocity impact by means of a purposely designed particle impactor. Results showed that under calcination-hindered conditions attrition and fragmentation patterns are much different from those occurring under air-blown atmospheric combustion conditions. Noteworthy, attrition/fragmentation enhanced particle sulfation by continuously regenerating the exposed particle surface. 13 refs., 8 figs.

  12. Properties of Combustion Gases

    Science.gov (United States)

    Wear, J. D.; Jones, R. E.; Trout, A. M.; Mcbride, B. J.

    1986-01-01

    New series of reports: First report lists data from combustion of ASTM Jet A fuel and dry air; second report presents tables and figures for combustion-gas properties of natural-gas fuel and dry air, and equivalent ratios.

  13. Combustion of Fractal Distributions

    OpenAIRE

    Sotolongo, Oscar; Lopez, Enrique

    1994-01-01

    The advantages of introducing a fractal viewpoint in the field of combustion is emphasized. It is shown that the condition for perfect combustion of a collection of drops is the self-similarity of the distribution.

  14. Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — For more than 30 years The Combustion Research Facility (CRF) has served as a national and international leader in combustion science and technology. The need for a...

  15. Dryout heat flux experiments with deep heterogeneous particle bed

    International Nuclear Information System (INIS)

    A test facility has been constructed at Technical Research Centre of Finland (VTT) to simulate as accurately as possible the ex-vessel core particle bed in the conditions of Olkiluoto nuclear power plant. The STYX particle bed reproduces the anticipated depth of the bed and the size range of particles having irregular shape. The bed is immersed in water, creating top flooding conditions, and internally heated by an array of electrical resistance heating elements. Dryout tests have been successfully conducted at 0.1-0.7 MPa pressure for both uniformly mixed and stratified bed geometries. In all tests, including the stratified ones, the dry zone first formed near the bottom of the bed. The measured dryout heat fluxes increased with increasing pressure, from 232 kW/m2 at near atmospheric pressure to 451 kW/m2 at 0.7 MPa pressure. The data show some scatter even for the uniform bed. The tests with the stratified bed indicate a clear reduction of critical power due to the presence of a layer of small particles on top of the uniform bed. Comparison of data with various critical power (dryout heat flux) correlations for porous media shows that the most important parameter in the models is the effective particle diameter. Adiabatic debris bed flow resistance measurements were conducted to determine the most representative particle diameter. This diameter is close, but not equal, to the particle number-weighted average diameter of the bed material. With it, uniform bed data can be calculated to within an accuracy of 3-28% using Lipinski's 0-D model. In the stratified bed experiments, it appears that the top layer was partially fluidized, hence the measured critical power was significantly higher than calculated. Future experiments are being planned with denser top layer material to eliminate non-prototypic fluidization

  16. Fluidized-bed gasification under pressure of fuel element graphite in an industrial-scale reprocessing plant for HTR fuel elements

    International Nuclear Information System (INIS)

    In the head end of nuclear fuel reprocessing, the graphite cladding of spent HTR fuel elements is separated from the fissible material. Fluidized-bed combustion has some advantages over fixed-bed combustion. It is the method of choice in the design of a large-scale plant of 50.000 MWe HTR power. By means of an excess pressure of about 5 bar, a threefold increase in efficiency of a fluidized-bed ractor can be achieved. For an optimum layout of a prototype combustion plant, jacket cooling and internal heat exchangers are required. For an assessment of fluidized-bed combustion under pressure as a process step in the head end of a reprocessing plant, the author presents heat transfer calculations on the basis of a varying specific combustion load and investigations of the necessary peripheral equipment (reactor vessel, dust removal systems, gas supply and distribution, etc.) in several model set-ups. (RB)

  17. Combustion of Biomass Poluted by Heavy Metals from Phytoextraction

    Czech Academy of Sciences Publication Activity Database

    Šyc, Michal; Pohořelý, Michael; Durda, Tomáš; Jeremiáš, Michal; Svoboda, Karel; Punčochář, Miroslav

    -: -, 2013. ISBN N. [ISWA 2013 World Congress. Vienna (AT), 07.10.2012-11.10.2013] R&D Projects: GA TA ČR TA01020366 Institutional support: RVO:67985858 Keywords : biomass * fossil fuels * fluidized bed combustion Subject RIV: CI - Industrial Chemistry, Chemical Engineering http://www.iswa2013.org/uploads/posters_list_168_EN.pdf

  18. Bed mixing dryer for high moisture content fuels

    Energy Technology Data Exchange (ETDEWEB)

    Hulkkonen, S.; Heinonen, O. [Imatran Voima Oy, Vantaa (Finland)

    1997-12-31

    Bed mixing dryer is a new type of fuel drying technology for fluidized bed combustion. The idea is to extract hot bed material from the fluidized bed and use it as a heat source for drying the fuel. Drying occurs at steam atmosphere which makes it possible to recover the latent heat of evaporation to process. This improves the thermal efficiency of the power plant process considerably, especially in combined heat and power applications. Imatran Voima Oy (IVO) has developed the Bed Mixing Dryer technology since early 1990s. The first pilot plant was built in 1994 to IVO`s Kuusamo peat and wood fired power plant. The capacity of the plant is 6 MW{sub e} and 20 MW of district heat. In Kuusamo the dryer is connected to a bubbling fluidized bed. Since it`s commissioning the dryer has been used successfully for about 3000 hours during the heating season in wintertime. The second application of the technology will be a demonstration project in Oerebro (S). IVO Power Engineering Ltd will supply in 1997 a dryer to Oerebro Energi`s peat, wood and coal fired CHP plant equipped with circulating fluidized bed boiler. The fuel to be dried is sawdust with fuel input of about 60 MW. In Kuusamo the dryer produces 3 MW of additional district heat and in Oerebro 6 MW. The fuels in Kuusamo are peat, saw dust and bark. In addition to the municipal heat production this type of drying technology has its benefits in pulp and paper industry processes. Disposal of paper mill sludges is becoming more difficult and costly which has resulted in need of alternative treatment. Drying of the sludge before combustion in a boiler for power production is an attractive option. At the moment IVO is carrying out several studies to apply the Bed Mixing Dryer in pulp and paper industry processes. Economy of drying the sludge looks promising

  19. The optimisation of combustion systems for the burning of cereal straw as a fuel

    OpenAIRE

    Washbourne, John Fryer

    1986-01-01

    International interest in fluidised bed combustion (F.B.C.) derives from the fact that it involves new technology and it is the only combustion system that can use low grade fuels (including those of high or variable ash content) efficiently. This thesis presents a study of the combustion of straw in a fully fluidised and systematically interrupted flow test rig. In the interrupted flow mode, it was found that during the period in the cycle when the bed was slumped, due to the reduction...

  20. Biomass Conversion into Solid Composite Fuel for Bed-Combustion

    Directory of Open Access Journals (Sweden)

    Tabakaev Roman B.

    2015-01-01

    Full Text Available The purpose of this research is the conversion of different types of biomass into solid composite fuel. The subject of research is the heat conversion of biomass into solid composite fuel. The research object is the biomass of the Tomsk region (Russia: peat, waste wood, lake sapropel. Physical experiment of biomass conversion is used as method of research. The new experimental unit for thermal conversion of biomass into carbon residue, fuel gas and pyrolysis condensate is described. As a result of research such parameters are obtained: thermotechnical biomass characteristics, material balances and product characteristics of the heat-technology conversion. Different methods of obtaining solid composite fuel from the products of thermal technologies are considered. As a result, it is established: heat-technology provides efficient conversion of the wood chips and peat; conversion of the lake sapropel is inefficient since the solid composite fuel has the high ash content and net calorific value.

  1. Pilot plant apparatus for pressurized fluidized bed combustion and gasification

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Karel; Hartman, Miloslav; Čermák, Jiří

    Praha, 1999, s. 89-90. [International Conference on the Ecological Use of Coal in the Energy Sector "Clean Coal 2000". Praha (CZ), 31.05.1999-03.06.1999] Grant ostatní: INCO-COPERNICUS(XE) IC15-CT98-0513 Subject RIV: DI - Air Pollution ; Quality

  2. Bed agglomeration in fluidized combustor fueled by wood and rice straw blends

    DEFF Research Database (Denmark)

    Thy, Peter; Jenkins, Brian; Williams, R.B.;

    2010-01-01

    Abstract Petrographic techniques have been used to examine bed materials from fluidized bed combustion experiments that utilized wood and rice straw fuel blends. The experiments were conducted using a laboratory-scale combustor with mullite sand beds, firing temperatures of 840 to 1030 °C, and run...... particle surfaces by accumulation of liquid droplets preferentially in areas sheltered from turbulence and mechanical interaction. The composition of the film suggests melting of locally accumulated dust or aerosol mixture of ash particles and mullite. The film only locally enlarged bed particles. Large...... straw ash particles appear to have mostly been passively incorporated into the adhesive melt without melting or reaction....

  3. Simulation of transport phenomena in coke oven with staging combustion

    International Nuclear Information System (INIS)

    A three-dimensional transient mathematical model was developed for coupled coking chamber and staging combustion chamber in large-capacity coke ovens, to describe the flow–combustion–thermo behavior. The model was solved numerically using CFX CFD package and was validated by the central temperature evolution of coke bed. The fields of temperature, fluid flow and combustible gas concentration were analyzed, with special reference to the temperature difference of coke bed and NO concentration of exhaust. The results show that staging combustion plays an important role in improving temperature uniformity of the coke bed and reducing NO concentration of exhaust, especially for the large-capacity coke oven. It is beneficial for production optimization to decrease the gas mass flow rate at the bottom inlet while increase the rate at the upper inlet in the combustion chamber. In addition, it turns out that some measures such as coal preheating, adjustment of moisture content or/and coal densification may be used to improve the coke production efficiency. It is expected the developed model and relevant data in the present research will be beneficial to realize large-scale coke oven with a higher energy efficiency and lower emission. -- Highlights: • The application of staging combustion in coke ovens and its effects are analyzed. • A 3D model is proposed to describe flow–combustion–thermo behaviors in coke oven. • Optimizing operation parameters in full-scale coke oven are studied

  4. Biomass combustion power generation technologies: Background report 4.1 for the EU Joule 2+ project: Energy from biomass: An assessment of two promising systems for energy production

    International Nuclear Information System (INIS)

    New developments in biomass combustion technology in progress tend to go towards efficiencies which come close to the present fossil fuel fired systems. The objective of this study is to give a representation of the state of the art and future prospects of biomass combustion technologies and to compare those on a location-independent basis. This will be done both by a general boiler technology description on the basis of qualitative criteria and by a comparison of most recently built and planned power plants on more quantitative grounds. The methodology which has been used in gathering, selecting, presenting and comparing the information is discussed in chapter 2. In chapter 3, a general introduction is given on some basic principles of biomass combustion technology. This includes the combustion process, the Rankine steam cycle and NOx formation. Different boiler technologies which are in use for biomass combustion power generation are discussed in chapter 4. The main groups of boilers which are discussed are the pile burners, stoker fired boilers, suspension fired boilers and fluidized bed boilers. The description focuses on aspects such as construction, operation, fuel requirements, efficiencies and emissions. Chapter 5 deals with individual existing or planned biomass combustion plants, resulting from an international inventory. All the different technologies which have been discussed in chapter 4 are discussed in chapter 5 in the context of complete power plants. The information which is presented for each plant comprises a technical description, efficiencies, emissions and investment costs. At the end of chapter 5 an overview of comparable data from the literature is given, as well as an overview of the results of the inventory. 32 figs., 28 tabs., 4 appendices., 51 refs

  5. Combustion: an oil spill mitigation tool

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-11-01

    The technical feasibility of using combustion as an oil spill mitigation tool was studied. Part I of the two-part report is a practical guide oriented toward the needs of potential users, while Part II is the research or resource document from which the practical guidance was drawn. The study included theoretical evaluations of combustion of petroleum pool fires under the effects of weathering and an oil classification system related to combustion potential. The theoretical analysis of combustion is balanced by practical experience of oil burning and case history information. Decision elements are provided which can be used as a guide for technical evaluations of a particular oil spill situation. The rationale for assessing technical feasibility is given in the context of other alternatives available for response to an oil spill. A series of research and technology development concepts are included for future research. The ethics of using oil burning are discussed as issues, concerns, and tradeoffs. A detailed annotated bibliography is appended along with a capsule review of a decade of oil burning studies and other support information.

  6. Modeling and field observations of char bed processes in black liquor recovery boilers

    Energy Technology Data Exchange (ETDEWEB)

    Engblom, M.

    2010-07-01

    The char bed plays an important role in kraft black liquor combustion. Stable operation of the char bed promotes efficient and safe operation of the black liquor recovery boiler. It also plays a crucial role in the recovery of the pulping chemicals. Char bed operation involves controlling the char bed size and shape. Mathematical modeling based on computational fluid dynamics (CFD) haas been applied to recovery boilers for increased insights into the recovery furnace processes and to aid in the design of new boilers. So far, all CED-based char bed models reported in literature have used a fixed bed shape. This imposes restrictions on simulation of char bed burning by not considering inherently occurring changes in bed shape. In this thesis, a CED -based recovery furnace model is further developed to predict changes in bed shape. The new model is used in simulation of existing recovery boilers. The predictions of bed shape are compared with observations from real boilers. The furnace model is capable of correctly simulating the overall response of the char bed size to operational changes. This confirms the current quantitative overall understanding of char bed burning. In addition to modeling, visual observations of the char bed processes were made in this work. The observations provide validation data concerning the physical behavior of the char bed, and the findings from the observations can be used in further development of char bed models. Modeling and simulations of fundamental laboratory scale char bed experiments reported in literature are also carried out. The simulations complement the experimental data by providing detailed insights into gas phase reactions that can occur inside the gas boundary layer above a char bed. (orig.)

  7. INAA and PIXE of atmospheric and combustion aerosols.

    Science.gov (United States)

    Kucera, J; Havránek, V; Smolík, J; Schwarz, J; Veselý, V; Kugler, J; Sýkorová, I; Santroch, J

    1999-01-01

    Using instrumental neutron activation analyses and photon-induced x-ray emission techniques for analysis of size-fractionated atmospheric and combustion aerosols and other emission samples arising from fluidized-bed combustion of North Bohemian lignites up to 42 elements were determined in all samples types. This allowed the evaluation of element enrichment, time trends, and inter-element correlations and the performance of factor analysis of various fractions of atmospheric aerosols. The data obtained on mass and element size distributions of aerosols and emission samples obtained upon lignite combustion in an experimental scale atmospheric fluidized-bed combustor without and with added hydrated lime and limestone were used to elucidate the mechanism of abatement of toxic trace and matrix elements from flue gas. PMID:10676497

  8. Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Whitty

    2007-06-30

    University of Utah's project entitled 'Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer' (DOE Cooperative Agreement DE-FC26-02NT41490) was developed in response to a solicitation released by the U.S. Department of Energy in December 2001, requesting proposals for projects targeted towards black liquor/biomass gasification technology support research and development. Specifically, the solicitation was seeking projects that would provide technical support for Department of Energy supported black liquor and biomass gasification demonstration projects under development at the time.

  9. Experimental Studies on Combustion Characteristics of Mixed Municipal Solid Waste

    Institute of Scientific and Technical Information of China (English)

    Fan Jiang; Zhonggang Pan; Shi Liu; Haigang Wang

    2003-01-01

    In our country, municipal solid wastes (MSW) are always burnt in their original forms and only a few pretreatments are taken. Therefore it is vital to study the combustion characteristics of mixed waste. In this paper,thermogravimetric analysis and a lab scale fluidized bed facility were used as experimental means. The data in two different experimental systems were introduced and compared. It took MSW 3~3.5 rain to burn out in FB, but in thermogravimetric analyzer, the time is 20~25 min. It can be concluded that, in general, the behavior of a mixture of waste in TGA can be expressed by simple combination of individual components of the waste mixtures.Only minor deviations from the rule were observed. Yet, in Fluidized Bed, it was found that, for some mixtures,there was interference among the components during fluidized bed combustion.

  10. Enuresis (Bed-Wetting)

    Science.gov (United States)

    ... get out of bed to go to the bathroom. When do most children achieve bladder control? Children ... ask questions about your child's daytime and nighttime bathroom habits. Then your doctor will do a physical ...

  11. Particle fuel bed tests

    International Nuclear Information System (INIS)

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H2 for 12 hours with no visible reaction or weight loss

  12. Tapered bed bioreactor

    Science.gov (United States)

    Scott, Charles D.; Hancher, Charles W.

    1977-01-01

    A vertically oriented conically shaped column is used as a fluidized bed bioreactor wherein biologically catalyzed reactions are conducted in a continuous manner. The column utilizes a packing material a support having attached thereto a biologically active catalytic material.

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

    Science.gov (United States)

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

    2016-08-01

    A combination of thermogravimetric analysis (TG) and laboratory-scale circulated fluidized bed combustion experiment was conducted to investigate the thermochemical, kinetic and arsenic retention behavior during co-combustion bituminous coal with typical agricultural biomass. Results shown that ignition performance and thermal reactivity of coal could be enhanced by adding biomass in suitable proportion. Arsenic was enriched in fly ash and associated with fine particles during combustion of coal/biomass blends. The emission of arsenic decreased with increasing proportion of biomass in blends. The retention of arsenic may be attributed to the interaction between arsenic and fly ash components. The positive correlation between calcium content and arsenic concentration in ash suggesting that the arsenic-calcium interaction may be regarded as the primary mechanism for arsenic retention. PMID:27136608

  14. Refractory experience in circulating fluidized bed combustors, Task 7

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, R.Q.

    1989-11-01

    This report describes the results of an investigation into the status of the design and selection of refractory materials for coal-fueled circulating fluidized-bed combustors. The survey concentrated on operating units in the United States manufactured by six different boiler vendors: Babcock and Wilcox, Combustion Engineering, Foster Wheeler, Keeler Dorr-Oliver, Pyropower, and Riley Stoker. Information was obtained from the boiler vendors, refractory suppliers and installers, and the owners/operators of over forty units. This work is in support of DOE's Clean Coal Technology program, which includes circulating fluidized-bed technology as one of the selected concepts being evaluated.

  15. Co-combustion and gasification of various biomasses

    Energy Technology Data Exchange (ETDEWEB)

    Mutanen, K. [A. Ahlstrom Corporation, Varkaus (Finland). Ahlstrom Pyropower

    1996-12-31

    During the last twenty years the development of fluidized bed combustion and gasification technology has made it possible to increase significantly utilisation of various biomasses in power and heat generation. The forerunner was the pulp and paper industry that has an adequate biomass fuel supply and energy demand on site. Later on municipalities and even utilities have seen biomass as a potential fuel. The range of available biomasses includes wood-based fuels and wastes like bark, wood chips, and saw dust, agricultural wastes like straw, olive waste and rice husk, sludges from paper mills and de-inking plants, other wastes like municipal sludges, waste paper and RDF. Recently new environmental regulations and taxation of fossil fuels have further increased interest in the use of biomasses in energy generation. However, in many cases available quantities and/or qualities of biomasses are not adequate for only biomass-based energy generation in an economic sense. On the other hand plant owners want to maintain a high level of fuel flexibility and fuel supply security. In some cases disposing by burning is the only feasible way to handle certain wastes. In many cases the only way to fulfil these targets and utilize the energy is to apply co-combustion or gasification of different fuels and wastes. Due to the fact that fluidized bed combustion technology offers a very high fuel flexibility and high combustion efficiency with low emissions it has become the dominating technology in co-combustion applications. This presentation will present Alhstrom`s experiences in co-combustion of biomasses in bubbling beds and Ahlstrom Pyroflow circulating fluidized beds based on about 200 operating references worldwide. CFB gasification will also be discussed 9 refs.

  16. Bed rest and immunity

    Science.gov (United States)

    Sonnenfeld, Gerald; Aviles, Hernan; Butel, Janet S.; Shearer, William T.; Niesel, David; Pandya, Utpal; Allen, Christopher; Ochs, Hans D.; Blancher, Antoine; Abbal, Michel

    2007-02-01

    Space flight has been shown to result in altered immune responses. The current study was designed to investigate this possibility by using the bed rest model of some space flight conditions. A large number of women are included as subjects in the study. The hypothesis being tested is: 60 days head-down tilt bed rest of humans will affect the immune system and resistance to infection. Blood, urine and saliva samples will be obtained from bed rest subjects prior to, at intervals during, and after completion of 60 days of head-down tilt bed rest. Leukocyte blastogenesis, cytokine production and virus reactivation will be assessed. The ability of the subjects to respond appropriately to immunization with the neoantigen bacteriophage φX-174 will also be determined. Bed rest is being carried out at MEDES, Toulouse France, and the University of Texas Medical Branch, Galveston, TX. The studies to be carried out in France will also allow assessment of the effects of muscle/bone exercise and nutritional countermeasures on the immune system in addition to the effects of bed rest.

  17. Chemical Technology Division annual technical report, 1986

    Energy Technology Data Exchange (ETDEWEB)

    1987-06-01

    Highlights of the Chemical Technology (CMT) Division's activities during 1986 are presented. In this period, CMT conducted research and development in areas that include the following: (1) high-performance batteries - mainly lithium-alloy/metal sulfide and sodium/sulfur; (2) aqueous batteries (lead-acid, nickel/iron, etc.); (3) advanced fuel cells with molten carbonate or solid oxide electrolytes; (4) coal utilization, including the heat and seed recovery technology for coal-fired magnetohydrodynamics plants, the technology for fluidized-bed combustion, and a novel concept for CO/sub 2/ recovery from fossil fuel combustion; (5) methods for recovery of energy from municipal waste; (6) methods for the electromagnetic continuous casting of steel sheet; (7) techniques for treatment of hazardous waste such as reactive metals and trichloroethylenes; (8) nuclear technology related to waste management, a process for separating and recovering transuranic elements from nuclear waste, and the recovery processes for discharged fuel and the uranium blanket in a sodium-cooled fast reactor; and (9) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems. The Division also has a program in basic chemistry research in the areas of catalytic hydrogenation and catalytic oxidation; materials chemistry for associated and ordered solutions at high temperatures; interfacial processes of importance to corrosion science, surface science, and catalysis; the thermochemistry of zeolites and related silicates; and the geochemical processes responsible for trace-element migration within the earth's crust. The Division continued to be the major user of the technical support provided by the Analytical Chemistry Laboratory at ANL. 127 refs., 71 figs., 8 tabs.

  18. Chemical Technology Division annual technical report, 1986

    International Nuclear Information System (INIS)

    Highlights of the Chemical Technology (CMT) Division's activities during 1986 are presented. In this period, CMT conducted research and development in areas that include the following: (1) high-performance batteries - mainly lithium-alloy/metal sulfide and sodium/sulfur; (2) aqueous batteries (lead-acid, nickel/iron, etc.); (3) advanced fuel cells with molten carbonate or solid oxide electrolytes; (4) coal utilization, including the heat and seed recovery technology for coal-fired magnetohydrodynamics plants, the technology for fluidized-bed combustion, and a novel concept for CO2 recovery from fossil fuel combustion; (5) methods for recovery of energy from municipal waste; (6) methods for the electromagnetic continuous casting of steel sheet; (7) techniques for treatment of hazardous waste such as reactive metals and trichloroethylenes; (8) nuclear technology related to waste management, a process for separating and recovering transuranic elements from nuclear waste, and the recovery processes for discharged fuel and the uranium blanket in a sodium-cooled fast reactor; and (9) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems. The Division also has a program in basic chemistry research in the areas of catalytic hydrogenation and catalytic oxidation; materials chemistry for associated and ordered solutions at high temperatures; interfacial processes of importance to corrosion science, surface science, and catalysis; the thermochemistry of zeolites and related silicates; and the geochemical processes responsible for trace-element migration within the earth's crust. The Division continued to be the major user of the technical support provided by the Analytical Chemistry Laboratory at ANL. 127 refs., 71 figs., 8 tabs

  19. Combustion, pyrolysis, gasification, and liquefaction of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Reed, T.B.

    1980-09-01

    All the products now obtained from oil can be provided by thermal conversion of the solid fuels biomass and coal. As a feedstock, biomass has many advantages over coal and has the potential to supply up to 20% of US energy by the year 2000 and significant amounts of energy for other countries. However, it is imperative that in producing biomass for energy we practice careful land use. Combustion is the simplest method of producing heat from biomass, using either the traditional fixed-bed combustion on a grate or the fluidized-bed and suspended combustion techniques now being developed. Pyrolysis of biomass is a particularly attractive process if all three products - gas, wood tars, and charcoal - can be used. Gasification of biomass with air is perhaps the most flexible and best-developed process for conversion of biomass to fuel today, yielding a low energy gas that can be burned in existing gas/oil boilers or in engines. Oxygen gasification yields a gas with higher energy content that can be used in pipelines or to fire turbines. In addition, this gas can be used for producing methanol, ammonia, or gasoline by indirect liquefaction. Fast pyrolysis of biomass produces a gas rich in ethylene that can be used to make alcohols or gasoline. Finally, treatment of biomass with high pressure hydrogen can yield liquid fuels through direct liquefaction.

  20. Combustion, pyrolysis, gasification, and liquefaction of biomas

    Science.gov (United States)

    Reed, T. B.

    1980-09-01

    The advantages of biomass as a feedstock are examined and biomass conversion techniques are described. Combustion is the simplest method of producing heat from biomass, using either the traditional fixed bed combustion on a grate or the fluidized bed and suspended combustion techniques now being developed. Pyrolysis of biomass is a particularly attractive process if all three products gas, wood tars, and charcoal can be used. Gasification of biomass with air is perhaps the most flexible and best developed process for conversion of biomass to fuel, yielding a low energy gas that can be burned in existing gas/oil boilers or in engines. Oxygen gasification yields a gas with higher energy content that can be used in pipelines or to fire turbines. In addition, this gas can be used for producing methanol, ammonia, or gasoline by indirect liquefaction. Fast pyrolysis of biomass produces a gas rich in ethylene that can be used to make alcohols or gasoline. Finally, treatment of biomass with high pressure hydrogen can yield liquid fuels through direct liquefaction.

  1. Opportunities in pulse combustion

    Science.gov (United States)

    Brenchley, D. L.; Bomelburg, H. J.

    1985-10-01

    In most pulse combustors, the combustion occurs near the closed end of a tube where inlet valves operate in phase with the pressure amplitude variations. Thus, within the combustion zone, both the temperature and the pressure oscillate around a mean value. However, the development of practical applications of pulse combustion has been hampered because effective design requires the right combination of the combustor's dimensions, valve characteristics, fuel/oxidizer combination, and flow pattern. Pulse combustion has several additional advantages for energy conversion efficiency, including high combustion and thermal efficiency, high combustion intensity, and high convective heat transfer rates. Also, pulse combustion can be self-aspirating, generating a pressure boost without using a blower. This allows the use of a compact heat exchanger that may include a condensing section and may obviate the need for a chimney. In the last decade, these features have revived interest in pulse combustion research and development, which has resulted in the development of a pulse combustion air heater by Lennox, and a pulse combustion hydronic unit by Hydrotherm, Inc. To appraise this potential for energy savings, a systematic study was conducted of the many past and present attempts to use pulse combustion for practical purposes. The authors recommended areas where pulse combustion technology could possibly be applied in the future and identified areas in which additional R and D would be necessary. Many of the results of the study project derived from a special workshop on pulse combustion. This document highlights the main points of the study report, with particular emphasis on pulse combustion application in chemical engineering.

  2. Moving granular-bed filter development program. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Newby, R.A.; Yang, W.C.; Smeltzer, E.E.; Lippert, T.E.

    1994-04-01

    Advanced, coal-based, power plants, such as IGCC and Advanced-PFBC, are currently nearing commercial demonstration. These power plant technologies require hot gas filtration as part of their gas cleaning trains. Ceramic barrier filters are the major filter candidates being developed for these hot gas cleaning applications. While ceramic barrier filters achieve high levels of particle removal, concerns exist for their reliability and operability in these applications. An alternative hot gas filtration technology is the moving granular bed filter. An advanced, moving granular bed filter has been conceived, and early development activities performed by the Westinghouse Electric Corporation, Science and Technology Center. This document reports on the Base Contract tasks performed to resolve the barrier technical issues for this technology. The concept, the Standleg Moving Granular Bed Filter (SMGBF) has a concurrent downward, gas and bed media flow configuration that results in simplified features and improved scaleup feasibility compared to alternative designs. Two modes of bed media operation were assessed in the program: once-through using pelletized power plant waste as bed media, and recycle of bed media via standleg and pneumatic transport techniques. Cold Model testing; high-temperature, high-pressure testing; and pelletization testing using advanced power plant wastes, have been conducted in the program. A commercial, economic assessment of the SMGBF technology was performed for IGCC and Advanced-PFBC applications. The evaluation shows that the barrier technical issues can be resolved, and that the technology is potentially competitive with ceramic barrier filters.

  3. Chemical Technology Division annual technical report, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    Highlights of the Chemical Technology (CMT) Division`s activities during 1994 are presented. In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for fluidized-bed combustion; (3) methods for treatment of hazardous waste and mixed hazardous/radioactive waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for an unsaturated repository; (5) processes for separating and recovering transuranic elements from waste streams, concentrating radioactive waste streams with advanced evaporator technology, and producing {sup 99}Mo from low-enriched uranium for medical applications; (6) electrometallurgical treatment of the many different types of spent nuclear fuel in storage at Department of Energy sites; and (8) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems. The Division also conducts basic research in catalytic chemistry associated with molecular energy resources and novel ceramic precursors; materials chemistry of superconducting oxides, electrified metal/solution interfaces, molecular sieve structures, and impurities in scrap copper and steel; and the geochemical processes involved in mineral/fluid interfaces and water-rock interactions occurring in active hydrothermal systems. In addition, the Analytical Chemistry Laboratory in CMT provides a broad range of analytical chemistry support services to the technical programs at Argonne National Laboratory (ANL).

  4. Chemical Technology Division annual technical report, 1992

    International Nuclear Information System (INIS)

    In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for fluidized-bed combustion and coal-fired magnetohydrodynamics; (3) methods for treatment of hazardous waste, mixed hazardous/radioactive waste, and municipal solid waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for an unsaturated repository; (5) processes for separating and recovering transuranic elements from nuclear waste streams, treating water contaminated with volatile organics, and concentrating radioactive waste streams; (6) recovery processes for discharged fuel and the uranium blanket in the Integral Fast Reactor (EFR); (7) processes for removal of actinides in spent fuel from commercial water-cooled nuclear reactors and burnup in IFRs; and (8) physical chemistry of selected materials (corium; Fe-U-Zr, tritium in LiAlO2 in environments simulating those of fission and fusion energy systems. The Division also conducts basic research in catalytic chemistry associated with molecular energy resources and novel' ceramic precursors; materials chemistry of superconducting oxides, electrified metal/solution interfaces, and molecular sieve structures; and the geochemical processes involved in water-rock interactions occurring in active hydrothermal systems. In addition, the Analytical Chemistry Laboratory in CMT provides a broad range of analytical chemistry support services to the technical programs at Argonne National Laboratory (ANL)

  5. Chemical Technology Division, Annual technical report, 1991

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    Highlights of the Chemical Technology (CMT) Division`s activities during 1991 are presented. In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for fluidized-bed combustion and coal-fired magnetohydrodynamics; (3) methods for treatment of hazardous and mixed hazardous/radioactive waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for an unsaturated repository; (5) processes for separating and recovering transuranic elements from nuclear waste streams; (6) recovery processes for discharged fuel and the uranium blanket in the Integral Fast Reactor (IFR); (7) processes for removal of actinides in spent fuel from commercial water-cooled nuclear reactors and burnup in IFRs; and (8) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems. The Division also conducts basic research in catalytic chemistry associated with molecular energy resources; chemistry of superconducting oxides and other materials of interest with technological application; interfacial processes of importance to corrosion science, catalysis, and high-temperature superconductivity; and the geochemical processes involved in water-rock interactions occurring in active hydrothermal systems. In addition, the Analytical Chemistry Laboratory in CMT provides a broad range of analytical chemistry support services to the technical programs at Argonne National Laboratory (ANL).

  6. Chemical Technology Division, Annual technical report, 1991

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    Highlights of the Chemical Technology (CMT) Division's activities during 1991 are presented. In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for fluidized-bed combustion and coal-fired magnetohydrodynamics; (3) methods for treatment of hazardous and mixed hazardous/radioactive waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for an unsaturated repository; (5) processes for separating and recovering transuranic elements from nuclear waste streams; (6) recovery processes for discharged fuel and the uranium blanket in the Integral Fast Reactor (IFR); (7) processes for removal of actinides in spent fuel from commercial water-cooled nuclear reactors and burnup in IFRs; and (8) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems. The Division also conducts basic research in catalytic chemistry associated with molecular energy resources; chemistry of superconducting oxides and other materials of interest with technological application; interfacial processes of importance to corrosion science, catalysis, and high-temperature superconductivity; and the geochemical processes involved in water-rock interactions occurring in active hydrothermal systems. In addition, the Analytical Chemistry Laboratory in CMT provides a broad range of analytical chemistry support services to the technical programs at Argonne National Laboratory (ANL).

  7. Chemical Technology Division annual technical report, 1994

    International Nuclear Information System (INIS)

    Highlights of the Chemical Technology (CMT) Division's activities during 1994 are presented. In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for fluidized-bed combustion; (3) methods for treatment of hazardous waste and mixed hazardous/radioactive waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for an unsaturated repository; (5) processes for separating and recovering transuranic elements from waste streams, concentrating radioactive waste streams with advanced evaporator technology, and producing 99Mo from low-enriched uranium for medical applications; (6) electrometallurgical treatment of the many different types of spent nuclear fuel in storage at Department of Energy sites; and (8) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems. The Division also conducts basic research in catalytic chemistry associated with molecular energy resources and novel ceramic precursors; materials chemistry of superconducting oxides, electrified metal/solution interfaces, molecular sieve structures, and impurities in scrap copper and steel; and the geochemical processes involved in mineral/fluid interfaces and water-rock interactions occurring in active hydrothermal systems. In addition, the Analytical Chemistry Laboratory in CMT provides a broad range of analytical chemistry support services to the technical programs at Argonne National Laboratory (ANL)

  8. Chemical Technology Division annual technical report, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Battles, J.E.; Myles, K.M.; Laidler, J.J.; Green, D.W.

    1993-06-01

    In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for fluidized-bed combustion and coal-fired magnetohydrodynamics; (3) methods for treatment of hazardous waste, mixed hazardous/radioactive waste, and municipal solid waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for an unsaturated repository; (5) processes for separating and recovering transuranic elements from nuclear waste streams, treating water contaminated with volatile organics, and concentrating radioactive waste streams; (6) recovery processes for discharged fuel and the uranium blanket in the Integral Fast Reactor (EFR); (7) processes for removal of actinides in spent fuel from commercial water-cooled nuclear reactors and burnup in IFRs; and (8) physical chemistry of selected materials (corium; Fe-U-Zr, tritium in LiAlO{sub 2} in environments simulating those of fission and fusion energy systems. The Division also conducts basic research in catalytic chemistry associated with molecular energy resources and novel` ceramic precursors; materials chemistry of superconducting oxides, electrified metal/solution interfaces, and molecular sieve structures; and the geochemical processes involved in water-rock interactions occurring in active hydrothermal systems. In addition, the Analytical Chemistry Laboratory in CMT provides a broad range of analytical chemistry support services to the technical programs at Argonne National Laboratory (ANL).

  9. Chemical Technology Division annual technical report, 1985

    International Nuclear Information System (INIS)

    Highlights of the Chemical Technology (CMT) Division's activities during 1985 are presented. In this period, CMT conducted research and development in areas that include the following: (1) advanced batteries - mainly lithium-alloy/metal sulfide and sodium/sulfur; (2) advanced fuel cells with molten carbonate or solid oxide electrolytes; (3) corrosion-protective coatings for high-strength steel; (4) coal utilization, including the heat and seed recovery technology for coal-fired magnetohydrodynamics plants and the technology for fluidized-bed combustion; (5) methodologies for recovery of energy from municipal waste; (6) nuclear technology related to waste management, the recovery processes for discharged fuel and the uranium blanket in a sodium-cooled fast reactor, and proof of breeding in a light water breeder reactor; and (7) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems. The Division also has a program in basic chemistry research in the areas of catalytic hydrogenation and catalytic oxidation; materials chemistry for associated and ordered solutions at high temperatures; interfacial processes of importance to corrosion science, surface science, and catalysis; the thermochemistry of zeolites and related silicates; and the geochemical processes responsible for trace-element migration within the earth's crust. The Division continued to be the major user of the technical support provided by the Analytical Chemistry Laboratory at ANL

  10. Chemical Technology Division, Annual technical report, 1991

    International Nuclear Information System (INIS)

    Highlights of the Chemical Technology (CMT) Division's activities during 1991 are presented. In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for fluidized-bed combustion and coal-fired magnetohydrodynamics; (3) methods for treatment of hazardous and mixed hazardous/radioactive waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for an unsaturated repository; (5) processes for separating and recovering transuranic elements from nuclear waste streams; (6) recovery processes for discharged fuel and the uranium blanket in the Integral Fast Reactor (IFR); (7) processes for removal of actinides in spent fuel from commercial water-cooled nuclear reactors and burnup in IFRs; and (8) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems. The Division also conducts basic research in catalytic chemistry associated with molecular energy resources; chemistry of superconducting oxides and other materials of interest with technological application; interfacial processes of importance to corrosion science, catalysis, and high-temperature superconductivity; and the geochemical processes involved in water-rock interactions occurring in active hydrothermal systems. In addition, the Analytical Chemistry Laboratory in CMT provides a broad range of analytical chemistry support services to the technical programs at Argonne National Laboratory (ANL)

  11. The murderer is the bed: an unusual case of death by traumatic asphyxia in a hotel folding bunk bed.

    Science.gov (United States)

    Domènech, Mercè Subirana; Alcázar, Helena Martínez; Pallarès, Antoni Aguilar; Vicente, Ignasi Galtés; García, Josep Castellà; Gutiérrez, Claudina Vidal; Muñiz, Jordi Medallo

    2012-07-10

    This paper presents the first referenced case on a death by traumatic asphyxia in a folding bunk bed. A middle-aged man was found dead in a hotel room trapped into a lower folding bunk bed where he had been sleeping after a party. The autopsy showed signs of asphyxia and excluded signs of struggle and sexual intercourse. Toxicological analyses revealed alcohol intoxication. A differential diagnosis of the manner of death including a technical study of the bed which contributed to understand the circumstances of death was made. The medico-legal investigation of the case strongly supported the hypothesis of an accidental death by traumatic asphyxia. PMID:22361389

  12. Combustion modeling in internal combustion engines

    Science.gov (United States)

    Zeleznik, F. J.

    1976-01-01

    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

  13. Boiler using combustible fluid

    Science.gov (United States)

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  14. Numerical modeling of fluidized-bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    Sha, W T; Soo, S L

    1977-11-01

    Optimum design of fluidized-bed combustor requires high carbon burn-up, good sulfur retention, minimized sorbent (Ca) utilization, efficient feed distribution and mechanical layout. These parameters are strongly affected by the dynamics of the fluidized bed. The dynamic behavior of fluidized combustor is formulated in terms of multidomain - multiphase mechanics. Fluidization, bubble mechanics, coal combustion, sorbent sulfation, oxidation, solids movement and elutriation, and heat transfer are explicitly taken into account in the proposed numerical model. The model solves conservation equations of mass, momentum and energy coupled with chemical reactions as boundary value problem in space and initial value problem in time. Multi-fluid model and modified implicit multi-field numerical scheme are employed. The objective of this numerical model is for use in engineering design and scaling. Progress to date shows that all necessary relations can be incorporated within the framework of an overall multidomain - multiphase model for deterministic computation. Provisions are made for subsequent refinements of submodels of individual mechanism and improvements of the existing numerical model. These refinements and improvements can be achieved as better understanding of physical phenomena and more experimental data become available. The numerical model outlined in this report is specifically designed for the fluidized-bed combustor; however, it can readily be extended to various coal gasification systems.

  15. Tritium storage metal-bed pyrophoricity measurements

    International Nuclear Information System (INIS)

    A safety concern for metal-bed tritium storage systems is the possibility of spontaneous combustion and/or explosion if the bed is accidentally exposed to air. This may result in the dispersion of tritium or tritiated compounds. Of several materials being considered for use in tritium storage beds, uranium (U), zirconium-cobalt (ZrCo), and lanthanum-nickel aluminide (LaNi5-xAlx) are of particular interest. It is well known that uranium that has been activated by cycles of hydriding and dehydriding is extremely pyrophoric when exposed to air or other oxidizers. Uranium hydride has also been found to be mildly pyrophoric, but less is known about the pyrophoric natures of the hydrides of the other materials. An experiment is in progress to evaluate the pyrophoric response of these materials and their hydrides and deuterides in air. Small (<100 mg) samples of depleted uranium were hydrided and then exposed to atmospheres of air, oxygen, or nitrogen using a thermogravimetric analyzer to monitor the sample weight and temperature. There was not an immediate pyrophoric response at room temperature, but ignition occured at moderately elevated temperatures for air and oxygen atmospheres. The experimental apparatus has been upgraded, and tests are continuing on these materials

  16. Fluidised bed heat exchangers

    International Nuclear Information System (INIS)

    Problems that have arisen during the initial stages of development of fluidised bed boilers in which heat transfer surfaces are immersed in fluidised solids are discussed. The very high heat transfer coefficients that are obtained under these conditions can be exploited to reduce the total heat transfer surface to a fraction of that in normal boilers. However, with the high heat flux levels involved, tube stressing becomes more important and it is advantageous to use smaller diameter tubes. One of the initial problems was that the pumping power absorbed by the fluidised bed appeared to be high. The relative influence of the fluidising velocity (and the corresponding bed area), tube diameter, tube spacing, heat transfer coefficient and bed temperature on pumping power and overall cost was determined. This showed the importance of close tube packing and research was undertaken to see if this would adversely affect the heat transfer coefficient. Pressure operation also reduces the pumping power. Fouling and corrosion tests in beds burning coal suggest that higher temperatures could be reached reliably and cost studies show that, provided the better refractory metals are used, the cost of achieving higher temperatures is not unduly high. It now remains to demonstrate at large scale that the proposed systems are viable and that the methods incorporated to overcome start up and part lead running problems are satisfactory. The promising role of these heat transfer techniques in other applications is briefly discussed

  17. Experimental study on film combustion formed by spirally fluted horizontal tube

    Institute of Scientific and Technical Information of China (English)

    Ning MEI; Bin ZHANG; Jian ZHAO; Ming ZHANG

    2008-01-01

    Falling fuel film on the spirally fluted surface of a horizontal tube can provide rapid fuel evaporation and homogeneous mixture formation. This fuel film combus-tion could be applied in a micro-combustion system even without a fuel pump. A test bed was established and experimental comparisons were made between the pro-totype and a transferred cup atomizer micro-combustor. The theoretical and experimental results show that film combustion has a higher combustion efficiency, a lower pollutant emission and a better working performance.

  18. Ash chemistry and behavior in advanced co-combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M.; Skrifvars, B.J. [Aabo Akademi, Turku (Finland). Combustion Chemistry Research Group

    1997-10-01

    The purpose of this LIEKKI 2 project is to report results achieved within the EU/JOULE/OPTEB project to the Finnish combustion research community through the LIEKKI program. The purpose of the EU/JOULE/OPTEB project is to find prediction methods for evaluating ash behavior, such as slagging, fouling and corrosion propensity, in full scale combustion systems through chemical or mineralogical analyses, intelligent laboratory tests and chemistry calculations. The project focuses on coals, coal mixtures and coal biomass mixtures fired in advanced combustion systems, such as fluidized bed boilers, pulverized fuel boilers with critical steam values etc. The project will make use of (1) advanced multi-component combustion equilibrium calculations, (2) ash sintering tendency laboratory tests and (3) chemical evaluations of slagging, fouling and corrosion measurements in full scale units. (orig.)

  19. Circulating fluidized bed biological reactor for nutrients removal

    Institute of Scientific and Technical Information of China (English)

    Yubo CUI; Hongbo LIU; Chunxue BAI

    2008-01-01

    A new biological nitrogen removal process, which is named herein "The circulating fluidized bed bio-reactor (CFBBR)", was developed for simultaneous removal of nitrogen and organic matter. This process was composed of an anaerobic bed (Riser), aerobic bed (Downer) and connecting device. Influent and nitrified liquid from the aerobic bed enters the anaerobic bed from the bottom of the anaerobic bed, completing the removal of nitrogen and organic matter. The system performance under the conditions of different inflow loadings and nitrified liquid recirculation rates ranging from 200% to 600% was examined. From a technical and economic point of view, the optimum nitrified liquid recirculation rate was 400%. With a shortest total retention time of 2.5 h (0.8 h in the anaerobic bed and 1.5 h in the aerobic bed) and a nitrified liquid recir-culation rate of 400% based on the intluent flow rate, the average removal efficiencies of total nitrogen (TN) and sol-uble chemical oxygen demand (SCOD) were found to be 88% and 95%, respectively. The average effluent concentra-tions of TN and SCOD were 3.5 mg/L and 16 mg/L, respectively. The volatile suspended solid (VSS) concentra-tion, nitrification rate and denitrification rate in the system were less than 1.0 g/L, 0.026-0.1 g NH4+-N/g VSS.d, and 0.016-0.074 g NOx--N/g VSS.d, respectively.

  20. CFD simulation of gas and particles combustion in biomass furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Griselin, Nicolas

    2000-11-01

    In this thesis, gas and particle combustion in biomass furnaces is investigated numerically. The aim of this thesis is to use Computational Fluid Dynamics (CFD) technology as an effective computer based simulation tool to study and develop the combustion processes in biomass furnaces. A detailed model for the numerical simulation of biomass combustion in a furnace, including fixed-bed modeling, gas-phase calculation (species distribution, temperature field, flow field) and gas-solid two-phase interaction for flying burning particles is presented. This model is used to understand the mechanisms of combustion and pollutant emissions under different conditions in small scale and large scale furnaces. The code used in the computations was developed at the Division of Fluid Mechanics, LTH. The flow field in the combustion enclosure is calculated by solving the Favre-averaged Navier-Stokes equations, with standard {kappa} - {epsilon} turbulence closure, together with the energy conservation equation and species transport equations. Discrete transfer method is used for calculating the radiation source term in the energy conservation equation. Finite difference is used to solve the general form of the equation yielding solutions for gas-phase temperatures, velocities, turbulence intensities and species concentrations. The code has been extended through this work in order to include two-phase flow simulation of particles and gas combustion. The Favre-averaged gas equations are solved in a Eulerian framework while the submodels for particle motion and combustion are used in the framework of a Lagrangian approach. Numerical simulations and measurement data of unburned hydrocarbons (UHC), CO, H{sub 2}, O{sub 2} and temperature on the top of the fixed bed are used to model the amount of tar and char formed during pyrolysis and combustion of biomass fuel in the bed. Different operating conditions are examined. Numerical calculations are compared with the measured data. It is